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Scientific American 
 
 Home Mechanics 
 
 For Amateurs 
 
 BY 
 
 GEORGE M. HOPKINS 
 
 Author of ^^Experimental Science'' 
 
 Munn & Co., Publishers 
 
 SCIENTIFIC AMERICAN OFFICE 
 
 NEW YORK, 1903 
 
Copyrignt, 190J, by Munn & Co. 
 
 All rights reserved. 
 
 Entered at Stationers’ Hall, London, P'ngland* 
 
 Pkkss oh Andrew H. Khli-ogc; 
 Niiw York, U. S, A. 
 

 PREFACE 
 
 S PECIAL INTEREST alwaj’s attaches to a i^ost- 
 IniiiKois work. It is not always, however, that 
 a work of this character possesses ecpial merit 
 witli one entirely completed before the death of the 
 antlior. As a rule such works have not had the ad- 
 vantage of the final perusal and correction by the 
 author. Such has not, however, been the case in tlie 
 present instance, for the following work by the late 
 George M. Hopkins, was completed before his death. 
 There is no doubt, however, that this volume Avill come 
 as a surprise to thousands who have closely followed 
 Mr. Hopkins’ work, and who have enjoyed making 
 — tlie many experiments descril)ed by him. The present 
 volume contains much matter which has never before 
 appeared in iirint, and some articles which have al- 
 ready been piiblished in the Scientific American. The 
 object of the work is to furnish food for thought to the 
 amateur, and to give him suggestions whereby he may 
 pass nianj’ pleasant hours in his work-sliop. Mr. Hop- 
 kins was an expert mechanic. One of his chief pleas- 
 ures was to make experiments at his home in his well- 
 equipped work-shop and laboratory, and the work 
 described in the present volume is nearly all the result 
 of experiments made by liim during such “idle” hours. 
 It has been tlie intent of the autlior to make the present 
 
rUKFACE. 
 
 work as sug.c;estive as possible. No ootii])lieate(l aje 
 paratus is required in carrying out tlie (“xperiuieuts 
 described. Any one with ordinary mechanical inge- 
 nuity and having a lathe and a few tools ca!i make most 
 of the expei'iments described in these pages. 
 
 A few articb'S by other authors have Ix'en included 
 as they are germane to the sco})e of the book. It is 
 hoped that “Home ^lechanics for Amateurs” will prove 
 heliifnl to as many thousands as has “Experimental 
 Science.” 
 
Table oe Contents 
 
 PART 1. 
 
 Wood-Working 
 
 An Inexpensive Turning Lathe. Turning. Wood-Working on a 
 Lathe. Work Bench and Tools for Woodwork. Whittling. 
 Different Shapes of Saw Teeth and the Way they Cut. A 
 Wrinkle in Sawing. Wood Carving 1 
 
 PART 11. 
 
 How TO Make Household Ornaments 
 
 Home-made Grilles hnd Gratings. Wall Ornaments. Pseudo- 
 Ceramics. Imitation of Majolica. Stained Glass and Ob- 
 jects of Wire Cloth. Japanese Portiere or Curtain. 
 Repousse. An Easy Method of Producing Bas-reliefs. 
 Ornamental Iron Work for Amateurs. Some Things in 
 Wire. Some Things in Burnished Brass. Forming Plaster 
 Objects 31 
 
 PART III. 
 
 Metal-Working 
 
 Sawing Metals. Soldering. Grinding and Polishing. Silver 
 Work. Metal Foot Lathe. Drills and Drilling. Centering 
 and Steadying. Chucking. Metal Turning. Chasing and 
 Knurling. Rotary Cutters. Easily made Slide Rest. In- 
 dex Plates for Gear Cutting. Gear Cutting Apparatus. 
 Hints on Model Making. Metal Spinning 89 
 

 of coN'i'FX'rs 
 
 PART IV. 
 
 Model Engines and Boilehs 
 
 A Home-made Steam Engine. A Safe Way of Running a Small 
 Engine. A Miniature Caloric Engine. An Inexpensive 
 Water Motor 1G9 
 
 PART V. 
 
 Meteorology 
 
 Self-Recording Instruments. What may be learned by the Use 
 of the Meteorological Instruments. A Weather Vane. 
 Wind Pressure Gauge. Rain Gauge. A Metallic Ther- 
 mometer. A Simple Hygroscope. A Mercurial Barometer. 187 
 
 PART VI. 
 
 Telescopes and Microscopes 
 
 How to make a Telescope. The Microscope 207 
 
 PART VII. 
 
 Electricity 
 
 A Practical Primary Battery. Electric Lighting for Amateurs. 
 
 The Electric Chime. Home-made Electric Night Lamp. 
 
 An Electrical Cabinet. Simple Electric Motor. Small 
 lOlectric Motor for Amateurs. How to make a Sewing 
 Machine Motor without Castings. A Design for an Electric 
 Launch Motor. How to make an Edison Dynamo and 
 Motor. The Utilization of 110 Volt Electric Circuits for 
 Small thirnac.e Work. Recording Telegraiih for Amateurs. 
 
 How to make a Telei)hone 227 
 
PART I. 
 
 WOOD- WORKING 
 
 AN INEXPENSIVE TUKNING LATHE 
 
 T he boy wlio has a turning lathe can readily 
 make many things which he might not feel 
 disposed to buy ; for example, he can make tops, 
 ninepins, and ornamental and useful objects 
 without much trouble and with very little expense. 
 The ancient lathe consisted of two conical points, sup- 
 ported in position by suitable standards, and the work 
 to be done was whirled on these points by means of a 
 strong cord wrapped once around the stick to be turned, 
 with the upper end attached to a spring pole and 
 the lower end seciired to a treadle. The lathe we are 
 about to describe is one remove from this primitive 
 lathe of the olden time. It has the two standards with 
 points or dead centers, as they would be called by ma- 
 chinists, but one of the points projects far enough from 
 the standard to receive a hard wood pulley, having 
 inserted in its side, at diametrically opposite points, 
 two spurs, which enter the end of the piece of wood 
 to be turned, so that Avhen the pulley is revolved by 
 a belt, the wood will be turned on the centers. 
 
 This lathe is made almost entirely from strips of 
 hard wood, 1 inch thick and 2^ inches wide. These 
 strips can be easily furnished by any carpenter, cabinet 
 maker or wagon maker, and an old table may be used 
 for the frame. 
 
 The bed-piece is made of two such strips, 2 feet long, 
 and a block of the same material, 1 inch square and 2 
 
 [IJ 
 
2 
 
 HOME IIECIIAXK^S FOE AMATEIJI^S 
 
 inches long, at one (aid is plai'ed betwecai the strips 
 and lield in ])la(‘(‘ by wood scr(‘ws. A piiaa^ of tliick 
 paper is placanl between tlie lihx'k and one of tli(‘ strijis, 
 
 Fig. 1. An Easily Constructed Wood Lathe. 
 
 to niak(* 1 h(‘ space* lx*! w(*(*ii the strips a little wider than 
 th(* I liickiK'SS of i Ik* lilock. 
 
 n'o (*acl) (*ikI of I Ik* bed is S(*cni'ed a foof^ (‘onsistini2^ 
 of a pi(*c(* of 11k* saiiK* si rip, (> iiK'lK‘S lon<4’. Tln^se aiv 
 s(*(‘iir(*d by w'ood s( r(*\\'s passing iipwaixl tIiroui»li holes 
 
HOME MECHANICS FOR AMATEURS 
 
 3 
 
 in the lower edge of the foot, the holes being deeply 
 countersunk to let in the heads of the screws. 
 
 The head stock and tail stock are nearly alike, in 
 so far as the wood work is concerned. Each is formed 
 of three pieces of the strip from which the bed is 
 made. To opposite sides of a central piece, 7^ inches 
 long, are secured side pieces 4 inches long, by means 
 of screws. Tliese side pieces must of course be square 
 on the end so that they will set squarely on the bed 
 when the projecting end of the central piece is inserted 
 
 Fig. 2. Work in the Lathe. 
 
 in the slot of the bed. The lower end of the center piece 
 is mortised to receive a Avooden key or Avedge, Avhich 
 clamps the tail stock to the bed. In the tail stock, 4 
 inch from the top, is bored a hole in Avhich is inserted 
 a large Avood screAv, the point of Avhich is filed conically, 
 as shoAvn. In the head stock is also bored a hole 
 corresponding Avith that of the tail stock, to receive a 
 large Avood screAV, ^ or 5-16 inch in diameter. The head 
 of this screAv is cut off, and the head end is filed off 
 conically. This point shonld project about an inch 
 from the head stock, and to the plain, smooth pro- 
 
4 
 
 HOME MECHANTCS EOli AMATEURS 
 
 jeotiug part of tlie screw is fitted a small jrrooved 
 pulley about iuclies iu diam(‘t(“r at the bottom of 
 the groove. The ])ulley should be of Habbitt metal 
 or type metal. Ju the side of the ])ulley, about | 
 inch from the hole, are inserted two small screws, about 
 f inch long, which are allowed to ])i‘oject; these* screws 
 are filed to form chisel-edged sjeurs for driving the 
 work in the lathe. The jeoints should project as far 
 as the ]K)int of the conical end of the lai'ge scr<>w. 
 
 The lower end of the head stock — which is about 2} 
 inches long — is inserted between the strips forming 
 the bed, and fastened with screws; a piece of pa])er 
 being inserted to increase the space between the strips, 
 so that the tail stock can be moved easily. 
 
 The wood to be turned has a small hole^ — say, ^ inch 
 — bored in the center at each end, and is placed be- 
 tween the centers; the tail stock having been clamped 
 in the proper position, the tail screw is turned with 
 a screw driver until it is forced a short distance into 
 the end of the stick. Then the stick is driven for- 
 ward on to the center, and spurs of the head stock, and 
 the screw in the tail stock is turned so as to hold the 
 stick, but not enough to create friction. A drop of oil 
 should be put on each center, and the pulley should 
 be oiled. 
 
 The rest on which the gouge or chisel is placed while 
 the turning is being done consists of a piece of the 
 wood(‘n strip with a slot in it to allow a 5-inch car- 
 riage bolt to pass through. This bolt extends through 
 the slot of the bed, and through a block or washer be- 
 low. A wing nut is ])lac(“d on the bolt so that the rest 
 may be clamjx'd in any desired i)osilion. To the end of 
 the slotted piece is secured a shoi*t ])iece of the wooden 
 
HOME MECHANICS FOE AMATEUES 
 
 6 
 
 strip by two screws passing through the slotted piece 
 and into the wood. The wooden rest should be beveled 
 as shown. 
 
 It ninst be frankly admitted this lathe is not an 
 elegant machine to look at, but it is capable of turning 
 out quite reputable small work. 
 
 Having made the lathe, it will be necessary to pro- 
 vide some means to drive it. In almost every city and 
 town may be found old sewing machine tables, which 
 have been taken in trade as old iron. One of these can 
 be bought cheaply, and when the treadle is turned 
 around and a round leather belt applied to the lathe 
 pulley and the sewing machine wheel, the arrangement 
 is complete. 
 
 Some one may be found good enough to loan a sew- 
 ing table for the purpose. In this case, an assistant 
 will be obliged to work the treadle while the turning 
 is being done. 
 
 As the flywheel should be heavy, not less than 20 
 pounds, and as it should be about 20 inches in diameter 
 to secure the desired speed, it is perhaps better to fit 
 up the lathe with a wheel and table better adapted 
 to it than a sewing machine wheel and table would be. 
 
 The lathe shoAvn in the illustration is mounted on a 
 common kitchen table of the smallest size. In this 
 case, an old wheel is selected at the junk shop; one 
 with a groove in the edge is to be preferred, but a flat 
 rim will answer. The one here shown has a flat face 
 and is provided Avith a shaft, a crank and standards. 
 The standards are inverted and fastened with screws 
 to the under side of the table top. 
 
 A strip of board extending lengtlnvise of the table 
 is attached to the rear legs with screws, and the piece 
 
6 
 
 MVTUANICH FOR A^yiATFTIRS 
 
 of hoard foriniiiiij tlu‘ ti'(‘adl(* is to it in position 
 
 to rcM'oive tlie S(*rew wlii(di pass(‘s tliroipj^li tin* !ow(‘r 
 end of tlie pitman rod or eonn(‘etin<»: rod, tli(‘ n])p(*r 
 end beins’ apertnred to T'(H*eiv(‘ tli(‘ ('raidv ])in. A round 
 leatlier belt is used in tliis (*ase. 
 
 Tlie tools for tnrnin£>’ are not wry (^x})(msiv(‘ ; with 
 two o’oiioes and one or two flat (diisels a great varied j 
 of work may be done. 
 
 TUlINTXa 
 
 There is no secret in turning. Tt requires a great 
 deal of practice to bee-ome an expert, bnt beyond ac()nir- 
 ing the first principles nothing further than practice 
 is required. When reducing a piece of wood to the 
 
 Fig. 3. Lathe Turning Tools. 
 
 d(^sir(Ml approximate^ siz(‘, tln^ gouge is held on the 
 ri'st w ith its handl(‘-(‘nd ineliiKMl downward at an angle 
 of about ()0° wilh fin* borizonlal, lln^ re^st b(‘ing near 
 the work, and tin* gonge is inove^d ba(*k and forth on the* 
 
HOME MECHANICS FOE AMATEUKS 
 
 
 rest, taking off a slight shaving each time it is moved. 
 The handle is held in the right hand, while the blade 
 of the gouge is held in the left hand, with the thumb 
 pressing on the concave side. If a plain cylinder is 
 required it may be made by using the flat chisel, lay- 
 ing the beveled edge on the work in such a manner as 
 to produce a drawing cut as the wood passes the edge. 
 If the work is to be cut into at right angles or at any 
 other angle, the chisel is placed on its edge on the rest 
 and held firmly while moving it forward. 
 
 In cutting concave forms the gouge is made to make 
 a drawing cut by placing it partly on its edge on the 
 rest. It will be found necessary in either of these 
 cases to hold the tool very firmly on the rest to pre- 
 vent the edge from drawing itself forward on the wood 
 and spoiling the work. By practice the art of wood- 
 turning can be readily acquired even by the use of 
 the ^‘Simple Lathe.” 
 
 For hard wood and ivory a different class of tools 
 is required. The chisels are all flat, not oblique; some 
 of them have edges that are square across; some have 
 V-shaped points and others are round-nosed. For 
 under-cuts and odd work, special tools are bent at 
 different angles. Flat work, such as rosettes, etc., is 
 chucked upon the face plate, or attached with screws 
 to a board fixed to the face plate. 
 
 In finishing work the use of fine sandpaper is admis- 
 sible, but it never should be used to correct poor turn- 
 ing. Wood work, when smoothed a little with fine 
 sandpaper, may be finished by applying to it with a 
 cloth a mixture of shellac varnish and linseed oil, in 
 proportion of about one part of oil to two of shellac. 
 Only a little is applied to the cloth at one time, the pol- 
 
8 
 
 HOME MECHANICS FOE AMATEHRS 
 
 ish beiiifi: well shaken before it is a])])li(‘<l. The work in 
 the lathe is rapidly revolved nntil it is hri<,ditly polished 
 and the shellac varnish is hard. If desired, the work 
 may he stained before it is polished. The stains are 
 readily obtainable, and are described in the “Scientific 
 American Cyclopedia of Receipts, Notes and (^neries.” 
 
 WOOD-WORKING ON A LATHE 
 
 It is not the intention of the writer to enter largely 
 into the subject of wood-working, hnt simply to sng- 
 cest a few handv attachments to the foot lathe which 
 will greatly facilitate the operations of the amateur 
 
 Fig. 4. Saw Table. 
 
 wood worker, and will be found very useful by almost 
 any one workiiii^ in wood. It is not an easy matter 
 to split even thin lumber into strips of uniform width 
 by ni(‘ans of a handsaw, but by using the eireular saw 
 atlachimmt, shown in hhg. 4, the operation becomes 
 rapid and (^asy, and tln^ stuff may be sawed or slit at 
 any d(*sir(*d angh^ or b(‘\(^l. The atta(‘hm(ait consists 
 of a saw mandi‘(4 of lb(‘ usual foi'in, and a wood(ui table 
 supporl(*d by a I'ight angl(*d pie(*e, A, of round iron 
 
HOME MECHANICS FOR AMATEURS 
 
 9 
 
 fitted to the toolpost and clamped by a wooden cleat, 
 B, which is secnred to the nnder side of the table, 
 split from the aperture to one end, and provided with 
 a thumbscrew for drawing the parts together. By 
 means of this arrangement the table may be inclined 
 to a limited angle in either direction, the slot through 
 which the saw projects being enlarged below to admit 
 of this adjustment. 
 
 The back of the table is steadied by a screw which 
 rests upon the back end of the tool rest support, and 
 enters a block attached to the under side of the table. 
 The gauge at the top of the table is used in slitting and 
 for other purposes which will be presently mentioned, 
 and it is adjusted by aid of lines made across the table 
 parallel with the saw. 
 
 Fig. 5. Fig. 6. Fig. 7. 
 
 Saw between beveled Washers. Moulding Knives. 
 
 For the purpose of cross-cutting or cutting on a 
 bevel a thin sliding table is fitted to slide upon the 
 main table, and is provided Avith a gauge Avhich is 
 capable of being adjusted at any desired angle. For 
 cutting slots for panels, etc., thick saAvs may be used, 
 or the saAv may be made to Avabble by placing it be- 
 tAveen tAvo beveled washers, as shoAvu in Fig. 5. 
 
 The saAV table has an inserted portion, C, held in 
 place by two screws Avhich may be removed Avhen it 
 is desired to use the saAV mandrel for carrying a sticker 
 head for planing small strips of moulding or reeding. 
 
10 
 
 mmK AIKCMIANK^S FOR AAIATKURS 
 
 (Fi<>s. () and 7.) Tlu‘ li(‘a(I for lioldiiii; th(* moulding]; 
 knives is b(\st made of i>()od toui»li brass or st(‘am iindal. 
 Tlie knives ean be made of <»()od saw steel about J ineh 
 tliiek. Tliey may be RRmI into sliape and aft(‘rward 
 tempercHl. Tlnw air slott(‘d and lield to tlieir ])laees 
 on tlie bead by means of -|-in(‘li maeliine screws. It is 
 not absolutely lUH'essaiw to ns(^ two knives, but when 
 only one is employed a (‘onntca'balam'e should be fas- 
 tened to the head in ])la(‘e of the othei*. All kinds of 
 monldino-, beadin<»', tonf»nini> and i»i'ooviniL»‘ may be done 
 with this attachment, the <>ani»*e being used to guide the 
 
 edge of the stuff. If the boards are too thin to sup- 
 ]jort themselves against the action of the knives they 
 must be backed up by a thick strip of wood planed 
 true. The speed for this cutter head should be as great 
 as jiossible. 
 
 Fdg. 8 shows an attachment to be used in connection 
 with the cutter head and saw table for cutting straight, 
 s[)iral or irrc^gular tintes on turned work. It consists 
 of a bar, I), (*arrying a (*entral fix(‘d arm, and at either 
 (md an adjustable arm, the jinrjiose of the latter being 
 lo adapt lh(* d(*vi(*(* to work of dilfia'cmt haigths. The 
 arm [)roj(‘cting from th(‘ (*(ml(‘r of the bar, 1), sup- 
 
HOME MECHANICS FOR AMATEURS 
 
 11 
 
 ports an arbor having at one end a socket for receiving 
 tlie twisted iron bar, E, and at the other end a center 
 and a short Anger or pin. A metal disk having three 
 spurs, a central aperture and a series of holes equally 
 distant from the center and from each other, is at- 
 tached by its spitrs to the end of the cylinder to be 
 Anted, and the center of the arbor in the arm, D, enters 
 the central hole in the disk while its Anger enters 
 
 Fig. 9. Pig. 10. 
 
 Moulding Irregular Work. 
 
 one of the other holes. The opposite end of the cylin- 
 der is supported by a center screiv. A fork attached 
 to the back of the table embraces the twisted iron, E, 
 so that as tlie wooden cylinder is moved diagonally 
 over tlie cutter it is slowly rotated, making a spiral 
 cut. After the Arst cut is made the Anger of the arbor 
 is removed from the disk and placed in an adjoining 
 hole, when the second cut is made, and so on. 
 
12 
 
 HOME MECHANICS FOR AT\rA^J^EUl?S 
 
 Figs. 9 and 10 sliow a convoniont and (‘asily made 
 attaelinient for monlding tlu^ (Mlges of irr(\gnlar work, 
 snrli as brackets, frames, parts of ])atterns, etc. It 
 consists of a brass franu^, sn])])orting a small man- 
 drel turning at the top in a (‘oni(‘al bearing in the 
 frame, and at tlie bottom upon a eoni(*al S(*rew. A very 
 small grooved pnlley is fastemMl to the niandr(d and 
 surrounded by a rubber ring wliieh bears against the 
 face plate of the lathe, as shown in the engraving. The 
 frame, is let into a wooden table supported by an 
 
 iron rod which is received by the tool rest holder of 
 th(^ lathe. The cntter, (t, is made by turning upon a 
 ])\oco of ste(^l th(^ reverse of the required monlding, and 
 slotting it transversely to form cutting edges. The 
 shank of th(^ (‘iittcn* is fitted to a hole in the mandrel and 
 S(*cured in plac(‘ by a small set s(*i'(nv. The (Mlge of the 
 v'ork is j)(*rmi<l(‘d to b(‘ar against the shank of the (ait- 
 t(n*. Should lh(‘ fa(‘(‘ y)lat(^ of the lathe b(‘ too small to 
 give* lh(* r(Mpiir(*d sp(‘(*d, a wood(‘n disk may be attached 
 to il by m(‘ans of scr(*ws and (nrn(‘d off. 
 
HOME MECHANICS FOR AMATEURS 
 
 13 
 
 Figs. 11, 12, and 13 represent a cheaply and easily 
 made scroll saw attachment for the foot lathe. It is 
 made entirely of wood and is practically noiseless. The 
 board, II, snpports two nprights, I, between which is 
 pivoted the arm, J, whose nnder side is parallel with 
 the edge of the hoard. A block is placed between the 
 nprights, I, to limit the downward movement of the 
 arm, and the arm is clamped by a bolt which passes 
 throngh it and through the two nprights and is pro- 
 vided with a Aving nut. 
 
 A wooden table, secured to the upper edge of the 
 board, H, is perforated to allow the saw to pass 
 
 Fig. 13. 
 
 through, and is provided with an inserted hard- 
 wood strip Avhich supports the back of the saw, 
 and which may be moved forward from time to 
 time and cut off as it becomes worn. The upper 
 guide of the saiv consists of a round piece of 
 hard wood inserted in a hole bored in the end 
 of the arm, J. The upper end of the saw is secured in a 
 small steel clamp pivoted in a slot in the end of a 
 wooden spring secured to the top of the arm, J, and the 
 lower end of the saw is secured in a similar clamp 
 pivoted to the end of the wooden spring, K. Fig. 13 
 is an enlarged view showing the construction of clamp. 
 
 The relation of the spring, K, to the board, H, and to 
 
14 
 
 IlOMI^] JMKCIIAXK^S KOK A.MATKIJUS 
 
 the otlier part is shown in 12. It is atta(*li(Ml to tin* 
 side of tlie hoard and is i>ressed n])ward ))y an adjust- 
 ing screw near its fixed end. 
 
 The saw is drivcni l)y a wooden (‘('centric* ])la('(‘d on tin* 
 saw inandrel sliown in fXgs. -1 and A, and the sj)ring, K, 
 always press(‘d ni)war(l against th(‘ (‘('('(‘iitric' hy its own 
 elasticity, and it is also drawn in an n])ward direction 
 hy the npp(‘r spiang. Tin's arrang(‘inent insnr(‘s a (‘on- 
 tinnons contact hetween tli(‘ S])ring, K, and tli(‘ (‘ccen- 
 tric, and ('onsecjnently avoids n()is(‘. Tlie fric'tion snr- 
 fa('(‘s of tlie (‘('('(‘iitric* and si)ring may he Inhric'ated 
 with tallow and jilnmhago. The eccentric may, with 
 a(lvantag(‘, h(‘ made of metal. 
 
 Th(‘ tension of the u])])er s])ring may he varied hy 
 })ntting niidcm it blocks of differ(‘nt heights, or the 
 s('rew which holds the hack end may he used for this 
 jmrpose. 
 
 The saw is attached to the lathe hy means of an iron 
 hent twice at right angles, attached to the hoard, H, and 
 fitted to the tool rest support. The rear end of the saw- 
 ing apparatus may he supported hy a hrace running to 
 th(‘ lower part of the lathe or to the floor. 
 
 Th(‘ simple attachments above described will enable 
 th(‘ jiosscssor to make many small articles of furniture 
 w hich h(‘ would not undertake without them, and for 
 making models of small patterns they are almost in- 
 valnahl(‘. 
 
 WORK RF.NCII AND TOOLS FOK WOODAYORK 
 
 Th(^ first thing r(‘(piir(‘(l hy th(‘ amatcmr workman is 
 a hmich with a f(‘W tools for wood working. Tli(‘ heiu'h 
 n(*(*(l not n(*c(*ssarily lx* a long and heavy structure like 
 
HOME MECHANICS FOE AMATEUES 
 
 15 
 
 a carpenter’s bench, as the work to be done by the ama- 
 teur is mostly small, requiring but little material and 
 small room. A table like that shown in connection 
 with the simple lathe will answer, or the rear portion 
 of the lathe table may be used as a bench. A small 
 wooden vise is secured to the side of the table near the 
 left hand end, and in the top of the table is inserted a 
 common flat headed wood screw, which may be screwed 
 down even with the top of the table, or raised ^ or ^ 
 inch, as the work may require. This screw takes the 
 place of the usual bench dog, and holds the end of a 
 piece of wood while it is being planed. Two planes are 
 required to begin with, a jack plane and a smooth plane. 
 A good fine cross-cut saw will probabh^ answer for 
 all ordinary sawing, and it may be used as a rip saw 
 when only a little of this kind of work is required. Two 
 chisels, one f inch, the other | inch, and two gouges of 
 about the same width, will be needed. A hammer and 
 a screwdriver, together with a brad awl and a foot rule 
 complete an outfit that will enable the owner to do a 
 great deal of work. 
 
 Of course a good oil stone should be at hand for 
 sharpening the tools, and they should be kept sharp. 
 
 Chisels and plane irons must be held at an angle of 
 about 60° to the surface of the stone and moved back 
 and forth on the stone until an edge is produced. The 
 straight side of the tool must be kept from the oil stone. 
 
 While the tool is being sharpened the oil stone must 
 be lubricated with a few drops of sewing machine oil or 
 bicycle oil. When the tools need grinding it is advis- 
 able to have the work done by a competent workman. 
 
 The plane irons are set so that the edge is seen all the 
 way across the wood of the plane and secured by driv- 
 
1C 
 
 HOME MECHANICS FOR AIMATEURS 
 
 injj in the wedge. If the tool proj(‘ets so as to make a 
 thick shaving, the wedge is loosened slightly and the 
 iron is made to rise slightly hy lajtjting with a. hammer 
 on the top of the plane. The iron may lx* adjusted lat- 
 erally by tapping the iron on one (“dge or the other near 
 the to]>, and it may he forced downward by a few light 
 taps on the upper end. 
 
 After some observation — every hoy has opportnniti<‘S 
 for observation — and after practice, the amateur will 
 be able to do an ordinary job of car])entry, and he will 
 seek after a few more tools, such for example as a try- 
 square, a bit-stock and a few hits, a few clamps and a 
 glue pot. He can then enter into the work heartily, and 
 not only make needed repairs, hut construct many plain 
 little articles such as boxes Avith hinged covers, cabi- 
 nets, screen frames, etc. The main requirements are to 
 construct each part as carefully as possible, to assem- 
 ble the parts with equal care, and to never use plugs or 
 putty, or in other Avays patch up for bad Avorkmauship. 
 If a mistake is made, it is generally better to throAv the 
 part aAvay and begin again rather than to patch. 
 
 WHITTLING 
 
 The boy who is a good Avhittler Avill make a good me- 
 chanic, or Avill at least understand mechanics aa'cII 
 (‘iioiigh to knoAv a good job from a poor one, and Avill 
 be abl(‘ to help himself in many an emergency. Heal 
 [)roliciency Avith a jack-knife implies a knowledge of 
 mechanics and exhibits an ai)litude for meidianical 
 Avork Avhich only needs op[)ortunity and encouragement 
 lo reach a, useful stage of d(“V(‘lo])ment. 
 
 A jack-knife is a v(‘ry simph' tool, but Avithout doubt 
 
HOME MECHANICS FOK AMATEUFS 
 
 17 
 
 it is more generally useful than any other. For whit- 
 tling, an ordinary two or four-bladed knife should be 
 selected. It should have a good-sized handle and its 
 blades should be fine and well tempered. With the 
 knife should be purchased a fine, sharp oil stone, and 
 the knife should be kept sharp, as it is impossible even 
 
 Fig. 14. Knives adapted for Whittling. 
 
 for an expert workman to do good work with a dull 
 knife. 
 
 In sharpening the knife, the blade should be kept at 
 an angle of about 20° with the face of the 
 stone and rubbed back and forth the full length of the 
 stone about an equal number of times for opposite sides 
 of the blade, until it appears to be sharp, the stone 
 meantime being lubricated with water or oil ; then it 
 may be stropped like a razor on a strip of leather until 
 it is literally as sharp as a razor. 
 
 In whittling curious and ornamental objects, sea- 
 soned straight-gi’ained white pine should be selected. 
 
18 
 
 llOiMK AIl^X’IIAXK'S F()l{ AMATKl'IfS 
 
 TIi(‘ piece should be a little ]ar<i;er than (li(‘ finished 
 Avork, and tlu* desiiiu should he laid out in jxuieil on one 
 side of the block, Avheii it can be saAvc'd out with a scroll 
 saw. If the form eau be traced on tin* edj^e of the Avoi-k 
 much Avhittliiij? may be avoid(‘d by doin<i more sawiu}^. 
 The knife work may now ])roee(Ml. It is well to bejiin 
 Avith the lieaA'ier portions and finish AA'ith the lighter 
 ])oi‘tions. 
 
 As much should be done as possible AA ithout tin* use 
 of sand paper. If it can all be done AA ithout sand ])a])(‘r 
 so much the better. It Avill sometimes be found nec- 
 essary to lAut on the finishing touches Avith a pi<*ce of 
 A'cry flue sand }(ai)(*r. Blades of different forms are 
 found useful, and in some kinds of Avork a ])enknife 
 blade AA’hich has been broken off rather short aa III proA’e 
 e.xceedingly useful AA’hen the blade has been repointed. 
 
 The saAA’ used for shaping the AA’ork may be like the 
 one on pages 12 and 13, or one of the small scroll saAA’- 
 ing machines so much in use at one time AA’ould be still 
 better. 
 
 A A’ery pretty example of whittling is the chain AA’hose 
 liidvs are formed from a single bar of Avood of 0-shaped 
 cj'oss section. To make a good job the bar should be 
 (‘venly spaced, and the links draAvn on the sides of the 
 bar. Th(*n boles are bored diagonally through the bar. 
 i\t the angle the cutting proceeds sloAA’ly and cautious- 
 ly, finishing tin* link as far as possible before it is cut 
 loose. If any sandixipering is to be done it should be 
 done as far as }Missibl(! before the link is cut loose. In 
 flu* exam])l(‘ shown, only a ])ortion of the AA'ooden bar 
 has been foiMiied AA’ilh links, fhe remainder l)eing left 
 fo giv<‘ an idea of lh(‘ melhod. 
 
 It is more dilflcult to A\hiflle a pair of pliers from a 
 
HOME MECHANICS FOE AMATEUES 
 
 19 
 
 single piece of wood, so that the jaws work freely, and 
 at the same time the joints are neat. 
 
 Fig. 15. Examples of Whittled Work. 
 
 The blank for the pliers is sawed from |-inch pine. 
 The sides of the pliers where the joint is to be formed 
 are finished and the joint is carefully laid out in fine 
 
20 
 
 JiOJIE MECHANICS E<)1{ AMA'I'EniS 
 
 lines. Then with a veiy thin knife Ithuh* inserti'd from 
 eaeh side tlie eentral ])()rtion of the joint is cnf tlii-oii<;h ; 
 thin incisions are made* in the sides to intersect tlie 
 otlier ents. Tlie jaws of tlie jdiers are eariTiilly seji- 
 arated by cnttinfj from either side*, and tli(“ cuts which 
 separate tlie inside piece arc* then made with uri'at care. 
 The outside of the jaws and the handles ar<' now fin- 
 ished. In cnttiiijn' the joint tin* wood is somewhat com- 
 pressed by the insertion of th(‘ knife*, and tin* joint aji- 
 pears badly made. Ily soaking- the wood in water for 
 a lialf-honr or so the wood ri'snmes its normal condi- 
 tion, and the joint becomes tiuht. When the wood is 
 dry the finishing' may be done with a knife and with 
 fine sand paper. 
 
 The tower containing the balls and the revolving 
 spindle is cut from a single bar of wood, with the balls 
 and spheroid formed with a knife in the places they 
 now occupy. The design is carefully drawn on the bar, 
 and the work begins by making a diagonal cut across 
 each corner for the corner posts, not cutting through 
 the floors of the different stories. Then the inner 
 postern is cut roughly in the form of a cylinder. The 
 cross cuts are then made and the pieces are shaped into 
 balls. The spindle in the lower story is formed in the 
 same way, but it is cut loose by running the point of 
 the knife into the apexes of the cones formed above 
 and below the sjdu'roid, thus at one ojieration forming 
 the points of tin* sjiindle and tin* bearings for them. 
 The posts at tin* coi*n(‘rs an* h'ft as large as possible 
 and finished finally by taking off only enough wood to 
 make; th(“m straight and scpiare. 
 
 An anchor with its cross bar and ring is made of a 
 single |)i(‘c(* of 'wood a little thicker than the width of 
 
HOME MECHANICS FOR AMATEURS 
 
 21 
 
 the flukes. The cross bar is whittled out parallel with 
 the shank of the auchor, and the curved end is cut 
 across the grain. The hole in the shank is formed at 
 the same time the curved end is cut loose. The shoulder 
 on the bar is thus formed aud the bar is pushed through 
 the hole in the shauk. A small mortise is made in the 
 bar to receive the key which keeps it in place. The ring 
 at the top of the anchor is made in the same manner as 
 the first link of the chain. The anchor looks very sim- 
 ple, but it is in reality quite difllcult. 
 
 In all these examples the wood should not be cut 
 away more than is necessary, except to finish. 
 
 The puzzle shown assembled and separated cannot 
 readily be described. The pieces are notched so that 
 they will go together and form the symmetrical whole, 
 as shown in the engraving. 
 
 DIFFERENT SHAPES OF SAW TEETH AND THE 
 
 WAY THEY CUT* 
 
 The accompanying sketches show the different shapes 
 of saw teeth and the way that they cut the timber. Fig. 
 16 shows the dress of a shingle saw tooth. By examin- 
 
 Fig. 16. The “ Dress ” of a Shingle Saw Tooth. 
 
 ing it, it will be seen that it is a “sprung tooth,” and 
 the teeth cut on alternate sides of kerf, taking two teeth 
 to clear out the kerf on both sides. The bevel of the 
 teeth gives it a shear cut on the timber. The wood will 
 slip on the edge of the teeth, Avearing them on the inside 
 and leaving the outer corner full aud sharp, and a cor- 
 * PYom the Saw Mill Gazette. 
 
22 
 
 IIOMH MF.(MIANirS FOI? A^F\TFr^?S 
 
 iK^r to (‘lear np ili(^ si(l(‘ of tlu‘ k(M'f, (Inis inakinu^ sinoolli 
 lumber. 
 
 V\<^. 17 shows a sipiare dresscnl tootli. Tlie wood 
 
 Fig. 17. A Square 
 Dressed Tooth. 
 
 Fig. 18. 
 
 A Vertical Saw with Square Teeth. 
 
 wears off tlie corners, leaviiii> tliem dull, and they will 
 tly from timber to the other side if the wood is not 
 (M]ual in hardness, and lead the saw to that side of tlie 
 log. This trouble is found in wood with a hard and 
 soft grain or in knots, hut with the beveled teeth the 
 sharp corner will lead the saw straight. 
 
 Fig. 18 shows a vertical saw with square teeth, a very 
 (‘ommon dri^ss. The wood wears the out corner off, 
 leaving it round or blunt, and as there is nothing to sup- 
 port the inside of the teeth, they will fly from the wood, 
 
 Fig. 19. A Swaged Tooth of the Same Kind as Fig. 18. 
 
 I In* kiM-f iinlil worn in lli(‘ slia|)(* shown in (ait. 
 
 Fig. 1 !) is a swag(*d tool b of I li(‘ sanu^ kind of saw and 
 is a v(*ry good dress for sash, miil(\y, gang, and other 
 
HOME MECHANICS FOR AMATEURS 
 
 23 
 
 saws using light feed, but for heavy feed it is better to 
 swage the teeth out on both sides and joint off for set. 
 By referring to Fig. 20 it is seen that all teeth of this 
 shape cut with a scrape cut, not with edge cutting, like 
 
 Fig. 20. Teeth that Cut with a Scrape. 
 
 a chisel, but with the edge set at right angle with the 
 line of cut. For soft wood, such as white pine, ham- 
 mer the top of the teeth, turning the edge down enough 
 to give a cutting edge dotvnward. Figs. 21 and 22 are 
 circular log saws. 
 
 Fig. 21 shows a side view of a tooth. It is seen that 
 the back of the tooth lies close to the wood, and the 
 
 Fig. 21. Side View of Circular Saw Tooth. 
 
 tooth may be tiled thin without danger of breaking. 
 This dress of saws cut with a chisel cut, will carry more 
 feed than any other, and at the same time do the best of 
 work. 
 
^4 
 
 MKCTIANICS FOU AMATEURS 
 
 Fic;. 22 shows tlio shape of tlie edge of the same tooth.. 
 It heiiijn hollow on the (“dji’e, with the coiaiers shar]), 
 the wood will tly or slij) from the eoniei's, not weariiiij; 
 them as much as a S(inare tooth, leaving a i^ood corner 
 
 Fig. 22 . Fig. 23 . 
 
 Edge of Circular Saw Tooth. A Square Dressed Tooth. 
 
 to clear the sides of the kerf. It will be seen by refer- 
 rintf to Fig. 22 that it takes two teeth, one on each 
 side of the saw, to cut both sides of kerf, bat in this 
 dress each tooth cuts both sides, and again, if a beveled 
 sjirnng tooth is forced to do more than a medium 
 amount of duty, it will fly into the wood and be in dan- 
 ger of tearing off the teeth. 
 
 In Fig. 23 is si'cn a square dressed tooth. All teeth 
 swaged with a sipiare dress leave' the corners rather 
 weak and not much to joint off the side in setting, 
 n'his shows om* snch tooth cutting throngh cross 
 grained or twisled timbi'r, a sharp corner but nothing 
 1o ch'ar the side of tlii* keiT, the cross grain filling so 
 rnncli of Ihe kerf as to rub on the plate of the saw and 
 heat it. 
 
HOME MECHANICS FOE AMATEUES 
 
 as 
 
 Fig. 24 refers to a dress for hand and other saws that 
 
 Pig. 24. Dress for Hand and other Saws. 
 
 is used for cross-cutting soft wood that is to be cut very 
 smooth. 
 
 A WEINKLE IN SAWING 
 
 A trj-square is not ahvays at hand when it is desired 
 to saw a stick, and Avlien it is handy some mechanics 
 prefer to work “guess” than otherwise. When a 
 bright straight saw is placed upon a stick or on the edge 
 
 Pig. 25. Reflection Substituted for the Try Square. 
 
 of a board, the reflection of the stick or board in the 
 saw is sufticieutly well defliied to permit of placing the 
 saw so that the reflected image coincides with the object 
 reflected, forming a continuous straight line. If the 
 sawing is done while the image and the stick are in line, 
 tlie stick will be cut at right angles. 
 
 It is obvious that a line may be drawn at right angles 
 to the stick by arranging the saw as shown in Fig. 26. 
 If, after forming this line, the saw be placed across the 
 stick so that the line and its reflected image and the 
 
HOME MECHANICS FOE Ai\IATEUJ^S 
 
 26 
 
 sti(*k and its r(di(M‘t(‘(l iinaji^e form a scpiaro, witli tla^ 
 reflected ima<>e and the stick lying in tlie same plane, 
 
 Fig. 26. Laying out Work by Reflection. 
 
 Fig. 27. Forty-five Degree Angle by Reflection. 
 
 as shown in l^hg. 27, the stick may be sawed at an angle 
 of fo]*ty-tiv(^ d(^grees, provided the saw is held in the 
 saim^ ])osition ridative to the sti(‘k. 
 
 WOOD CAKVING 
 
 To one* having an id(‘a of foian and pro])ortion, wood 
 carving is not venw diflicailt, (‘ven though a practical 
 kno\\’h‘dg(‘ of drawing and imxhding he wanting. Cred- 
 
HOME MECHANICS FOR AMATEURS 
 
 27 
 
 itable specimens of carving liave been produced by 
 means of the pocket knife alone, by persons having 
 dextrous bands and good e^^es; but it takes a good 
 workman to produce a fine job with poor tools, or none 
 at all, therefore the average wood carver will be obliged 
 to rely somewhat upon tools and appliances. In fact, 
 the more complete the set of tools and the more perfect 
 the accessories, the more readily can the work be done 
 and the more satisfactorv the I’esult. 
 
 Fig. 28. Violet Panel. 
 
 The principal tools are gouges, chisels, parting tools, 
 curved and straight, a heavy mallet, a light mallet, a 
 solid bench, and some clamps. As to materials: For 
 the beginner soft woods are best, such as pine, white 
 wood, or cedar. After a little experience, pear, black 
 walnut, and oak may be tried. Nine-tenths of the dif- 
 ficulty in carving is in working one’s self tip to the 
 
28 
 
 IJOMI-: MI'XUIANK’S KOK AMA'I'Kin.’:^ 
 
 point of settiii”' out in (In* work. Tin* clianccs nro lluit 
 in tlio bc^innini' tin* tyro will not succeed in ])ro(lncin^ 
 the exact forms desired ; but ])rof>ress will be mad(“ with 
 every successive trial. 
 
 It is, indeed, diltieult to give any <“X])lieit diiaa-tions 
 for carving. W(‘ niigbt almost say, bere are tin* ma- 
 terials, tbe tools, and tbe design. The wliob* of carving 
 is to take these tools and cut this d(‘sign from this ])i(‘C(^ 
 of material, using your own judgment, at the same 
 time “making haste slowly.” 
 
 Fig. 30. 
 
 Fig. 29. Carving Tools. Edge View 
 
 of Tools. 
 
 'I'he (ools re(|uired ai’C shown in Fig. 29, 1 being a 
 firmer, 2 a straight gouge*, 2 a curved gouge, 4 a bent 
 chisel, o a fronl-beni gemge, (» a back-bent gouge, 7 a 
 parliiig lool, <S a curved parling lool, and 9 a macaroni 
 fool. 1'hes(‘ fools can be* pui‘e‘hase*d e*ithe*r se*])arate*ly 
 eir ill se*ls. 4'he‘re* are* e)fhe*r forms ami many elilfe*r(*nt 
 
HOME MECHANICS EOR AMATEURS 
 
 29 
 
 sizes. It is well to begin with a half dozen medinin 
 sized tools, and then learn by experience what further 
 tools are required. A flat and curved chisel and a flat 
 and curved gouge, each one-half inch wide, a narrow 
 deep gouge, and a parting tool are sufficient for the 
 first effort. 
 
 The design is marked upon the wood to be carved, 
 and the outline is shaped by means of a scroll saw, if 
 the design is to be in high relief, and the most promi- 
 nent is isolated from the rest. Avoid cutting too 
 deeply, or raising slivers that run into the wood and 
 spoil the work. Where the carving is done on a flat 
 surface in low relief, gouges having little curvature 
 are required. 
 
 The tools shoxdd be kept as sharp as possible, to se- 
 cure smooth Avork and to economize labor. Carving 
 tools are usually sharpened from both sides by means 
 of suitable oil stone slips and by leather strops charged 
 Avith crocus. 
 
 The Avood Avhile being carved is held in place on the 
 bench by means of screAv clamps, or by pointed screAvs' 
 passing upAAard through the bench into the back of 
 the Avork. 
 
 In Fig. 28 is shoAvn a panel of violets, Avhich may be 
 copied after some experience is gained. It is easier, 
 hoAveA^er, to copy other carvings than to produce the 
 Avork from engravings. 
 
 Simple subjects should be chosen, and no Avork 
 should be passed until it has been made as perfect as 
 the tools, materials, and ability of the carver Avill per- 
 mit. A final finish imparted Avith fine sandpaper is ad- 
 missible ; but neither sandpaper nor putty should be de- 
 pended upon as material aids in this kind of work. 
 
PART II. 
 
 HOW TO MAKE HOUSEHOLD 
 ORKAMEKTS 
 
 HOME MADE GRILLES AND GRATINGS 
 
 A DWELLING HOUSE without ornamentation 
 of the class mentioned above indicates one of 
 three things — either the owner or occupant 
 does not appreciate the value of this kind of 
 home decoration or he does not possess the skill to 
 make or the power to purchase it. It is true, the 
 beautiful metal and wood work now manufactured for 
 this purpose is very expensive ; but it is also true that 
 something equally as beautiful may be had without 
 much trouble or expense. 
 
 The grilles shown in Figs. 31, 32, and 33 are made of 
 rope, sized, bent into shape, dried, glued in a wooden 
 frame and finally painted an appropriate color or 
 gilded or bronzed. These ornaments when placed in a 
 doorway or window or across a hall from the stairway 
 to the wall, or in some corner in the library, add won- 
 derfully to the appearance of the room. 
 
 The materials required are some A inch sash cord, 
 glue, round sticks or doweling A inch in diameter, 
 paraffine (a paraffine candle will do), some strips of 
 wood, and paint or varnish. 
 
 There are in the present case only two fundamental 
 forms for the spindles or bars, but these are combined 
 in several different ways, as shown in Fig 36. The spin- 
 
 [31J 
 
32 
 
 HOME MECHANICS FOR AIViATEURS 
 
 die most used is shown in Fi<r. 34. It is formed by 
 windinc: tlie sasli cord — wliich lias lieen jirevionsly 
 stee])ed in the "lue size — ujion the wooden rod. The 
 rod is coated with melted ])aral1ine before use, to ]»re- 
 vent the size from adhei-inin’, and e(|uidistant marks ar(> 
 made upon the rod as unides for the windinii. These 
 marks are H inches a])art. The windiiii^ can be easily 
 done by jilaciii”' one (md of tin* woodim rod in a vise, 
 drivino- a tach through the end of the I'ojie into the rod. 
 If every turn of the rojK* ai'onnd the 7‘od is made to co- 
 incide with one of the marks, tin* s])indle will be true 
 enoipcih for all purposes. A tack should be driven 
 
 Fig. 31. Grille for Double Doors. 
 
 through the end of the finished spiral into the rod to 
 prevent the rope from unwinding. A number of rods 
 will be reciuired. Part of the spindles should be wound 
 in a rigbt-banded direction and tbe remainder in a 
 left-hamb'd direction. The rope should be allowed 
 to stand for a day or so to dry. It is well, espe- 
 cially in warm weathei', to add to the size some oil of 
 cloves or (airbolic acid to prevent it from souring while 
 drying. 
 
 Tin- othei' form of spindle is shown in Fig. 35. This 
 is made by bending the siz(>d rope* around pins driven 
 into a board in two rows, tin* pins of one row alternat- 
 
HOME MECHANICS FOR AMATEURS 
 
 33 
 
 Fig. 32. Rope Grille for Window, Door, or Hall. 
 
 ing in position with those of the other row. The board 
 and pins are covered with paraffine, as in the other case. 
 
 The spiral spindles may be combined with each 
 other, as shown at a, b, c, d, and e in Fig. 36, and with 
 
 Fig. 33. Grille for Window. 
 
31 IlOJll] JMKCIIANJCS FOR AMATEURS 
 
 a straiglit rod, as sliowii at /. At fi tliey are sliowii in 
 eoinbiiiatioii with the zigzag r()])(\ At li the zigzag ro])e 
 is shown in coinhination witli straiglit rods. 
 
 Tlie circles and s(\gnients of ('ir(‘l(^s sliown in hdgs. ?>2 
 and 33 are made l)y winding tlu^ siz(Ml ro])e ai'onnd a tin 
 pail, a can, or some otlu^r (‘vlindrical body and allowing 
 it to dry. To form a complete' ring, one turn of the i' 0 ])e 
 is cut off, its (‘lids are cut off diagonally and fastened 
 together with strong glue. 
 
 The spindles arc' cut by means of a sharp knife. The 
 various parts of tlie work are fastem'd togetlu'r and at- 
 tached to a light wooden frame, and, as a rule', no fas- 
 tening other than glue Avill lie reepiirc'd. If, liowevc'r, a 
 stronger fastening is nec'cssary at some jioints, small 
 brads or wire nails, or even screws, may be used. 
 
 In Fig. 33, the rosette, is formed of a circular ring 
 filled with segments of a similar ring in the manner 
 shown. Each pair of spirals, consists of one right- 
 
 Fia. 34. Spiral Spindle. 
 
 handeil oik* and om* l(*ft-hand(*d. The spindles, h, 
 a F*(' spii'als. 
 
HOME MECHANIC'S FOR AMATEURS 
 
 35 
 
 manner as wood. They may be stained or painted to 
 match the work into wliich they are fitted, or they may 
 be painted white and relieved by a little gilt on the pro- 
 jecting part. 
 
 It is obvious that a large number of patterns may be 
 worked out by the aid of these suggestions. Different 
 
 Fig. 36. Forms of Spindles and Bars. 
 
 kinds and sizes of rope may be used alone or in combi- 
 nation. 
 
 These grilles may be placed in windows, doorways, 
 across halls, above mantels, across niches, between win- 
 dows, and in many other places which will suggest 
 themselves. Like many other household ornaments, if 
 well and carefully made, they will repay the labor and 
 trouble of making. 
 
 WALL ORNAMENTS 
 
 There is a great deal of satisfaction in the possession 
 of home made ornamental objects, because they are the 
 work of one’s own hand, and, besides this, they are not 
 obtained by the expenditure of money that might per- 
 haps, be needed for other purposes. 
 
 Ornaments belonging to the wall go a long way in 
 furnishing and beautifying the house. Pictures, care- 
 
IIOJIM MI-X'IIAN’ICS Foi; .\:\r.\'l'KU KS 
 
 XG 
 
 fully sel(*(‘t('(l, arc* liijilily <“(r(“c( iv(“. Many of (la* nio<l- 
 (“I'li |)liot<)i>ra])lis, ]>liol()-,i>vavur(‘s, and jilioto-ciijui'aviiiii's 
 which are rc'ally iiK'riloiMous can l)e ohiaiued for lifiy 
 (■(‘iits or a dollar (“acli. Soin<“ fairly nood elchiii^s and 
 imitations of water colors ai-e also sold at reasonahh^ 
 ])rlces. Th(‘ jii'cat il<*ni in conn<“clion wilh a low-]>riced 
 l)ictnre is the fi-ann*; hnt any one with such tools as are 
 commoidy found about tin' house* and with a small 
 (inantity of mat<*rial can readily make a Aai'iety of 
 frames Avorthy (»f any ])lace in the house*. 
 
 The sim])l(*st frame? tee make* is that sheeAvn in Fi_y .‘>7. 
 This is maele* freem a narreew tiat beearel eef e*he*stnnt, 
 
 Fig. 37. Wooden Frame. 
 
 l)uli(‘i*Tni1, ()]* (‘V(Mi asli or oak, liavini»“ its inner ed<»‘e 
 i'al)l)(*1(*(l io r(MM‘iv(‘ ili(‘ i^lass, mat, and l)a('kin<»‘. Tliis 
 sli'ip is stained and (inisln*'! b(‘ror(‘ ii is mit(a'(Ml. Tlie 
 staining is doin* by brnsbin<»- lli(‘ strip (‘V(ady witli a 
 thin coating- of asi)lial tnin, or with a thin slain of log- 
 
HOME MECHANICS FOR AMATEURS 
 
 Z1 
 
 ■wood, or Avith a stain forniod of either of the following 
 dry pigments, burnt umber, burnt or raw sienna, mixed 
 with turpentine and a very small proportion of boiled 
 linseed oil. Chemical ink or writing fluid, reduced 
 with water so as to produce a greenish gray tint, 
 answers a good purpose. 
 
 After the stain is dry, the tint is lightened along the 
 inner or outer edge of the strip, as taste may dictate, 
 by scraping the wood by means of an ordinary wood 
 scraper, or by rul)l)ing the surface down by means of 
 fine sandpaper. It is obvious that the stain may be 
 applied to the wood in such a way as to graduate the 
 tint without the necessity of scraping or sandpapering, 
 but this requires practice. 
 
 The tint should be so graduated as to be very light, 
 or nearly the natural color of the wood at one edge of 
 the strip, while the other edge should be quite dark. 
 The strip may be finished by flowing over it three thin 
 coats of shellac varnish, allowing each coat to dry thor- 
 oughly before axqilying the next. The first two coats 
 should be rubbed down with very flue emery paj^er 
 after they become thoroughly dry and hard. The last 
 coat may be left bright, or its luster may be toned 
 down by means of the fine emery pax>er. The mould- 
 ing or strip thus xjrejjared is mitered in the usual way 
 by the aid of a miter box, and nailed and glued to- 
 gether at the corners. 
 
 The mat in this case consists of a piece of thick paste- 
 board in which is cut an opening of the desired form. 
 The edges of the pasteboard are beveled around the 
 opening, and canvas, crash toweling, or white or tinted 
 cotton velvet is secured to the pasteboard by means 
 of bookbinder's paste (flour paste with glue added). 
 
38 
 
 HOME MEC'JIANK'S FOR AJIATEUIJS 
 
 After tlie paste becomes dry, if desii-ed, a design may 
 be painted on tlie mat witli wat(‘r colors. 
 
 The frame sliown in Fijjc. 38 is made on a different 
 plan. In this case the wooden monldinij is half round 
 on its face. A saw kerf is made at the inmm side of tin* 
 rabbet. The edji’e of a strip of white or “ivoiw” zylon- 
 ite is inserted, in the saw kerf, and held there by a thin 
 
 Fig. 38. Zylonite Frame. 
 
 strip of Avood glued in. A small percentage of glycer- 
 ine or even common molasses should be added to the 
 glue used for this pur])ose. The zylonite is AAu^apped 
 around the moulding and fastened by means of a thin 
 strip of wood laid ov(U' it and secured by small nails or 
 brads. cormu'S of ibis frame are formed by means 
 
 of r(M‘tangular blocks of Avood paint(Hl Avhite on their 
 si(l(is and furnish(‘d on tlu^ front with a scpiare of zylon- 
 it(^ li(*ld in pla(‘(‘ l)y an ornaimaital bi'ass nail. 
 
 if a larg(*i* fraim^ is i‘(‘([uir(‘d, that (‘an b(^ made Avith 
 
HOME MECHANICS FOR AMATEURS 
 
 39 
 
 a single strip of zylonite, the joint may be covered by 
 means of a curved half round strip of brass well pol- 
 ished and lacquered, and applied as shown in the en- 
 graving. 
 
 This frame may have a gilt lining as well as the mat. 
 It has a verj^ chaste appearance, looking much like a 
 frame of ivory, and it is withal durable. 
 
 Fig. 39. Feather Ornament. 
 
 A very pretty and easily made wall ornament is 
 shown in Fig. 39. It consists of a number of peacock 
 feathers arranged I’adially or in the form of a fan witli 
 the quills attached to an elliiitical piece of pasteboard 
 by means of sealing wax. The pasteboard is fitted to 
 an iridescent shell and fastened in with sealing wax. 
 A wire loop inserted in the pasteboard serves for hang- 
 ing the ornament. It may be placed between windows, 
 
40 
 
 nOMH MKdIIANICS F()|,> Ai\[.\TETIKS 
 
 !il)(>vo or bolow ])ictiir(‘s, juid in iiuuiy olli(‘i‘ ]>lac(‘s wifli 
 fiood effort. 
 
 Iti Fi.i'-. 40 is sliowii a wall cabiiuff, wliicli is not only 
 liiyldy ornamental, but V(‘i-y ns(‘fnl. Tin' body of (li(‘ 
 oabinet is of pirn* (tr otber soft wood. Tin* doors ai-e 
 
 Fig. 40. A Wall Cabinet. 
 
 io r(‘(‘(MV(^ tlie Ix^autifiil zyloiiite bas-reliefs 
 sold by lli(‘ inaniifacd iir(‘rs of this sii])erl) material. In 
 opcMiiii^s in 11i(‘ l)aek of ilu^ (‘abim^t are inserted oriia- 
 nnads of lln^ sann* (diai'acter. They rescmible ivory 
 and ar(* v(a'y s(‘r\ie(*abl(\ 
 
 Th(‘ body of IIk^ eabin(‘t is m^atly eovcaxHl witli (*an- 
 
HOME MECHANICS FOE AMATEUES 
 
 41 
 
 vas, toweling, or lighth^ tinted cotton velvet, on Avhicli 
 are painted designs in water or oil colors. The edges 
 of the shelves are preferably covered with sheet zylon- 
 ite, although they may with good effect be covered with 
 the material used on the other jjarts of the cabinet. Or- 
 namental brass hinges and trimmings should be applied 
 to the doors, as shown in the engraving. 
 
 PSEUDO-CEKAMICS 
 
 The ceramic art is generally practiced under condi- 
 tions which render it exceedingly difficult for an ama- 
 
 Fig. 41. Square Vase. 
 
 teur to make progress in it, even so far as to produce 
 work of the most modest and unassuming character. 
 
4-2 
 
 II()MI<: MECIIANJCS KOR AMATEURS 
 
 111 the first placi' it is (lifiiciilt to obtain the jirojicr 
 <]iiality of elay, iinli'ss oii<> is in lln* vicinity of a jiotti'rv 
 or elay bed; in the second jilace, even 1 hon,i>h one* lias 
 the shill and practice which will enahh* him to shajic* 
 the clay into the desired forms, still it is dilficiilt, if not 
 impossible to hake the work after it is done in othm* 
 respects, and it can scarcidy h<> (‘xpc'cled that a ])ott<‘r 
 will bake these odd articles. These* and other ditficnl- 
 
 Fig. 42. Triangular Vase. 
 
 <i(^s prevent tlie wonld-be aiuatenr potter from attempt- 
 ing wlial, nn(l(‘r more favorable eiriaimstaiu'es, niii»lit 
 lx* f)ro(lnet i v(^ of w'oi'ks creditable to both the art and 
 th(^ artisan. 
 
 K(*c(*ntly sonui (‘xc(‘(*dini>l y plain aitich'S of i)ottery, 
 with (*xt,r(‘m('ly siniph^ ornaimmta t ioip (‘onsisting 
 m('r(*ly of a lilll(‘ i)aint and a little^ e,Iaz(‘, hav(‘ bec^ome 
 V(a‘y fashionabl(‘, and liav(‘ Ixuai aexx^pted as works of 
 
HOME MECHANICS EOE AMATEEKS 
 
 43 
 
 art. Some of these articles are handsome, others are 
 not. Inasmuch as these articles have no practical 
 utility, they do not require to be made of materials 
 either fireproof or waterproof. The requisites are 
 simply shape, strength, and a. resemblance to pottery. 
 
 The materials required for making imitation pottery 
 are junk-board — a strong, thick board having a smooth 
 surface — glue, and small wire nails. The ornamenta- 
 tion may consist of siich floral or landscape decorations 
 as the maker is able to produce if he or she be artist 
 
 Pig. 43. Cylindrical Vase. 
 
 enough to paint in oil colors. Withoiit this ability the 
 aid of chronios must be invoked. This will certainly 
 afford very satisfactory results, and the expense will be 
 slight, as very passable German chromos may be ob- 
 tained for twenty-five cents each. The engravings show 
 several examples of pseudo-ceramics which are de- 
 signed with reference to the material to be employed, 
 and compare favorably with the high-priced articles to 
 be found in the shops. 
 
44 
 
 MI^XMIANI(!S YOU A^WTV.VU^^ 
 
 Tli(‘ l)()(ly of ili(‘ vas(‘ sliowii in 41 consisls of 
 
 r(H*taiiii>ulai' ])i(M‘(‘S of juiik-boai'd iiail(‘(l and :nln(*(l to- 
 ^(Xlier at tlie (‘onun's, aft(‘r tli(‘ fasliion of an oi'dinary 
 Avoodoii box. The nails used are tlie small \vii'(‘ nails 
 used in braeket-Avork. T1 i(\a" are about I br(M‘-(‘i,i>btbs 
 of an inch loni>’, and about the size of an oi'dinary pin. 
 
 1 n tli(^ abs(m(‘e of such nails coiumon pins may be cut off 
 and ns(*d to f>()od advantaj>e. Holes for these nails 
 nnisl b(‘ niad(^ with a fine-])ointed awl. The bottom of 
 tli(^ vas(* consists of a single ])ie('e of junk-board, Avith 
 \"-sliai)(Ml nolcli(*s (uit from the corners to j^ive it the 
 b(*v (d. 
 
 Tli(‘ con(*av(' sid(^s of ilui top (‘onsist of send ions of 
 
HOME MECHANICS FOR AMATEURS 
 
 45 
 
 paper tube such as is employed for mailing pictures. 
 The bead around the top is of wood. Any imperfec- 
 tions in the joints may be filled with a mixture of glue 
 size and whiting formed into a putty. 
 
 Fig. 42 shows a vase which can readily be made after 
 the above hints. It is triangular in form, and has three 
 wooden balls for legs. The band around the top is 
 merely a narrow strip of pasteboard glued on. 
 
 Fig. 43 shows a cylindrical Aaise made of a strip of 
 junk-board scarfed or beA eled on the edges and lapped 
 
 Fig. 45. Elliptical Vase. 
 
 and glued. To facilitate bending the junk-board, the 
 side which is to be outermost in the vase is wet. The 
 bottom is glued and nailed in, and the corners are 
 rounded with a moderately coai’se file and sandpaper. 
 A band of pasteboard finishes the top, and three or four 
 wooden balls form the legs. The inner corner of this 
 vase at the bottom may be filled in slightly Avith glue 
 and AA'hiting to strengthen it. 
 
46 
 
 HOME MECIIANMCS FOR AMA4M^]UI?S 
 
 Tlie yn^Q sliowii in Fij». 44 is made in tln^ sann^ way 
 as that last des(‘ribed. Tlie bottom is ])lac(‘(l al)ov(‘ tlu^ 
 lattice work. The latter is fornuMl by cnttini; out |h(‘ 
 holes with a chisel. The rini»* and its fixture ai‘(‘ mad(^ 
 of wood. 
 
 Figs. 45, 46, and 47 are examples of ^^pilgrim” rases 
 of different shapes. That shown in Fig. 47 is circnlar, 
 and has convex sides or heads. Tlie hoo]) is Ixmt in tln^ 
 manner already described, i. c., after first wetting the 
 
 Fig. 46. “ Pilgrim ” Vase. 
 
 outer side. The heads are made convex by wetting the 
 jnnkdioard and liammering it in the middle, in the same 
 way tliat a shoemaker hammers a shoe sole, or tap, to 
 make it conv(*x, that is, it is placed upon an ordinary 
 flat-iron or sad-iron, and hammered with a round-faced 
 hamiiKa* until it ac'cpiires the desired convexity. The 
 sidles ar(^ nailed and gliuMl to the hoop, and a thin paste- 
 board circle is gln(‘d lo each of the ('onvex surfaces of 
 the vase to form a border. Idle mouth of the vase is 
 
HOME MECHANICS FOE AMATEUKS 
 
 47 
 
 made of four pieces of junk-board, glued and nailed to- 
 gether and secured to the vase by glue. The legs of this 
 vase consist of two pieces of paper tube closed at the 
 ends with turned pieces of wood. The corners of the 
 vase may be filed and sandpapered to make it ready for 
 further operations. 
 
 After what has already been said the construction of 
 the vases shown in Figs. 45 and 40 will need no descrip- 
 
 tion, except that the vase shown in Fig. 46 has wooden 
 legs and wooden strips at the sides of the mouth. 
 
 The body of the vase shown in Fig. 48 can be con- 
 structed without special description. The ornamenta- 
 tion consists of ordinary artificial flowers and vines, se- 
 cured to the body of the vase with common glue. They 
 are stiffened by spraying or spattering shellac var- 
 nish on them from an old tooth or nail brush. They 
 
48 
 
 nOMK MECHANICS V()\l A.MATKUl^S 
 
 {^lioiild be S])raye(l tilings io oiye IIkmii a uood 
 
 heavy (‘oatiiii!,’ of vaniisli. WIkmi tliis l)(‘(‘oin(*s di'y tie* 
 leaves and dowers may l)e paintcHl in tln^ saim* manii(*i* 
 as the otlier j)arts of tli(‘ vas(‘. Tli(*se vas(‘s slioidd 1)(‘ 
 smootldy finished and tlioroni>ldy dried b(*for(‘ any at- 
 tempt at finishini>‘ is made. Tlie lirst opcn-ation in 11i(‘ 
 way of finisldnj»- is to give the vase two ('oats of sln^llac* 
 
 varnish inside and out, 
 
 allowing one coat to be- 
 
 come dry before the 
 other is a])])lied. When 
 both coats of varnish are 
 dry and hard, which will 
 reqnire about two daj'S, 
 the painting miij be 
 done. 
 
 It is not the design of 
 this section to enter into 
 all of the details of 
 painting necessary to 
 enable the tyro to paint 
 landscapes or flowers, 
 blit a suggestion or two 
 in regard to the paint- 
 ing will not be out of 
 place. The best results 
 will be obtained by giv- 
 ing <h(^ vas(^ two (‘oats of white paint before attempting 
 to lay on tlu^ color. The sides and bordcu' of the vase 
 should be of a lUMdi'al tint, slightly mottled. An olive 
 green or a gray looks w(‘ll and gives relief to any de- 
 sign lhat may be chosen. 
 
 No attempt should b(^ made to ay)ply the colors 
 
 Fig. 48. Vase with Leaves 
 and Flowers in Relief. 
 
HOME MECHANICS FOR AMATEURS 
 
 49 
 
 smootlily. The Avliole slioultl be done in a bold, dashing 
 wav. 
 
 If painting is ont of the question, some of the ehro- 
 inos before mentioned may be used with good effect. 
 The edges of the chromos may be concealed beneath the 
 jmsteboard border. In eitlier case after the paint on 
 the article has become thoroughly dry and hard, which 
 will probably .require four or six weeks, it may receive 
 a coat of pottery varnish, to be obtained at any of the 
 color stores. 
 
 In tlie case of the applied artificial flowers, they 
 should he heavily painted with, say four or five coats of 
 white paint before applying the color. 
 
 Ornamental articles of this kind cost little save the 
 labor, and will well repay the trouble of making. 
 
 IMITATION OF MAJOLICA 
 
 Cements and sealing wax are useful for giving to 
 paper and wooden articles a hard glaze, resembling that 
 of majolica ware. The cwlindrical vase shown in the 
 following engraving consists of a paper mailing tube 
 3 inches in diameter, and 6 inches long, furnished 
 with a pasteboard bottom, which is glued in. The 
 inside and bottom of the vase are provided with two or 
 three coats of asphaltum or shellac varnish to render 
 it waterproof. The outside is covered Avith jeweler’s 
 cement of different colors, or Avith sealing Avax, or 
 both. The bar of cement or wax is melted at the end, 
 and applied to the paper cAdinder in the same manner 
 as it is applied in sealing packages. No particular care 
 is required in applying the Avax. It is, liOAveA^er, neces- 
 sary that the edges of adjoining patches of aa'Ux be 
 
50 
 
 .MKCIIAXICS FOR AMATEURS 
 
 l)roni>lit into (‘oiiUK't witli (‘acli oihvr to insure^ tlio roin- 
 plete c()voriii!L»' of ilu^ ])a])(‘i‘. In tlie (‘xa]n])l(^ sliowii in 
 tlie eii<»Taviiii»', olive i>r(‘(‘n j(^\v(‘le]‘'s ('(Miaait foians the 
 coveriiii;' of tlu^ lower ])art of tli(‘ Tliis is blcaHlcMl 
 
 into (‘emeiit (-oIoixmI Avitli VeiHhian riMl or Iiulijui red, 
 and the (‘enient at the to]) is tl(H‘k(Ml witli y(^llow. 
 
 The mass of e(mient is laid on in s])iral lim^s, and 
 when the (‘overini»’ is eoni])let(^, th(^ yas(^ is h(‘ld over a 
 
 sniok(‘l(‘ss tlani(‘, sm'li as 
 that of a U>nns(m burner 
 or ab'ohol lamp, or it 
 may Ix^ h(*ld over a coal 
 fire until the cement 
 fuses. The vase should 
 be turned in such a way 
 as to cause the variously 
 colored cements to run 
 into each other. The 
 vase is held l)y means of 
 a paper tube or a stick 
 inserted in its open end. 
 
 Ornamentation may be 
 applied by cutting 
 leaves, stems, petals, 
 etc., from pieces of thick 
 paper, dippiug them in 
 melted cement of appro- 
 priate color, allowing 
 th<*m to cool, afterward 
 arraiigiiig them upon the Yas(“; finally softening the 
 cement of I Ih' vas(‘ and I lie ornament by holding a dame 
 ora hot iron ovin- lliem iinlil llie c(‘ment softens, and 
 the oi-nainenis are allaclied. ('are is reipiired at this 
 
 Fig. 49. Imitation of Majolica. 
 
HOME MECHANICS FOR AMATEURS 
 
 51 
 
 point to avoid the complete fusing of the cement, as 
 this would spoil the job. Care is also required to 
 avoid igniting the cement or wax, as it is nearly impos- 
 sible to extinguish it. 
 
 STAINED GLASS AND OBJECTS OF WIRE 
 
 CLOTH 
 
 A little stained glass work judiciously distributed 
 imparts a bright and cheerful air to the house by intro- 
 ducing a few brilliant colors in a legitimate way, where 
 they would be entirely out of place if introduced in 
 draperies, carpets, or furniture. 
 
 It is an easy matter to make stained glass work after 
 the more simple designs. It onh^ requires a knowledge 
 of the use of the glazier's diamond, or the very efficient 
 
 Fig. 50. Details of the Lead Work. 
 
 substitute for the same known as the roller glass cut- 
 ter, and some proficiency in the use of the soldering 
 iron. 
 
 The colored glass can be procured from almost any 
 dealer, and for the grooved lead strips in which the 
 glass is set, the amateur will have to depend on the 
 stained glass works. Some manufacturers are willing 
 
52 
 
 JIOMK ]\IKCMIA.\I(^S Vi)\l AMA1M^U1I8 
 
 to fiiniisli it ill small (jiiaiil ii i(‘S, wliih* ollua's ar(^ ri^liic- 
 taiit. It is to 1)0 i'(\i>rott(Ml that lh(*r(‘ is no siin])l(‘ ^vay 
 of iiialviiii> ili(‘So stri])s. Ev(*rv slaiiKMl i^lass mainifac- 
 tiiror is ])rovi(lo(l with a imu'hiiu^ hy m(‘aiis of whi(‘h he 
 rolls them from lari>(‘r stri])s of about th(‘ same form, 
 made at the load works, ami known as (‘am(‘S. 
 
 Fig. 51. Stained Glass Work “ Crazy ” Pattern. 
 
 Two kinds of load strips aro gonorally nsod in this 
 kind of work, on(‘ of whic'h is shown at o, in Fig. 50. 
 This is nai'row and con vox, and woll adaptod for small 
 ourv(*s, oiia-h^s, (hv. Tho othor, shown at in the same 
 fignri^, is widen' and ihinnor and bedtor adaptod for 
 straight work. At in tln^ saim^ fignro, is shown the 
 imdliod of allae'hing oo])p(‘r wire's te) tho b'ael fe)r twist- 
 ing are)nnel I he* re>els whie'h snp])e)rt the* Ave)rk, as slmwn 
 at (I. 
 
 A el rawing e)f the* palte*rn is maele* ni)e)n ste)nt papor, 
 
HOME MECriAXICS FOR AMATEtlL’S 
 
 63 
 
 and tlie "work is besivm by cutting,' tlie ,nlass according 
 to the pattern, fitting tlie lead strips and soldering* 
 them at tlieir junction. After all of the glass pieces 
 have been fitted and secnred, the Avork is turned OA^er 
 and soldered upon the other side. The AA’ires are then 
 attached by first tinning them and then securing them 
 by means of solder. These AA’ires are tAA’isted aronnd 
 
 Fig. 52. A Leaded Glass Butterfly. 
 
 iron rods, AAdiich are so arranged as to support the AA’ork. 
 
 Small pieces aa IU not require the iron rods, but larger 
 
 ones are liable to sag and buckle of their oaa ii AA'eight. 
 
 They are also apt to be blown out of shape by a lieaA^y 
 
 AA’iud. The easiest pattern to ]>roduce on stained glass 
 
 is that shoAA’n in Fig. 51. It is hardly AAorthy of classi- 
 
 * For the soldering, an ordinary soldering iron is employed, and 
 common tinner’s solder is used in fastening the joints. Tallow is 
 used as flux. A tallow candle is commonly employed for this pur- 
 pose. The joint to be soldered is rubbed with the end of the 
 candle, and the solder is applied. Of course the iron must be well 
 tinned and hot, and the touch of the iron upon the work must be 
 very quickly and dexterously done. 
 
54 
 
 HOME MECllANJCS EOli AMATEURS 
 
 fication among patterns, l)iu it is ])leasing if ])ro])(‘riy 
 done. Some eare is ne(*(‘ssarv to secure liaianony of 
 color, but there is little cliance of failure in tliis kind of 
 work. 
 
 It is a common practice to gild over the h^ad stri])s 
 after the Avork is done, l)y means of gold paint, but it is 
 a question Avhether it is any im])royement over the nat- 
 ural color of the lead, espe(‘ially in work exposed to the 
 action of the elements. I^)r some indoor Avork, such 
 as fire screens, sash screens, lant(*rns. lamp shades, et(*_ 
 the gilding is not objectionable. 
 
 The screen shoAvn in Fig. 52 is not difficult. All of 
 the glass pieces are of such form as to be easily cut, and 
 the Avork of joining the lead strii)s is quite simple. As 
 to colors, it Avould be Avell to folloAV the example of na- 
 ture, or in any case to select such as Avill harmonize. It 
 is hardly possible to produce more gorgeous coloring 
 Than is found among the butterflies. Green, blue, 
 greenish-blue, red, yelloAA^, broAvu, black and Avhite 
 (opalescenU^ are colors from Avhich to select for this 
 object. 
 
 The Avire frame which supports the glass is carried 
 along the lead strips and secured by solder. The an- 
 tenme are of Avire. The base is of Avood, neatly stained 
 and polished. 
 
 A class of ornamental objects may be made from Avire 
 cloth Avhich rival in Ix^auty any kind of stained glass 
 work. Figs. 53 and 54 are examples of this kind of 
 Avork. 
 
 Tli(‘ wir(^ (‘loth for this ])ur])()S(^ should be made of 
 firui wir(*, th(^ m(*sh should 1)(‘ (‘oars(‘, say 10 to the iiu'h, 
 and, mor(X)V(*]*, tli(‘ clotli should b(‘ |)aint(‘d and alloAved 
 to dry before the ornamental AVork is applied. The 
 
HOME MECHANICS FOR AMATEURS 
 
 55 
 
 wire cloth is sui^ported a short distance from a design 
 drawn on paper and the different colors are introduced 
 into the meshes by means of an ordinary writing pen. 
 A gelatine solution is used for this purpose. It should 
 not be very tliick, and it must be kept warm. Ordi- 
 nary, transparent gelatine maj^ be colored for this pur- 
 pose by adding’ aniline. Colored lacquers answer ad- 
 
 Fig. 53. Lamp Shade. 
 
 Fig. 54. Hanging Lantern 
 of Wire Cloth. 
 
 iiiirably for filling the squares. Common white glue 
 answers very well for filling the bodj' of the design. 
 The beauty of this kind of work and the simplicity of 
 the method by which it is produced recommend it for 
 many purposes. 
 
 The construction of the frames for the lamp shade 
 and hanging lantern requires some mechanical skill. 
 
5G 
 
 UiniK IMKCIIANICS FOl? AMATEURS 
 
 Urobablv ilio aid of tlio tiiisiiiitli will liav(‘ fo Ix^ iii- 
 vok(Ml in tli(‘S(^ ('as(‘s. It will i)ay, lio\v(*\(‘i', as ilu* ai'ti- 
 (‘les will Avell r(‘])ay iln^ 1r()ul)l(‘ and (‘X])(*ns(\ 
 
 Tli(^ lian,i>in<»- lantcaai, 54, is d(‘si^’n(*d foi' a ball. 
 Tt may (-ontain a k(‘r()S(ai(‘ lain]), or ili(‘ d(*vi(‘(‘ known 
 as tlu‘ ‘‘fairy lain])/’ in Avbirh a lari^o candl(‘ is (an- 
 l)loy(Ml as a sonrc'C of lit^lit. 
 
 The colored cb(H*ks in (be wire ('loth a])p(au' lik(‘ |i>*enis 
 when illnniinated. 
 
 An expcaanient showiiii^’ a phase of (‘apillarity is illus- 
 trated by the annexed enj>Tayings, Avliich give patterns. 
 
 Fig. 55. Method of producing Designs on Wire Cloth. 
 
 This experiment was originally intended for illus- 
 ti'ating tapestry and other designs formed of small 
 s(jnai'(^s, in colors, upon the screen; bnt it has another 
 practical a])])lication, which is capable of considerable 
 ('X])ansion. f'or ])roj(H'tion, a piece of brass Avire cloth, 
 of any d(*sir(*d m(‘sh, say from 12 to 20 to the inch, 
 is moiinl(Ml in a imhallic franu' to ada])t it to the slide 
 liohha' of lh(^ lanba'ii, and lh(‘ Avii'e ('loth is ('oated 
 lighlly w ilh la('(|n(a' and all()W(Ml lo dry. 
 
 Th(‘ slid(* jhns pr(‘par(‘(l is ])la('(‘(l in Ihe lant(a‘n and 
 fo('nse(l. 4di(' r(*(jni]x*(l (l(‘sign may noAV b(‘ tra('e(l by 
 
HOME MECHANICS FOR AIMATEITRS 
 
 57 
 
 means of a small camel's liaiv Itimsli, colored inks or 
 aqueous solutions of aniline dyes beiu}^' used. The 
 small squares of the wire chRli are filled with the col- 
 ored liquid, and show as colored squares upon the 
 scT’een. Different colors may he placed in juxtaposi- 
 tion without liability to mixing;, and a design traced 
 Avithout special care will appear regular as the rec- 
 tangular apertures of the wire cloth control the differ- 
 ent parts of the design. 
 
 The colored liquid squares are retained in the meshes 
 of the wire cloth by capillarity. A damp sponge will 
 remove the color, so that the experiment may be re- 
 peated as often as desired. In this experiment the 
 colored squares have the appearance of gems. 
 
 These designs may be made permanent by employ- 
 ing solutions of colored gelatine; but in this case the 
 squares are so small that they are not very effective 
 without magnification. Really elegant designs may be 
 produced in this way for lamp shades, windoAV and fire 
 screens, signs, etc., as described above. 
 
 JAPANESE POKTIEKE OR CURTAIN 
 
 There is a certain delicacy in a curtain made of 
 long lashes formed of straw or bamboo and beads 
 Avhich is not found in a fabric of any kind. Cur- 
 tains of this sort haA’e been largely introduced into 
 this country of late, some of them being simple, plain 
 and cheap, Avhile others are really A-ery elaborate and, 
 of course, correspondingly expensiAm. It is a very 
 simple matter to make a curtain of this class, pro- 
 vided the materials are at hand ; but where neither 
 bamboo nor straAv nor beads are available, it becomes 
 
58 
 
 HOME MECHANICS FOR AMATEURS 
 
 more diflieult. Hut a very prescoitable ciirlain may 
 he made from paper, wliicli is ohtaimil)l<‘ everywhere. 
 'I'lie large engraving shows a very simjile ]»attern 
 made of straws of dilfeirnt lenglli, and glass heads 
 of different colors, strnng on strong thread or tine 
 strong twine. 
 
 The first thing to 1)0 done toward making the enr- 
 tain is to draw a design roughly on a sheet of pajXT, 
 then tie a thread in a head which is to form tin* fin- 
 ish of the lower end of the lash. Then the head is 
 
 Fig. 56. Method for making Paper Rolls. 
 
 fastened in its place on the pattern hy driving an 
 ordinary pin throngh it into the hoard or table be- 
 neath. The stringing of the straws and heads is thus 
 proce<‘ded with according to the requirements of the 
 ])alt(‘rn. 
 
 ^N'lien one lash is finished, its upper end is fastened 
 on till* design hy an ordinary pin driven throngh a 
 knot lied in the (liread. Th<‘ ne.xt lash in order is pro- 
 ceeded will) in 1h(‘ same manner, and so on nntil the 
 entire series of lashes is don(^ A stout string is 
 
HOME MECHANICS FOR AMATEURS 
 
 6d 
 
 stretclied along the series of pins by which the upper 
 ends of the lashes are secured. Each thread is then 
 tied around the transvere string. If desired, the threads 
 may be spaced by beads arranged on the string be- 
 tween the lashes. As all the knots are necessarily 
 trimmed close, it is well to touch each knot with muci- 
 lage. When this is dry, the curtain is finished. 
 
 A verv handsome curtain mav be made from beads 
 alone, or from beads and plain uncolored straws, or 
 the straws may be d^’ed different colors by means 
 of aniline dyes, or by dipping them into thin colored 
 lacquers. 
 
 A curtain or portiere of bamboo and beads is made 
 in the same wav, but on a larger scale. 
 
 It is easy to make a good imitation of these curtains 
 Avith paper tid)es and beads, or the tubes alone. The 
 manner of making these tubes is shown in Fig. 56. The 
 paper from wliich the tubes are made should not be 
 thicker than common Avriting paper. It may be either 
 colored or Avhite. The best results Avill be secui’ed by 
 using common Avhite Avriting paper and coloring the 
 tubes after they are formed and dry, by means of thin 
 broAvn or Avhite shellac Amrnish, colored Avith pigments 
 or the anilines. 
 
 The pieces of paper from which the tubes are made 
 are preferably cut in trapezoidal shape, as shoAvn at 
 1 and 2, so that Avlien the tube is finished it Avill liaA^e 
 conical ends, as shoAvn at 5, 6, and 7. The Avire shoAvn 
 at 3 is used as a mandrel upon Avhich to roll the paper. 
 The larger end of the piece of paper is applied to the. 
 Avire Avhen the paper is rolled up in the manner illus- 
 trated at 4. The narrower end of the paper is gummed 
 and pressed doAvn closely, Avhen the Avire is removed 
 
GO 
 
 IIOMK MKdIAXICS I'oi; AMA^ri-:( i;s 
 
 I-'k;. r>7. CurUun lortiK'd of S(i-;iw, Haniboo, or Pai)('r, and Beads. 
 
HOME MECIIAXICS EOll AMATEURS 
 
 61 
 
 and the operation is repeated. It is not advantageons 
 to gmn the entire surface of the paper. h''astening at 
 the end is sufficient. The wire used as a mandrel should 
 not be more than one-sixteenth inch in diameter, as 
 too large a hole through the rolls allows them to ar- 
 range themselves irregularly. At 7 is shown a part of 
 a lash formed of a long tube, a bead, and a short tube. 
 
 In stringing both the straws and the paper tubes a 
 long slim needle will be required. If this is not ob- 
 tainable, a very good substitute for it mav be made bv 
 forming an eye or loop on the end of a thin wire of 
 suitable length. 
 
 There is scarcely any limit to the amount of labor 
 that may be expended upon an article of this kind; 
 but very jdeasing results will be secured by the adop- 
 tion of simple designs, which may be easily carried 
 out. 
 
 HEPDUSSE 
 
 This art, as practiced bj^ the silversmith and the art- 
 ist, is almost entirely dependent upon the manual dex- 
 terity of the operator. A kind of repoussd is here sug- 
 gested which depends more upon appliances than skill. 
 It is not, however, assumed that any set of devices can 
 be made to serve in lieu of taste and judgment. 
 
 To carry out this method, a piece of heavy cotton 
 lace, or heavy open work fabric, or a piece of a basket 
 may be glued to a block of hard wood to serve as a sort 
 of die for producing the impression in the metal. The 
 fabric or basket work is not only attached to the 
 block by means of glue, but its finer interstices are 
 filled with glue so as to present a surface resembling 
 tlie original fabric only in tlie most general Avay. 
 
62 
 
 HOME MECHANICS EOlt AMM'EUltS 
 
 Wilt'll the sine is perfi'cily diy iuid hard, Hk' die is 
 laid n])ion a solid l'ounda.l ion, and a [lii'cc* of very 
 thin, soft copper or brass is secured to the block so 
 
 Fig. 58. Embossing Thin Metal. 
 
 Fig. 59. Basket Pattern. 
 
 iiH to covcM^ tli(‘ la(*(‘ as sliowii in V\<^, 58. A piece of 
 cork, aI)oul | inch tln(‘k, ajid aboni three iindies wide 
 and b oi* 8 inch(‘s loni»j is laid over the metal and 
 
HOME MECHANICS FOR AMATEURS 
 
 63 
 
 struck with a mallet, as shown. The cork yields suf- 
 
 7 fL/ 
 
 ficieiitly to push the metal down upon the die, and 
 cause it to take the pattern of the lace or whatever 
 is used iu forming the die. A piece of rather hard 
 rubber packing will answer this purpose equally as 
 well as the cork. 
 
 Fig. 60. Die formed of Pasteboard. 
 
 Designs may be cut from strong paper or pasteboard, 
 and glued to the block. Fig. 60 shows a design which 
 may be reproduced in this manner. 
 
 In Fig. 61 is represented a stencil design to be sawed 
 
()4 IIOMK ]\IK(’IIA.\I('S I'Olt AiMA'I’KlMIS 
 
 Fig. 61. Stencil Pattern. 
 
 from liard wood. The lines and scrolls are discon- 
 tinued in places so as to cause the Avood to hold to- 
 If it is desired to render the lines continuous 
 at tlK^se ])oints, they may be run througli with a V- 
 tool. Tlie dots are picked out with a small i»‘ouge or 
 
 Fjg. (>2. Rope Pattern. 
 
HOME MECHANICS FOR AMATEURS 
 
 65 
 
 the point of a revolving drill. In all these cases the 
 metal is attached to the block and treated as shown 
 in Fig. 58. 
 
 In Fig. 62 is represented in side elevation and in 
 section a die formed of a small rope, glued in a semi- 
 circular groove in a bar of hard wood. The embossing 
 is done in the manner before described. In this case 
 a thick piece of soft rubber is preferable to cork for 
 forcing the metal into the depression of the die. 
 
 Fig. 63. Vase formed of Embossed Plates. 
 
 Either panels or continuous strips may be embossed 
 in the manner described, and these are to be used iu 
 making frames, vases, and various ornamental objects. 
 If the metal is too thin for a certain case, it may be 
 strengthened by flowing soft solder over the back of the 
 plate by means of a soldering iron. 
 
 The vase shown in Fig. 63 is formed of four embossed 
 
66 
 
 nom: imkcmiaxk^s you 
 
 plates of (*op])er, fasicauMl lo lli(‘ l)a(*k of four vcu'lical 
 brass stri])s by sol(l(U‘, 11u‘ wliol(‘ Ixuiii^ s(‘(*ur(Ml to tli(‘ 
 bottom ])ie(‘(‘ in tlH‘ saiiu^ inaiim*!'. Tli(‘ l)ottom (‘onsists 
 of a disk of eo])])er sobbuxMl in. Tli(‘ bas(‘ is foriiuMl of a 
 brass stove-pipe collar sobbuxMl to tln^ low(U‘ i)art of the 
 body of the vase. The rim around tlu^ to]) consists of a 
 strip emboss(Ml on tlu^ ro])(^ di(‘. 
 
 Fig. 64. A Bas-relief in Lead. Copper, or Brass. 
 
 As to finish, anv of the usual methods of brass finish- 
 inj»‘ should b(‘ (unployed. This vase is especially 
 ada})t(Ml for containin<> a jialni or other lari^e foliage 
 [)lant. Th(‘ c^arth and roots may Ix^ ])la(‘ed directly 
 in th(^ vas(^ or th(\v may Ix^ contaimxl by a pot which is 
 (mcloscxl by th(‘ vas(*. 
 
HOME MECHANICS FOR AMATEURS 
 
 67 
 
 It is obvious that vases of other forms and other em- 
 bossed designs may be made on this plan. 
 
 Bas-reliefs may easily be made by a method which 
 is a modification of the one described. Fig. 64 shows 
 such a relief, and Figs. 65 and 66 illustrate the tools 
 required for making it. 
 
 To the Avooden frame, A, is fitted a board, B, upon 
 
 Fig. 65. Frame and Form for making the Bas-reliefs. 
 
 Avliicli is drawn in outline the design which is to be 
 prodnced in relief. The board may be of pine or any 
 close-grained soft wood for lead work ; but for brass or 
 copper, the wood should be hard. To the frame. A, is 
 attached the plate of metal by means of scretvs. 
 
 The board, B, is removed from the frame, and the 
 
68 
 
 JLOME MECHANICS EOI{ AMATEURS 
 
 portion of tlie design wlii(*li is to form tlu^ most pi*omi- 
 nent feature of tlie relief is suwcmI out of the board, 
 when tlie latter is re])Ia(*ed in tlie fi'aim^, and the m(‘tal 
 is forced into the ojiening of tlu^ hoard by pressing upon 
 the snrfa('e of the lead o])])osit(^ the hoh^ in the hoard, or 
 hy pounding it hy nutans of the mallet, (', shown in hhg. 
 ()6. As soon as this feature is ('omplete, the m^xt in 
 order is sawed out of the hoard, and the operation is 
 
 Pig. 66. Tools for Repousse. 
 
 repeated until all of the general features are developed. 
 The pi'ogress of the work can he observed at any time 
 hy removing the hoard, 11. 
 
 The f(^atiii‘(^s may he corrected or modified hy work- 
 ing from (htli(a‘ side of the plate hy means of the con- 
 v(*x mall(‘t and tln^ wooden ])nn(‘hes and chisels, D 
 (hhg. ()(>j. If a snppoi't is di^sired for any part while 
 tli(* work is pi'ogi'(‘ssing, a stout hag tilled with sand 
 may h(* plac(‘d uml(*r lh(‘ jiai't. A f(nv very small hags, 
 
HOME MECHANICS FOE AMATEUES 
 
 69 
 
 say 1 inch or inches in diameter, will be found con- 
 venient. If desired, the drapery or the background 
 may be chased by means of hard Avood or metal punches, 
 bearing on their faces the desired figures. 
 
 The relief, if of lead, looks well with an antique fin- 
 ish. 
 
 AN EASY METHOD OF PKODUCING BAS- 
 
 KELIEFS 
 
 The production of patterns from which to cast orna- 
 mental articles is confined to a class of artisans who, 
 by long experience in carving and modeling, have at- 
 tained great excellence in workmanship. An amateur, 
 while he may not hope to attain such excellence, and 
 
 Fig. 67. 
 
 Pig. 68. 
 
 Bas-reliefs in Wax. 
 
 cannot expect to produce, by the usual processes and 
 with limited practice, such exquisite articles as may be 
 seen in many of the city shop-Avindows, may, if he pos- 
 sesses even a modicum of artistic taste and skill, do 
 something in that direction. 
 
?0 
 
 HOME MECITANIOS FOR Ai\IATETJRS 
 
 The articles required to carry out Hie process are 
 some thin sheets of semi-transparent wax, a knife hav- 
 ing a narrow, dull blade, and the ])rinted or drawn 
 design of the form to be ]U‘oduced. The backing, or sur- 
 face on which the relief is made, may be of any of the 
 materials of which patterns are commonly made. 
 
 ITaving given the backing the required form and 
 located thereon the position of the relief, a sheet of wax 
 is laid over the design and the extreme outline of the 
 figure is trac(‘d on the surface of the wax with a dull 
 fioint. The wax is now laid upon a smooth board and 
 cut upfin the line just mad(' with the knife, the blade 
 being slightly warm. The wax thus cut is now placed 
 
HOME MECHANICS FOE AMATEUES 
 
 71 
 
 on the foundation or backing-, and fastened by heating 
 the knife blade quite hot and touching the wax at sev- 
 eral points, so as to cause it to melt and adhere to the 
 
 Pig. 71. 
 
 Pig. 72. 
 
 Patterns for Bas-reliefs. 
 
HOME MECHANICS EOU AMATEUKS 
 
 72 
 
 backing. Siipi)()sing Hiis }»i(‘cc* of wax to liavc the 
 thickness required in the thinnest i)ortion of tlie relief, 
 another sheet is laid upon the design and traced within, 
 and a small distance from, the outline of the design. It 
 is ent and laid ni>on the first piece and made to adhere* 
 hy pressing it down slightly. 
 
 Another sheet of wa.x is traced within the outline of 
 the second, and cut and lelaced upon the two already 
 secured to the hacking, and so on until the design is 
 produced in Avhat might he termed the roKf/li. This 
 stage is illustrated in Figs. GT and 08, which are re- 
 spectively front and edge views, which give the idea of 
 the arrangement of the several sheets. 
 
 After the sheets are i)laced upon one another in the 
 manner first observed, the edges may he burnished 
 down hy the rounded hack of the knife, or by any 
 smooth, rounded implement, which must he slightly 
 warmed. 
 
 Superfluous wax maj^ be removed by scraping when 
 cold, and indentations and interstices may be filled by 
 adding a little wax. A scroll design is shown in Fig. 69. 
 
 When the model is to he reproduced in metal cast in 
 sand moulds, the wax should be slightly varnished with 
 pattern varnish ; but when the design is to he produced 
 in plaster, a mould of plaster may be taken from the 
 model after it has been oiled. 
 
 A bas-relief may be made in this way from a profile 
 photograj)h or from an engraving. 
 
 Tlie juoeess may be em])loyed to advantage in orna- 
 menting i)atterns for the coarser and heavier kinds of 
 work. 
 
 Figs. 70, 71, and 72 represent surfaces ornamented in 
 this manner. 
 
HOME MECHANICS FOE AMATEUES 
 
 73 
 
 OKNAMENTAL IRON WORK FORI AMATEURS 
 
 Although artistic wrought iron work dates from very 
 early times, it was never more popular than it is at 
 present. This remark applies especially to movable 
 
 Fig. 73 . Fig. 74 . 
 
 Iron Lamp Supports. 
 
 articles such as tables, stands, racks of various kinds, 
 fuel baskets, lamp supports, etc. Many of these arti- 
 cles of recent manufacture are copies of antique ob- 
 jects, while others are of modern design. As works of 
 
74 
 
 HOME MECJIANICS EOJ{ AMATEUES 
 
 art they are fully equal, if not superior, to the speci- 
 mens of earlier work. 
 
 Now, while no imitation can ev(“r e<pial the oriijinal 
 article, it must be admitted that imitations often prove 
 very satisfactory to those who can neither make nor 
 purchase the real article. 
 
 The examples of iron work here illustrated are styled 
 imitations, as they are made without foryiiif!:, i. c., the 
 iron is bent either cold or hot, without the use of a 
 hammer, while the iron bars or rods maintain their 
 original cross section. Anv one us(‘d to the hammer 
 and anvil can, in addition to the curves, apply forced 
 portions, or twist and forae the bars used in the scrolls. 
 
 Fig. 75. Jaw for Bending. 
 
 The only special tool used in making articles of this 
 class is the steel jaw shown in Fig. 75. Its slot re- 
 ceives the bar to be bent, and its flattened shank is 
 designed to be held in an iron vise. A scroll is formed 
 by placing the end of a bar in the jaw, and winding the 
 bar around the jaw and upon itself, afterward unwind- 
 ing the bar to open the spiral as much as may be re- 
 quired. After the scroll is complete, the inner straight 
 end of th(‘ bar is cut off by jueans of a hack saw. The 
 sharp angles may also b(‘ bent by the use of the jaw. It 
 will facilitate Ihe opcuation if the bar is heated red hot 
 at th(‘ point of Ixuiding. A hammer may prove useful 
 in this part of the operation. 
 
HOME MECHANICS FOE AMATEUES 
 
 75 
 
 The standard of the lamp support consists of a piece 
 of gas pipe. The feet are attached by means of screws, 
 and the different parts of the iron work are fastened 
 together by means of small screws or bolts. 
 
 A rod is fitted to the gas pipe and has at its upper 
 end a frame or cup for receiving the lamp. A clamp- 
 ing screw passing through the gas pipe holds the rod at 
 the desired height. 
 
 An easy and satisfactory way of blacking the work 
 after it is finished is to coat it with a thin varnish 
 of stick or seed lac cut in alcohol, with refined lamp- 
 black stirred in to give it the required color. The var- 
 nish should be made quite thin to avoid any gloss, and 
 should be strained through cheesecloth or similar 
 material. 
 
 It is obvious that grilles, gates, screens, doors, and 
 other objects may be made from iron in this way with 
 little trouble or expense. 
 
 SOME THINGS IN WIKE 
 
 There is scarcely a limit to the number of useful and 
 ornamental things that can be made from wire. Two 
 examples are shown in the engravings, Figs. 76 and 77, 
 representing respectively front and edge views of a 
 newspaper and magazine holder formed of a wooden 
 back and wire scrolls; Fig. 78 showing a small Avire 
 stand or card receiA^er having a zylonite top. 
 
 The scrolls of the newspaper holder are formed of 
 three-sixteenths inch square brass wire; the seA^eral 
 pieces being bent in the form shown and held in place 
 by clips of the same material soft-soldered by means of 
 a blowpipe. The overlapping portions of the scrolls 
 
HOME MECHANICS FOR AMATEURS 
 
 are alse soft soldered. Tlie lower pari of each main 
 scroll is held by a stronj; stai)le passiiiff over tin* wire 
 of the scroll and thronj>h the cleat and backboard and 
 clinched on the back of the board. Tin* threi* wires at 
 the center of each scroll are prolonj'ed below the cleat, 
 as shown, to form a stop for limiting the swing of the 
 scroll. 
 
 Fig. 77. Edge View of 
 Newspaper Holder. 
 
 Fig. 76. Newspaper Holder. 
 
 If care is taken in soldering the clips, the brasswork 
 will re(jnire little preparation for laccpiering. A stiff 
 brush charged with finely jiowdered jmniice wet with 
 water and a|)|)li(‘d vigorously to the work will (piickly 
 remove all stains, and will give the work a uniform ap- 
 
HOME MECHANICS FOR AMATEURS 
 
 77 
 
 pearauce. The backboard, which may be of Avalnut, 
 mahogany, cherry, oak, ash, or mai^le, should be var- 
 nished and well rubbed down before the cleats are 
 applied. 
 
 A holder of this kind will receive a large number of 
 periodicals. 
 
 The wire stand or card receiver, shown in Fig. 78, is 
 
 Fig. 78. Wire Stand or Card Receiver. 
 
 made of one-quarter inch or three-eighths inch round 
 brass wire. It may be made of brass tubing three- 
 eighths inch or one-half inch outside diameter and 
 rather thick. In this case the tubes are annealed and 
 filled with lead before bending. The lead is melted out 
 
78 
 
 HOME MECHANICS EOR AMATEURS 
 
 of the tubes after beu(liiif>. Tlie spirals are formed 
 separately by wi‘a])piiif? the tulx' oi- wire around a 
 eyliiidrical bar of wood or iron in a closc^ helical coil, 
 then stretcbinjj' out the coils, ])lacin<f tluMii toi^etber, 
 as shown. They are then clamped on a smaller cylin- 
 drical bar and their upper ends are twisted together. 
 Two rings surround the lower ])art of the spiial and 
 to these rings are secured the legs lyv means of sohh'r 
 or screws. 
 
 Th(‘ small rings surrounding the legs may he pur- 
 chased and secured in ])lace by solder. 
 
 The top of the stand consists of a disk of wood, con- 
 caved at the top and furnished with an embossed disk 
 of zylouite. 
 
 The under surface of the stand top is provided with 
 a ])erforated block, which fits over the closely twisted 
 end on the standard. This receiver may be made so 
 small as to stand upon a table, or it may be made of 
 the usual table height. 
 
 SOME THINGS IN BURNISHED BRASS 
 
 The old and commendable fashion of making orna- 
 mental objects from solid hand-wrought metal is being 
 i-<‘viv(*d to a wonderful extent. Steel, iron, brass, and 
 co)»p(M- are wrought into a thousand beautiful and use- 
 ful forms, and the gilded and tinsel objects of recent 
 days are now s(,“t aside for substantial and elegant solid 
 cast and hand-wrought ornaments. It will require only 
 a suggestion to set the amateur mechanic at work at 
 this sort of thing, when his dwelling will soon be 
 adorned with articles that will be the more valuable 
 for having b(*en ])rodnc(‘d at home. 
 
HOME MECHANICS FOR AMATEURS 
 
 79 
 
 Fig. 79. A Brass Easel, 
 
80 
 
 HOME MECHANICS FOR AMATEURS 
 
 Brass tubing and rods of round, liexagonal and oc- 
 tagonal section, plain and ])erforat(“d strips of different 
 widths and tbicknesses, half round and s(‘nii-liexagonal 
 strips, and brass buttons, knobs, and nails of various 
 shapes, may be purchased so that the amateur will 
 
 Fig. 80. A Brass Frame. 
 
 readily find availahk^ materials for the kind of work 
 sii^j^ested. llalf-ineh s(inare tubes, strips of brass half 
 an inch by on(*-sixth of an iiK'li, a lew brass buttons, 
 and a f(*w knobs, ar(‘ i'(M|uir(Ml for Ihe easel shown in 
 
HOME MECHANICS FOE AMATEUKS 
 
 81 
 
 Fig. 79. The tubes may be draw-filed, then finished 
 with the different grades of emery paper with oil, or 
 they may be polished on an emery wheel, and the final 
 finish may be imparted by using the finest French 
 emery paper with oil. 
 
 When two tubes cross each other they may be halved 
 
 Fig. 81. A Nautilus Card Receiver. 
 
 together precisely as in wood work, and may be fas- 
 tened by soldering with soft solder. 
 
 When the end of a tube abuts against the side of an- 
 other tube it may be fastened solid enough for all 
 practical purposes by soft soldering by means of a 
 blowpipe. Of course the joint may be brazed or sol- 
 
82 
 
 HOME MECHANICS EOlf A.MATEUKS 
 
 derod ■with silver solder, loit as .ureat streiiijth is not 
 required, it is nnnecessary to take that amount of 
 trouble. 
 
 A very good ■way of fastening is to solder a plug in 
 the end of the tube tliat abuts against the side of 
 another tube, and to put a screw ]at<‘rally tlirougli one 
 into the plug in the other. In this case it is well to l<*ave 
 a slight feather on op])osite sides of the abutting tube 
 
 Fig. 82. A Brass Clock. 
 
 to engage the corners of the tube to which it is at- 
 tached. 
 
 d'he scrolls should he attached by means of small 
 screws. "I'he ]»auels consist of thin ])ieces of board cov- 
 ered will) velv(‘l or ])lush of any suitable color. They 
 arc; inserted from Hk* hack, and are provided with a 
 nuTuher of large; conve.x nails. The su])port for the pic- 
 ture is movahh* up and d<»wn on the side* jeieces of the 
 
HOME MECHANICS FOR AMATEURS 
 
 83 
 
 easel, and may be secured at any desired point by the 
 milled screws. 
 
 The frame shown in Fig. 80 will require no special 
 description. The main portion of it is made of square 
 brass tubing. The side bars are made of round brass 
 
 Fig. 83. A Brass Table. 
 
 rods with turned end pieces, as shown. The mat of 
 thin wood is covered with velvet or plush. The picture 
 and glass are placed behind the mat ; the latter is pro- 
 vided with small brass ears which are fastened to the 
 back of the frame by screws. The knobs at the top, 
 
84 
 
 llOiMI'] iMKGJlAiN'ICS K()J{ AMATKlJItS 
 
 bottom, and sides of the frame and (‘asel an* turned and 
 attaelied witli solder. 
 
 Fig. 81 shows a tripod stand for a nautilus slu'll, with 
 an ornamental shell ])laeed below it in tin* eentm' of lln* 
 
 cdoc'k case, consisting of an ordinary box of suitabb' 
 size covered with plush or velvet, and inclosed in a 
 frame of brass. 
 
 The frame is built up in the manner already de- 
 scribed from s({uare brass tnbing sjilit lengthwise 
 through diagonally opposite corners. The lower i)or- 
 
 Fig. 84. Examples of Paneling. 
 
 tion of the frame consists of a wide band of brass, hav- 
 ing a light bead soldered to its upper edge and a heavy 
 bead soldered to its lower edge. A number of the brass 
 nails are placed at regular intervals and soldered at 
 the back of the brass base. The rail at the top is made 
 of h(!xagonal brass tubing, and the small balusters are 
 turiKMl from brass rods. '^Ihe- palette and brushes are 
 sawed from a plate of brass and attached by tacks 
 soldered to the back. The ])atch(“s of color are pro- 
 duced by diff(“i‘ent colois of s<*aling wax. Four brass 
 nails are ins(‘rted around llu* dial to relieve the blank 
 
HOME MECHANICS FOE AMATEUES 
 
 85 
 
 spaces on the plush. The clock and its plush-covered 
 case inav be removed from the brass frame when it is 
 desired to clean the latter. 
 
 The table shown in Fig. 83 is of the same general 
 character as the other articles, and will not, therefore, 
 need particular description. The central portion is of 
 three-quarters inch round brass tubing. The legs are 
 of five-eighths square brass tubing. The top is of 
 wood, plush-covered and fringed, and provided with a 
 border of perforated brass. 
 
 Fig. 84 shows different kinds of panels. The balus- 
 ters in the upper one are turned ; in the two lower ones 
 they are cut from sheet metal. 
 
 All of these articles may be lacquered, but they pre- 
 sent a more elegant appearance if the metal is left un- 
 protected and cleaned occasionally with rottenstone 
 and oil. 
 
 There is hardly any limit to the number of pretty 
 and useful articles that may be made of such materials, 
 with the expenditure of little thought and labor. 
 
 FORMING PLASTER OBJECTS 
 
 It is sometimes convenient to form objects of cir- 
 cular section from plaster of Paris. This is a very sim- 
 ple operation, requiring only A^ery simple tools and 
 apparatus. An iron rod, bent at one end to form a 
 crank, and carrying a conical wooden roller, two 
 notched bars of wood for supporting the iron rod, and 
 a pattern made from a thin piece of hard wood, com- 
 prise the outfit for making these articles. The rod is 
 held in its bearings in the bars by pins inserted 
 obliquely in holes in the wood, so as to project over 
 
86 
 
 HOME MECHANICS FOE AMATETHIS 
 
 the rod. The pattern is cut so that its ed^e is a profde 
 of one side of the article to be made. The wood slionld 
 he made thin on the workinc^ edf>;(‘. The patterns may 
 be made to advantage of metal backed by wood. 
 
 The conical wooden roller should be flattened on 
 three or four sides to prevent tin* ]>laster from tiirninfj 
 aronnd on it. The roller is oiled or smeared over with 
 grease, and a batter of plaster of Paris is prepared by 
 mixing the dry plaster with water to the consistency of 
 cream. As soon as the plaster begins to set it is appli(‘d 
 plenteously to the roller, and while the rod is turned 
 
 Fig. 85. Forming Plaster Objects. 
 
 by means of the crank the pattern is moved forward 
 toward the rod, and the surplus plaster is removed by 
 the pattern which acts as a scraper, xiny deficiencies 
 are supplied by a new application of the batter. 
 
 When the object is of the right size and form, the 
 pattern is removed and cleaned, and again applied to 
 th(‘ object, the latter having Ix'en brushed over freely 
 with water. This giv(‘S the finishing touch. 
 
 j\fter the plaster becomes ])(“rf('ctly dry and hard, 
 llie roller is knock(“d out, and I In* obj(“ct is subjected to 
 
HOME MECHANICS FOR AMATEURS 
 
 8^ 
 
 a dry heat at a temperature of about 212 degrees Fahr. 
 for an hour or so. It is then brushed over with thin 
 glue size until it has absorbed as much as possible, 
 when it is allowed to dry for several days. The latter 
 treatment renders the plaster hard and strong. 
 
 The final operation consists in painting, lacquering 
 or bronzing the object, as taste may dictate. 
 
• ' • 
 
 ...IT * 
 
 ?r. 
 
 
 - 1^.1 
 
 — ^ 
 
PART III. 
 
 METAIi WORKING 
 
 SAWING METALS 
 
 GEEAT DEAL of hard labor in working 
 
 metals may be avoided by the use of hack 
 saws and jeweler’s saws. The large hack 
 saw has a malleable iron frame and a handle 
 
 and tail piece which will revolve so as to adjust 
 the saw to any desired angle. The tail piece has an 
 adjusting screw by which the tension of the saw may 
 be regulated. Several kinds of saws can be used in 
 this frame, i. e., saws with coarse and fine teeth, which 
 are set more or less according to the kind of metal on 
 which they are used. These saws all have very hard 
 teeth, but the main portion is soft, so that the saw 
 does not readily break. These saws are cheap, and 
 when one becomes dull or is broken it is replaced by 
 another. They are so hard they cannot be filed. 
 
 The next saw in size has a heavy wire frame. Slits 
 are cut in opposite ends of the frame to secure the saw, 
 and small pins extending through holes in the ends of 
 the saw rest in notches cut in the frame. The spring 
 of the frame holds the saw under tension. To put in a 
 new saw, the ends of the frame are sprung inwardly 
 with considerable pressure. The saws for this frame 
 are also hardened on the toothed edge, the remainder 
 being soft. They are much thinner than the large saws. 
 
 The smaller saw frame is adjustable as to length and 
 is designed to receive very small saws made from mate- 
 rial like watch springs. 
 
 [ 89 ] 
 
00 
 
 |[()ME MECHANICS FOR AMA'I'EIMIS 
 
 This saw is for more delicate woik than Hie oHkws. 
 No attempt is made to sharpen them with a tile. ,\ dull 
 one is thrown away and replaced by a mnv one. 
 
 There are many kinds of work in which a fjreat d(‘al 
 of time and labor may be saved by tin' use of these 
 saws; for example, cuttin<^ off iron, steel and brass bars 
 and tubes, cutting various strajis out of thick sh(*et 
 brass; cutting slots in work when reipiired. They 
 may also be used in place of tiles in places where a file 
 cannot be introduced. 
 
 Nothing is more useful for the amatcMir than a knowl- 
 edge of the art of soldering. It is a very simple om*. 
 
 Fig. 86. Articles used in Soldering. 
 
 tlie tools required are inexpensive, and there is real 
 satisfaction in doinii^ it ratlier tlian being delayed to 
 employ a rc^gnlar tinsmitli or other meeliaiiie. 
 
 of eopi)(T, j)oint(Hl at one (aid and having a large wire 
 s(‘r(‘\v(‘d into the otlier (aid, tlie wire Ixang provided 
 witli a woodiai liandh*. Soim^ soft soliha' will be re- 
 (jiiirc'd, say a (jiiai'lia' or lialf pound. It is better to buy 
 
HOME MECHANICS FOE AMATEUES 
 
 91 
 
 this in the form of solder wire, but it can be readily 
 made by melting together eqnal parts of pure tin and 
 pure lead. 
 
 To carry on the work a small box of pulverized rosin 
 and a bottle of soldering fluid will be required. 
 
 The soldering fluid can be purchased. It is readily 
 made by filling a small bottle half full of hydrochloric 
 acid. (This acid must be handled with care as it is 
 poisonous and very corrosive.) Into the acid drop lit- 
 tle strips of zinc, a few at a time, until it will dissolve 
 no more. This operation must be done in the open air, 
 as the fumes are suffocating and injurious. When the 
 boiling of the acid ceases the bottle should be filled up 
 with water and closed with a rubber stopper. In addi- 
 tion to these things already mentioned a small tin 
 box containing a wet cloth will be required. 
 
 Before soldering can be done the copper must be 
 heated so that it will melt the solder readily. Then 
 the pointed end must be cleaned with a file and a piece 
 of the solder wire is dipped in the soldering fluid. 
 When the end of the wire wet with the fluid is placed in 
 contact with the side of the hot soldering iron it will 
 melt and the soldering fluid will cause the solder to ad- 
 here to the copper. This may be repeated until the four 
 sides of the pointed end are covered with solder, or 
 “tinned” as the smiths have it. 
 
 To solder, the joint to be made is scraped clean ; then 
 a very small amount of the soldering fluid is applied 
 if the work to be soldered is iron or copper, or brass, 
 but if it is bright tin a little of the rosin will answer 
 rather better than the acid. The iron is to be heated, 
 not too hot, however, then quickly wiped on the damp 
 cloth and applied to the solder, to take up a drop, then 
 
1)2 
 
 HOME MEOIIANK'S FOR AMATEEIiS 
 
 l)laml on tlio joinl and niovod slowly alonic, allowinjj; 
 the solder to follow. If the tinnini;; is hnrned off the 
 solderinsj iron, it innst of course lx* r(‘tinn<*d. The 
 secret of success in soldering is to have the iron just hot 
 enough, and to have the surface to which the solder is 
 applied very clean. 
 
 GRINDINCx AND POLTSITING 
 
 Removing surplus metal by grinding, sharpening 
 tools, and smoothing and finishing work are most readi- 
 ly accomplished hy the amateur by means of emery 
 wheels of various degrees of fineness, or corundum or 
 carborundum wheels used in the lathe. If a fine lathe 
 is available, the wheels may be carried by suitable steel 
 mandrels mounted between the lathe centers, or bv a 
 single mandrel held by a chuck; but when these things 
 are not available, the wheels may be mounted on a hard 
 wood mandrel. The mandrel has a shoulder against 
 which the wheel is clamped by a wooden collar, and a 
 pin or key passing through a hole in the mandrel. 
 Washers of leather or pasteboard may be used to adapt 
 the mandrel to emery wheels of different thicknesses. 
 In selecting an emery wheel, one should be chosen 
 which will cut freely without glazing. Such Avheels 
 revolved in a lathe cut rapidly and serve well for re- 
 moving surplus metal and for sharpening tools. A 
 rath(‘r fiiui wheel is preferable to a coarse one for the 
 latter purfX)se. 
 
 h'or jxdishing, a wheel may be made of a disk of wood 
 turned in the lathe and cov(*red on its peri])hery or side 
 OT- both with l<‘athei'. Sole leather which contains no 
 oil or gi'casc is tin* Ix'st for tin* ]Hir]X)se. If the leather- 
 
HOME MECHANICS EOK AMATEUllS 
 
 93 
 
 covered wheel is not true it may be turned off in the 
 lathe and smoothed with fine sandpaper. The leather 
 on the edge of the wheel should be scarfed and lapped 
 so as to make a smooth joint. 
 
 After the leather is properly finished it should be 
 coated witli emery of the degree of fineness required. 
 This is done by warming the wheel, coating it with 
 strong glue and rolling it in the powdered emery. To 
 insure a good job, the eineiy itself should be warm. 
 Probably the best way to secure good results is to 
 spread the eiiiery^ out on a fiat metal plate which has 
 been heated. The leather-covered wheels are very use- 
 ful. They may even be used in place of the solid emery 
 wheel in many kinds of work. If they" are used care- 
 fully they will last a long time After one is partly 
 worn it is even more useful than it is Avhen new. For 
 polishing steel a leather-covered wheel of the kind de- 
 scribed charged with crocus instead of emery will be 
 required, also another charged with fine rouge or putty 
 powder for a vei\v fine finish. For buffing silver and 
 other soft metals a wheel of chamois skin or buck- 
 skin drawn over a padding of soft felt and tacked at 
 the sides of the wheel will be found valuable. The skin 
 will have to be lapped on the periphery of the wheel, 
 but it cannot be glued. Fine rouge is the best to apply 
 to this wheel. For polishing irregular surfaces bristle 
 brushes must be used, a coarse brush charged with 
 powdered pumice stone for doing the rougher work; 
 this to be followed by a finer brush charged with tripoli 
 or whiting and Avater. 
 
 The brushes, Avhich have wooden hubs, are carried by 
 tapering screAvs held in the lathe chuck or inserted in 
 the mandrel in place of one of the centers. 
 
94 
 
 HOME MECHANICS E()l{ AMA'PECI.’S 
 
 SILVER WORK 
 
 Silver is not a very expensive material for Die manu- 
 faetnre of small objects, and it is easily worked and 
 finished. The objects when finislied have an intrinsic 
 value, and if the effort to produce a fim* articl(* results 
 in failure, the material is not lost; it can he sold as old 
 silver, with little loss. 
 
 The eice,ravin,<>, shows articles wliich an amateur can 
 make. The bonbon dish and spoon shown in the illus- 
 tration were (piickly made by an amat(‘ur silversmith. 
 
 Pig. 87. Examples of Silver Work. 
 
 It is first folded in the center, then opened and folded 
 at rif^ht anolcs to the first fold ; then opened and folded 
 ajfain pai'allel with the first fold, and so on until the 
 entire surface is crossed Avith folds about three-fourths 
 of an inch ajiart. The ed,i>es are turned up all around 
 for al)out -g- of an inch, and the corners are 
 crimped a littl(‘, and small folds are made. The Avhole 
 work up to this jioint can be done Avith the fingers 
 alone. The folds at the corners are hammered down 
 
HOME MECHANICS FOR AMATEURS 
 
 95 
 
 with a Avooden mallet while the sheet rests at the corner 
 on a round support. From time to time the silver 
 should be annealed, i. e., heated to a low red heat, and 
 plunged into cool AAmter. This will permit of bending 
 the silver without breaking it. 
 
 Little folds should be made in the sides at the upper 
 edges if necessary, to allow the sides to be straightened ; 
 then the upper edge should be trimmed off with shears, 
 so that the dish is the same height all around. Then a 
 piece of holloAV silver wire which has not been soldered 
 is opened slightly at the seam by drawing a knife 
 through the seam. A piece of this wire long enough 
 to reach around the upper edge of the dish is slipped 
 over the upper edge of the dish and soldered at differ- 
 ent points, with silver solder. If this is not Avithin the 
 power of the amateur, he may attach it at frequent in- 
 tervals by means of A’ery small pieces of soft solder 
 melted after the application of a A^ery minute quantity 
 of soldering fluid, by holding the edge of the dish Avitli 
 a pair of pliers o\'er a gas flame tAA'O or three inches 
 above the top of the flame. If this is carefully done, the 
 small particles of solder Avill soak into the joint and 
 become invisible. Across the corner of the dish is se- 
 cured a tree limb made of sih^er, and on this are secured, 
 the birds. The siher limb is made bv hammering a 
 stout silA’er Avire into a half-round notch in the end of a 
 piece of steel, grooA^es being formed in the notch to give 
 the flattened Avire the appearance of having bark on it. 
 The birds are of special make, used for other purposes. 
 If the amateur sih^ersmith desires to use the birds he 
 Avill be obliged to purchase them, as they cannot readily 
 be made by one having no experience in this line. They 
 are of bronze and are colored. 
 
9G 
 
 UOMK MKCTTANK'^S FOIl AMATFTKS 
 
 Tliis pai‘ti(‘iilar disli was oxidizcMl Ix^forc* lli(‘ l)iT*ds 
 wore applicMl. The disli was oxidi/XMl Iiy iinin(‘rsiiii»- it 
 for a few miiintes in a solution of liisuljiliurcd of soda. 
 It was tluui wasliod and dricnl and lli(‘ oxid(‘ was r(‘- 
 nioved from tlio proj(H'lini» ])oidions by in(‘ans of a 
 cdianiois skin (*liai\i]^ed witli roiyi»(‘. Tliis dish may rc^ad- 
 ily be made round, (dli])ti('al, or trian,i>nlai*, as tast(‘ 
 may indicate. It is w(dl in a easc^ lik(‘ this to try the 
 experiiiKUit of niakinf>^ the dish in cojiper or soft brass 
 before trying silver. 
 
 :\rETAL FOOT LATHE 
 
 The amateur after using the simple wooden lathe will 
 no doubt ask for something more jiretentions, a lathe 
 that can be used for working metals in various ways, 
 and drilling and turning hard wood, horn, ivory, rub- 
 ber, etc. Lathes vary in price from |15 to |50 and up- 
 ward. In fact, almost any amount of money may be 
 invested in a foot lathe and the accessories Avhich can 
 be used in connection with it to great advantage. 
 
 The better way to proceed is to purchase a lathe 
 complete, with fi\^-wheel, treadle, belt, chucks for turn- 
 ing wood, centers for turning metals, a face plate, one 
 or two lathe dogs, a drill chuck, three or four hand 
 tools for turning brass and other metals, and three or 
 fouT- lools for turning wood. 
 
 Not a gre^at d(‘al can be said in regard to the various 
 kinds of work to b(‘ done on a foot lathe of this kind. 
 ]\Ior(‘ can b(‘ l(*a]‘n(‘d in a half hour by the observation 
 of a skilhxl woi'kman than ('an b(^ a('(|nired by a day’s 
 ])racti('(^, or by a dudy of books. However, any one 
 having a ni(*chaui('al lui'ii of mind ('an tak(^ the various 
 
HOME MECHANICS FOR AMATEURS 
 
 97 
 
 tools, and with the aid of a little common sense can 
 soon master the art of hand turning. 
 
 After practice with the lathe the amateur soon finds 
 that other tools are required, and he will either make 
 them or buy them, and thus gradually add to his outfit 
 until he is able to undertake any work that may come 
 along. 
 
 To turn longer pieces of metal than can be held ad- 
 vantageously in the chuck, the pieces are centered, 
 drilled, and then countersunk to fit the centers of the 
 lathe, one of which is iu the mandrel, the other in the 
 tail-stock spindle. A lathe dog is placed on one end 
 of the piece of metal and inserted in the slot in the 
 face plate of the lathe, while the lathe center is inserted 
 in the countersunk drill-hole in the end of the bar to be 
 turned. The center carried by the tail-stock is brought 
 forward and inserted. The tail-stock is then made fast 
 to the lathe bed, and the center is adjusted by turning 
 the tail-stock screw ; the work should turn easily with- 
 out chattering and the center should be oiled. 
 
 It is a good plan to finish the work without filing, 
 but the file and emery paper may be used ; they should 
 be used with care, however, as they are liable to injure 
 the angles and finer features of the work. A tool will 
 give a fine finish on steel work if it is sharpened on a 
 fine oil stone and the work is wet with oil or some 
 other liquid ; even saliva is often made use of with good 
 effect. Brass and other materials softer than steel are 
 readily turned in any form desired, and of course hard 
 rubber and hard and soft woods are still more easily 
 worked. 
 
 Turning brass. Babbitt metal, or type metal is not 
 materially different from turning hard wood, The tools 
 
98 
 
 HOME jAIECJIANICS EOE A]\I A1’ET'1!S 
 
 are practically tlie same, and llie metliods are the same, 
 hut the metal tui'iiin!i> is dom* at a sonu'what sl()AV(*r 
 speed. In lh(‘ case* of nndals, lln* linishin<> of tlu* shar[»- 
 ening of flu* turning tools is done on an oil slom^ lo 
 insure the smoolhiK'Ss of the work. The work should 
 he so smoothly done that no final finishing will he 
 required. If, however, brass work is to he finished it 
 may be done by means of veuy fine emery ])a])er or 
 cloth. This may be a])])li(“d by the hand or strips of it 
 may be glued on flat or convex stri])s of wood which are 
 used in the same manner as a file. 
 
 The amateur cannot expect to cut screw thn^ads with 
 chasers as readily as a skilled mechanic, but he can 
 make some headway with practice on brass and hard 
 wood. Chasers may be purchased for cutting inside 
 and outside threads. The chaser is moved along the 
 lathe rest at what is judged to be the speed the thread 
 would carry it along if already cut in the brass or 
 wood. The chaser is at the same time pressed firmly 
 on the rest and brought into engagement with the ma- 
 terial revolving in the lathe. 
 
 l\fake-shifts are not to be generally approved, but 
 the writer will relate a circumstance which came to his 
 knowledge some years ago that may be helpful to some 
 one caught in a similar pr(*dicament. 
 
 A lathe was available but no sci’ew-cutting tools of 
 any kind were at hand. It was necessary to make one 
 or two fittings for a half-inch gas pipe. Two old files 
 were found and anneal(>d, and in the end of one were 
 filed with an ordinary triangular file the teeth to fit the 
 threads of tin* gas ]*ip(“. In flu* side* of the other file 
 were filed teeth to fit th(‘ t(“(‘fh of the first chaser. 
 Thes(‘ teeth w<‘r(‘ filed at a slight inclination to cor- 
 
HOME MECHANICS FOR AMATEURS 
 
 99 
 
 respond roughly with the pitch of the screw thread. 
 These chasers were hardened and tempered and used to 
 good advantage in finishing work which would other- 
 wise have been delayed at considerable inconvenience. 
 
 METAL-WORKII^G ON A LATHE 
 
 INSTRUCTIONS ABOUT DRILLS AND 
 DRILLING 
 
 An ordinary flat drill for most purposes will answer 
 nearly, if not quite, as well as a twist drill. It is not 
 a difficult matter to make them, since we have such 
 reliable material as Stubs’ steel wire of every size. The 
 best form of flat drill for general purposes is shown in 
 Figs. 88, 89, and 90. It is made by milling or filing the 
 opposite sides of the wire, so as to form a bit or blade 
 having a thickness equal to about one-fourth of the 
 diameter of the wire. The angle of the point should be 
 90 degrees, and the angle of its cutting edge about 45 
 degrees for most uses. For a drill for very hard sub- 
 stances these angles may be more obtuse. 
 
 Having formed the drill, it should be hardened by 
 heating it to a low red and plunging it straight down 
 into cool (not cold) water. In case of a very small 
 drill, it may be held in the flame of a gas burner or 
 lamp in a pair of spring nippers over a vessel of water. 
 When it attains the required degree of heat it may be 
 dropped into the water. 
 
 To temper for most cases, the drill, after being 
 brightened on an emery wheel or piece of emery paper, 
 is heated ; if it is a small one, in an alcohol or gas flame, 
 until its color at the point runs down to a brownish 
 
100 
 
 HOME MECHANICS FOE AMATEUES 
 
 yellow vermin"; on a ])urple. If the drill is very larjje 
 it nnvy be heated ovei" a forjj;(‘ fire*, or ov(‘r a heavy pi(‘C(‘ 
 of red-hot iron. If the drill is a very small om*, it may 
 be hardened and tem])ered at one oi»eration by heatinj' 
 to a low red heat and plun^injj it imim'diately into a 
 piece of beeswax. 
 
 If it is desired to have the point of the drill very hard, 
 without being liable to breakage, its temper may be 
 drawn In^ holding its point in pliers, as shown in Fig. 
 88, while the main portion is held over a gas flame. 
 The cool jaws of the pliers prevent the point from be- 
 coming heated. 
 
 Another method, applicable to larger drills, is to em- 
 ploy a notched block of lead, as shown in Fig. 89. The 
 drill in this case is driven a short distance into the 
 load before? it is hardened; then, as it is tempered, it is 
 rej)Iaced in tin* l(*ad to ])reserve the hardness of the 
 cutting edges while the temper is drawn in the other 
 portions. 
 
HOME MECHAXICS FOR AMATEURS 
 
 101 
 
 When a drill is liardened by iramersiug its point in 
 mercury instead of water, it acquires a diamond-like 
 liardness. The point of the drill just described is 
 shown in perspective and in section at D in Fig. 90. 
 The drill P is similar to the drill D, the point of dif- 
 ference being a half-round groove along each face ad- 
 jacent to the cutting edge. This device gives the cut- 
 ting edge a more acute angle, which is desirable for 
 some kinds of work. G is a straight drill having con- 
 cave or fluted sides, and E is the well known twist 
 drill. The drills, G E, are shown in cross section in 
 the central figure. Twist drills of recent manufacture 
 have a central longitudinal line, which locates the point 
 in grinding. 
 
 The best ride for grinding twist drills is to preserve 
 as nearly as possible the original form. The ordinary 
 pin drill, H, is used for counterboring, a hole being 
 first drilled to receive the pin. The drill I is employed 
 to give an ornamental appearance to plates in which 
 pivots or small shafts are journaled, as in clock work. 
 The bottoming drill, J, has three cutting edges, one 
 upon each side, and a central transverse one connecting 
 the other two. This drill, as its name indicates, is de- 
 signed to make a fiat bottom in a drill hole. 
 
 The pin drill, K, which is shown in side and end 
 views in Fig. 93 is first carefully turned and afterward 
 milled with the rose bit, L, producing the cutting points 
 or lips, which are afterward beveled with a file. This 
 drill is used for boring large holes in sheet metal, a 
 small hole being drilled first to receive the pin. M is 
 an expansion drill for the same purpose; its construc- 
 tion will be readily understood from the engraving. 
 The spindle is mortised to receive the tool carrying 
 
102 HOME MECHANICS EOK AMATEUES 
 
 arm, which is scoured in the mortise by a k(*y. The 
 lower end of tlie s])indle is bored to receive tlie drill, 
 Avhich also forms the ]>in for <;ui<liii_n’ tin* cutter. 
 
 Wliile uuiversal chucks are recommended for holding 
 drills, another form of chuck, shown in Fig. 91, may 
 be used with (‘qual advantage. Tt consists of a main 
 
 Fig. 90. Forms of Drills. 
 
 portion. A, wliicli screws on tlie lathe spindle, and has 
 a tajiering thr(*aded end for receiving the milled nut, B. 
 The thread(‘d end is split to admit of its contraction as 
 till' nut, B, is sci'ew(*d on. The jijirt, A, is bored longi- 
 tudinally to i‘(‘c(‘i v(‘ sect ions, C, of iron or steel rod. To 
 lirepare Ibis clinck for holding drills, the pieces, C, 
 
HOME MECHANICS FOE AMATEUES 103 
 
 are inserted in the chuck, centered with a pointed tool, 
 and are drilled Avith the drill Avith AA'hich they are 
 intended to be used. They are then split longitudinally 
 with a saAV for about three-fourths their length. The 
 pieces, C, Avhen once prepared, AA’ill alAA'ays ansAA^er for 
 the same sized drill ; they may also be used with an 
 ordinary chuck liaA'ing a set screw. 
 
 Fig. 91. Drill Chuck. 
 
 The fluted countersink, O, may be classed among the 
 drills; its special application is to form the centers of 
 articles to be turned. It has the same form as the lathe 
 centers, and makes a truly circular conical hole, provid- 
 ing the number of flukes or cutting edges is odd. 
 
 EA^ery lathe should be provided with a plate, or drill 
 rest, P, fitted to the tail spindle, for supporting plain 
 AA’ork while drilling it. The lathe should also have a 
 
Fig. 92. Lathe, with Work Support. 
 
HOME MECHANICS FOE A]\rATEUES 105 
 
 hinged or pivoted rest, Q, which niav be clamped at any 
 desired angle for drilling irregular work. This plate 
 shonld have several perforations for receiving pins, 
 for preventing the work from slipping. For supporting 
 cwlindrical objects to be drilled transversely, a fork, 
 E, is inserted in the tail spindle. 
 
 Fig. 93. Drills and a Rose Bit. 
 
 As to the matter of drilling, little need be said, as 
 nearly everything must be learned by experience; how- 
 ever, a few points may be mentioned. The work should 
 be carried forward with a. regular and not too heavy 
 pressure. The speed of the drill will vary with the ma- 
 terial being worked. For steel, wrought iron, and cop- 
 per, the speed should be slow ; for brass and cast iron, it 
 may be quite rapid. In drilling steel or wrought iron, 
 oil is the best lubricant for the drills ; in drilling glass, 
 the drill should be wet with turpentine. 
 
lOO 
 
 \\(n\K ]\IK( liANI(\S VOW jUIATVXW^ 
 
 HINTS (M)N(;fj{nin(} (m:ntkihn(} and 
 sti:adyin(j 
 
 To conter a (‘vliiidric'al ])i(M‘(‘ of iiuTal i'(‘a(lily and 
 a(‘curat(dy is a very sini])l(^ mat tin' wlnm tin* workman 
 is providcMl with tools osjxM'ially d(‘sii»n(Ml foi* th(‘ ])nr- 
 poso, and it is not ditticnlt wlion an (miL»in(‘ latln^ or (*v(*n 
 an engine rest is availal)le ; l)nt to do it (^asily and ])ro])- 
 erly in an ordinary ])lain foot latlie may ])nzzle some of 
 
 Fig. 94. Centering with a Forked Tool. 
 
 the amateur meelianieians. Although some of these 
 imdliods ar(^ w(d] knowip they Avill neA^ertlieless be de- 
 s(‘ril)(Ml for tlie Ixuudit of some who may require the in- 
 format ion. Th(‘ imdliod of (‘(mtering shown in Fig. 94 
 is on(‘ of 1h(‘ most (‘ommon wlna-e tlie latlie is provided 
 with an (mgim^ i'(*sl. A fork(‘d tool. A, is (damped in 
 t1i(^ lool post in smdi a position tliat a lim^ drawn from 
 th(‘ point of th(‘ tail (*(mt(‘r will biseet the 
 
HOME MECHANICS FOE AMATEUES 
 
 107 
 
 angle of tlie fork. A square pointed renter, 
 G, is inserted in the tail spindle and moved 
 against the end of the rod being centered with 
 
 Fig. 95. Centering. 
 
 a slight pressure, the tool. A, being at the same 
 time moved forward by the screw of the engine rest un- 
 til the rod turns smoothly in the fork and the square 
 
 Fig. 96. Centering with a Hand Tool. 
 
 pointed center has found the center of the rod; the tail 
 spindle is then moved forward until the cavity is suffi- 
 ciently deep to permit of starting the center drill. The 
 
108 
 
 HOME MECHANICS EOIf AIMATEUHS 
 
 aiiyle of sqiiare ((“TitoT, (I, foi' voiy liai’d inatorial, 
 sliould bo a little more obtuse tlian that shown in Fiji. 
 97. In any ease, it slionld be of _<«(>od niat(*i ial and well 
 tempered. 
 
 In Fif>-. 95 is shown a eenterinf>: tool wbieb is desif,nied 
 to take the place of the engine rc'st and fork in Fig. 94. 
 The part R is fitted in place of the ordinary tool rest, 
 
 and the .jaw. Cl, which has in it a V-shaped notch, is 
 hinged to the part R at I). A screw, E, passes throngh 
 Hie ni)j»ei' end of the part R, and hears against the jaw, 
 (J. After what has aln^ady been said in connection 
 with the engiTie r<“st, th<“ manner of using this con- 
 trivance w'ill l)(“ T'(*adily nmh'rstood. 
 
 [ti I'dg. 9(1 the hand tool, F, is employed for steadying 
 
HOME MECHAxNTICS FOR AMATEURS 
 
 109 
 
 the shaft and bringing it to a center. This tool is bent 
 to form a right-angled notch for receiving the shaft, 
 and when in use it is supported by the tool rest after 
 the manner of an ordinary hand turning tool. 
 
 Work that is too large to be readily centered in this 
 manner is often centered apjjroximately by means of 
 the universal square, as shown in Fig. 98. A diamet- 
 
 Fig. 103. 
 
 Steadying Devices. 
 
 rical line is drawn along the tongue of the square, 
 the work is then turned through a quarter of a revolu- 
 tion, and another line is drawn. The intersection of 
 these lines will be the center, at least approximately. 
 
110 HOME MECHANICS EOK AMATEUKS 
 
 Fig. 104. Turning Long Rods. 
 
HOME MECHANICS FOR AMATEURS 
 
 111 
 
 This point may now be marked with a center punch, 
 and the work may be tested in a lathe. If it is found to 
 revolve truly on the centers it may be drilled, otherwise 
 the center must be corrected with the center punch, and 
 the work again tested in the lathe. 
 
 After centering by any of these methods, the center 
 must be drilled and countersunk with a suitable tool, 
 so that it will fit the lathe center, as shown in Fig. 99. 
 The angle of the lathe centers should be sixty degrees. 
 To insure uniformity in everything pertaining to the 
 centers, the center gauge, shown in Fig. 100, should be 
 used for getting the required angle on the lathe centers 
 and on the drills used in centering. 
 
 The matter of steadying the long, slender rods while 
 l)eing turned in the lathe is often perplexing. 
 
 In some cases it may be done tolerably well in the 
 manner illustrated in Fig. 101. The fork, H, is sup- 
 ported by the standard, I, which is inserted in the 
 socket of the rest support, J. The device shown in Fig. 
 95 may be used in a similar wav. 
 
 Fig. 102 represents a steady rest, the construction of 
 which will hardly need explanation. For light work it 
 may be made of wood ; the upright being secured to the 
 cross piece, L, which rests upon the lathe bed. The 
 slotted pieces, M, are adjustable lengthwise to accom- 
 modate the size and position of the shaft. When it is 
 required to support a bar which is not round, the sleeve, 
 N, shown in Fig. 103, is employed. It slips over the 
 shaft and revolves in the steady rest. The bar is cen- 
 tered by the screws, O. 
 
 The device shown in Fig. 104 is used where a hollow 
 mandrel lathe is not at hand. A piece of gas pipe, Q, 
 is held by the chuck, P, and is secured by a set screw in 
 
112 HOME MECHANICS EOli AMA1MHIRS 
 
 Hie sleeve, 1>, \vlii(*li is jouriialiMl in the standard, S, 
 and (‘arries the ehnek, T. Tliis ai*ran<;(*in(Mit may also 
 be employed for tnrninj^ the ends of loni^ rods wherc^ it 
 is not desirable to ])nt them r(\i»nlarly on the centers of 
 the lathe. 
 
 CHUCKING 
 
 In spite of all possible a])pliances to be used in a 
 general way for chucking work in the lathe, a degriM^ of 
 inventive skill is often rininired to accomplish it (piickly 
 
 Fig. 105. Chucking a Metallic Disk. 
 
 and securely. Tln^ accompanying (aits are designed to 
 aid the arnatcair in chn(*king, but after all is said, there 
 is a world of knowbalge that can be gained by experi- 
 (aice only. 
 
HOME MECHANICS FOR AMATEURS 
 
 113 
 
 The arrangement of a metal disk in the lathe so that 
 it can be turned on its face, and upon its edge, cannot 
 well be accomplished by means of chucks; for this pur- 
 pose recourse is freqtiently had to cement. A good 
 
 Pig. 106. Chucking a Spindle. 
 
 cement for this purpose consists of Burgundy pitch, 2 
 pounds; resin, 2 pounds; yellow wax, 2 ounces; dried 
 whiting, 2 pounds; melt together the pitch, resin, and 
 wax, and stir in the whiting. 
 
 Pig. 107. Chucking Work on Pace Plate. 
 
 To chuck work with this cement, apply a small por- 
 tion of it to a face plate devoted especially to this pur- 
 pose; heat the plate so that the cement will cover the 
 
114 
 
 HOME MECHANICS FOE AMATEIJES 
 
 fjroator portion of its snrfaco. Tin* plain may bo al- 
 lowed to cool. AVliomw(“r it is (b'sirabb"' to clmck a 
 motallic disk, it is boated and plao(‘d a<j;ainst the eenn'iit 
 on the face plate, and allowed to remain until tin* 
 eement begins to stiffen, Avhen a. tool having a right- 
 angled notch is a])plied to the edge of the disk, as shown 
 in the cut, the lathe being rotated until, by Ihe^ com- 
 pound action of the tool pressure and the rotary mo- 
 tion, the disk becomes jx'rff'ctly true. 
 
 To chuck a spindle or any similar object a cement 
 chuck like that shown in section in Fig. 10(5 is some- 
 times used. The larger ])ortion is screwed on the lathe 
 mandrel, and the inner end of the hole in the outer por- 
 tion terminates conically. The hole is tilled Avith 
 cement, and the article to be chucked is warmed and 
 introduced. It mav sometimes be necessary to heat the 
 chuck Avith an alcohol or gas flame. The lathe is 
 rotated, and the spindle is held lightly until it becomes 
 true and the cement begins to harden. 
 
 To remove the Avork from a cement chuck, it must be 
 Avarmed by means of a lamp or otherAvise. Most of the 
 cement adhering to the AAork may be Aviped off after 
 heating it; AvhateA'er remains may be remoA^ed with a 
 little turpentine. 
 
 A common method of chucking Avork on the face plate 
 is shown in Fig. 107 ; the Avheel is temporarily retained 
 in place by a jiointed rod. A, Avhich is forced against the 
 Avheel by the tail spindle. A little rapping one AA’ay or 
 the other readily c(*nters the Avheel. A piece of crayon 
 h(*ld in a crayon holder suj>])orted by the tool rest may 
 be used to discover wbicb side of the Avheel is “out.” 
 After the wh(*el is trued, it is fast(m(“d by the short bars, 
 15, whose outer ends rest upon any convenient blocking 
 
HOME MECHANICS FOE AMATEUKS 
 
 115 
 
 while they are drawn by the bolts, so as to clamp the 
 wheel firmly to the face plate. 
 
 It is sometimes preferable to use the yoke shown in 
 Fig. 108 instead of the bars shown in Fig. 107 ; it is 
 placed diametrically across the wheel and secured by 
 two bolts. 
 
 Fig. 108. Yoke. 
 
 Fig. 109 represents a chuck consisting of a wooden 
 disk, c, bored to receive the wooden hoop, d, which may 
 be forced inward by the common wood screws, e, which 
 bear upon it. This chuck is useful where a consider- 
 able number of similar pieces are to be turned or bored. 
 
 Fig. 109. Wood Chuck for Duplicate Work. 
 
 Fig. 110 represents a simple and well known chuck. 
 It is simply a block of wood secured to a face plate by 
 a screw center and turned out to fit the work. 
 
116 
 
 HOME MECHANICS EOII AHATEUliS 
 
 Fijj. Ill reprosonts an oasilv made clinck, wliicli is 
 useful for lioldinj'' pluj^s of wood to be turned or bored. 
 It consists of a ])iece of bard wood lifted to tlie inaTnlrel, 
 turned, bored, and split longitudinally, as shown in the 
 
 Fig. 113. 
 
 Chucking Devices. 
 
 onj]jravinj]j. Its outor end is taj)('red, and to it is fitted a 
 metallic ring that serves to contract the chuck when it 
 is forced on. 
 
 Fig. 112 represents a ta[)ei'(‘d and split mandrel. 
 
HOME MECHANICS FOR AMATEURS 
 
 117 
 
 which may be either of metal or wood according to the 
 purpose to which it is to be applied. The part P is 
 bored conically at the smaller end before splitting, and 
 to this hole is fitted the conical plug, G, which being 
 forced in expands the mandrel. 
 
 In Fig. 113 the mandrel, C, has permanently attached 
 to it the cone, D, and upon it is placed the movable 
 
 Fig. 114 . Fig. 115 . 
 
 Chucking on Angle Plate. Face Plate Jaw. 
 
 cone, E, which is forced against the work held between 
 the two cones by a nut which turns on the threaded end 
 of the mandrel. 
 
 Tn Fig. 114 the manner of chucking work on the 
 angle plate, H, is shown so clearly as to require no 
 explanation. It may be well, however, to state that 
 when the work is rotated rapidly a counterbalance 
 
118 HOME MECHANICS FOR AMATEURS 
 
 sliould 1)0 attsiclicd to tlx* face plaU* on tin* si<l(“ dia- 
 inotrically opposite tlio anj>l(‘ ])]at(*. 
 
 Fig. 115 shows a jaw for attacliiu'nit to tlie face plate*, 
 wlii(‘h consists of a right-angled jeiece, I, a jaw, J, which 
 has two guide ])ins, entering holes in the piece, I, and 
 the screw, K, which j)asses throngh a tapjeed hole in 
 the piece, I, and hears against the jaw, J. The ])iece, I, 
 has a dowel, a, that kee])s it from turning, and a screw, 
 b, by which it is secured to the face plate. 
 
 In Figs, lie and 117 the pin, L, is fitted to the face 
 ])late, and has form(‘d on its projecting end an eccen- 
 tric which fits the jaw, M. It has also a hexagonal head 
 for r(‘c(*iving tin* wN'iicli by which it is tnrned. Three 
 j)ins, U, are fitb'd to the fac(> plat(‘, which is (piite thick, 
 d'wo of I lie ])ins n(‘ed not be* tiirnc'd aftc'r bc'ing adjusted 
 for a certain kind of work; tin* third is loosened and 
 turned when work is put in and tak(‘n out of the lathe. 
 
HOME MECHANICS FOR AMATEURS 
 
 119 
 
 After the work is clamped tightly by turning the eccen- 
 tric the nut on the back of the face plate is tightened. 
 
 In Fig. 118 is shown a type of the most convenient 
 and most universally useful chuck in existence. Its 
 
 Fig. 118. Scroll Chuck. 
 
 construction and use are so well known as to need no 
 description. • The jaws are simultaneously moved to 
 or from the piece of metal which is being machined by 
 the aid of a key. Such chucks hold drills admirably. 
 
 METAL TURNING 
 
 In selecting a lathe an amateur may exercise more or 
 less taste, and he may be governed somewhat by the 
 length of his purse; the same is true in the matter of 
 chucks; but when he comes to the selection or making 
 of turning tools he must conform to fundamental prin- 
 ciples ; he must profit as far as possible by the experi- 
 ence of others, and will, after all, find enough to be 
 learned by practice. 
 
 Tools of almost every description may be purchased 
 at reasonable prices, but the practice of making one’s 
 
120 
 
 HOME MECHANIC'S EOl! AMATEURS 
 
 own tools cannot be too strongly rcconinKMidcd. Tt 
 affords a way ont of many an cincrgcncy, and wlicri* 
 time is not too valuable, a saving will be lealized. A 
 few bars of fine tool steel, a hammei-, and a small anvil, 
 are all that are reqnirc'd, aside from fire and water. 
 The steel sbonld be b(‘at(“d to a low red, and sbajK'd 
 with as little hammering as ])ossible; it may then be al- 
 lowed to cool slowly, when it may be filed or ground to 
 
 Metal Lathe Tools. 
 
 give it tbe required form. It may now be hardened by 
 healing it to a cherry red and plunging it straight down 
 into clean coo] (not too cold) water. It should then be 
 I)olished on two of its sides, when the tem])er may be 
 drawn in Ibe flaiiK' of an alcolnd lamp or Bunsen gas 
 bniaier; or, if these are not conveni(‘nt, a heated bar of 
 iron may lx* used instead, the to<d being placc'd in con- 
 
HOME MECHANICS FOE AMATEUES 
 
 121 
 
 tact with it until the required color appears. This for 
 tools to be used in turning steel, iron, and brass may be 
 a straw color. For turning wood it may be softer. The 
 main point to be observed in tempering a tool is to have 
 it as hard as possible without danger of its being 
 broken while in use. By a little experiment the ama- 
 teur will be able to suit the temper of his tools to the 
 work in hand. 
 
 Fig. 122. 
 
 16 . 
 
 Fig. 123, 
 
 Metal Lathe Tools. 
 
 In the engravings accompanying the present section 
 a number of hand turning tools are shown, also a few 
 tools for the slide rest. These tools are familiar to ma- 
 chinists and may be well known to many amateurs ; but 
 we give them for the benefit of those who are unac- 
 quainted with them and for the sake of completeness in 
 this volume. 
 
122 HOME MECllAxNIlCS FOE AiMATHUHS 
 
 No. 1, Fig. 110, is tlie ordinary diamond tool, 
 made from a s(iuare bar of sl(‘(‘l gronnd <liag- 
 onally so as to give it two similar cutting edges. 
 This tool is ])(‘i-lia])S moi-e genei'ally useful than 
 any of the others. The maniu'r of using it is 
 
 Fig. 124. Metal Lathe Tools. 
 
 shown in Fig. 127 ; it is placed on the tool rest 
 and dexterously moved on the rest as a pivot, caus- 
 ing the point to travel in a circular path along the 
 metal in the lathe. Of course only a small distance is 
 traveled over before the tool is moved along on the 
 
 Fig. 125. Drill and Holder. 
 
 rest. After a litth* experience it tvill he found that by 
 exercising can* a good Job in plain turning may be 
 done with th<‘ tool. 
 
 No. 2, Fig. 12b, shows a shai-j) V-sha])ed tool which 
 will be found useful for many ]»urpos(“S. No. 3 is a 
 V-shaped tool for finishing screw thr<“ads. Nos. 4 and 
 
HOME MECHANICS FOR AMATEURS 123 
 
 5 are round-nosed tools for concave surfaces. No. 6 
 a square tool for turning convex and plane surfaces. 
 The tool shown in No. 7 should be made right and left; 
 it is useful in turning brass, ivory, hard wood, etc. No. 
 8 is a separating tool. No. 9 is an inside tool, ^vhich 
 should be made both right and left, and its point may 
 be either round, V shaped or square. 
 
 Fig. 128 shows the manner of holding an inside tool. 
 No. 10 is a tool for making curved undercuts. No. 11 
 
 is a representative of a large class of tools for duplicat- 
 ing a given form. 
 
 These figures represent a series of tools which may be 
 varied infinitely to adapt them to different purposes. 
 The user, if he is wide awake, is not long in discovering 
 what angle to give the cutting edge, what shape to give 
 the point, and what position to give the tool in relation 
 to the work to be done. 
 
124 HOME MECHANICS EOH A:\tATEURS 
 
 Having; had expeiicau'O witli liaiid tools it rcMpiires 
 only a little practice and observation to apply the same 
 principles to slide rest tools. 
 
 A few exainph^s of tin's class of tools are ij^iven. No. 
 12 is the ordinary diamond ])oint(*d tool, which should 
 be made rii»ht and left. Tln^ (‘nttini»* ed<»:(^ may have 
 a more or less acute angle, according to the work to be 
 
 Fig. 127. Using the Diamond Tool. 
 
 done, and the inclined or front end of the tool may be 
 slightly s(piared or rounded, according to the work. 
 Eig. is a se])arating tool, which is a little wider at 
 th(‘ cutting edge than anywhere else, so that it will 
 ch^ar itself as it is forced into the work. 
 
 Eor brass this tool shonld b(^ Ix^T^led downward 
 slightly. Hy giving tln^ ])oint tlu^ form shown in No. 
 d it will beadapt(*d to scn^w cutting. 
 
HOME MECHANICS EOK AMATEUES 
 
 125 
 
 No. 14 shows an inside tool for the slide rest; its 
 point may be modified according to the work to be 
 done. No. 15 is a side tool for squaring the ends of 
 shafts; Nos. 16, 17, 18 and 19 represent tools for brass; 
 No. 16 is a round-nosed tool for brass, No. 17 a V-shaped 
 tool, No. 18 a screw thread tool, and No. 19 a side tool. 
 In boring, whether the object is cored or not, it is de- 
 sirable, where the hole is not too large, to take out the 
 first cut with a drill. The drill and the drill holder 
 
 for the purpose is shown in Fig. 125, and the manner 
 of using in Fig. 126. The drill holder, B, is held by 
 a mortised post placed in the rest support. The slot of 
 the drill holder is placed exactly opposite the tail cen- 
 ter and made secure. The drill, which is flat, is drilled 
 to receive the tail center, and it is kept from turning 
 by the holder, and is kept from lateral movement and 
 chattering by a wrench, C, which is turned so as to 
 bind the drill in the slot of the holder. 
 
 The relative position of the tool and work is shown 
 
126 
 
 HOME IVIECIIANICS KOll AM\TVA \l^ 
 
 in Fig. 129. Tlie upper eut sliows flu* position for brass; 
 the next for iron and st(‘el ; tin* tliii'd, tln^ n^lativc^ posi- 
 tion of tlie engine rc^st tool and its work, and the fonrtli 
 the ])osition of tlie tool for soft iindal and wood. 
 
 In all of these eases the jioint of th(‘ tool is above 
 
 Fig. 129. Position of Cutting Tools. 
 
 the center of the work. In the matter of the adjustment 
 of the tool, as well as in all other operations referred 
 to, experiment is recommended as the best means of 
 gaining valuable knowledge in the matter of turning 
 metals. 
 
 CHASING AND KNURLING 
 
 Among the multitude of operations possible with a 
 foot lathe jierhaps none is more vexatious to the ama- 
 t(mr than that of cutting a good screw thread, and no 
 a(‘(|uir(mient is more valuable than to be able to chase 
 a scnnv thread (^asily and ac(‘uratelj. 
 
 Th(‘ ordinary ('baser, No. 1, l^Mg. 130, is a simple 
 tool which is (uisily made wlum one has the hubs for 
 tin* (lillei'cmt siz(*s; but wanting th(‘S(% we recommend 
 tin* purchase^ of chas(n'S. A blank for an outside ('baser 
 is shown in No. 2, and lh(‘ hub used iu ('utting the 
 t(adh is r(*pres(Mil(Ml in Fig. 131. The latt(a* (‘ousists 
 
PUTTING ON NEW WARP WITHOUT RE-THREADING THE 
 
 HEDDLES. 
 
 After the new warp is on the beam each new end is tied to a correspond- 
 ing old end. 
 
HOME MECHANICS FOR AMATEURS 
 
 127 
 
 of a piece of good steel having a thread of the desired 
 pitch, which is traversed by spiral grooves to form 
 cutting edges. This tool must have about the same 
 temper as that of a tap. When used it is placed be- 
 tween the lathe centers and revolved at a slow speed, 
 
 Fig. 130. Chaser and Blank. 
 
 Fig. 131. Hub. 
 
 Fig. 132. Inside Chaser. 
 
 while the end of the chaser blank is held against it, 
 being at the same time supported by the tool rest. The 
 hub should be oiled during the cutting process. After 
 cutting, the tool is hardened and tempered, and ground 
 on the elevated portion, which is the face, and smoothed 
 on the back which slides upon the tool rest. 
 
128 
 
 mniK MECHANICS foe amateurs 
 
 An inside (*liaser is sliown in V\g, 132, tlie l)lank 
 from wlii(*li it is made in V\^^. 133. f'or (‘onvcmicaicc^ 
 in cnttiiifi^ the teetli, tlie l)laidv is Ixait at ri<»lit anf»l(‘s; 
 after (aittinji^ and IxTore liardeninj>* it is strai!L»iitened. 
 
 Pig. 134. Starting a Thread. 
 
 The manner of starting a thread for chasing is shown 
 in Fig. 134, the tool used being shown. The rest is 
 placed a short distance from the work, the tool is held 
 
 Fig. 135. 
 
 firmly upon it, and while tlie work revolves with a 
 uniform sjieiMl th(^ tool is moved dexterously so as to 
 mak(^ a sjiiral lim^ on iln^ work, whi(*h is nearly, if 
 not exactly, of lh(‘ sam(‘ jiitch as lh(‘ thread to be cut. 
 
HOME MECHANICS FOR AMATEURS 
 
 129 
 
 If the operator is fortunate in the attempt, it will be 
 a simple matter to start the chaser and move it along 
 as indicated in Fig. 136. After a little practice it will 
 in most cases be found an easy matter to chase threads 
 without first starting them with a pointed tool. It is 
 much easier to chase an inside thread than an outside 
 one. A chaser seldom goes wrong when working on 
 the inside. 
 
 Fig. 136. Chasing a Thread. 
 
 A method of chasing thimbles is shown in Fig. 137. 
 The threaded thimble which forms the guide screw is 
 driven on the larger end of the tapering mandrel ; the 
 thimble on which the thread is to be cut is placed on 
 the smaller end of the mandrel. One arm of the forked 
 tool has a vertical chisel edge, which engages the guide 
 screw ; the other arm has a chasing point which cuts 
 
JIOME MECHANICS FOR A:MA'1'EURS 
 
 130 
 
 the thread. Tlie chisel <‘(1,i>e is first l)r()U,iili( into eii- 
 ji'af'eineiit with the jiu'de screw, tlie, ])oint is tlicii 
 (juickly br()n_i>ht apiinst the work with more or ](‘ss 
 ])rcssnre. After tlie thread is well startcil it may he 
 finished with an ordinary chaser or with a ])ointcd 
 tool. 
 
 Fig. 137, Chasing Thimbles. 
 
 138 sliow8 a metliod of starting an inside thread. 
 Tlie cliascT* lias a tracing edge that follows the guide 
 scrcnv projcM'ting from the center of the chuck, and a 
 ('lining point that forms the thread. Fig. 139 shows 
 I li(‘ tool in d(‘tail. 
 
 Tlir(‘ads cut by a ('liascn' without S(>me kind of a 
 giiid(^ to start tlnmi ai'(‘ oft cm niorc^ or less ('rooked or 
 dninlom. 1'o cori'(*(‘t such thr(‘ads and in (mtting large 
 ilir(*ads, tln^ doclor, shown in h'ig. 140, is sometimes 
 
HOME MECHANICS EOK AMATEURS 
 
 131 
 
 eiiiplojed. The folloAver opposite the chaser is moved, 
 up by the thumbscrew as the thread deepens. 
 
 The most expensive, and at the same time the most 
 desirable, contrivance for chasing- screw threads is 
 shown in Fig. 141. A casting fitted to the lathe bed 
 has two ears, which are bored to receive the round 
 
 Pig. 138. 
 
 Fig. 139. Chasing Inside Threads. 
 
 sliding rod carrying the tool holder and tracer. The 
 tool holder is placed on the sliding rod between the two 
 ears, and it carries a well-fitted screw, which bears 
 against the horizontal bar supported by two square 
 posts, which form a part of the main casting. This 
 bar forms a guide which may be adjusted within nar- 
 row limits by the screw seen in the right hand post. 
 
Tlio latlie is ])! ovided wiili a fa(‘(‘ plate* lia\iiii»; a loiiij 
 boss aia‘aiii>(*d to r(*(‘(*i\(^ tliiiid)l(*s liaviiii;- l(*adiiii»’ 
 threads of different pitedies cut on th(*ni. Tin* traeaiiji^ 
 
 thimbles, and is ea])al)le of yi(ddini» to admit of mov- 
 inj»‘ the (mttinf>' tool foi'ward ai^ainst tin* obj(*('t l)(*iiiij; 
 tliread(*d; bnt beini»' w(dl fitted to tlie mortise* in tlio 
 arm it e'anne)t me)ye late*rally Ayitlie)nt e‘arryini»‘ tliei 
 slielini»“ re)el anel all attaeduMl te) it. The* tra(*in<» te)e)l is 
 sle)tted te) ree(*iye a ])in \yhie-h ])asse*s transye*i‘se*ly 
 
 Fig. 140. A Doctor for Cutting Large Threads, 
 
 throiiftli tlie heael of the tracing arm, and in the slot is 
 ])laceel a spiral si)ring which tends to throw the tracer 
 fe)rwarel. 
 
 The* e)peratie)n of this deyice neeels ne) special ex- 
 planatie)!!. The arm that carries the entting toed is 
 me)ye*el fe)rwarel until its aeljnsting screw strikes the 
 he)rize)nta1 gniele* bai*; the* trae-ing te)e)l at the same 
 time* e*ngage*s the* le*aeling s(*re*w anel e‘arrie*s all tdrward. 
 \\die*n I he* je)e)l has ti‘aye*le*el as far as de*sirable it is 
 elraw n bae*k anel reitnrne*el te) ils e)]dginal ])e)sitie)n. With 
 I his loe)l lhre*aels may be* emt e)n e*ithe*i' e'yl inelrie'al or 
 ta[)e*i‘iiig we)r‘k. 
 
HOME MECTTAXirS FOE Al\rATEITBS 
 
 133 
 
 Fig. 141. A Good Method for Cutting Threads. 
 
134 
 
 IIOMK MKCniANK^S KOII AMAIM^UKS 
 
 It is S()in(4i]n(‘S (l(‘sii'al)l(‘ io form s])iral ^roov(*s in 
 tlio fa(‘(^ of a disk; tliis may a(*(‘om])lisli(*(l in (^xa(*tly 
 tlm same manma' as in the (*as(^ of ili(‘ (‘vlimli'icad work. 
 Tlu^ nudliod of (loin<» if is illnsfraf(Ml by 142. 
 
 Knurls of various ])ai terns ai'(‘ sliown in f'i^. 14‘k 
 These are eni])loy(Ml in ^d)(mdinjL»*;’ ^bnillinjL>:,” or knurl- 
 iiic^tlie lieads of s(*rews, the liandles of small tools, (dc. 
 The manner of usini]^ this tool is shown in 145. 
 
 Fig. 142. Cutting Spiral Grooves. 
 
 The knurl is placed between the forks of a holder and 
 upon a j)in that passes through the fork, and is held 
 with eonsiderable pressure against the work as it re- 
 volves. 
 
 Th(^ knurls shown in hdg. 144 are easilv made. 
 All that is r(*(piir(‘d is a hub something like that 
 shown in hig. 12>1. This is ])la(‘(‘d b(‘twe(m the centers 
 of lh(‘ lath(% and 1h(^ knni'l blank is brought in (‘ontacd 
 with it and aIlow(Ml io n^viAvi^ in a holder su])ported 
 
HOME MECHAHTOS FOE AiAIATEUES 
 
 135 
 
 bj the tool rest. The straight blank is moved np and 
 down until every part of the surfaee is cut in the same 
 way. The concave blanks cannot be moved, but the 
 
 Fig. 143. Knurls. 
 
 Fin. 144, Examples of Knurling. 
 
 Fig. 145. Knurling. 
 
 Ilub should fit the hollow of the face of the blank. The 
 fancy knurl showu in Fig. 143 must be made by a die 
 sinker. Fig. 144 represents examples of knurling 
 done with knurls shown in the preceding figure. 
 
mniK MKCIIAXK^S Foil A.MA1M^i:ilS 
 
 KiG 
 
 KOTAKiV (U TTKKS 
 
 The sayiiii»’ of iiiahaGals and j)ati(‘iic(^, hy 
 
 tlie oiuployinoiil of siuGi rotai'y (aitt(a‘s as may 1 k‘ 
 ])rofital)ly iis(m1 in (•oiin(‘(‘tion Ayiili a foot lalln^, can 
 liardly be a])])r(M‘iat(Ml l)y oin^ wlio lias iH^ycn* att(*in])t(‘d 
 to use this (Gass of tools. It is astonishin,i; lio\y ininGi 
 y(‘ry hard labor may be say(Ml by im^ans of a small 
 
 Fig. 146. Metal Circular Saw. 
 
 circular saw like that shown in Fig. 140. This tool, 
 lik(^ maiiA^ of the others described in this section, 
 can, in most instances, be piii’chased cheaper than it 
 can be made, and the chances are in faA’or of its being 
 a more perfect article. However, it is not so difficnlt 
 to make as one might suppose. A piece of sheet steel 
 may he clincked ipion the face plate, or on a Avooden 
 block attached to the face jdate, Avhere it may he bored 
 lo fit tin; saw mandi'el, and cnt in circnlar form hy 
 means of a suitable hand tool. It may then he placed 
 npon fhe inandi'cl and tnrm'd trm*, and it is Avell 
 enoimh lo make it a, little Ihinmn* in flu* middle than 
 nl lln^ ])(*ri|)h(*ry. 
 
 1di(i!‘(‘ nr(^ s(*v(*ral mcGhods of forming ilu^ t(H41i on 
 n circnlar saw. 1 1 may lx* spac'cd and lilcd, or it may 
 
HOME MECHANICS FOR AMATEURS 
 
 i:h 
 
 be knurled, as sliown in Fig. 147, and then filed, leaving 
 every third or fourth tooth formed by the knurl; oi* 
 it may, for some purposes, be knurled and not filed 
 
 at all. Another way of forming the teeth is to employ 
 a hub, sometliiug like that used in making chasers, as 
 shown in Fig. 148. The difference between this hub 
 and the other one referred to, is that the thread has 
 one straight side corresponding with the radial side of 
 
138 IIOAFK IMKCIIAXK^S KOI? AMA^M^TIJS 
 
 tlie tootli. Tli(‘ blank fi'oin wliicli IIk* saw is nnub* is 
 ])la(‘e(l on a stnd ])r()j(M-lin^ fi'oin a liandb* niacb* sjx*- 
 (dally for tln^ ])nr])os(^, and liavini;' a i'onnd(*d (mkI wlii(‘li 
 sn])])orts tlu^ of tin* l)laidv, as th(‘ ai'(^ foiaiKMl 
 
 by tlie (Mitters on iln‘ linl). 
 
 Fig. 149. Small Saw. 
 
 The saWj after tlie teeth ai'(‘ fornuMl, may Ix^ liaixbmed 
 and teni])ered l)y li(‘atin:L> it slowly until it attains a 
 cherry red, and plnn<>ini>' it straii>ht down (Mli»(^wis(" into 
 cool, clean water. On reinovino* it from the Avatcn* 
 it should be dried and cleaned with a ])i(M'(^ of (mi(M*y 
 paper, and its temper drawn to a ])nrple over a T>nn- 
 sen i»as flame, over the flame of an alcohol lamp or 
 over a hot plate of iron. The small saw shown in Fig. 
 149 is easily made from a rod of tine steel. It is very 
 nsefnl for slitting sheet brass and tubes, slotting small 
 shafts, nicking screws, etc. Being quite small it has 
 
 Pig. 150. Mandrel. Fig. 151. Cutter. 
 
 1h(* advaniag(^ of having few tcxhli to kee]) in order, and 
 il may Ix^ niad(‘ hard(‘r than 1hos(^ of largiT diameter. 
 A s(iri('S of IIkmii, varying in dianudcu' fi'om one-eighth 
 to I hr(X‘-(4ghl hs of an inch, and varying ('onsidei'ably 
 in lhickn(*ss, will IxM'onnd v(‘ry (M)nv(mi(mt. 
 
HOME MECHANICS FOE AMATEHES 
 
 139 
 
 These cutters or saws, witli tlie exception of the 
 smaller one, may be used to the best advantage in con- 
 nection with a saw table, like that shown in Fig. 153. 
 This is a plane iron table having a longitudinal groove 
 in its face to receive the g^liding rib of the carriage, 
 shown in Fig. 154, and a transverse groove running 
 half way across, to receive a slitting gauge, as sliown 
 in Fig. 153. The table is supported by a standard or 
 shank, Avhich fits into tiie tool-rest socket. The saw 
 
 Fig. 152. Making a Cutter. 
 
 mandrel is supported between the centers of the lathe, 
 and the saw projects more or less through a slot formed 
 in the table. The gauge serves to guide the work to 
 be slotted, and other kinds of work may be placed 
 on or against the carriage, shown in Fig. 154. 
 
 It is a very simple matter to arrange guiding pieces 
 for cutting at anv angle, and the saw table mav be 
 used for either metal or wood. The saws for wood 
 differ from those used for metal; the latter are filed 
 straight, the former diagonally or fieaming. Among 
 
IIOMI-] 1\1 KCIIAXICS I 'OK* AMA'I'KIJI.’S 
 
 140 
 
 11i(> many iis(>s (o wliicli mclal saws may he ajtjilicd w(‘ 
 immlion tlm sliltinf>- of slmot im-tals, s])liti iiij^ wii-os ami 
 rods, slottiiio- ami j>rooviii,i^, jiickiin;' screws, clc. fi”-. 
 155 shows a lioldm* for rec<‘iviii<r scr(‘ws io he iiieke<l. 
 It is used in coinieetion with the saw tahh*, ami is 
 moved over the saw against the nanse. 
 
 To facilitate tin* removal of tlie screws tlie holdei" 
 may lx* s]>lit loui>itndinally and liiiiijed to<,u‘th(*r. An- 
 othei' im'tlnxl of niekiny sei*ews is illnsti-at(*d hy h5<r. 
 
 150. simple lever, fulcrumed on a bar held hy the 
 tool post, is drilled and tapped in the end to receive 
 tin? screw. After adjustini*’ the tool all that is required 
 is to insert tlui ser(*w and j^i'oss down the handle so 
 as to hi-inj>- tin* sei-(*w head into contact with the saw. 
 
 W'heix* a la tin* is provid<*d with an en<>'ine rest, the 
 cutter sliowu in hi”-. 151, monnt(*d on the mandrel 
 shown in h'ii*-. 150, is v<‘ry ns<*fnl ; it is ns(*d hy clamp- 
 ing Ihe work Io lln* slid(* rest and moviiif' it under the 
 enller hy workinji (In* slide rest screw. 
 
HOME MECHANICS FOR AMATEURS 
 
 141 
 
 To make a cutter of tliis kind is more difficult than 
 to make a saw, and to do it readily a milling macliine 
 would l)e recjuired. It may be done, however, on a 
 plain foot lathe, by employing a V-shaped cutt(*r and 
 
 using a holder (Fig. 152) having an angular groove 
 for receiving the cylinder on which the cutting edges 
 are formed. The blank can be spaced with sufficient ac- 
 curacy, by means of a fine pair of dividers, and after 
 the first groove is cut there will be no difficulty in 
 getting the rest sufficiently accurate, as a iiib inserted 
 in the side of the guide enters the first groove and all 
 of the others in succession and regulates the spacing. 
 
 One of the best applications of this tool is shown 
 in the small engraving. In this case a table similar 
 to the saw table before described is supported in a 
 vertical position, and arranged at right angles with 
 
 Fig. 155. Holder for Screws. 
 
 the cutter mandrel. The mandrel is of the same diam- 
 eter as the cutter, and serves as a guide to the pattern 
 which carries the work to be operated upon. The prin- 
 cipal use of this contrivance is to shape the edges of 
 
(*ui‘V(m 1 or irr('i»iilar iiK^tal work. Tin* cast ini;’ to 1)(‘ 
 finisluMl isfast(Mi(Ml — by (‘(aiKMit if small, and by (‘lam])S, 
 if lai\ 2 :e — to a i)ati(am haviiif;' exactly the shape re^piircMl 
 ill the fiiiisluHl work. 
 
 Fig. 156. Nicking Screws. 
 
 By movini» the ])atterii in coiita(‘t with the talile and 
 the mandrel, while the latter revolves, the ed^es of 
 the Avork will be shaped and finished at the same time. 
 By snbstitntino’ a conical cutter for a cylindiacal one, 
 the work may be beveled; by nsini>’ both, the edge may 
 be made smooth and square, Avhile the corner is bei^eled. 
 
 The tool shown in Fig. 157 might properly be called 
 a barrel saw. It is made by drilling in the end of a 
 
 Fig. 157. Barrel Saw, 
 
 st(‘(d I'od and foianing the t(‘etli with a file. To avoid 
 cracking in Bmijxalng a small hole should be drilled 
 throngh 1h(* sid(‘ n(‘ar tlu^ bottom of the larger hole. 
 To insure^ lln*^ fr(*(" working of the tool it shonld be 
 tnriK'd so lhal ils cniling (xlgc^ will be ratlun' thi(‘ker 
 Ilian lh(‘ ])orlion Ixdiind it. This tool shonld be made 
 in various sizes. 
 
HOME MECHAJ^ICS FOR AMATEURS 
 
 143 
 
 EASILY MADE SLIDE REST 
 
 While the most of the work to be done on the foot 
 lathe may be accomplished as expeditiously and quite 
 as well without a slide rest as with it, yet there are 
 some operations that are greatly facilitated b}^ means 
 of this tool. Boring, for example — a very difficult thing 
 to do with hand tools — may be done quickly and ac- 
 curately by using a slide rest. In gear cutting — de- 
 scribed in another part of this section — a slide rest is 
 essential. 
 
 Pig. 158. The Complete Slide Rest. 
 
 In the case of this tool, as well as others previously 
 described, the purchase of a well-made article is recom- 
 mended. A"et, if one has time and feels so inclined, he 
 mav make a reallv efficient slide rest with no other 
 tools than his lathe and ordinary turning tools. Figs. 
 158 to 160 inclusive represent a slide rest that may be 
 made in this way. Fig. 158 being a perspective view, 
 and Figs. 159 and 160 respectively longitudinal and 
 transverse sections of the tool carriage. 
 
144 
 
 MKCILANICS KOU A.MATKUKS 
 
 Tlie T-slia])(Ml (‘astiiii;', A, lias a loiii^il udinal slot, 
 which is ma(l(‘ T-shaj)C(l in (‘ross scMdion to i'(‘(*(‘iv(‘ 1h(‘ 
 head of the bolt that ('oiitiiu^s it in ])osiiioii upon the 
 plate fitted to the lathe bed. Tln^ veidieal (^ai's at oji- 
 posite ends of the casting’ i\n) bored to r(M‘(‘i\(‘ tin* (aids 
 of the rods, 11, npoii which the tool carriai;(^, C, slides. 
 
 The first operation in niakinj;* the slide r(‘st is to 
 make one side of the casting, C, perfectly plane. It is 
 
 Fig. 159. Longitudinal Section of Slide Rest. 
 
 Pig. 160. Transverse Section of Slide Rest. 
 
 tlnai chnck(Hl in the lathe with the plane side next 
 th(‘ fac(‘ plat(\ Three holes are bored through it, two 
 for th(^ 1 ‘ods, r>, and a smaller one for the screw, (i. 
 It is llnai (*hnck(‘d on an angle ])late, so that the holes 
 f(a‘ tli(‘ rods, I>, ar(‘ cMpially distant from tlu^ (‘enter liiui 
 of lh(i lath(% and IIk* hol(‘ for ih(‘ rod 1>, is bori^d very 
 (‘arcdiilly lo insure* IIk* parall(‘lisni of its sid(\s. Tin* 
 casling. A, is now pla(‘(*d upon a plane surface, and the 
 
HOME MECHANICS FOR AMATEURS 
 
 145 
 
 casting, C, is clamped to the ear at one of its ends, and 
 adjusted so that a line drawn through the center of 
 the holes is exactly parallel with the bottom of the 
 casting. The casting, C, is used in this manner as a 
 template for drilling both of the ears for the reception 
 of the rods B. It will be necessary to exercise great 
 care in drilling these holes, as it is of vital importance 
 to have the rods, B, perfectly parallel. 
 
 The casting, C, may now be tapped to receive the 
 screw, G, and the tool-carrjdng bar, D, may be fitted 
 to its place, and turned down and threaded to receive 
 the internallv threaded boss of the wheel, E. This 
 boss is fitted to the base of the casting, C, and is grooved 
 circumferentially to receive a split ring, F, the latter 
 being drilled to receive the ends of three screws that 
 project through the casting into it and prevent the 
 boss of the wheel, E, from moving lengthwise of the 
 hole, while the arrangement permits of the free rotation 
 of the wheel. The bar, I), has a head which is drilled 
 vertically to receive the tool post, and is provided 
 with a heavy feather at the top, which is received by 
 the slot formed by sawing into the upper portion of the 
 casting, C. To render the bearing of the bar, D, sonie- 
 Avhat adjustable, two screws pass through the casting 
 aboA’e the feather. The tool post is of the usual de- 
 scription, having a loose collar above the head of the 
 bar, I), and a nut below it. The mortise for receiving 
 the tool extends a little below the loose collar, so that 
 Avhen the tool is clamped the post and ring Avill also 
 be clamped. A slot is cut through the bottom of the 
 casting, C, into each of the guide rod holes, to permit 
 of adjustment in case of Avear by means of the screws 
 Avhich pass transversely through the slot. The ends of 
 
14G 
 
 WOMh] iMKCIIANICS ¥i)\l A^\\TK¥\IH 
 
 llie rods, 1>, are fastcauMl hy a similar <1(‘\ i(‘(‘. Thy s(‘T'(nv, 
 (), is ])reveiit(‘d fi'om (aid motion l)y a slioidd(‘r on tlie 
 outside of tlie (air at tlie (-rank (md, and a (‘ollai* on 
 tlie insidca Tlie rods, 1> and I), may lie mad(^ of stead 
 or of cold rolled iron; the latter Avill h(‘ tian^ (‘noni»li 
 without tnrnini*'. The eastini»’ may Ix^ (dth(‘i‘ of brass 
 or iron; a i>‘ood (]iiality of iron will jaadiajis ])rov(‘ the 
 most satisfactory. The slots may be cut with the 
 
 Fig. 161 . Boring Attachment. 
 
 saws descrilxal in a former article. The tools to be 
 ns(xl with the slide rest have also been previously 
 (h'scrilxxl. 
 
 In kit;. Kil is r(‘])r(‘S(mt(al a borini^* d(Ai(‘e whi(di will 
 lx* r(*adily nnd(*rstood without S]x*(dal d(*S(*rii)t ion. The 
 castinit, A, is titt(‘d to tlui tool r(*st so(‘k(*t and ])i*ovide(l 
 Avith a sliding bai*, l>, \\dii(di is like* tin* bai', 1), in the 
 slide* r(*st above* ele*scidbe*el, (‘xe‘(*pt in<»- that its ba(*k end 
 
HOME MECHANICS FOE AMATEUES 147 
 
 is rounded and provided with a pin which slides in the 
 slotted arm attached to tlie tail spindle of the lathe by 
 which it is moved, instead of havhi<>’ a moving device of 
 its own. With this tool, boring and some kinds of out- 
 side turning may he done. It is less expensive than 
 the slide rest and answers a good purpose. It is prob- 
 able that in making both these tools the services of a 
 mechanic provided with a planer or shaper will be re- 
 quired. 
 
 INDEX PLATES FOH GEAK CUTTING 
 
 There aie manv amateurs who would make their 
 own gear wheels were it not for the expense of pur- 
 chasing or the trouble of dividing and drilling the 
 index plate, which is the principal item in the ap- 
 paratus required in cutting small gears. 
 
 Of course an index plate may be purchased, but the 
 money thus laid out would go a long way toward pay- 
 ing for cutting all the gears that Avould ever be re- 
 quired l\y most amat(Mirs. 
 
 It is admitted that it is difficult to obtain absolute 
 accuracy l)y ordinary methods, but the plans here sug- 
 gested Avill probably give as uearh^ perfect results as 
 can be obtained without copjdng another index plate 
 or using a dividing engine. 
 
 The index plate, before being divided, should be 
 ■ nicely turned and fitted to the place it will occupy on 
 the lathe. Tliis will generally be on the larger side of 
 the cone pulley. 
 
 Two methods of graduating an index plate are il- 
 lustrated by the accompanying engravings. One con- 
 
148 
 
 iwm: ]\iKciiAxi(^s foii amai^ki i?s 
 
 sists ill l()(‘atiii|L> tli(‘ liol(‘s by iisiiijL>* |>a])(*i* s(*al(‘s wlncli 
 ai'(‘ ])riiit(‘(l from (aii»iii(^ dividiMl ])lat(‘S, and ari^, 
 forc^, Aery nearly aeimrati*. Tin* otlna' (‘(insists in divid- 
 ini» tlie plate by aid of a lari>(‘ ])a])(n' disk gradual (*(1 by 
 hand. 
 
 Vov the most of ])nr])()S(^s four rows of liol(*s Avill 
 answei'. The Ix^st nnndxa' of h()l(‘S foi' tin^ (lirf(‘r(mt 
 I'ows is as follows: 240, 200, 144, 122. 240 (‘an b(‘ 
 
 dividiMl as follows: 120, 00, 48, 40, 20, 20, 15, 12, 0. 
 AVith 200 divisions: 100, 50, 40, 25, 20, 10 and 5 may 
 be made. 144 divides into 72, 48, 2(i, 24, 18, 10, 12, 
 
 I) , 8, 0. 122 into 00, 44, 22, 22, 1 1. 
 
 The best method of dividing’ an imhvx ])late of whi(‘h 
 the Avriter has any knoAvl(Hl<»e, asid(^ from dn])lieatinf>f 
 another, or nsinj>* a dividing* enjL^im^, is shoAvn on the 
 next pai>e. A Avooden block. A, is attached to the fa(‘e 
 ])late of the lathe by means of screAvs, and turned doAvn 
 truly on the face and n])on the ed<;e. A portion of the 
 edji^e is turned to a suitable diameter for receivinjj^ a 
 (‘ertain len!L>th of paper scale, C. The other portion of 
 the is pressed by a brake shoe, F, Avliich is kept 
 
 II ] ) by a s(‘rew in the standard, 1). An index, E, is 
 slotted and secnixxl to the top of the standard, D, liy 
 a s(‘rew. To the fa(‘e of the bl()(‘k. A, is secured the 
 imh^x ])late, 11, and in front of the plate there is a drill 
 snpjiort whi(‘h tak(‘S the ])lace of the ordinary tool ix^st. 
 Tho drill is (‘a])abl(‘ of longitudinal as Avell as rotary 
 mol ion in ils sn])p()rt; it is driv(m l)y a Ixdt from the 
 (lriv(^ \\4i(*(d of IIk^ lalln*, and is inisluxl forAvard a lim- 
 il(xl (lislan(‘(‘ by lli(‘ handb^ swiv(‘l(‘(l to tlu^ end of the 
 drill S])in(ll(*. Tlui siz(‘ of lh(‘ di'ill Avill Ix^ i»()V(n‘n(xl 
 allo.!4(4 li(n‘ by I In* siz(‘ of IIkj plal(S bnl in any (‘ase 
 it should b(‘ as lari;(^ as |x)ssibl(‘, always b(‘aring‘ in 
 
HOME MECHANICS EOK AMATEUES 
 
 14!? 
 
 mind tliat the space between the holes should he of sub 
 ticient width to insure the recpiired strength. 
 
 That portion of the wooden block, A, which receives 
 the paper scale, C, is carefnllj turned so as to permit 
 the ends of the scale to abut ; the scale being very care- 
 fully cut so that its ends will join accurately and render 
 
 Fig. 162. Method of Graduating Index Plates. 
 
 the graduations of the scale tiniform throughout. The 
 scale is best attached to the block by means of paper 
 tacks or small screws. For the greatest number of 
 graduations given above, a two foot paper scale, or 
 two pieces of shorter scales, will be required. The 
 inches should be divided into tenths. The block should 
 be 7.04 inches in diameter where it is surrounded by 
 
150 
 
 IIOAIK MI^XUIANICS ]’OK AAIA'l'KUIlS 
 
 llie scale. Tlic diaiiK'lcr of lliat ])avl ciimaiLied l»y I lie 
 hi'ake slioc is n(»t liiiiilcd io any pari ictilar siz(“. 
 
 It is obvious tliat for drilliu*^ 240 liol<‘s cvci-y mark 
 oil tile seal(‘ must be brou,i>lit o])])osit(! tin* imb’x, J'], 
 and stopjied by means of llie brake, k', while a bob* is 
 drilled. After drillini*’ this row of liob*s, tin* row eoii- 
 taininj; 144 boles sbould be drilb“d, b*avinf>’ a siiaee 
 between it and tlie 240 row foi* tlie 200 row. for Ibe 
 144 row the ojx'ration is the same as that alri-ady 
 described, except that a scale divided into twi'lftbs is 
 used, and alternate graduations only are noticed. The 
 intermediate oiii's should be crossed out, so that the 
 scale will really be a scale of inches divided into sixths. 
 For the 132 row the block is turned down to 7 inches 
 diameter, and the scale last used is shortened to 22 
 inches and again applied to the block and used as 
 before. 
 
 After completing these rows of holes the drill is 
 moved to the space between the first and second rows, 
 the block is turned down to 6.36 inches, and 20 inches 
 of the paper scale first used (inches divided into 
 tenths) is employed. Every graduation on the paper 
 scale is used in this case as in the first instance. This 
 gives 200 divisions. 
 
 Th(i pap(*r scales recommended for this purpose are 
 I hose used by engineers and draughtsmen. They may 
 b(! obtaiiK'd for a f(*w cents from any dealer in mathe- 
 matical instruments. 
 
 In I'ig. 163 lh<* larg(‘r circle represents a disk of 
 payx'r which is carefully divid(*d into large spaces by 
 means of ordinary dividei*s, and the large spaces are 
 subdivided in llie sanu* way. 
 
 In tlie c<‘nl<‘r of (be |ia])er disk is i)lac(“d the ])late to 
 
HOME MECHANICS FOE AMATEUES 
 
 151 
 
 be divided, aud from the center of the plate rises a 
 stud, to which is accurately fitted the sleeve attached 
 to the eud of the radius bar. The radius bar extends 
 beyond the outer circle on the paper disk, aud carries 
 au adjustable sleeve, to which is accurately fitted a 
 
 drill which may be rotated by means of a small drill 
 stock. The sleeve that forms the bearing of the ra<lius 
 bar is shown in detail in the lower left hand corner of 
 the engraving, and the sleeve that receives the drill is 
 shown in the opposite corner. 
 
 While drilling, the radius bar is held in place by a 
 
152 IIOMK. MKCTTANICS FOU AMATFUKS 
 
 Avciii>lil or by inoaiis of a claiii]). Af((‘r (Irilliiiju: (‘acli liolo 
 tli(‘ l)ar is iii()V(m1 forward oik^ s])a('(* and s(M*nr(Ml l)y lli(‘ 
 Aveii>lit or (dani]). A\dH‘n om^ i*ow of liol(‘S is (‘oin])l(^t(Ml, 
 tlie sloovo wlii(di iiiiides ilie drill is niov(Hl toward tlio 
 renter of tlie disk^ and ilie o])(n'ation of dialling is ('ur- 
 ried on as before. this nudliod wliate^a^r errors may 
 exist in the <>i'adnations on the ])ai)er disk aia^ i>r(‘atly 
 redneed in the ind(‘x ])lat(^, and llie ])lat(^ ])rodn(‘(Hl will 
 be a(‘enrate enon<>li for most pnrposc^s if tlu^ work on 
 the ])ap(a‘ disk has been earc^fnlly don(‘. Tln^ smalh^st 
 plate should be at least three-sixtcHmihs of an inch 
 thiekj and the holes shonld not Ix^ dialled (piite throni»h. 
 Either iron or lirass may lie used for the disk. The lat- 
 ter works the easiest and will answer eA^ery purpose. 
 
 GEAE CUTTING ArrAEATUS 
 
 The index plate. A, is attached to the larger of the 
 ])nlleys on the mandrel of the lathe l)y means of three 
 or four screAA s, and the stop, C, provided Avitli a point 
 Avell fitted to the holes in the plate, is held in position 
 on the bed plate, B, by a screAV X3assing throngh a slot in 
 the foot into the bed piece. The stop, C, is capable of 
 siiringing sufficiently to admit of aa ithdraAA ing the pin 
 fi'om the hole in the x>hite, and it is strong enough to 
 hold the ])late Avithont vibration. Tavo standards, G, 
 moiint(xl on the ])late, B, snjiport pulleys oxev Avhich 
 tin* diaving b(dt runs. The gear (aitter head consists of 
 a casling, 1), filt(‘d to the tool ])ost of the slide rest, 
 and th(^ mandixd, E, i)rovid(xl with a ])nlley and 
 nionnj(xl on (‘arcdully litt(‘d c(mt(‘rs in ihe (-asting. The 
 casi ing, I ), has ni>on ojiposih^ sid(‘S, m^ar tln^ upper end, 
 (*ai‘S (as shown in fdg. Ibr)) for rcHaaving the jinlleys, 
 
HOME MECHANICS FOR AMATEURS 
 
 153 
 
 Fig. 164. Apparatus for Gear Cutting. 
 
154: 
 
 IIOMK i^II^XJIIAXKJS VOU AMAIManW 
 
 f/ />, wliicli i;ni(l(^ ihv driviiii; l)(*ll, so Dial IIk^ 
 may 1)(^ rcanovcMl aci'oss lli(‘ fa(*(^ of I Ik* \v1k*(*I ))(*iiii» rui 
 wiflioTit (‘liani»iiij» IIk* l(*iision of 11k* ))(*lt. TIk* (*x- 
 ti*(*me end of tlie loop formed l)y IIk* l)(*lt is sii])port(*d 
 
 Fig. 165. Detail of Gear Cutter. 
 
 l)y the pulley^ IT, mounted on a standard rising from 
 the lathe bed. The standard may be placed far enough 
 from the slide rest to admit of putting the tail stock 
 l)etween it and the slide rest in case it should be neces- 
 sai'y to use the tail stoi'k for supporting the work. 
 
 Detail of Pulleys. 
 
 Cutters. 
 
HOME MECHANICS FOR AMATEURS 
 
 155 
 
 The mandrel, E, is provided with a collar and a nnt 
 for clamping the cutter, E. It will be noticed that the 
 cntter comes exactly opposite the line of the lathe cen- 
 ters, and that it occnpies abont the same position, in 
 relation to the tool post, that the point of an ordinai\y 
 turning tool does. The cntter, E, is shown in Eig. KtB, 
 enlarged. The upper view represents the side, the 
 lower view the edge of the cntter. It has but a single 
 tooth and is adapted to brass and similar alloys only. 
 It maj^ be sharpened by grinding. When iron or steel 
 is to be cut the cutter should have several cutting edges, 
 and the mandrel, FI, should have a larger pulley, as 
 more power will be required and tbe speed must be 
 slower. By setting the slide rest at an angle bevel 
 gears may be cut. 
 
 HINTS ON :\IODEL MAKING 
 
 It is a simple matter for au experienced instrument 
 maker or macbinist to ]U'oduce a tine model with turned 
 shafts, cut gearing, true pulleys, and smooth working 
 cams, but it is quite another thing for an inventor, 
 Avithout tools or materials, to embody his ideas in a 
 Avorking model even though he may have a mechanical 
 taste. 
 
 It is fair to suppose that cA'ery mechanical inA’entor 
 in these days of cheap machinery possesses some sort 
 of a lathe, as these iudisi>ensable machines are noAv 
 made for prices Avithin the reach of almost aiiA- one. 
 
 It is quite evident, from an inspection of the models 
 of the Patent Office, that most inventors who under- 
 take to make their oavu models expend a great deal of 
 labor Avithout corresponding results. In the matter of 
 
150 
 
 irOMF. MFCniAXK^S Foil IIS 
 
 <»(‘ariiim, for iiisiaii('(‘j oii(‘ will wliitlF* liis w1h*(‘1s in 
 Avood, anollKn^ will boi'roAv liis i»(^ai'iii!L> from soim^ (1(‘- 
 fiincl (‘lo(‘k, Avliile sOll aiiollior will ])iir('Iias(^ I'c^ady- 
 made avIkhOs from om* of oni' w(dl known fiimis makinij^ 
 a bnsim^ss of fnrnisbin<> ])arts of imxbds. 
 
 Of the tlir(‘o nu^tliods of obtaining’ tbo ^(^aia‘ni»: tlm 
 latter is undoubtedly iln^ best, as all that is nec-essary 
 to l)e done, in (‘ase of tlie (-ast <»(^ar avIkmOs, is to bore 
 them and tile np tbe t(Hdli, and as tin* (*nt i»ear Avliecds 
 
 Pig. 167. Friction Gearing 
 
 are iG^enerally bored, the shaft may be fitted Avithont 
 fnidlna' Avork on tbe Avheids. It is, lioAvever, seldom 
 absolntidy mxx^ssary to use toothed j[]^earin«;, as rotary 
 mol ion may b(^ ix^adily transferrcxl by suitable fri(‘tioii 
 aa'Ikx'Is ot* by <»i'oov(‘d or s])roeket Avheels and a round 
 b(‘lt. 
 
 1()T shows a form of fiacdion j[*’earin<ij Avhich is 
 both sim])le and (idVel i v(*. Th(‘ lai\i»(‘r Avheel is simply 
 a disk of slnxd brass having* round(Ml (xl<»("S, and boss 
 
HOME MECHANICS EOK AMATEUliS 
 
 157 
 
 spun or soldered on, and a smaller wheel consists of two 
 swaged disks of steel having their convex faces sepa- 
 rated by a metal washer a little thinner than the large 
 wheel. These three members are secured to a common 
 boss by spinning the end of the boss partly over one of 
 the disks, as shown in the sectional view. No. 2. This 
 form of friction gearing is noiseless and runs strong 
 enough for the requirements of almost any model. 
 
 Figs. 168 and 169 show a form of sprocket wheel 
 
 Fig. 168. 
 
 Sprocket Wheels. 
 
 Fio. 169. 
 
 Avliich is readily made and is almost as positive in its 
 action as gearing. In this case the two wheels are 
 alike ; they consist of disks of sheet metal nicked to a 
 uniform depth from the edge, and the arms thus formed 
 are bent alternately in opposite directions, forming a 
 groove for receiving the round belt used in transferring 
 motion from one wheel to the other. It is evident that 
 a belt cannot slip on a wheel of this construction. 
 
 Fig. 170 shows a form of friction geainng for trans- 
 ferring motion at right angles, and for imparting a 
 variable speed to a shaft from another shaft running at 
 
158 
 
 JlOiMi^] MJailA.NICS Fi)\l .UWTKIU^ 
 
 a luiiforin rat(^ Tlie lar!L»(* wIkm^I in lliis inslanc(‘ is 
 luerc^ly a ])lan(^ disk of in(*tal inouidfMl in ili(* inaim(*i‘ 
 already described. Tlu^ sinall(‘r w1h‘(* 1 is a i»i'<)ov(m 1 
 metal ])ulley snrronmbMl by an (‘lasti(* rnblxn' riniL». 
 Tin’s is ])ress(Ml with more or b^ss for(‘(^ ai^ainst tln^ im*- 
 talli(‘ disk, and its S])eed may b(^ vaincMl by moving it 
 towaiul or away from the axis of tln^ <lisk. 
 
 As to the matter of irref»nlar motion nsnally im- 
 ])arted by cams, it is difficult to make a cam in tlie ordi- 
 
 Fig. 170. Transferring Motion at Right Angles. 
 
 nary Avay with the millino^ machine, and there appears 
 no verw simple way of cutting them from solid castings. 
 There is, however, a simple way of building them up 
 from readily obtained materials. 
 
 hbg. 171 shows a cam consisting of a cylinder of brass 
 or a short S(H*tion of brass tubing provided with two 
 In^ads and monnt(‘d on a shaft. The (‘am groove is laid 
 out on this surface*, and 1 wo ])arallel ])ieces of sepiare 
 brass wir(‘ are* solde*i‘e*d fo the* sniTae‘(* of the e'ylinder, 
 or fasle*ne*el by nie*ans of se‘re*ws. The*y are ])lae‘e*el uni- 
 formly dislant llii'onghoni I he* entire e‘irenmf(*rene‘(* of 
 tliei cylinele*r. 
 
HOME MECHANICS FOR AMATEURS 
 
 159 
 
 Fig-. 172 shows a cam built up in the same way on the 
 face of a disk. 
 
 As to shafts, the model maker may save himself much 
 labor and expense by using Stul)bs’ steel for small 
 shafts, and cold rolled iron for larger ones. Either 
 the steel or iron may be bought in one and three foot 
 lengths. 
 
 Almost anything in the wa_y of parts of models may 
 be purchased ready for use, so that all the inventor need 
 do is to combine them and mount them on a suitable 
 
 Fig. 171. Drum Cam. Fig. 172. Disk Cam. 
 
 frame; but even so simple a matter as a wooden frame 
 for a model sometime proves troublesome. 
 
 The small tenons and mortises are difficult to make, 
 and the frame to be strong enough to bear handling 
 must be made so heav}' as to be entirely out of propor- 
 tion. A simple and easy method of securing the joints 
 of small frames is to clamp the parts in the position 
 they are to occupy in relation to each other, and then 
 drill, with a sharp twist drill, two holes through one 
 piece from side to side and into the end of the abutting 
 piece, then inserting two hard wood pins, having previ- 
 ously coated them with glue. This makes a joint far 
 stronger than the mortise and tenon, and it is very 
 quickly done. 
 
IGO 
 
 ilOMK MI^XUIANK^S Vi)\l AMA^M^RS 
 
 METAL SIMXMNX; 
 
 Tlie opcn-ation of s])iiniiii!L» nuMals, alllioii^li (‘X(‘(‘(‘(l- 
 simple and (‘apal)le of Ixaiii* j)ra(‘l i(‘(Ml to advan- 
 ta<»’e ill almost every slio]), and also by (li(‘ amatiair m(‘- 
 clianie njion tln^ foot latlu^, is not <>’(‘n(M'all y inuba'stood. 
 One reason for this is that the artisans who follow this 
 
 Fig. 173. Metal Spinning. 
 
 branch of m(*chani(‘S as a. business nsnally condind it 
 niKha* locki^l doors, and it is \yith considerable diffi- 
 culty that theamat(Mir in sear(*h of information on this 
 and kindri'd subj(M‘ls (‘an oblain (uitraiu'c^ to one of 
 lli(^s(^ ('slablishmcmts. ''PIk* r(‘ason of ihis S(‘cr(M‘y is 
 plain (mough, as (he ^‘kink’’ or* ^‘wrinkh*/^ or, in plain 
 
HOME MECHANICS FOE AMATEUES Id 
 
 English, the knowledge required to do the mechanical 
 part of spinning is so slight that secrecy is the only 
 protection. 
 
 The tools required are few. They consist of a lathe ; 
 a form or mould on which to shape the article; a tool 
 rest with a series of holes for receiving a pin to keep the 
 
 Fig. 174. 
 
 Fig. 175. Spinning Tools. 
 
 tool from slipping, and a few spinning tools or burnish- 
 ers of different sizes and shapes. 
 
 The lathe the amateur is supposed to possess; the 
 tool rest he may easily make ; and the only other addi- 
 tion to the lathe will be a back center of the form shown 
 in Fig. 174. This form of center answers as a step to 
 the work holder, and will bear considerable pressure 
 without undue friction. 
 
 The tools required are shown in Fig. 175. These are 
 
H;2 ilOMK MKClIAN’ ICS KOI! AMA'I’KKKS 
 
 sim])ly liard sic'cl hiiniislicrs of I lie form sliowii, jiiid 
 Viiryiiifi' in sizo with the siz(* and kind of work to h<* 
 <loii(*. The siz(‘ yiven in the en^i-ivini; is about ri^ht foi- 
 amateur work on a foot lathe. No. 1 shows i!i two 
 
 Fig. 176. Fig. 177. 
 
 The Forms in the Lathe. 
 
 viow s a ))all tool. No. 2 sliows hath sido and edge views 
 of a (:iirv(*d iooL No. shows a i)laiii i-onnd biiriiislier. 
 In soiiKi inslnii(*(‘s ii- may l)(‘ n(‘(*(‘ssary fo make tools of 
 diHViMMil foniis. ’ TIk* o|)(‘i‘alor will Ix^ gnidcxl in tlie 
 sel(*clion of his (ools by (h(‘ paidienlar work in liand^ 
 
HOME MECHANICS FOR AMATEURS 163 
 
 and practice will bring new suggestions as to tlie tools 
 and the manner of using them. 
 
 The materials generally used in spinning are brass, 
 copper, zinc, hritannia metal and lead. All of these 
 may be worked on the foot lathe, but perhaps the ama- 
 
 Fig. 179. Fig. 180. 
 
 The Movement of the Tool. 
 
 teur will dorive the most satisfaction at first by using 
 hritannia metal, as it works easily and does not require 
 annealing. Articles in this metal also present a hand- 
 some appearance when done, whether simply polished 
 
 Fig. 181. Spinning without a Form. Fig. 182. Spinning a Ring. 
 
 or plated. Zinc must be spun quite hot. Articles of 
 brass, if of considerable depth, must be annealed when 
 partly done. 
 
Tlie form on wlii(‘li tlu^ im^lal is s])uii ma,y lx* 
 liard or soft wood oi' nudal. A !L»()od (*los(^ i»i'ain(‘d ])in(‘ 
 answers as av(‘11 as anvtliinin^ for most ])iir|)os(‘Sj and is 
 vcaw rc^adily tiirmnl to tlie recinired form. It mav 
 attached to tlu^ fa(*(‘ ])lat(% 1>, and tlu^ disk to b(‘ s])iin 
 may he held against it at first hv a liard wood oi‘ medal 
 ])i(‘co, (', ;is sliowii ill Fiji's. 17<! and ITT, wliicli is forced 
 aiiainst tlie disk by tlie tail center. After the spinning' 
 is a little advanced, a cipi-sliajied bolder is ajijilied, as 
 shown ill dotted lines in l''ig'. ITT. Sonietinies the 
 
 Fig. 183. Concave Reflector. 
 
 Fig. 184. Cup. 
 
 holder is secured by a holt that runs through both it 
 and the form or mould, as shown at D, Fig. 1T8. In 
 some cases a little rosin is applied to the form to in- 
 crease the friction, hut this is rarely necessary. The 
 motion of the lathe should he quite rapid, and the disk 
 should receive a coating of grease (lard or heavy oil) 
 before applying the hnrnisher. A very strong solution 
 of soap may h(‘ used instead of oil. The position of the 
 workman and I he manner of holding the tool may be 
 seen in k'ig. IT^k It will be noticed that the iiin in the 
 tool res! serves as a fnlcrnm for the tool, which must 
 be brongiil will) considei'able pressure against the siir- 
 
HOME MECHANICS FOR AMATEURS 
 
 165 
 
 face of the disk. This pin is moved forward from time 
 to time as the work advances. The movement of the 
 tool may be seen in Figs. 179 and 180. The shape taken 
 by the metal in front of the tool will also be seen. In 
 swinging the tool toward the form it is moved in the 
 
 direction of the arrow as shown in Fig. 179, and it is 
 carried back as shown in Fig. 180. This last operation 
 is very essential to the proper fitting of the mould, and 
 it also thickens the metal. Too much should not be 
 attempted at a time. A succession of quick movemeuts, 
 as indicated in Figs. 179 and 180, under a moderate 
 pressure is much better than to do a great deal of exe- 
 cution at a single stroke. Should the metal tend to 
 
160 
 
 iroMK MK(:ilANI(;S foi; AMAI’FUKS 
 
 vibrato or biickl<‘, a |>i<>c(* of wood may !)(> a])])li<“<l to tlie 
 back witli tlic loft liaad, as sliowii in 1-^^. 178. 
 
 Tlie niotbod of spiiuiiiif' a cii]) or pol witliont a form 
 is illnstratod in Fi,<«-. 181. lion* tlio im-lal is sni)]»orlo<l 
 bj a plain cylindrical mandrel, and is tirst spnji into 
 
 tlio form indicatod by the dotted lines, and then bring- 
 ing tlio l»nrnisb(‘r on the return stroke only to the 
 slionidor winch forms tin* larger ])art of the ves- 
 sel. For small work on the foot lathe the liandles 
 of the tools n(*ed not, b<‘ as long as repn^sented, 
 in t'ig. I7.‘>. 'I'Ik' l(‘nglb commonly employed for wood 
 turning tools will answer. 
 
 To spin a ling, a mandrel like that shown in Pig. 
 
HOME MECHANICS FOR AMATEURS 167 
 
 182 will be reciiiired. A plain flat ring placed between 
 the shoulders of the mandrel is pressed upon by the 
 roller seen above the mandrel until the ring assumes 
 the desired form. Napkin rings are made in this way. 
 
 Fig. 190. Base. 
 
 Fig. 191. Vase. 
 
 Fig. 183 shows a concave reflector. Fig. 184 represents 
 a simple cup formed of two pieces. Fig. 185 represents 
 a small vase made of three pieces, the smaller end of 
 the upper or conical part and the upper portion of the 
 
1C8 
 
 HOME MECHANICS F()|{ AMATEUHR 
 
 base i)iece l)eiiif>’ soldered in a sidierical connecting 
 piece. Tlie two lialves of the ball, Eig. 18(!, are made 
 upon the saine form. Tlie edges are beveled and sol- 
 dered together. Tlie i)itcher, Thg. tST, is made of five 
 span pieces, a short cast and turned ])iece that nnites 
 it to its base, and a handle made of s(piare wire. The 
 card receiver. Fig. 188, has a span top and base, and 
 a cast standard. The Aase, Fig. 18!), consists of four 
 spun pieces and three legs of S(piare Avire, uniting the 
 body Avith the base. Fig. 1!)0 shoAvs a base for a mag- 
 netic needle or other small apparatus, hdg. 191 repre- 
 sents a vase composed of seA-en span pieces and tAvo 
 handles of s<piare Avire. ^lore comidex (;xamples of 
 Avork done by the ]n'ocess of spinning might be fur- 
 nished. The ones giA'en are undoubtedly sufficient to 
 enable the amateur to get an idea of the endless variety 
 of articles that may be made by this simple and easily 
 acquired art. 
 
PART lY. 
 
 MODEL ENGINES AND BOILEBS 
 
 A HOME-MADE STEAM ENGINE 
 
 A STEAM ENGINE carefully made is a piece 
 of mecliaiiism to be proud of, no matter 
 what its particular design may be. A 
 double-acting engine of good proportion, 
 with a bored cylinder and forged crank and crank 
 shaft, and other parts made in keeping, is, of 
 course, the better form of steam engine to make, but, 
 as we are presuming that not every amateur has the 
 facilities for building such an engine, a description of 
 a simple single-acting engine which could be made by 
 any boy handy with tools is given. It can be made a\ ith 
 an ordinary light foot lathe, as no boring is required, 
 nor is there any turning to be done that does not come 
 Avithin the range of such a lathe. 
 
 A vieAV of the engine and the boiler and engine is 
 given, and also a sectional view shoAving the construc- 
 tion of the valve and valve-operating cam, and the 
 steam passages in the base. 
 
 The cAdinder consists of a piece, A, of mandrel-draAvn 
 steel tubing (Avhich needs no boring) 2^ inches long 
 and i inch internal diameter. The thickness of the 
 metal forming the tube is tV inch. This piece of tub- 
 ing is fitted to a boss, a, about i inch high, formed 
 on the brass block, near one end. This block is 1^ 
 inches long and i inch thick, and is provided Avith 
 lugs for receiving screws, by which it is attached to 
 the base plate. In this block are formed the steam 
 
 [ 169 ] 
 
170 
 
 WOMK MKCIIAXICS FOI? AMATFUI^S 
 
 l)assai>“(^Sj h (% and valve (‘lianilxa'. Tliis liol(‘ drillcMl 
 from tli(‘ front backward and foianin<»’ tin* ])assa|L»(*, />, 
 i'(H‘eives tlu^ stcniin sn])])ly l)il>e, H. A liol(^ is drilb'd 
 from tlie rc^ar (md of tlu^ block forwai'd to a point 
 about o])posite the (‘ent(‘r of the cvlimba*, forming with 
 the hole, d, the steam dm-t, r* d. Near tln^ r(‘ar (md of 
 the block is drilled a tV hoh^, fi*om Ixnnmth, which 
 forms the valve seat, c, just Ixwond tlu^ ])assa,^(‘, h. A 
 tV inch hole is startcxl at the valv(‘ scmt, c, and con- 
 tinued to the to]) of the block. This smalhu' hoh^ is 
 counter-bored from tlu^ top with a in(*h drill, leav- 
 ing* the vahm (diamber. The counter-borcxl jx)rtion of 
 this hole receives the plug, /, which is bored longitudi- 
 nally to receive the valve stem, //, of the conical valve, 
 e'. The valve stem is about 3} inches long, and is 
 provided with the adjustable collai*, //, between whicdi 
 and the plug, /, is placed a spiral spring which tends 
 to keep the valve normally closed. The steam pas- 
 sages, 1) and c, are closed with screw plugs, as shown. 
 
 To the steel tube which forms the cylinder is fitted a 
 piston of cast iron. It is about 1^ inches long and is 
 packed by the steam or water contained in the grooves 
 in the piston. The upper end of the piston is slotted 
 to receive the loAver end of the connecting rod, which 
 is pivot(xl tlnu'ein upon a ^-inch pin passing through 
 the piston and lower end of the connecting rod, as 
 shown in dott(xl lim^s in the sectional view. 
 
 Tlie brass blo(‘k whi(‘h supports the cylinder has 
 lugs on op]X)sit(^ sid(‘s rcxxdving screws wdiich pass 
 tlii'ougli tli(*m into base ])late. Tliis plate is 4 
 incli(*s w id(^, 5 incli(‘s long and i iin^h thick. At the 
 r(*ar of I lx* valve* chamb(*r is a post fornuxl of a -l-iiudi 
 scpiare* brass rod IJJ inches long, securcxl to the base 
 
HOME MECHANICS FOE AMATEUES 171 
 
 plate by a screw passing upward through the plate 
 into the end of the post. A similar post is placed near 
 the rear end of the base plate. The ends of the posts 
 are squared in the lathe. Both posts are bored trans- 
 
 Fig. 192. Simple Steam Engine. 
 
 versely near the top to receive the shaft, which is ^ 
 inch in diameter and 5 inches long. The space be- 
 tween the posts is 2 inches, and the distance between 
 the shaft and base plate is inches. On the shaft, 
 between the posts, is placed the iron fly-wheel, which in 
 
172 HOME MI'X'IIANIOS FOIt AMA'I’HKUH 
 
 the present ease' consists of an old valve wheel 41 inches 
 in diameter, hashed to lit the shaft and fastemsl Avith 
 a set screw. 
 
 The (‘ 11(1 of the shaft which ])rojects lu'yond the ])()st 
 OA‘er the cylind(*r carri(‘s a |-inch crank on which is 
 placed a conne(*tinf>’ rod. This rod ni(‘asni'(‘s If inch(*s 
 betAveeu tlie centers of the holes for the crank ])in and 
 the ])in in the ])iston. 
 
 In the side of the cylinder are drilled thr(‘e iV ineli 
 holes in a horizontal line, and close tos>eth(‘r to foian 
 the exhaust jiort of the (‘njiiiu*, Avhich is (‘ntirely nn- 
 coA'ered hy the ]nston avIk'ii it is in the position shown 
 in the eiij’ravinf^. The exhaust r(‘niains op(*n for about 
 a (piarter of the reA'olution. This jiort is left exposed 
 for clearness, but it may he covered hy a hollow ring 
 Avhich encircles the cylinder and receives an exhaust 
 pipe. 
 
 On the left shaft is placed a cam, in whose boss 
 there is a circumferential groove, and upon the upper 
 end of the valve stem is placed a fork, the upper ends 
 of Avhich slide in the groove in the boss of the cam. A 
 stud inserted in the fork has upon it a roller which 
 rolls on the higher part of the cam and opens the Anlve 
 at the prop(*r instant. This cam opens the valve just 
 before the piston reaches the lower limit of its stroke, 
 and allows the valve to close just before the exhaust is 
 op(‘ne(l by the piston. 
 
 4'he boiler of this engine consists of a copper float to 
 b(‘ found in the niark(‘t, ma(l(‘ by an electrolytic de- 
 posit of coj)])er. Such a, float forms a seandess boiler 
 ca])abl(( of withstanding a gr(“at j)ressure, say 100 
 y»(»nn(ls. The Ixtilcr is mounted in a tri]) 0 (l made of 
 band iron and is furnislu'd with a safety valve ^ inch 
 
HOME MECHANICS FOK AMATEUES 
 
 173 
 
 in diameter, the lever of which is about 2 inches long, 
 and graduated and weighted so that it will blow off at 
 35 pounds, thus insuring perfect safety. (The ordinary 
 copper float is not recommended.) A brass steam pipe, 
 I inch internal diameter, is screwed into the safety 
 
 Fig. 193. Simple Steam Engine. 
 
 valve casing below the valve sat, and has at its end a 
 miniature angle valve which is connected to the engine 
 by the inclined pipe, and by elbow and nipple which 
 extends into the base. As the angle valve is a trouble- 
 some piece of work, an ordinary stop cock is recoin- 
 
174 IlOiMK MECHANIC'S EOlJ A.MATKIMIS 
 
 in(Mi(l(Ml in its stead. It slionid l»(‘ ])lac(“d in tlie in- 
 clined ])i])e. 
 
 Tile best Imrner for tliis boilin' is an Arn^and jjas 
 Itnnsen burner like that sliown. Of course an aleoliol 
 lam]) \yill answer, bnt it is not as safe as the "as 
 bnriier. 
 
 Itolli enj>ine and boiler shonld be mounted on a 
 suitable basi* board. 
 
 The engine is capable of inakiu" a thousand or 
 twelve hundred revolutions jier minute. It must be 
 well balanced for Ibis si>eed. 
 
HOME MECHANICS FOR AMATEURS 175 
 
 The boiler is filled when cold through the safety 
 valve opening by means of a funnel having a slim cor- 
 rugated tube. The boiler should be about two-thirds 
 full of water at the start. 
 
 It is obvious a larger engine could be made on the 
 same principle; but the front support for the shaft 
 should be made A-shaped and placed next to the 
 crank, and the cam should be placed between the sup- 
 port and the fly-wheel ; the shaft support would then 
 extend over the cylinder-base. 
 
 A SAFE WAY TO RUN A SMALL ENGINE 
 
 Almost every youth at some time in his life has 
 coveted a steam engine, or some other motor having 
 energy and ability to move of itself and to impart mo- 
 tion to other machines, but through fear of fire from 
 the lamp used to generate steam, or anticipating pos- 
 sible explosions, has been obliged to forego the pleasure 
 of being a boy engineer, and seek amusement in other 
 directions. Every boy can own a steam engine, since 
 one can be purchased for 50 cents, fl, |2 or more, and 
 the engine can be run with safety by means of com- 
 pressed air. Any engine that will run by steam will 
 run equally well with compressed air. 
 
 Rut how is the compressed air to be furnished and 
 stored for use? There are very few families without 
 bicycles, and every bicycle requires a pump for in- 
 flating the tire; why not use the same pump to com- 
 press air for an engine? The boiler constitutes a small 
 reservoir, and an auxiliary reservoir may be connected 
 with the boiler by means of a small rubber tube. The 
 auxiliary reservoir may consist of a piece of strong 
 
17G 
 
 TIOMK MfiCTTANTCS FOR AMATEURS 
 
 3-incli s<ilvanize(l iron leader, with caps soldered on the 
 ends, with a small tube inserted at any (*onv(mient 
 point to receive a bicycle valve, and another small 
 tube to receive the piece of small rnl)ber tnbinj]^ which 
 forms the conne(*tion between the reservoir and the 
 engine or the boiler belonging to the engine. 
 
 This boiler and reservoir when pnm])ed np as mnch 
 as possible by ordinary exertion, will run the (mgine 
 while driving the boat for about 15 minntes. The (‘aps 
 to the reservoir mentioned are made conical so that 
 the reservoir may be drawn in the water after the boat, 
 the connecting rubber tube forming the hawser for tow- 
 ing the reservoir. 
 
 If it is desired to rnu a stationary engine with com- 
 pressed air, the reservoir may consist of a tin can. A 
 1-gallon varnish can answers very Avell, bnt it can he 
 forced out of shape and even exploded unless it is en- 
 cased in a strong wooden box fitting it closely and put 
 together with screws. 
 
 A MINIATURE CALORIC ENGINE 
 
 The hot air engine is not a very recent invention. A 
 number of engines of this class, of different sizes, were 
 devised and nse<I in the early part of the present cen- 
 tury, and in the latter part of the last century there 
 were in existence engines constructed to be operated by 
 the expansion of air. 
 
 Nothing in the way of a motor, aside from a wind- 
 mill or wat(*r wh(“(‘l, can he more simple than this, and 
 it is a pity ihat it is not cai)ahl(' of moi'e general ap- 
 ])Iica(ioti. M(»tors of tliis kind have Ikkui used to some 
 exieiit for driving ligld, machin(‘i-y, and they have been 
 largely employed in pumping wat(“r. 
 
HOME MECHANICS FOR AMATEURS 177 
 
 Quite recently caloric engines have been made in the 
 form of a toy, as illustrated in the following engrav- 
 ing. In the motor here shown, the air contained in 
 the expansion cylinder is alternately heated and cooled, 
 and no fresh air is introduced. This action is so rapid 
 
 Fig. 195. Small Caloric Engine. 
 
ns 
 
 IIOMI*; MKCIIAXICS KOI; A,MA'l’h:ri;S 
 
 ill a small (“iinim* tlial Ilia ci-ank sliafi can make (lOO or 
 70(1 rcvoliilioiis a miimlc. in cxamiiiini- Hu* sectional 
 vi(“\\s (2, ;? ami 4, K’ifi'. 100) a j^ood idea of the e(mstrne- 
 tion and operation of the motoi- may he ohtaiiH'd. In 
 
 P^iG. 19f). Sectional Views of Small Caloric Engine. 
 
 l)ri(*r, tli(^ lari»(‘i‘ and lonj^ca* of tlie two (‘vlinders (the 
 (expansion cyliinh*]*) contains a lon<>‘, Iiollow piston 
 call(*d I ‘d ransIVi* pislon-’ wlii(‘li fils 1 he (‘vlindca' very 
 loos(dy. 1\) lliis |)islon is at(a(‘li(Ml a I'od (\\l(nulint>‘ 
 I liron^^li a clos(* iii I ifii; sI(m*v(‘ in tln^ iop of ilu^ cylinder^ 
 
HOME MECHANICS FOE AMATEUES 179 
 
 the piston rod being provided witli a connecting rod 
 fitted to the crank at the middle of the shaft. The up- 
 per part of the expansion cylinder is furnished with a 
 Avide flange forming a cap Avhich fits over the sheet iron 
 fire box, and to the top of the expansion cylinder are 
 secured the standards in Avhich is journaled the crank 
 shaft. 
 
 To the flange is attached the jiOAver cylinder, Avhich 
 is shorter and smaller in diameter than the expansion 
 cylinder. This cj’Iinder is provided Avith a piston to 
 Avhich is pivotally connected the loAver end of a connect- 
 ing rod, the upper end of Avhich receives a crank pin 
 projecting from one of the fly AA’heels at right angles to 
 the transfer piston crank. A hole bored in the flange 
 connects the expansion cylinder and the bottom of the 
 power cylinder, as shoAvu in No. 2, Fig. 190, and the 
 outer end of the hole is stopped by screAV plug Avhich 
 can be removed for cleaning the hole, should it become 
 stoi)pod by oil or other Avise. 
 
 An alcohol lamp is provided for heating the expan- 
 sion cylinder, it being placed in position to heat the 
 loAver end of the cylinder, as shoAvn in the larger view. 
 The top of the lamp is provided Avith a hemispherical 
 cavity, at the bottom of Avhich is the aperture for filling. 
 The stopper consists of a marble dropped into the 
 hemispherical cavity and serA'ing the double purpose of 
 stopper and safety valve. 
 
 The expansion and poAver CAdinders contain a certain 
 amount of air Avhich is neA’er changed during the op- 
 eration of the engine, except by expansion and contrac- 
 tion. Heat having been applied to the loAA’er end of 
 the expansion cylinder, the engine is started by giving 
 the crank shaft one or tAA’o turns in the direction indi- 
 
180 TIOJMI^ IMKCIIANICS FOK A:yiATFlIRS 
 
 oated hy tlie ari'ows on tin* rims of tlu^ fly wlnuds. Tlie 
 air at tlu^ io]) of ilie (\x])ansion (‘vlimha* is lransf(a*r(*(l 
 to tlie lower end of tln^ (*vlind(a' by tli(‘ fransf(*]‘ ])iston 
 as it rises; at tlie sanu^ tinu* ])ow(a' ])islon (b^seimds, 
 and by this time tlie air is lu^atcMl in fli(‘ lower ]>art of 
 the ex])ansion cylinder and be;L;ins fo (‘xjiand. The 
 ])ower ])iston is in position to be ])nsh(Ml nj) by the air 
 pressure. As the ])ower jiiston reaeln^s the n])])(a‘ (Mid 
 of its stroke, the ti*ansfVr piston dc^secMids and transf(M‘s 
 the heated air to the n])i)er end of the (Mxjiansion (*ylin- 
 der, where it is cooled, thus r(Hln(Mni>’ the ])r(‘ssnr(^ and 
 allowino^ the ])ower ])iston to desc(Mid ai>ain. This op- 
 eration is ri^peated at every stroke. It is almost impos- 
 sible to believe that the air can be heated and cooled 
 so rapidly. 
 
 The efficiency of the motor can be increased by sur- 
 rounding the upper portion of the expansion cylinder 
 by a Avater jacket provided Avith a Avater supply pipe 
 at the bottom and a discharge pipe at the top, as 
 shoAvn in No. 5, Fig. lOb, and keeping a continual floAV 
 of cool Avater through the jacket. When the motor is 
 used for pumping, the Avater is forced through the 
 jack(d. 
 
 This little motor is only a toy, but it A^ery completely 
 illustrat(^s the princi])le of one of the most successful 
 hot air enginc^s (wer deviscnl. ‘ If the reader is mechan- 
 ically inclin(‘d, he may make a motor on this plan on a 
 nimdi lai‘g(M' S(‘ale, and us(^ it for driving macdiincuw. 
 Th(M'(‘ can b(‘ no doubt about its siuMM^ssful construc- 
 tion or o])(M'ation, if it is mad(^ airtight and the bear- 
 ings and friction sni‘fa(*(‘s ai'(‘ made to run frcH^ The 
 j)ro|)ort ions may b(^ about tlu^ same as shown in the 
 cnt. 
 
HOME MECHANICS FOK AMATEURS 181 
 
 The dimensions of tlie motor from wliieli the views 
 were made are as follows: 
 
 INCHES 
 
 Length of expansion cylinder 4f 
 
 Internal diameter of expansion cylinder li\ 
 
 Length of transfer piston 2\i 
 
 Diameter of transfer piston 1^ 
 
 Length of power cylinder If 
 
 Diameter of power cylinder fi 
 
 Lengtli of cranks tV 
 
 Diameter of fly wheels 3 
 
 Height of firebox from base. 5^ 
 
 AN INEXPENSIVE WATEK iMOTOR 
 
 A simple but A’ery effective water motor can be 
 made by any one according to the plan here shown, 
 Avith little trouble or expense. It may be necessary to 
 have a few' minutes’ Avork done by a tinsmith. The 
 maker may do this if he understands soldering. 
 
 In a pine board 7 inches square and 1 inch thick,' 
 make a round hole 5 inches in diameter, by the use of 
 a scroll saAv, or in any other convenient Avay. To the 
 sides of the board fit tAvo thin boards f inch thick, 
 one on either side. In a small hole in the center of 
 each side drive a short piece of brass tube of about | 
 inch internal diameter, and to these tubes fit a straight 
 steel wire so that it will revolve freely. This wire is 
 the shaft of the motor Avheel. It should be of sufficient 
 length to project an inch beyond its bearings, to receive 
 a small pulley. 
 
 To the center of the shaft is soldered a sheet brass 
 disk 3 inches in diameter, so that it Avill run true as 
 
182 
 
 iroMK iMKdIANICS FOR AMXVVA'U^ 
 
 ili(‘ sliafi T'(‘V()lv(*s, and lo llin disk is snld(*r(*d a disk of 
 brass wir(^ i>anz(‘ »>() ni(‘sli. 1dH‘ (*d<»(*s of tin* bi'ass wiiH^ 
 gaiizo iiiustj as lln^ ladic^s would say, lx* s(nv(Ml ov(a* and 
 ov(‘r witli a iuw (*o])])(‘r wiix^, to ])r(‘V(‘nt it from ravcding 
 A^dlen tlu^ AvluHd r(^volv(‘s rapidly. If tlu‘ workman is 
 an adei)t In^ may soldcu' a rini» of brass wire, say No. 
 18 or No. 20, to the edge of the wire elotli. 
 
 Fig. 197. Motor Driving Sewing Machine. 
 
 Th(^ simplest Avay to secure a nozzle for tlie Avheel is 
 to l>ny a ch(‘a]), small oil-c'an having a long nozzle, witli 
 an ofxming in tln^ small(‘r (md of about tV inch. This 
 nozzh^ is ins(*rt(‘d inlo tln^ (xlgc^ of the Avooden Avlieel- 
 cas(‘, as shown, and iis smalhu' cmd is Ixmt so that it 
 forms a small angh* with lln^ A\di(X‘l, Avilh the point of 
 tln‘ nozzl(‘ as m*ar lln* wir'(‘ (dolh as ]x)ssible Avithont 
 loiicliing. To (‘ans(* lln* wh(M*l Ihns madcHo k(X^]) a cen- 
 
HOME MECHANICS FOE AMATEUES 183 
 
 tral position in its case, pieces of the small tube before 
 named may be slipped on the shaft each side of the 
 wheel. 
 
 A f-inch hole may be made in the casino at the bot- 
 tom, and provided with a short tube for receiving a rub- 
 
 Fig. 198. Small Water Motor. 
 
 ber pipe, to carry off the waste water, and there slionld 
 be a -|-inch hole in each side near the top to admit air. 
 The casing may be secured to the wooden foot-pieces 
 with screws. It is desirable to make the casing im- 
 pervious to water. To do this, the various parts may 
 be boiled in hot paraffine for ten minutes. If it is 
 
184 HOMJ-: MECHANICS EOIJ AlIATEUES 
 
 found difficnli. to socnro ])in‘nninc in bulk, a ])onn(l of 
 parattine caiidlos will fni-nisli (■non”li for ibis ])ni-])os(*. 
 Tlio inHaniinabb* na1ni-e of ])ai-aflin(“ sbonbl be ke])t in 
 mind, and a cover slionld be ])rovided for the v(>ssel in 
 wliicb it is ni(“Ifed, so lliaf if may instanfly l»e (‘xfin- 
 gnislied by the covei' slionld it b(‘com<‘ innifi'd. The 
 metal used in the conslrncl ion of this wheel should bi^ 
 of brass, exce])tinf>- the shaft. Tin* sci-ews with which 
 the casing' is put toi>ether should be brass. The toji of 
 the oil-can is cut olf to form a ]»art of the coipdinn' for 
 receiving* the rubber jiipe leading from the wash-bowl 
 faucet to the motor. 
 
 Fig. 199. Diagram Showing Position of Nozzle. 
 
 To prevent the checking of the v ooden parts of the 
 inotoi-, tlie parts should be arranged with the grain 
 lying in the same direction. 
 
 AVitli sufficient water pressure, this motor will make 
 from 1,500 to 2,000 revolutions per minute. With a 
 A (aw ll(a\il)l(i coi'd 1x^1 1 — a leather shoestring, for ex- 
 amphj — it laay b(‘ mad(^ to drive a light sewing machine, 
 fan, oi* any otlua* macliim^ recpiiring a small amount 
 of ])ow(a' 
 
 If moi‘(‘ ])ow(‘r is ]‘(*(|uir(‘d Ilian can be secured by one 
 j(‘l, addil ional nozzl(*s may b(‘ distributed around 
 \\'lie(d, oi* moiM^ w1i(m*Is may be jdaced on the same 
 
HOME MECHANICS FOR AMATEURS 
 
 185 
 
 shaft, but nothing will he gained unless the water 
 pressure is maintained. This pressure should be from 
 25 to 40 pounds per square iueh. 
 
 In a small high-speed motor of the class here de- 
 scribed, the full power is realized only when it is pro- 
 vided with a very small pulley connected bj^ a very 
 flexible belt with a large pulley on the machine to be 
 driven. 
 
 It is obvious a non-corrosive metallic case would be 
 better than a wooden one, and the metal one is advised 
 when the builder has conveniences for making a casing 
 of that kind. 
 
» 
 
 4 
 
 ) 
 
 .S.-' 
 
 . I 
 
 — k 
 
 
 ... Ji sJt 
 
 I 
 
PART Y. 
 
 METEOROLOGY 
 SELF RECORDING INSTRU:\rENTS 
 
 I F these instruments Avere constructed so that 
 each would produce a permanent record of 
 .its movements, it would certainly add to 
 their usefulness as well as their convenience, 
 but it is thought best to confine the construction 
 to these simple forms of apparatus, trusting to 
 the ingenuity of the reader to apply clock mechanism 
 for keeping the records. One eight-day clock could be 
 made to do duty for all the instruments. It could be 
 geared to a drum so that it Avould make one revolution 
 in one day, or in one Aveek, and each instrument could 
 be made to mark on a piece of paper carried by the 
 drum. The paper Avould need to be graduated so that 
 the pen carried by each instrument could be readily 
 traced. There should be divisions for duA’S and hours. 
 
 t/ 
 
 The pen by Avhich the record is made is simply a 
 small glass tube about ^ inch in internal diameter, 
 A\’ith the end Avhich bears upon the paper draAvn out to 
 almost a capillary tube and cut off and made round and 
 smooth by heating in a gas or alcohol flame. The ink 
 used in this pen is a drop of red ink mixed Avith an 
 equal amount of glycerine. This ink remains in the 
 narroAver end of the tube and does not evaporate. 
 
 METEOROLOGY 
 
 The subject of meteorology has claimed the atten- 
 tion of men to a greater or less extent doubtless since 
 
 [ 187 ] 
 
188 HOME ]\IE(MIANICS FOl? AMATKUFS 
 
 <() 1)(‘ iiilial)il(‘<l hy Ininiaii l)(*iii<;s. TIi(‘ 
 ])h(ai()iiuaia of tlic^ air iniisl liav(‘ (*arly atli'actcMl atl(‘ii- 
 tioii and (‘aus(‘d tli(‘ ()l)S(a-v(*rs to i'(‘ason fi'oni rausc* to 
 cdt‘e('t nntil ('ani(‘ <>radiially to an nnd(‘r- 
 
 standinj> of eartli, air and watca- — not always ronxx-t — 
 but in tlie main ])oinlin<> to tli(‘ ])i'(‘S(‘nt d(‘V(^lo])ni(mt 
 of tile S(‘ien('e, so that aft(‘r tln^ la])S(^ of many c*(*ntnri(‘s, 
 the (dose stmbmt of nature is abb^ to (explain various 
 ])lienomena and to jircxliet Avitb moix^ or b^ss (-(‘rtainty 
 what will ba])])(m, (^sjxHdally in tln^ immcHliate future. 
 
 To be able to jnxxliet the weatlna^ Avitli a little more 
 certainty than the ordinary ^Sv(‘ath(n* ])i' 0 ])li(d’^ (‘an do, 
 the student should lie in communication with the (lov- 
 ernment Weather Bureau, so as to avail himself of 
 the ()bs(u*vations of others; but cw(ui Avithout such 
 facilities as these many interesting observations may 
 lie made Avith the simple apparatus hereinafter de- 
 scribed, and notes iiiaA^ be kept for future reference. 
 
 This kind of obseiwation is instriu'tive in seA^eral 
 Avays. The A^ery act of making frequent obserA^ations 
 induces a methodical habit Avhich Avill be Amluable 
 through lif(^, and the obseiwations are interesting and 
 instructive in themseh^es. Besides all this, the record 
 formed is likelj^ to be Amluable for both present and 
 future use. 
 
 WHAT :\rAA^ P>E LEAliNEl) BY THE USE OF THE 
 HETEOBOLOtMCAL INSTBUMENTS 
 
 \\'(^ find lh(‘ w(‘aih(U‘ vam^ ])()inting toAvard the 
 AV('st w(* look for ( b‘ar w(‘alh(M‘, and as a I'ule Ave are 
 not disa})iioinl(*d ; bid w li(*n fh(‘ van(‘ in(li(‘at(^s that the 
 wind is lilowing from tlu^ (‘asf, a storm is expe(‘te(l. 
 
HOME MECHANICS FOR AMATEURS 
 
 189 
 
 ^VTien it blows from the north, cool Aveather may be 
 looked for, and A\dien it blows from the south, it hardly 
 ever fails to bring sultry days in summer and thaAvs 
 in Aviuter. 
 
 When the Avind bloAvs strong from any direction, 
 curiosity is aroused as to the pressure it is exerting. 
 This may be ascertained by observing the Aviud pres- 
 sure gauge ; pounds pressure shows that the Avind is 
 blowing fifteen miles per hour ; pounds pressure per 
 square foot represents a A’elocity of thirty miles per 
 hoAir; 18 pounds pressure indicates a A'elocitA^ of sixty 
 miles an hour, and 50 pounds pressure is registered 
 during a tornado one hundred miles an hour. In 
 calculating the pressure as indicated by this gauge 
 it must be remembered that the board Avhich offers 
 resistance to the Avind has only a half square foot 
 area. 
 
 The A'elocitA’ of the Avind is shOAvn bv the anemometer. 
 Wind is hardlv noticeable Avhen it bloAVS a mile an 
 hour. When it blows fiAe miles an hour it is a pleas- 
 ant breeze; Avhen it bloAVS ten miles an bour it is a 
 brisk breeze; Avhen it blows at a twenty-mile rate it is 
 a stiff breeze; at thirty miles it is a high wind, and at 
 forty miles it is a A*ery high AA’ind. At eighty miles it 
 is a hurricane, and at a hundred miles per hour it is 
 a tornado. 
 
 THE WEATHER VANE 
 
 The weather Amne hardly needs explanation to make 
 it understood. In the top of a stout pole is inserted 
 a ^-inch rod Avhich is Idnntlj" pointed at its upper 
 end. On this is placed a A'ane consisting of a Avedge- 
 shaped piece of hard Avood Avith a hole through it, a 
 
190 
 
 IIOMK MKCMIAXK^S VOU \^\\TVA:\l^ 
 
 ])i(‘(‘(^ of liooj) iron Ixmiii; fasl(*n(*(l ov(*r tin* liol(* and 
 i' 0 stin<> on tln^ n])])(‘r (‘inl of tin* l)lnnl-])oinl(‘(l I'od. 
 
 of j-incli l)oard 4 iindn^s wid(‘ and 20 incln^s lonu. 
 Tliose i)i(‘(‘(‘S ar(‘ 1(4 into tin* facets of tli(‘ so 
 
 Fig. 200. Weather Vane. 
 
 so that their fri^e ends are al)out 24 inches apart. 
 Til is construct ion insures steadiness. 
 
 Tile thin end of the wedge has an arrow-headed arm 
 ])rojecting from it to indicate the direction of the 
 wind. In the sides of the pole, near the upper end, 
 are inserted four rods arranged at 90 degrees 
 
 with each other, and in slots sawed in the ends of the 
 rods are riveted letters which indicate the points of 
 compass, N., S., E. and W. These, in connection with 
 the arrow-h(nid(Ml arm, enable the observer to tell which 
 way th(i wind blows. 
 
 WIND PKESSURE GAUGE 
 
 Th(‘ (‘onsf land ion of a wind pressure gauge is as 
 simple^ as that of th(i ordinary windmill, whicdi every 
 hoy knows hoW' to mak(\ A w ind van(‘ 0 imdies Avide 
 ami 24 im ln^s long is mad(‘ of a board, on tln^ 
 
HOME MECHANICS FOR AMATEinJS 
 
 191 
 
 edge of which is secured a piece of band iron which pro- 
 jects over the end of the hoard about 11 indies. In the 
 end of the board are inserted two screw-eyes for receiv- 
 ing the rod upon which the vane swings. The upper 
 end of the rod is pointed bluntly, so that the piece of 
 hand iron which rests upon it allows the vane to swing 
 freel}^ in any direction. 
 
 The middle portion of the board is cut away from the 
 upper edge to admit of placing a spring scale for the 
 measurement of the wind pressure. In the upper 
 edge of the board at opposite ends of the scale-notch 
 are inserted wire screw-eyes to receive the horizontal 
 wooden rod which carries the wind-pressure board, 8 
 by 9 inches long and | inch thick. 
 
 The hoard is stiffened by a cleat on the hack, which 
 is bored to receive the rod. A screw hook is inserted 
 in the rod, and another is inserted in the upper edge 
 
 of the vane for receiving, respectively, the eye and 
 hook of the scale. The spring scale is adjusted so as 
 to hold the thin board a little more than the length 
 of the slot in the spring-scale away from the pivot 
 of the vane when the wind is light or nil. When the 
 wind Idows the vane keeps the instrument headed 
 
102 
 
 IlOMK MK(MIANI(^S YOU AMATKUIJS 
 
 toward tlie wind, and tl)(‘ s('al(‘ indi(‘at(‘s fli(‘ ])r(‘ssnr(‘ 
 on a lialf S(|nar(‘ foot, so lliat lli(‘ r(*adin,!Lj^ innst Ixi 
 nnilti])li(‘d by 2 to S(M-ni‘(‘ a (‘oi'ixxd ])i'(*ssnr(‘. 
 
 Tlie I'od slionld ins(ad(‘d in a ri<;id ]x)st and ninst 
 1)0 oxac'tly vcndic'al. 
 
 Tlie amount of rain fallin<>* in a iL»iv(m tinu* (‘an 
 Ix^ as(*(a‘tain(Ml a])])roximately by ])la(‘in,<;* any bind of 
 v(^ss(d lia\inj»’ ])arall(d sid(‘s out of doors in an o]x*n 
 ])la(X' wlun'e it may r(X‘(Mve all tln^ rain, and tlxm 
 measnrinf>‘ the d(‘|)tli of tlie wat(‘r after the rain by 
 nutans of a small sti(‘k ])lnn^(xl into it; th(‘ depth 
 beini>' r(\i>istered by the w(d jxirtion of the sti(‘k. This 
 method, howcwer, is ernde and op(m to objcx'tions ; 
 some of the water will sjiatter over, some will be lost 
 by evaporation, and some will be displaced by the 
 stick. 
 
 If the observer is really in earnest he should make, 
 or have made, a copper vessel like the one shown in 
 the illustration. It is 4 inches in diameter and b 
 inches high, with the bottom set in 1 inch so as to 
 receive the copper tube, Avhich is bent twice at right 
 angles, with its inner end inserted in the recessed bot- 
 tom and its outer end extended np outside the vessel, 
 and even with the bottom to receive a |-inch glass 
 tnlx^, which is (‘eniented therein with a cement consist- 
 ing of white lead i)aint and litharge formed into a soft 
 jiiitly. 
 
 The glass tube is 7 inches long, and furnishes a 
 r(‘ady m(*ans of asc(‘rtaining the d(^])th of water in 
 11i(‘ v(^ss(d wlnm viewcxl in (‘onmx'tion with the S(‘ale 
 of in(*li(*s alla(‘li(*d lo tin*' v(‘SS(‘l. 
 
 In th(‘ joj) of lli(‘ v(‘SS(‘l is ins(‘rl(‘d a fumud 84 iiu'hes 
 long, wdlli a cylindri(*al poi'lion at the? top 2 inches 
 
HOME MECHANICS FOR AMATEURS 
 
 193 
 
 deep. The upper and lower edges of the main vessel 
 are wired to give them rigidity, but the cylindrical 
 top of the funnel is not wired. 
 
 A rubber band may be stretched around the funnel 
 at the junction of the cylindrical and conical portions 
 to prevent waste by evaporation at this point. To 
 
 Fig. 202. Rain Gauge. 
 
 insure accuracy the copper pipe which holds the glass 
 tube should be filled with water before the observa- 
 tion begins. 
 
 When the gauge is used in a windy place it should 
 be clamped to some fixed object by three screws en- 
 gaging the wire rim at the bottom of the vessel. 
 
104 
 
 nOMK MECHANICS Foil Ai\lAlMa;KS 
 
 A ]\[I]TALLK^ THEimOMF/rFII. 
 
 A iiier(*TTi'ial tli(‘rin()in(4(a- (‘alls for ]naTii])iilal ions 
 whi(‘li ar(^ not Avitliin lln^ si'oja^ of tin* ainatcMii', but 
 rcMjnirc^ the skill and ex])(‘ri(ni(‘(* of tin* i‘(\^ulai‘ niann- 
 fac'tnrer. A nietalli(‘ th(n‘inoni(‘t(a‘, how(*v(a‘, is vcn'v 
 easily made, and S(a'V(^s llu^ ])nr])ose fnlly as av(‘11 as a 
 nierenrial tliermonuder. It ean 1 )(‘ imnh^ as s(‘nsitiv(‘ 
 to the variations of t(an])eratn]‘e as may h(‘ d(^sir(Ml. 
 
 It is made by ])la(‘ini»’ toi»eih(n‘ a s<i‘i]) of st(‘(d and 
 one of l)rass (! inelu^s loni», ] ineh wid(^ and 3V iiu'h 
 tliiek. The ends of the stri])s ar(^ tiniuMl for about f 
 of an ineh at (^aeh end of their adja(*ent fa(‘es, and 
 then pnt toi^etlier and luxated tirst at one end and them 
 at the otlier, so as to solder them toj»ether at the 
 ends. 
 
 The brass strip is made about ^ ineli ]onf»nr than 
 the steel strip, and is bent over and ])erforated to re- 
 eeive a silk thread as Avill be presently explained. Com- 
 monly, when strips of steel and brass are nsed in a 
 eom])onnd bar, they are riveted at short intervals, to 
 kee]) them fi'om buckling. In the present case the 
 com])onnd ])ar is provided Avith a Avinding of soft Avire 
 (No. *> 0 ) Avhich k(^eps the strips close together. To in- 
 sure ])(n‘manen(‘y the bars are drilled and riveted Avith 
 a single rived at (^a(‘h end. 
 
 Th(‘ (‘01111)01111(1 bar thus made is inserted in a round 
 lioh^ in th(^ middh^ of a hard Avood bhx'k 2J inches 
 long, and h(4(l tlnae by an ordinary AVOod S(‘reAV in- 
 S(a‘led in 1h(‘ (*nd of lh(‘ blo(‘k and (‘lam])ing the end of 
 ll)(^ bar. ''rh(‘ woodem bIo(‘k is S(‘(‘iir(Ml to a base i)ie(‘e, 
 1 iii(‘li(*s s(piai‘(* and in(‘h lhi(‘k, having atta(‘h(Ml to 
 jl a ba(‘k board } inch lhi(‘k, 1 inches \vid(^, and about 
 
HOME MECHANICS EOK AMATEUKS 
 
 195 
 
 10 inches high. A wire nail about tV inch in diameter 
 and 1| inches long is driven through the back with its 
 pointed end projecting about 1^ inches. The nail is 
 about I inch from the upper free end of the compound 
 bar. A paper roll is formed upon another nail or a 
 piece of wire a trifle larger than the one used in the 
 construction of the thermometer. The strip of writ- 
 ing paper used for this roller should be 1 inch wide 
 and about 8 inches long. Enough of the paper is wound 
 to make the roller ^ inch in diameter. The paper, 
 except the first layer, is pasted as it is rolled, so that 
 it forms a solid paper roll when it is dry. 
 
 This roll, when dry, is transferred to the nail pro- 
 jecting from the back piece, and a pointer, or index, 
 about 2| inches long is cut from thick writing paper 
 and glued to the end of the roll. Then a silk thread 
 is tied in the eye in the free end of the compound bar, 
 and passed over the roller on the nail, and wound 
 three times around the roll, and it has attached to it a 
 small weight. In the present case this weight consists 
 of a lead bullet split half open with a. knife, and 
 closed down upon the thread by pliers or by hammer- 
 ing. With every change in temperature the compound 
 bar swings, so as to cause a movement of the index by 
 the pulling or releasing of the thread and the raising 
 or lowering of the weight. 
 
 The index should be placed in a vertical position 
 when the temperature is about 70° ; then the winding 
 of the silk should be separated a little, and a small 
 drop of mucilage shoiild be placed on the middle con- 
 volution of the thread at the top of the roller, so as 
 to cement it to the roller and prevent any change of 
 adjustment. 
 
19G 
 
 JIOMK MIOCIly\NI(JS KOU AMA'I’KIJUS 
 
 A semicircular piece of bristol l)oar(], about b inches 
 in diameter, is temporarily sui)ported behind the index 
 by a block ijlued to the back ])iece. Tbe brislol board 
 is to form the thermometer scale and is fast(“ned to 
 
 Fig. 203. A Metallic Thermometer. 
 
 11i(" ))]ock ))y ta(*lvS or ()ili(aA\is(‘, so that it can be re- 
 niov'CMl and a(‘(airat(‘l y r(‘])Iac(*(l. A ])(ai(al mark is now 
 mad(^ on the scab? at lh(‘ |)oint of tln^ index whi(*h indi- 
 calc'S tin* t(*m|>(a'a< iir(^ as shown by a nnaaairial thei‘- 
 moni(*l(a* at tin* tinnx If it is 70°, Ihe mark on the new 
 
HOME MECHANICS FOR AMATEURS 
 
 197 
 
 scale represents this teniperattire, and whenever the 
 index points to this mark the observer knows the 
 thermometer is 70°. 
 
 Now the thermometer is placed in a refrigerator 
 along with a mercnrial thermometer. They are left in 
 the refrigerator for an hour, and then a pencil mark 
 is made at the point of the index. This will, perhaps, 
 be 40°. The space between these two marks is divided 
 into thirty even spaces, representing as many degrees, 
 or it may be divided into fifteen spaces, each of which 
 will represent 2°. This graduated space serves as a 
 guide for constructing the balance of the scale. If 
 2° spaces are used, twenty such spaces laid off on the 
 leftdiand side of the scale will extend the scale to 
 zero. Twenty more such spaces will extend the scale 
 to 40° below zero, which is lower than any temperature 
 experienced in this climate. The space between 40° 
 and 70° is already graduated, and the space above the 
 70° mark is graduated as described for the lower end 
 of the scale. As each line represents 2°, 10° would 
 be represented by five lines, so that the fifth line could 
 be extended beyond the other lines for the sake of con- 
 venience in reading. Figures from 0° are placed op- 
 posite the long lines so as to read 10°, 20°, 30°, 
 40°, and so on, as in an ordinary thermometer scale. 
 
 The amateur can refine this thermometer as mxich as 
 he pleases. He may, if he desires, place the entire de- 
 vice in a case and cover the dial with a glass, provided 
 he furnishes several apertures to enable the air to cir- 
 culate and thus keep the temperature the same as that 
 of the external air. The free end of the compound bar 
 may have a spring riveted to it, as shown in the de- 
 tached view, and an adjusting screw may be inserted in 
 
IIOMF. MFCMfAXlC^S YOU AMATFTJRS 
 
 \\) 9 > 
 
 tli(‘ (‘()in])()nii(l 1 )^ 1 ' so as 1o l)(*ar a^ainsi IIk* s|)riiiiL!:. 
 VVitli tliis ('oiistiaK'i ion, ili(‘ silk 11ii'(‘a(l may lx* ti(*<l in 
 a liol(* in the fr(*(* (*n(l of tlie s])riniL», and tin* d(*sii‘(*d 
 adjustment may be made by tnriiin<» the S(*r(*\y om* way 
 or tlie otlier. 
 
 I^y making’ the (‘om])onnd l)ar lon<»(n', oi* <liminis]nne: 
 tlie diameter of the (‘ylind(*r aronnd \ylii(‘li tin* tlir(*ad 
 extends, or both, the sensitiyeness of tlie instrnm(*iit 
 may be <>reatly increased. 
 
 SBIPLK inXHJOSCOPE 
 
 No instrument is recjiiired to indicate a snperabnn- 
 ilaiH'e of hnmidity in the air. Eyeryone know s tin* dis- 
 comforts of a moist, hot day in the snnimer without 
 recpiiring a hyj>roscope. Still, to one scientifically 
 inclined it is some satisfaction to know^ the hygrometric 
 state of the air, and to compare one day with another 
 of the same year or preyions years. 
 
 A yery simple hygroscope wiiicli is accurate enough 
 for all practical purposes is illustrated by the engray- 
 ing*. Its construction Ayas suggested by a panel made 
 of two pieces of Ayood glued crossAyise to keep it straight 
 — the y(*ry best arrangement of the grain for causing 
 it to assume a concayo-coiiAOX form under all condi- 
 lions of the atmosphere except that in Ayhich it Ayas 
 gln(*d tog(*ther. It has a baseboard 4 inches square 
 and J inch thi('k, with a back piece 4 inches Ayide and 
 lo inch(*s high and ] inch thi(‘k, attached to one edge. 
 X(*ai‘ 1h(* right-hand (*dg(* of the base is secured a block 
 to w'hi(‘h is attach(*d a hygros(' 0 ])i(‘ strip made u]) of 
 a longitudinal ])!(*(*(* of any (*lasti(‘ wood (such as Ayhitc- 
 w'ood j \2 inch(*s long, 1 inch wdd(‘ and tV iu(di thi(*k. 
 
HOME MECHANICS FOE AMATEUES 
 
 199 
 
 and a transverse piece of wliitewood of the same thick- 
 ness 1 inch long and 12 inches wide, carefully glued to 
 it, so that the grain of one strip is at right angles to 
 that of the other. These strips of wood should be well 
 
 Fig. 204. Hygroscope. Fig. 205. Hygroscope Strip. 
 
 seasoned. This coinpoimd strip is secured to the small 
 block on the base of the instrument, and a piece of plain 
 cardboard is attached by two tacks to the wooden back 
 at the center of the board, leaving the ends of the card 
 free. The concave side of the strip should be arranged 
 
200 HOME MECHANICS E()]{ AMATKEIiS 
 
 to face tho l(‘ft-liaii(l sido of tlu* iiisli-uiiuMd, and a sliort 
 ])i(H‘e of small wii^*, say No. 24, or a li(‘adl(*ss |)in should 
 1)(‘ iiisertcHl ])oint out^^'ard in tli(‘ fi‘(‘(‘ (md of th(‘ strij) 
 to servo as an index. 
 
 Tli(‘ S(‘ale is ('onstrnet(Ml hy first ])la(*ini»; Hi(‘ instrn- 
 nient niuha' a Ixdl i»lass with s(n(‘ral ])i(M‘(‘s of w(‘t 
 hIottini» ])a])(a‘ near l)nt not toindiini; th(‘ sti'i]). Tli(‘ 
 loni»’, narrow stri]) do(*s not (‘han<>(^ its l(‘n;L»th, but is 
 bent one way oi- tli(‘ otlH*r by lli(‘ sw(dlin<» oi' slirink- 
 ing of the pie(‘e wliieh is ('rosswis(‘. Tin* liyi>i'o- 
 
 seo])ie stri]) will straij»ht(Mi out or ev(m eni'V(^ in tln^ 
 oj)])osite direc'tion wlum snl)initt(*d to tin* intbumec^ of 
 moisture, and after the lapse of six or (4!L»ht lionrs 
 the glass is removed and a jxmeil mark is mad(^ on th(^ 
 card at the point of the index, whi(‘h will rej)- 
 resent 100 degrees, or the point of saturation. The 
 instrument is allowed to assume the normal position 
 by drying it in the open air, after which it is again 
 placed under the bell glass with a dish of calcium chlo- 
 ride and allowed to remain five or six hours. The cal- 
 cium chloride removes the moisture and causes the 
 cross-grained side to shrink and tlins curve the strijj 
 considerably. It now indicates the maximnm diwness 
 of the ail', and a mark is made at the point of the index, 
 indicating zero. Tln^ spaces between zero and satura- 
 tion should now b(^ divided into ten equal spaces, and 
 (^ach si)ac(‘ may be subdivided into ten spaces, each 
 r(q)r(*s(mring om^ d(\gr(Hc 
 
 Th(*s(^ lin(*s should b(‘ m^atly made with a drawing 
 |)(m. h]v(*ry Hmlh graduation should be extended a 
 litth^ and nnmb(*r(*d; th(‘ (*ntii'(^ s('al(^ Ixdng nnmbercMl 
 from 0 to 100, v. c., 0, 10, 20, :{0, (dc. 
 
 This insi riiimml is not inl(*nd(*d to a(‘cnrately show 
 
HOME MECHANICS FOR AMATEURS 
 
 201 
 
 the exact amount of moisture, as is the case with the 
 more elaborate hygrometers, but to affoi’d a simple 
 means of showing the ever-varying state of the air. 
 
 MERCURilAL BAROMETER 
 
 The variations of atmospheric pressure are shown 
 by the barometer. The pressure of the air in round 
 numbers is 15 pounds per scpiare inch ; that is, a col- 
 umn of air 1 inch square, the height of the atmosphere 
 (which is not positively known), weighs 15 pounds, 
 and will balance a column of water 1 inch square and 
 34 feet high, or a column of mercury 1 square inch in 
 area and 30 inches high. 
 
 A mercurial barometer is here shown on account of 
 facility of construction and the acciiracy of its opera- 
 tion. To make the simplest form of mercurial barom- 
 eter, a strong glass tube a little more than 33 inches 
 long and about tV inch internal diameter is required. 
 It must be sealed at one end, and left open and con- 
 tracted to ^ inch at the other. This work is readily 
 done b}’ a glass blower. The open end is fused to 
 remove the sharp edges. A small glass bottle is pro- 
 vided, the body of which is about 1 inch internal diam- 
 eter and 1^ inches high. The neck is short and a 
 little larger internally than the outside of the tube. 
 A board f inch thick, 3 inches wide and 39 inches long 
 has a shallow half-round groove to receive the glass 
 tube, and two brass straps extend over the tube and 
 are clamped to the board by means of screws. Near 
 the bottom of the board a hole is cut for the glass 
 bottle or cistern, as it is called ; a small shelf is secured 
 by screws to the back board, even with the lower 
 
202 
 
 HOMK MKC0IA\M(^S YOU A^WTYYU^ 
 
 side of tlio liol(‘ hi <li(^ board. A small bob* is made* 
 ill tli(‘ liac'k lioard lu^ai' tli(‘ lo]) to r(M‘(*iv(* tlH‘ nail oi* 
 S(‘r(^w 111)011 Avliicli the iiistriiiiKmt lianas. 
 
 Fk;. 20f>. Scale and Indicator. Fig. 207. Mercurial Barometer. 
 
 Of eonrs(^ all Uk* ])arts will be triinl in pla(*e before 
 at h*iii |)l i to fill tli(‘ tiib(‘ with iiieriairy. 
 
 "riu* tiilx^ must b(^ ])(a'le(‘lly (di^aiij and only re-dis- 
 tilbxl iiKaaairy should b(^ ns(*d. In the bottom of the 
 
TTOirE JIECHANTCS foe AIMATETTES 
 
 203 
 
 j>lass bottle is placed a laj-er of pure beeswax iV incb 
 thick. The wax is made smooth and level by meltiiijj; 
 it by "eiitly heating the glass bottle over an alcohol or 
 Rnnsen gas flame. When the wax is cold the tilling' 
 of the tube with mercury may l)e proceeded with. The 
 tube and the mercury are first warmed by passing 
 them over an alcohol or gas flame ; then mercury is 
 poured into the tube through a small paper funnel. 
 The tnbe should be filled fo within ^ inch of the 
 end with mercury. Then the clean, dry forefinger is 
 held over the ojien end of the tube and the tube is 
 placed in a horizontal ])osition and tilted one way and 
 then the other, to allow the bubl)]e of air to gather 
 up as much as possible of the air contained in the tube. 
 The tube is then ])laced open end np and entirely filled 
 with mercury. It is then invert(‘d while it is kept 
 closed hj the finder. The end of the tnbe is placed be- 
 low a body of mercury in a suitable vessel and a little 
 of the mercury is let ont so as to produce a partial 
 vacnnm at the top. Tlien the tnbe is (‘losed and again 
 turned into a horizontal position and tilted in one way 
 and then the other, and at the same time turned or 
 rolled over so as to cause the bubble to gather up any 
 air that may remain. The tube is again inverted and 
 filled, until it is entirely full of mercury. The finger 
 is again applied, and a vacuum is produced by allow- 
 ing a small amount of mercury to escape, when the 
 tube is vertical as before. It is closed and tilted, allow- 
 ing the bubble to again gather air. This operation is 
 repeated two or three times. The tube is finally in- 
 verted and filled witli mercury, so as to present a 
 convex surface above the open end of the tube. Tlie 
 glass bottle containing the wax is placed over the 
 
204 nOMh] MKC41Ai\M(^S FOR AMATVA UH 
 
 open end of tlie tube and ])r(‘ss(Ml dowip (*ansin<» tb(‘ 
 wax to inak(^ a i^ood (‘onta(*t with tli(‘ (aid of iW tub(*. 
 
 Tlie bottle is held fiianly in ])laf*(^ by tla^ lin<»(‘r, and 
 tlie bottle and tlie tube may now b(^ inv(‘id(Ml toiL»(‘tli(a', 
 and after jmttin^* a little ineiaairy in tli(‘ bottb^, tb(‘ 
 latter may be jilaecMl on the slndf ])r(‘])ared for it, and 
 the tube may be raised a litth^j so as to eb^ai' its ojxai 
 end from the wax, and the tub(‘ is fastemxl in ])la('(^ 
 by (danipinj> it with the brass strijis and s(‘rews. .Morci 
 mereury is added to that in the bottle so as to make 
 the depth about ^ uwh abov(^ the low(‘r end of the 
 tube. A quantity of clean cotton wool is plaecxl in the 
 month of the bottle around the tube to exclude dust, 
 at the same time to admit air fre(dy. The barometer 
 is now finished Avith the exce])tion of the scale. 
 
 A scale of inches f inch Avide and 4 inches long is 
 laid out in the center of a card 24 imdies Avide and 
 tii inches long. Each inch is divided into tenths, and 
 the divisional lines for the inches and lialf inches are 
 extended beyond the f inch limit. The beginning of 
 the scale is numbered 27. The upper end of the first 
 inch is numbered 28, the second inch is numbered 29, 
 the third inch 30, and tlie fourth inch 31. The scale 
 is [ilaced behind the tube and the division line corre- 
 spomling Avith the line at the top of the mercury in a 
 standard bai'ometcu' is placed in the same position rel- 
 atives to th(^ mercury, and fastened by small tacks. 
 
 To enable^ tlus obscu-yeu' to mark the height of the col- 
 iimu of imuaairy, so that h(‘ may compare the present 
 obseu'vation with tlu^ ])i‘(‘yious one, an indie-ator is pro- 
 yieh'd, which ('ousists of a rod su])])ort(xl by ])osts at- 
 lacli(‘d to ili(* boai'd, and a shoil, sexdion of sjiiral 
 spring j)lac(*d on tlu^ j'od, with the upiier extremity 
 
HOME MECHANICS FOR AMATEURS 
 
 205 
 
 straightened and extending over the barometer tnbe. 
 This end of the wire is flattened by hammering to make 
 a more delicate index. 
 
 In a general way the changes of the barometer are 
 given, but they must be taken with some allowance. 
 High winds and storms usually follow the sudden drop 
 of the mercury. The rising of the mercury generally 
 indicates fair weather; the drop of the mercury indi- 
 cates bad weather. The fall of the mercurv in sultrv 
 weather is followed by tliunder ; the rise of the mercury 
 in winter indicates frost. In frosty weather the fall 
 of the mercury precedes a thaw, and the rise is followed 
 bv snow. Sudden changes in tlie barometer indicate 
 similar changes in the weatlier. Cpntinned foul 
 weather may be expected if the mercury falls slowly; 
 on the contrary if it rises slowly continned fair weather 
 may be looked for. Changeable weather is indicated by 
 an unsettled barometer. 
 
 It is perhaps unnecessary to caution the maker of 
 the barometer to conduct the various operations of 
 Ailing and adjusting above a large iflatter or piece of 
 smooth paper, witli the edges turned up to avoid un- 
 necessary waste of mercury. 
 
PART YI. 
 
 TELESCOPES AND MICROSCOPES 
 
 HOW TO MAKE A TELESCOPE 
 
 N O ONE can look into the starry depths at 
 night without a feeling of wonder and awe, 
 nor is this feeling lessened when the mind 
 grapples the question of space and con- 
 templates the awful abysm that separates ns from 
 even the nearest star, to say nothing of the points 
 of light faintly visible to the naked eye, nor of the 
 telescopic stars removed to such distances as to be- 
 wilder the mind and baffle the imagination in the 
 attempt to realize their remoteness. 
 
 Who does not desire to become more familiar with 
 these distant bodies and to possess all the knowledge 
 that can be obtained by observation? Much can be 
 done by the unaided eyes, and a great deal more can 
 be accomplished by means of a telescope of very mod- 
 erate proportions and power. An ordinary opera glass 
 is not to be despised, but of course an instrument with 
 a larger objective and a longer focus is much more 
 efficient and desirable. 
 
 Our engraving represents the telescope, its standard, 
 and the various parts, in section and in detail. The ob- 
 ject glass, A, shown in the engraving, is a meniscus 
 lens 2| inches in diameter and 36 to 38 inches focus. It 
 is mounted in a wooden cell, B, having an internal 
 flange or fillet about -ij inch wide, forming a true sup- 
 port for the lens and bearing against the end of the 
 paper tube, D, which forms the body of the telescope. 
 
 [ 207 ] 
 
208 
 
 IIOMI-: MKCIlANlCR FOIJ AMA'I'EURS 
 
 Tlu“ Ions is retained in its cell by a flat stri]), E, of brass 
 wbicb is sprang- into tbe cell and is pushed down 
 against tlie lens. Tin* (-(‘II is fastian'd to tbe tnbe by 
 
 Fig. 208. A Simple Telescope. 
 
 ooininon wood screws, wlii(*li pass tliroiii»’li tlie collar 
 into tin* |)a|)(M‘ foraniiiiL*' tli(^ tul)(\ It is ])crlia])S needless 
 to sny (hat tla^ (*(*II slioiild 1)(‘ inad(‘ of soiu(‘ thoroniL»ldy 
 
HOME MECHANICS FOE AMATEURS 209 
 
 seasoned hard wood, which is not liable to atmospheric 
 influences. Hard maple answers a good purpose, but 
 mahogany is to be preferred. 
 
 To protect the objective when not in use a cap, F, of 
 tin or pasteboard neatly covered with morocco or 
 velvet is fitted to the cell. 
 
 The paper tube of which the telescope body is formed 
 is such as is commonly used for rolling engravings for 
 mailing. It is 3 inches external diameter and 32 inches 
 long (about 4 inches shorter than the focus of the 
 objective). The exterior of the tube is covered with 
 Java canvas attached by means of bookbinder’s paste 
 (flour paste with ghie added), and varnished when dry 
 with two or three thin coats of shellac varnish. This 
 gives the tube an elegant and durable fluish. 
 
 The focusing tube, G, which is of brass, Ir} inches 
 internal diameter, and 12 inches long, is guided by a 
 turned wooden piece, II, fitted to the end of the jjaste- 
 board tube, D, and held by three or four ordinary 
 round-headed wood screws. 
 
 The piece, II, has a shoulder, a, against which the 
 end of the pasteboard tube abuts, and only about three- 
 quarters of an inch of the piece, 11, actually fits the 
 tube, the portion from b to c being tapered as indicated 
 in the engraving, and near the extreme inner end, 
 about 3^ inches from the shoulder, there are three 
 screws, d, used in collimating the fociising tube, G. 
 
 The bore of the piece, H, is somewhat larger than 
 the focusing tube, G, and is provided with a cloth lin- 
 ing, e, at each end to insure the smooth working of 
 the tube. 
 
 A short distance from the .shoulder, a, a mortise 
 about three-quarters of an inch square is made through 
 
210 
 
 IIOMIO MKCUIANK'S KOIJ AMA'I’Kl' l.’S 
 
 tlio side of (lie tub(‘, 7), and (lie ]iiece, II, and a (rans- 
 vei'se slot, /, is formed to receive* tlie wood(*n s]»indl(‘, I, 
 which is enlarijed in the niiddh* to r(*ceive the rnhher 
 thimhle, J, and has on om* (*nd a milled head h_v which 
 it may he turned. The sjiindle, I, is held in place hy 
 concave pieces, (}, which in turn are retaim'd hy the 
 curved ])late, 7.*, attached to the tube, I), hy screws. 
 The rubber thimhle, J, must he of sufficient diameter to 
 reach to and jiress upon the focusing' tula*, and the 
 latter has a series of transverse liroovc's tih'd in it. 
 This Avill insure sulticient friction to move tin* tube, 
 G, in and out when the s])indle, T, is tuimed. This sim- 
 ple device replaces the usual focusinij nu-chanism, and 
 is to he preferred to a rack and pinion, uidc'ss the latter 
 he i^erfectly made, and it is certainly superior on the 
 score of cheapness. 
 
 The cell, B, piece, H, and spindle, I, should he 
 blacked and polished on the outside, and the cell should 
 he left dead black on the inside. The interior of the 
 tubes should also be dead black. This surface may he 
 secured hy adding lampblack to a little very thin shel- 
 lac varnish, and aiDplying it to the inside of the tube hy 
 means fif a swab. The focal lengths of the lenses of 
 the astronomical eyepiece should he to each other as 
 three to one; the field lens, which is nearest the object 
 glass, having the greatest diameter and the longest 
 focus, and the convex side of each lens should he turned 
 toward the; object glass. Their distance apart should 
 he one-half the sum of tlu'ir focal lengths. These lenses 
 are mounted in a wood(*n cell, L, whose (‘xterior is 
 fitted to th(i focusing tube, (J, and grooved circumfer- 
 entially to receive* a striji of cloth, which is glued in, 
 ami insni'cs a good fit. d’lu* c(*ll is bored in different 
 
HOME MECHANICS FOR AMATEURS 
 
 211 
 
 diameters to receive the field lens, h, the diaphragm, i, 
 and the eye lens, /, all of which ai’e held in place against 
 the shoulders formed in the cell by circular springs of 
 brass, which are sprung in as in the case of the object 
 glass. The eye aperture should be about tf inch, and 
 the aperture of the diaphragm should be about the 
 same. 
 
 It is well enough to make the diaphragm adjustable, 
 so that it may be moved back and fortli to secure the 
 best position. It will be found, however, that, if placed 
 just beyond the focus of the eye lens, it will give the 
 best resiilts. 
 
 A circular recess, /.•, is formed in the face of the eye- 
 piece to receive a sun glass, which is retained in place 
 when in use, by a short curved s]U‘ing, 1. The sun glass 
 is simply a disk of very dark glass. It must, in fact, 
 be nearly opaque; some of the glass, known as black 
 glass, answers the pui'pose very well. 
 
 If but one astronomical ejmpiece is made, probably 
 the most satisfactory combination would be : Field 
 lens, inches focal length ; eye lens, inch ; distance 
 apart, 1 inch. It is advisable, however, to have three 
 ej'epieces for different purposes — one of higher power 
 and one of lower power than the one descril)ed. 
 
 In this connection, I will describe a terrestrial eye- 
 piece, referring to the sectional view. Fig. 209, al- 
 though it is of little use to adapt such an eyepiece to 
 this instrument unless it is first provided with an 
 achromatic objective. It is then a powerful telescope, 
 which will enable one to see well for many miles. The 
 method of mounting the lenses described in connection 
 with the astronomical eyepieces will be followed here, 
 thei’efore little more than the diameter and focus of 
 
213 
 
 iioMK ]\ii:crjANi(:s foii ama'phi’ijs 
 
 tlie lensos and tlioir distance apart need be fjiven. 
 There are fonr plano-convc'x lenses, A', 15', 1)', 
 
 nionnted in two ]>airs in Avood(‘n cells, E', E', litted to 
 the tnbe, (}', Avhicli in turn is tittcd lo th(‘ focnsini^ 
 tnbe, (r. The cell, py, has a |-inch ap(*rtnr(“ for the (*y(* 
 and a bead which ])roj(‘cts beyond the tnla*, (}'. 
 The lens. A', is abont xV iin-h in diaiindi'r and 1 inch 
 
 Fig. 209. Details of Telescope and Terrestrial Eyepiece. 
 
 focus. Tli(^ l(Mis, iVy is 2 incli diamotor and inch 
 focus. "rii(‘ haiSj O'y is iV in(‘li dianictcr, 1 1 inch focus. 
 FIk* 1(*iis, I)', is 2 iiK'li diani(‘i(‘r and 1 j inch fo(ais. Tlie 
 })lini(‘ fpc(^ of i\' is I7 in(‘lH‘s from tlu^. ])lanc face of 
 J>', and a stop, IT, having a iV inch apertni'e, is placed 
 
HOME MECHANICS FOR AMATEURS 
 
 213 
 
 inches from the face of the lens, A'. From the plane 
 face of the lens, B', to the plane side of the lens, C', 
 it is 3f inches. The distance between the plane side of 
 the lens, C', and the plane face of the lens, D', is 
 inches. At a distance of iV inch from the face of the 
 lens, €', there is a diaphragm, I', having a ^-inch aper- 
 ture. It will be observed that the convex sides of the 
 lenses, C' D, are turned toward each other. 
 
 Fig. 210. Details of Telescope. 
 
 At the extreme inner end of the tube, G', there is a 
 diaphragm, K', of if aperture, which is held in place 
 by two circular springs. The interior surfaces must 
 be well blacked to prevent reflection. 
 
214 llOMI^ MKCniANK^S KOI? AMA1M^nM?S 
 
 I liav(^ ('lu^aj) y(‘i (‘fficicMil in(*lli()(ls of holding 
 
 the l(‘iiS(‘S. If (l(‘sir(Ml Ok* i'(‘a(l(*r may, of ooinsc*, make* 
 flu* moTnitiiiiL»s of l)rass, and lit Ok* insti'iim(*iit ii]) a(*- 
 ('oi'diiii;‘ to Ids tast(* and ability. 
 
 TIk* arrani>(*nK*nt of tin* vaidons ])ar<>s is (d(*ai'ly 
 sliown in tlio se(4ional view, No. kb'iL»\ 20!), and Ok* 
 foousin<»* d(*vi(‘e is sliown in No. 2, V\<^. 210. 
 
 In r(*i>ard to the mattnr of (‘olliniation 1 liav(* found 
 tliat by (*nttin<>’ off tin* (*nds of Ok* ])a])(*r tnb(* tiaily in 
 a lathe, the ('(*11, 1>, and tin* ])i(*('(*, 11, will b(* nK*as- 
 nrably true. To determine wheth(*r tin* fo('nsini> tnlx*, 
 (x, and ('(*11, B, are axially in lim*, a truly ('lit eardboard 
 disk Avith a pin hole exa('tly in the ('enter, may be 
 placed in the e(*ll, B. A similar disk may also lie placed 
 in each end of the focnsin<»‘ tube, (x. 
 
 Now, by adjnstino’ the pi(*ce, II, by means of the 
 three screws, (/, the three pin holes in the disks may be 
 readily brought upon the same axial line; then, if the 
 lenses have been carefully centered by the maniifac- 
 tnrer, the telescope Avill be found sufficiently well 
 ('ollimated. If, however, it is desired to ascertain 
 whether the lens is trnlv centered, it mav be turned in 
 its cell, Avhile the telescope is in a fixed position, and 
 directed at some immovable object. If the image moves 
 as th(* l(*ns is turned, it shows that the work has been 
 ('ar(*l(*ssly dom*. 
 
 If OK*r(* ar(* doubts as to vdiether the axis of the 
 obj(*('tiv(* ('oiiK'id(*s with the axis of the tube, the tube 
 laay b(* snp[)()rt(‘(l in V-shap(*d supports adapted to the 
 tridy tKT‘iK*d (*n(ls. Then by placing a candle at some 
 (listaiK'(* from IIk* fa('(* of tin* l(*ns, and turning the 
 tube in ils V sn|)ports, at IIk* saiiK* liiiK* viewing the 
 i'(*ll(*('tioii of tin* ('aiidb* in the l(*ns, it will at once be 
 
HOME MECHANICS FOR AMATEURS 
 
 215 
 
 known by the movement of the reflection that the cell 
 requires adjustment to render the axis of the objective 
 and that of the tube coincident. 
 
 With a telescope of this description a large number 
 of celestial objects may be examined with great satis- 
 faction. The Moon furnishes an unending source of de- 
 light, showing, as it does, a face that is ever changing 
 throughout the lunar month. Jupiter may be coming 
 into good position and affords an interesting study 
 of which one does not soon tire. The telescope de- 
 scribed will show the satellites in their varying posi- 
 tions from night to night. It will show the dark band 
 across the face of the planet, and will afford a realizing 
 sense of the magnitude of this great body. 
 
 Saturn may be in a good position for observation, 
 and his ring may be clearly seen. The meniscus lens 
 will show a little color, and its definition will be quite 
 defective Avhen directed to such bright objects as the 
 Moon, Jupiter, Saturn, Mars, or Venus with the 
 full aperture, therefore the aperture should be re- 
 duced by a diaphragm of cardboard. A little experi- 
 ment will determine the best sized aperture. For nebu- 
 Im, star groups, and double stars, the full aperture 
 should be used. The great nebula of Orion is an inter- 
 esting object; many of the star groups are very pleas- 
 ing, the Pleiades for instance. The sun also, when the 
 spots are visible, is a satisfactory object for this instru- 
 ment. Of course, the sun glass will be applied before 
 the observer attempts to view the Sun, otherwise the 
 eye may be injured or destroyed. It may be that some 
 reader of this article may have a double or plano-con- 
 vex lens of long focus, which he might desire to press 
 into the service. Either of these may be used, but the 
 
2i(; 
 
 HOME TMKCIIANICS EOi; AMAI'KUKS 
 
 iiuMiiscus is 1)(><H‘i‘. If a .nood j(»1» is made of flu* nioinif- 
 iiijUS it will ii(»t be loiijn befoiM* Hk* iiienisciis, or Hi<? 
 piano or double eonv(“x lens will b(‘ snp])lan1ed b.v a 
 ^'ood aebroniatie objectivi*, which will increase* tine 
 efiliciency of the instrninent many fold. Such a hms 
 is not very (*x])ensive. It may he procni'esl from almost 
 any optician. 
 
 As to the telescope stand little m-ed he said, as its 
 construction is so ch'arly shown in the (“ivi>ravin;L’’. I 
 will say, howev(*r, in the h(‘|i> inning', that there* is ne» 
 dange*r of i*ettin;>- it teeee seeliel. If it is ve*ry e-Inmsy it is 
 no matter. If it is sle*neler it will he* like* a “re*e*el shaken 
 bj’ the wind,'’ eenly “men-e se),” as e*ve*ry trenieer has the* 
 henetit of the maj>nifyin,i>’ i)e)we*rs eef the tele*se-e)pe anel is 
 amplified to a wonderful exte*nt. 
 
 There are undonht(*elly hette*r stands than the* erne 
 represented, hnt it is easily constrncte*el anel answers an 
 excellent piirpeese. I*T*om the gronnel tee the top of 
 the hexagonal hnh, AI, it is fonr feet. Thr(*e of the al- 
 ternate sides of the hnh are wider than the internieeliate 
 ones, to receive the wronght iron hinges by wliieh the 
 legs are attached. To attach the hinges, the pin is first 
 driven ont; one-half of the hinge is then attached to 
 the leg, and the other half to the hnh, AI, when the pin 
 is replaced. 
 
 No. 1, Fig. 209, is a top view of the hnh and the npper 
 poi tion of the l(*gs. No. 4, h'ig. 210, is a vertical section 
 on 1h(* line, //, (/, in Fig. 209. A 1-^-inch hole is bored 
 Hii*(mgh the hnh to rec(*iv(* the standard, N, which sup- 
 ports tin* t(*l(*scop(* and is clami)(*d at any desired 
 h(*iglit by I In* flinnd) scr(*w, m. To i)r(*v(*nt marring the 
 stamlai'd a pi(*c(* of sob* l(*alh(*r is int(*rposed between 
 tin* scr(*w and standard. An arm, n, is hing(*d to each 
 
HOME MECHANICS FOR AMATEURS 217 
 
 of the legs and folds down upon the standard, so as 
 to spring the legs outwardly, and thus render the stand 
 very rigid. The lower ends of the legs terminate in 
 spikes, and a strap is attached to one of the legs to 
 fasten them all together when the instrument is not 
 in use. 
 
 The upper end of the standard, N, is reduced in 
 size, and made slightly conical for receiving a socket, 
 O, to the upper end of which is jointed an arm attached 
 to the V-shaped trough, P, in which the telescope is 
 secured by straps. The form of the joint is shown in 
 Fig. 210, which is a vertical transverse section taken 
 through the socket, O, trough, P, and body of the tele- 
 scope. A strong bolt, o, forms the pivot of the joint 
 between the socket, O, and trough, P, and is provided 
 with a wing nut by which it may be tightened. The 
 surfaces of the joint as well as the upper end of the 
 standard should be coated with black lead to insure 
 smooth working. A post set firmly in the ground, 
 while it cannot be moved from place to place, has the 
 advantage of being rigid, and forms one of the best of 
 cheap stands. A fixture screwed in the window casing 
 of a south window, and another attached to a north 
 window, afford solid supports for the instrument, and 
 have the additional advantage of permitting the ob- 
 server to remain under cover. 
 
218 IIOMI': MKCIIANJCS FOR AMATEURS 
 
 THE .MI('i;,()S(’()FE 
 
 Tlie man who has passed hovliood witliout kiiowini; 
 somethiuj;' of wliat is revealed hy the mieroseojK*, lias 
 missed one of (lie pl(‘asui(>s of life, and has failed to 
 look into one of tlie most inteiestinj;’ and pi'otitahle 
 studies oiien to the sec'ker after knowl(Hl<;e. 
 
 Frohahlj the best form of sim])le mieroseojie foi* tlie 
 beginner is a Doublet, of whieb three forms are shown 
 in the engi'aviug. If this eannot be had, a cloth tester, 
 or a jeweler’s eyeglass, will show niueli which the eye 
 cannot see distinctly. The doublet consists of two 
 plano-convex lenses mounted in a short tube with their 
 convex surfaces facing (‘ach other, and separated by a 
 distance equal to one-half the sum of their focal 
 lengths. 
 
 The habit of using the lens creates the habit of ob- 
 servation, and this rapidly increases one’s fund of 
 general information. 
 
 The doublet is convenient and inexpensive. Its 
 power, however, is fixed. If a different power is re- 
 quired another doublet will be needed. Probably 
 three-fourths inch is the most useful focus. 
 
 Better for real work is the microscope shown in 
 Fig. 212. It has a glass plate on which to place 
 the object to be examined, and is provided with a 
 ndrror to reflect light from below up through trans- 
 ])arent or translucent objects. The arm which carries 
 the lens swings so as to bring the lens over any part of 
 1h<‘ ])late and sli])S r<‘adily up or down to bring any part 
 of (h(M)bjeet into focus. The lenses are doublets. They 
 may be had of 1i inch, 1 in., -1 in., and | in. focus. 
 Probably (he, il im h and | inch will prove the most 
 
HOME MECHANICS FOR AMATEURS 219 
 
 serviceable. The wooden base is beveled at either end 
 to form rests for the hands in manipulating' the objects 
 and lens. 
 
 In a slide under the base is placed a metal plate 
 enameled black on one side and white on the other. 
 This is to be placed on the glass stage when opaque 
 objects are tinder examination. 
 
 This instrument will not take the place of a com- 
 pound microscope, but it answers very well when only 
 
 Fig. 211. Dissecting Microscope. 
 
 a low power is needed. If the user develops a taste 
 for microscopy and purchases a regular microscope, the 
 dissecting microscope will still be of value to him in 
 the preparation and preliminary examination of objects 
 to be examined Ity the higher power of the compound 
 microscope, so that the purchase of a dissecting micro- 
 scope is only introductory to the study of microscopy. 
 
 Interesting objects for the dissecting microscope are 
 plant hairs on the back of the leaf of the Deutzia 
 
^20 HOME ]\ri-]Cir ANTES T-'OIT A:\IA'l’KrUS 
 
 .Cfrncilis, or spimon, and many otlior loav(“s with sur- 
 faces ronfili to the toncli. ^Tany of the mints and fi^- 
 worts have hairs Avond(*rfnlly InaTiclied. T’olhm, 
 seeds, Willi's and antennae of hntterflies, mosses, s])ore- 
 cases of ferns, insects, jiarasites, hairs, featliers, min- 
 erals, crystals, — all are interestin';;- and instructive. 
 The formation of ciystals on the j;lass staj^e is very in- 
 teresting-. 
 
 Drop a small (quantity of a solution of alum, com- 
 mon salt, sulphate of copper, or other chemical salt, 
 sal ammoniac for exam])le, u])on the glass stage and 
 allow it to evaporate while the operation is watched 
 through the lens. For best results spread the drop 
 of solution with the edge of a paper cutter or card into 
 a thin film. A little practice will enable one to make 
 a very uniform film in which the crystals form very 
 beautifully. 
 
 Of course the glasses must be perfectly clean. Per- 
 fect cleanliness is absolutely essential in every part 
 of microscopic work. Dust especially is the worst foe 
 of the microscopist. It is well nigh impossible to be 
 entirely rid of it, and every mote which remains is 
 magnified by the higher powei’s into a beam. 
 
 A l)ee furnishes a good object for dissection and 
 preparation. The wings and the sting are especially 
 interesting. The wings are provided with hooks de- 
 signed to engage a rib on the other half. It is stated 
 that no human being has ever been able to fasten the 
 wings together. The feet and respiratory apparatus 
 are also interesting. 
 
 l>y a little labor one may dissect from a flower or in- 
 sect iiit(‘rior parts of great interest. Indeed, it is by 
 dissection that most objects are prepared for perma- 
 
HOME MECHANICS EOK AilATEUKS 
 
 221 
 
 uent preservation and nse. Tlie tools for tins work are 
 few and simple, and altliongli those sold by dealers 
 are to be preferred, yet one may prepare for himself 
 such substitutes as will enable him to do really good 
 
 Fig. 212. A Practical Microscope. 
 
 work. Our space does not allow much to be said upon 
 this point. The indispensable articles are needles 
 and knives. Dissecting needles are simply sewing 
 needles set in handles. Even a splinter of wood or 
 
222 
 
 IIOM K M K(MIA\ K^S Foil AMAIM^FIIS 
 
 AV()()(l(‘n ])(‘iili()l(l(M' answ(‘rs all ])in‘])()S(*s of a liaadh^, 
 and th(^ (‘V(‘ (aid of a ihmmIU* may lx* ])nsli(*d into it so 
 as to lx* fiianly S(*t in its s(*at. S(*v(*i'al siz(*s of n(*(*dl(*s 
 slionld lx* nionnt(*d r(*ady for ns(*. A small ])oint(*d 
 blade* of a ]x*nknif(* will answ(*i' for cnttini*’. A v(*ry 
 suitable knife may be made* by <;rindin<; tin* (*nd of a 
 ne(*dle to an ed,<»e and sliar]x*nin<> it on a stom*. Tli(*s(* 
 tools tlioni>b sim])le, are s(‘rvi(‘(*abl(*. 
 
 To diss(*(‘t a t1ow(*r, for (*xam])l(*, ])la(‘(* it n]X)n tln^ 
 stai»(* of the microsco])(* and bi'ini»' into forns with the 
 lens so that it is distimdly visible*. At tirst ns(* the 
 lens of loni»(*st forns. Th(*n take* a nee*dle* in e*ae‘h lianel 
 anel ope*n the tlowe*r, while yon le)e)lv inte) it. ()bse*rve* 
 its petals, their eole)rs, markings anel hairs, if any are 
 present, its stamens, their sha])es anel pe)lle*n, its seH*d 
 ve*ssel anel any peeadiarity. ^tany an exepiisite view 
 into Nature's me)st beantifnl ree‘esse*s is te) be hael in 
 this way. So beantifnl are many tle)wers that e)ne feeds 
 it to be almost a profanation e)f a sacreel shrine to ex- 
 pleme fnrthen\ Rnt still the nnle)edvino' of the shrine 
 may elisede)se more profonnel mysteries, so we proceed to 
 cut with one of onr tinv knives across the seeel vessel 
 which e)ccnpie*s the cemter of the flower. Notice the 
 symme*try e)f its arrani»ement, perhaps in three sections, 
 else in four or five*; sometimes as many as ten rows of 
 se(*ds may be found. It is a very interestino- point to 
 study lh(* arraniL»(*ment and phu'e of attachment of the 
 s(*(*ds in lh(* v(*ss(*I. This mode of working* is the mode 
 ns(*d by all botanists in th(*ir ])r(*liniinarv study of a 
 plant. An (*ntonioloi^ist stndi(*s an ins(*(‘t in the same 
 AN'ay. 
 
 Afl(*f* lli(* limits of vision with tin* loniL» bxmsed 
 h*ns is reacli(‘d, a liii;li(‘r po\\’(‘r is tak(*n and tlu* s(*arch 
 
HOME MECHANICS FOR AMATEURS 
 
 223 
 
 is continued to the shortest focus the student may have. 
 All of the “coarse anatomy” of an object is studied 
 by means of the dissecting microscope. The com- 
 pound microscope inverts the view of an object so that 
 a motion to the right seems to be toward the left, and 
 towards, seems to be from one. It is very difficult to 
 become accustomed to this inversion in dissecting, and 
 for that reason the compound microscope is rarely used 
 even by the most expert. Then, too, its field of view 
 is small, and high powers are not needed in dissecting. 
 
 The beginner is earnestly advised to study all sorts 
 of minute things which he may find, since discoveries, 
 surprises and most sublime views into the hidden 
 things of Nature await him at every turn. A most 
 useful book for this line of work is “Common Objects 
 for the Microscope,” which the student is advised to 
 buv. 
 
 But with even the highest skill there is a limit to the 
 use of simple magnifying glasses. The desire to know 
 what lies beyond must be gratified in other ways. A 
 compound microscope is the only instrument which 
 will meet this condition and disclose all that can be 
 seen by lenses. This consists of two lenses, one at each 
 end of a tube, which is in two parts, one sliding within 
 the other. The lens nearest the object is the objective 
 and is really a very fine simple microscope in itself. 
 The upper lens, the eyepiece, increases the magnifica- 
 tion of the objective and enables the eye when in the 
 proper position to take in at once the entire picture 
 produced by the instrument, and to study it in detail. 
 
 The particular instrument shown in Fig. 211, 
 although very plain and simple, is exceedingly well 
 made, and very useful. It will receive the standard 
 
224 
 
 IIOAIK MKCMIANMCS VOU AMA4M^:rRS 
 
 ()l)j(M*tivos and oyei)i(M‘es. Tt lias a \(^vy sinootli rack 
 motion, wliicdi admits of v(a*v fim^ adjiistimmt. Tin* 
 mai>iiifi('ation of a comjionnd mi(*ros(‘ 0 ])e is vai'icMl by 
 nsin<»‘ obje(‘tiv(^s of diffVi'ent fo(‘al b‘ni»'tlis, (*y(‘])i(*(‘(‘s of 
 different ])ow(M's, and by elianain^ tli(‘ bmi^tli of tlie 
 tnlie. Tliis mi('ros(‘ 0 ])(‘ is nsiially jii'ovided witli a lialf 
 ineli objective wliicdi may lie se])ai‘at(Hl to form a om? 
 and a lialf in(*li objective also, and an iiK'li and a half 
 <\ve])ie(‘e. 
 
 If one wishes to put more money into the micro- 
 scope he will next need a one-half inch eyepiece and a 
 one-fourth iiu'h objec'tive. Witli thes(‘ he will have six 
 degrees of magnitication at his (‘omniand, varying from 
 25 diameters to about 400 diameters. By diame- 
 ters is meant the number of times bi'oader an object 
 a])pears. This is the usual mode of stating magnifica- 
 tion. The numb(‘r of times an oliject is magnified is 
 found by multiplying the diameter by itself. Thus, 
 if a seed is magnified fifty diameters it is made to ap- 
 pear twenty-five hundred times its real size. 
 
 A micros(‘ope of the value of this one should be 
 handled with extreme care. There are certain simple 
 points to be observed in the use and care of fine glasses. 
 Never touch th.em with the bare fingers. It greases 
 them and injures their transparency. Wipe them only 
 with a very soft clean cloth, or bit of chamois skin. 
 Th(^ glass of whi(*h tln^ lenses are made is very soft and 
 (‘asily sci'at(*hed. The finest dust may be composed 
 of hard grit, whi(‘h will leave its mark upon the lens if 
 nibb(*d across it. It is well to blow the dust off be- 
 foi'c^ wiping th(^ hms. Lensc^s a7*(‘ (^asily broken if 
 dr'opp(‘d. Th(‘ iriost (‘ommon a(‘(‘id(ait is the di'opping 
 of I Ik* obj(*ctivm while scrcwving it into its ])la(‘e or re- 
 
HOME MECHANICS EOH AMATEUIIS 
 
 225 
 
 moving it. Even with care this sometimes happens. 
 There is but one way of screwing or unscrewing the 
 lens from the tube which is certain to prevent accident. 
 Take the lens between the first and second fingers of 
 the left hand, just as one would a cork or a lead pencil. 
 Now hold it in the position to be screwed into the tube 
 and turn it in Avholly by the right hand. Proceed in 
 the same manner in unscrewing the lens. No accident 
 can happen. 
 
 With this microscope fitted with the half inch separa- 
 ble objective and the one and a half inch eyepiece an 
 exhaustless field of study and delight is opened to its 
 possessor. 
 
 ■ 
 
PART YII. 
 
 ELECTRICITY 
 
 A PKACTICAL PRIMARY BATTERY 
 
 E very amateur who delights in “making things” 
 dabbles more or less with electricity. Most of 
 these are so situated that they have no access 
 to the large sources of supply of the electric cur- 
 rent, such as lighting stations can furnish, and if they 
 would do any real work must make their own genera- 
 tors and apparatus. It is to the assistance of such 
 that the present section is devoted. 
 
 The battery, represented by Fig. 213, can be made at 
 a minimum cost, and when made will give a maximum 
 of output. The materials to be purchased are glass 
 jars, porous cups, carbons, zincs, burrs, screws, bind- 
 ing posts and some sheet copper. 
 
 All the pieces for the cell come ready for use, except 
 the carbons, which are peculiar to the special form of 
 cell. As the cut shows, there is a ring of carbons to be 
 placed in the glass jar and to fit in the jar as closely as 
 may be without exerting pressure upon the jar. Six 
 plates of carbon are required for each ring. Each 
 plate has two holes of a size to lit the screws. The 
 holes may be made most easily by awls and reamers, 
 such as are to be found in a set of tools in an awl 
 handle. A little patience and experience will enable 
 any one to make the holes neatly. Carbon is verj^ hard 
 and will wear a drill very fast. Hence, it is better not 
 to attempt drilling holes in a carbon plate. Of course 
 the holes should be eqiially spaced, if the appearance 
 of the finished work is to be considered. 
 
 [ 227 ] 
 
Tli(^ (*()])])(‘r should lx* about 1-.‘^>2(1 of an iiudi in thick- 
 n(*ss and about § wide*. II (*an be* bon^iil of 
 
 this width, or ont by tin* d(*al(*r or by a sinilb with lai‘<»(* 
 sboai's. A stri]) must lx* lx*nl into a six-sid(*d rinjL» of 
 siudi size that when tin* eai'bons an* fast(*ned to it tin* 
 whole will slide* snugly into I In* i»lass jar. It will lx* 
 better after oiu* stri]) has b(*(*n titl(*d |o its ])la('(* to 
 straighten it out and use it as a pattern, or template*. 
 
 Pig. 213. A Practical Primary Battery. 
 
 by wliicli to drill the holes in the rest of the copper 
 strips. They will then be all alike and interchange- 
 able*. A t(‘inplate shonld also be nsed for making the 
 lioles in the* carbons, tlioiigh all holes may be reamed a 
 liltb* on one side* eei* the* eether te> allow the screw te) pass 
 1 l)i*e»iigli. If I lie* \\e»)-ke*r has ne> means eif tapping a 
 llii-e'ael feir (lie* se*i'e*w, he* sliemlel bay nuts feer the screws 
 alsei. H’lie* lie)le*s in I lie* e-eijipe*!* s(ri]is may b(^ ]mne*hed 
 wil li a nail pnne-li, if enie* has iiei nie*ans e)f elrilling them. 
 
HOME MECHANICS FOE AMATEUES 
 
 229 
 
 For punching holes in this way the end of a stick of 
 hard wood should be used as a bed to rest the copper 
 upon wlien punched. The strip of copper which leads 
 up out to the binding post may be riveted to the ring, 
 or one end of the ring may be left long enough to bend 
 up a couple of inches above the top of the jar. The car- 
 bons should be long enough to reach above the jar so 
 that the metal parts shall not touch the glass. In this 
 battery the fluid employed will corrode metals very rap- 
 idly. To prevent the fluid from creeping up through 
 the pores of the carbon and reaching the copper, the 
 ends of the carbons should be dipped in hot melted 
 paraffine and saturated by it before clamping them to 
 the copper ring. 
 
 The binding posts may be of any available form ex- 
 cept those with wood screws. A machine screw is nec- 
 essary because the l>inding post is to be clamped to the 
 copper strip by it. When these parts are screwed to- 
 gether the battery is ready to be assembled. 
 
 Nothing has been said about the sizes of jars and the 
 rest, since the cell may be made of a size to fit any jar 
 into which the porous cup and carbons Avill go. Hound 
 porous cups may be had from inches up to 5 inches 
 in outside diameter, and round glass jars may be had 
 from 2i inches up to 7 inches in inside diameter. There 
 is thus ample range of size for any one to consult both 
 the depth of his pocketbook and tbe quantity of current 
 which he Avishes the battery to giA^e. This is a point 
 not understood by many amateurs. The voltage Avhicli 
 a cell gives is determined by the kind of chemicals used 
 in it and not by the quantities of chemicals consumed. 
 The current in amperes, Avhich, the voltage being fixed, 
 the cell will give, and the work it can therefore do, are 
 
2:50 
 
 llOiMK MKCIIANICS FOll A^IATKVWH 
 
 l)y tli(‘ (|naiility of clKMiiicals (‘oiishhkmI l)y 
 the (‘ell ill its ac'lioii. It may Ix^ statixl as a fair av(‘r- 
 aiL»e rc^siilt that oih^ ])oiiii(1 of ziiie will i»i\(‘ :52() ainjx^re 
 hours ill a (*(^11 such as this. 
 
 Carbon jilates (‘an be had in a ,i^T(‘at vanety of sizi^s 
 and sha])(\s. Tin* b(‘st way is for tlu^ oiu* (‘ont(mi])latinii^ 
 inakini>' the batt(n'y to writ(^ to a d(^al(n‘ in (de(‘tri(‘al 
 sni)])li(^s and ask for a (‘atal()i»n(^j Avhi(‘h h(^ will be f;lad 
 to furnish. All tlu^ ])arts (‘an tlnni b(‘ s(*l(X‘ted of ])ro])er 
 jiroportion to ea(‘h other, so that tluw will <»() toi;ether. 
 Either the Daniell, bottle or Enller zin(‘ should be (^(xl. 
 The ent shows the Daniell zinc. It is a e,ood form be- 
 (‘anse of the lari»e snrfa(‘e exposed to the aetion of the 
 tlnid. 
 
 The best solution for this cell is the (‘hroniie acid 
 fluid. It should be made by weight, taking chro- 
 mic acid 18 parts, water 60 parts, snlphnric acid, con- 
 centrated, 9 parts. A pint of water may be taken as a 
 pound, and a pint of the snlphnric acid as 1.8 pounds. 
 The chromic acid is a solid and can be most easily 
 weighed directly. Put the chromic acid into the water. 
 It dissolves readily. Then pour the snlphnric acid into 
 the mixture very slowly, a little at a time, stirring it 
 in thoroughly, else a disagreeable accident may be had 
 from the heat produced. It is considered by many that 
 this solution is improved by adding 1 part of chlorate 
 of j)()tash. When it is cold it is ready for use. 
 
 The zinc in all cells of this character must be amal- 
 gaiiiat(Hl; that is, (‘()at(xl with mercury. This may be 
 doiK^ (lir(X‘tly by dipping tlu^ zinc into the solution for 
 a short tinn^ and tlum i‘nbbing m(n‘cnrv ni)()n it, or, bet- 
 1(*]*, by initting an onm‘(^ of m(‘r(‘nry into the bottom of 
 (‘a(‘h ])oi‘ons (‘iip. Another way is to add to the solu- 
 
HOME MECHANICS FOR AMATEURS 
 
 231 
 
 tion in each porous cup, as much bisulphate of mer- 
 cury as will lie on a quarter of a dollar. The zincs 
 will then be amalgamated directly from the solution. 
 
 The cell may be set up in various ways with only 
 slight differences in the resulting current, durability 
 and constancy of action. We will give four modes of 
 arranging the cells : 
 
 First — Fill the glass jar to within an inch of the top 
 and the porous cup to the same level with the solution 
 described above. 
 
 Second — Fill the porous cup with a mixture of water 
 10 parts and sulphuric acid 1 part, and the glass jar 
 with the chromic acid mixture given above. 
 
 Third — Fill the glass jar with the chromic acid solu- 
 tion and the porous cup with water to which table salt 
 has been added at the rate of 4 oz. to the pint. Sul- 
 phate of zinc may be used in place of salt, 6 oz. to the 
 pint. 
 
 Ftour — Fill the glass jar with chromic acid solution 
 and the porous cup with clear water. This will start 
 slower than any of the other modes of filling, but will 
 work, because enough of the chromic acid solution 
 passes through the pores of the cup to act upon the 
 zinc. 
 
 The adaptedness of this cell for many uses is shown 
 by the fact that it can be arranged as a one fluid cell 
 also. Removing the porous cup hang the zinc in the 
 center of the glass jar by means of a board cover of the 
 jar through which a hole is made to receive the end of 
 the zinc. The fluid used will be the chromic acid solu- 
 tion. The zinc must be fully amalgamated before put- 
 ting it into service, and the bisulphate of mercury 
 should be used to maintain the zinc in condition. In 
 
232 
 
 HOME MECHANICS EOl? AMATEHES 
 
 Hiis form flu* coll _i>ivos its stroii<rost current, but will 
 only last about half as lou"'. 
 
 Whcuovor this coll is to Ix' out of use the zinc should 
 be rouiovod from the ll(|ui(l. The porous cup should 
 be taken out and sot in a dish of the sauu* solution 
 as it coiitaius. In this way all waste of the chemi- 
 cals is prevented. 
 
 The battery, as doscrilxal, is one of the stroupjest and 
 most I’eliable primary batteries. AVith its strongest 
 current it readily heats tine iron and ])latiunm wires. 
 With the porous cup it is ada])ted to drive motors, fans, 
 and excite electromagnets. A large' battery will light 
 small incandescent lamps. Eight or ten cells, holding 
 two quarts each, will drive the motor of Hcientific 
 American Snpplcmcnt, No. 041, to full power, and run 
 a sewing machine or turn a small lathe, or do any other 
 equal work. The expense of maintenance is not great. 
 The liquid when it becomes green is exhausted and 
 must be replaced by fresh solution. The zincs can be 
 used till they are entirely dissolved. This battery is 
 not a toy, but a serviceable piece of working apparatus. 
 
 ELECTRIC LIGHTINCx FOR AMATEURS 
 
 It is now possible for any one to procure small incan- 
 descent lamps from the Edison Lamp Co. and from 
 most dealers in electrical goods. These little lamps 
 can be o[X‘rated (piite successfully by means of easily 
 constructed batteries. It is, of course, a little trouble- 
 some, and the (*x]x*use of the electric light produced in 
 this way is somewhat grc'ater than other lights, but 
 amat(‘urs can d(‘riv(' a gr<‘at deal of satisfaction from 
 Hiese (‘xix'riux'iits in eh'ctric lighting. 
 
 Tin; battejy may be made at home, from materials 
 
HOME MECHANICS FOR AMATEURS 
 
 233 
 
 that may be purchased from the manufacturers of the 
 lamps or from any dealer in electrical supplies. Each 
 cell of battery consists of two plates of carbon 2 in. 
 wide, 4^ in. long, and | in. thick, one zinc plate 2 
 in. wide, 4 in. long, and i in. thick, two strips of wood 
 4 in. wide, 4 thick, and 4 in. long, two strong 
 rubber bands, and an ordinary" tumbler. 
 
 The zinc is amalgamated by dipping it in dilute sul- 
 
 phuric acid (acid one part, water twelve parts), then 
 sprinkling on a few small drops of mercury, rubbing it 
 about with a swab formed of a piece of cotton cloth 
 tied around the end of a stick. Every portion of the 
 surface of the zinc should be covered with mercury. If 
 the amalgamation is perfect, it need not be repeated. 
 
 The carbon plates before use should each be heated 
 
IIOMK MKCMfAXICS KOI? AMM^KKIJS 
 
 2:U 
 
 a( one end and salnrat(‘d wiOi ])arariin(‘ for a dislaina* 
 of 1:1 in. from tlu^ n])i)(‘r (*nd (and no inoi^*) to ])!*(*- 
 V(mt tlu^ solution fr'oin as(‘(mdin<i tln^ ])lat(‘ ))y (‘a])illar- 
 ity. Tills is ae(‘oni])lisli(*<l liy In^atinin lli(‘ (*nd of tin* 
 plate over a lam]) and a])])lyini»' a ])i(*e(‘ of ])ai'anin(^ or 
 a ])araffine (-andle until it is till(Ml. No fi‘(‘(^ ])araf11n(‘ 
 should be allow(‘d to rcmiain on tin* snrfae(‘ of tln^ eai‘- 
 1 ) 011 , as it will int(n'f(n'(^ with niakini»‘ a i>()od (*l(M*trieal 
 eonne(*tion with the plate. 
 
 Fig. 215. A Tumbler Battery. 
 
 The zinc plate is jilaeed between the two wooden 
 stri])s. The (‘arbon plates are placed outside of the 
 strips and held by the two rubber bauds, as shown in 
 Fio. 214. 
 
 The coiiuectiou between the carbon plates and the 
 wire leading' away from tln^ cai'bon ])ole is made by a 
 donbl(*d strip, e, of (‘opper, tlu^ (mds of Avhi(4i are in- 
 S(n't(Ml b(4 w'(*(m lh(‘ woochm stri])s and the (*arbon ])lates. 
 In a similar way a (*op|)(*r strip, />, is inserted betw^een 
 
HOME MECHANICS FOR AMATEURS 235 
 
 f 
 
 the zinc plate and one of the wooden strips. The 
 tumbler forming the battery jar should be deep enough 
 to allow the wooden strips to rest upon its rim, so as 
 to support the plates a short distance from the bottom 
 of the tumbler. 
 
 The ordinary bichromate of potash solution is used 
 in the battery. It is prepared by making a saturated 
 
 solution of common bichromate of potash in warm 
 water ; then, after cooling, adding very slowly a quan- 
 tity of common sulphuric acid, equal to about one-fifth 
 of the bulk of the bichromate solution. It is advisable 
 to add to the solution a very small quantity of bisul- 
 phate of mercury, say one-eighth ounce to the quart of 
 solution, to maintain the amalgamation of the zinc- 
 
230 HOME MECHANICS EOT? A^rATECRS 
 
 Tli(‘ salts known as tlio (\ k ( \ 1>a<l(‘ry (‘oin])onn(l ar(‘ 
 oxrellont and V(nw com (‘iiicnit for ns(^ in l)att(*ri(*s of 
 this (‘lass. It is only n(‘(‘(‘ssary to dissoHa^ this conn 
 pound in wat(n‘ to form th(‘ (‘Xf'itinjj^ solution. 
 
 This mat(n‘ial is sold in tin (‘ans (‘ontainini^ two or 
 thiTG pounds. It absoT'hs moisture^ i‘a])idly, so that 
 wlum it is to Ix^ ns(‘d in sinall (|nantiti(‘S it shonld 1)(‘ 
 transf(n‘r(Ml to a sto])])Gr(Ml ,i>lass jar. 
 
 It is, ])erha])S, ikmxIIc^ss to say that ^r(‘at (‘an^ shonld 
 
 Fig. 217. A Series of Connected Lamps. 
 
 1)0 Gxerciscxl in handlinj]^ the solution, as it is poisonous 
 and (h^structive to clothing, carpets, etc. The same re- 
 mark a})])li(^s to the battery compound. 
 
 One c(dl of ibis battery should be allowed for each 
 candh^ j)ower of the lamp. The zinc of one cell should 
 b(i coniKX'bxl with tli(^ cai'bon of the lu^xt, khg. 215. The 
 batt(a‘y may lx* ari‘ang(*d as a ])lunger. Directions for 
 making a, batl(*i‘y of Ihis kind w(*r(* giy(*n on page 11(5, 
 of volnnui 57, of IIk* >SV‘/cn//7/r; A ntrrwan. 
 
HOME MECHANICS FOR AMATEURS 
 
 237 
 
 In Fig. 216 is shown a convenient bracket for sup- 
 porting small electric lamps. It consists of two curved 
 wires attached to a small piece of board by means of 
 screws, which also serve as binding screws for attaching 
 the wires. The lamp is suspended from eyes formed in 
 the ends of the wires. Tliis device may be used as a 
 standard, as shown at 1, as a hanger, as shown at 2, or 
 as a bracket, as at 3. 
 
 In Fig. 217 is shown a series of three small lamps 
 connected with three cells of battery. 
 
 The lamps in this case are connected in parallel or 
 multiple are, i. e., one binding screw of each lamp is 
 connected with one wire from the battery. The other 
 binding screws of the lamps are all connected with the 
 remaining pole of the battery. 
 
 Copper wire. No. 18 or larger, should be used for 
 making the connections. The battery will run continu- 
 ously with a single charge of the solution for about 
 three hours. Should the solution become warm and 
 give off hydrogen, the zinc should be reamalgamated at 
 the points where it is violently attacked. 
 
 THE ELECTRIC CHIME. 
 
 To secure practice in mechanics or in electrical work, 
 the amateur may as well construct something for 
 actual use. A very useful and pleasing electro-me- 
 chanical device is an electric chime to be used as a 
 door bell or call bell, or in connection with a clock. It 
 serves its purpose as a call and gives an ever-changing 
 series of harmonic notes. 
 
 The first step toward the construction of this device 
 is to purchase the toy known as the tubophone, and 
 
238 llOMK MI^XnrANK^S FOR AMA1M^:URS 
 
 sele(‘t tlire(" of tli( tubes wliieh pro(lii(*(» a (*lior(l, or if 
 the maker ])ref(‘rs it, lie may Imy a jiicM-e of maiulrf^ 
 drawn brass tnliinij;*, f in(*li (‘xternal diaimdca', with 
 walls sV in(‘b tlii(*k, and (*nt off tlircn^ |)i(H*(‘s r(^s])e(*tively 
 7f, 8f, and b| inebes in l(miL>;tli ; (nu'li of tbesc^ should b(^ 
 laid upon two short jiieees of soft woolen eord, with 
 
 th(^ cord tonehinf* at nodal points, that is, at exactly 
 oiK^ (piarter of the lenf»th from the end. Arranoed in 
 this way tlie tulx^s ^iv(‘ out a clear note when struck 
 with a small wood(*n malhh. ]>y com])arin<> these notes 
 with 1hos(* of a piano oi‘ otlnu' musi(*al instrument, the 
 tulx^s may Ix^ tum‘d. Tli(‘ iiitch is raised by shortening 
 
 Fig. 218. Electric Chime. 
 
HOME MECHANICS FOE AMATEUES 
 
 239 
 
 the tube, but as there is no practical way of lowering 
 the pitch after the tube has once been shortened, it 
 would be advisable to cut the tubes a little longer 
 than the measurements given. A baseboard having a 
 short standard is provided, and to the upper portion of 
 the standard is secured a board into Avhich are driven 
 three pairs of wire nails, the nails in each pair corre- 
 sponding in position with the nodes of one of the tubes. 
 The tubes are suspended from these nails b}" soft 
 cords passing around the tubes at the nodes or points 
 of no vibration, leaving the tubes free to vibrate at the 
 center and at the ends. 
 
 Now it remains to constriict the electro-mechanical 
 device for striking the tiibes. To the baseboard are 
 secured the angled ends of three strips of spring brass, 
 A inch wide and gV inch thick, which extend above 
 the tubes and carry small wooden mallets in position to 
 strike the middle portion of each tnbe. The mallets are 
 secured to the springs by means of ordinary wmod 
 screws passing through the springs into the mallets. 
 
 Behind the springs, at or near their mid-length, is 
 placed a diagonal strip of wood, having secured to its 
 outer edge a strip of felt or chamois skin. The spring 
 strikes this piece and allows the mallet to strike the 
 tube and spring back without jarriug. Behind the 
 springs is supported a small shaft on which is placed 
 a wooden cylinder about 1 inch in diameter and 2^ 
 inches long. In the cylinder and opposite the springs 
 are inserted wire nails, arranged to strike short in- 
 clined strips riveted to the springs. The nails are 
 placed so that they will strike the inclined strips in 
 different orders; for example: 1, 2, 3 ; 3, 2, 1 ; 2, 3, 1 ; 
 1, 3, 2. 
 
240 ][()MI': MECHANICS FOl! A:\I ATHUItS 
 
 A toy (“l(“cti‘ic motor liaviiij; a tlir(‘(‘-))ol(‘ armature* 
 is list’d for tiiriiiu<i: tlie cyliiidcr, ami two clock wlu’cls 
 and a pinion are* emplovt’d for ri’ducinn tlie siioed. A 
 worm is jilaccd on tlu’ armatiiro sliaft of the motor, 
 Avliich (*n<ja,i>(’s tlu* first of the clock wheels. This worm 
 may lie cut in a lathe, hut if this is inconvenient, a 
 Avire may be Avoiind sfiirally around tlu’ armature shaft 
 and solderc’d. It Avill, of course*, he ne*e-e*ssary tei Avinel 
 the spiral so that it Avill fit the teeth eef the chick Avheel, 
 and the surplus seileler shemhl he scra])e*el fi-emi the Avire 
 to eliminish friction. The motor is preivieled Avith hinel- 
 ini*' posts to receive the hatte’rv Avii-e*s. One eir tAvei cells 
 of dry battery Avill run the chime. The* chime is nseel 
 in place of an eirelinary call eir deieer he*ll, or it may he 
 used in connectiem Avith a clock, as sheiwn, for making 
 calls at certain hours. 
 
 The iiiish button shoAvn in the sectional A’ieAV is made 
 to close the circuit Avhen the chime is nseel in place of a 
 call hell or door hell. The hnttou is readily made by 
 boring a small block. A, of hard Avood in two diameters 
 to receive the head and back of the pearl collar button, 
 the back of Avhicli is held in place by the apertured 
 piece of A'eneering secured to the face of the block by 
 small screws, AA’hile tlie head of the button rests on a 
 cnrA'ed brass spi'ing, C, secured in a slot in the back of 
 the block. A, by a scroAV. The outer end of the spring 
 proj(*cts b(*yond the side of the block to receive one of 
 the circuit wiri’s. This slot is filled beloAV the spring 
 Avilh insulating mat(*rial, and a brass plate, D, is 
 secured to tin* back of tin* block, .1, and has upon one 
 edg(* an ap(*i( iir(*d (*ar for r(*c(*iving the other circuit 
 Aviri*. Tin* plalc*, />, is secnri’d lo tin* back of the block 
 by small scri’ws. Tin* fr(*(‘ end of the spring, C, is 
 
HOME MECHx\XICS FOR AMATEURS 
 
 241 
 
 curved over to a point near the brass plate, D, so that 
 when the spring is depressed by pressing the button. 
 B, it will touch the plate and close the circuit. 
 
 The annexed diagram shows an appliance which en- 
 ables the chime to be used in connection with a clock. 
 
 
 In front of the dial of an ordinary clock are secured 
 the rings, A, B, made of inch square brass wire. 
 The supports are of insulating material, and the rings 
 are concentric with the arbor carrying tlie hands. The 
 hands are bent outwardly to permit of extending over 
 the rings without touching them, and to insure the 
 hands against electrical contact with the rings a thin 
 short sleeve of paper is slipped over each hand near the 
 free end. Each ring has several small radial holes 
 bored in it to receive the brass nails, the heads of which 
 project sufficiently bej’ond the front surface of the 
 rings to enable the hands to touch them as they pass. 
 
 The circmit wires connecting the battery and the 
 chime are connected one with the outer ring. A, the 
 other with one of the springs of the cut-out switch 
 shown in the opening formed by the breaking away of 
 the dial. The other spring is connected with the inner 
 ring, B. The springs are insulated from each other. 
 
 On the sleeve which carries the hour hand is mounted 
 the crossed slotted cam, C, also shown detached in the 
 
242 
 
 llOMI^] MECHANICS EOJI A.MATEUl^S 
 
 lar|L>er figure. In tli(‘ slot of tliis (‘am is a boat-shajxMl 
 follower, which sliders easily in the slot and is longcn* 
 than the width of tlu^ slot, so that it can, in following 
 
 Fug. 219. Chime with Clock connection. 
 
 1h(^ slot, 1ak(^ th(‘ inmn* and oiitcn* portions of the slot 
 in alt(n‘nat ion. Tlu^ followin' is j)i voted to the angled 
 l(W(*r, (/, which is juisIkmI by ilu^ (‘am Ixdwaxm the par- 
 all(‘l springs and w ithdrawn from them in alternation 
 
HOME MECHANICS FOR AMATEURS 
 
 243 
 
 once in 12 hours. The object of this arrangement is 
 to cut out the chime at night and put it in circuit in the 
 daytime. The cam, C, and the angled lever, a, are 
 insulated from the clock movement. 
 
 A switch, D, is provided for throwing the device out 
 of action at anv time. 
 
 It will be seen that the hour hand must come into 
 contact with the nail on the inner circle and the minute 
 hand must touch the nail in the outer circle to com- 
 plete the circuit, and cause the chime to sound. The 
 duration of the chiming is limited by the time the 
 miniite hand is in contact with the nail. The clock 
 when arranged as here shown sets off the chime at 8 
 o’clock, 12 o’clock and 5 o’clock. It is now about to 
 ring the chime for 12 o’clock. 
 
 HOME-MADE ELECTRIC NIGHT LAMP 
 
 A very simple device, which will produce a temporary 
 light of one-half of one candle-power, is shown in the 
 illustration. It will be found convenient for observing 
 the time at night, or for momentarily lighting a closet 
 or an area where the light of a candle or an oil lamp 
 would be objectionable. 
 
 The miniature electric lamp, and the dry batteries 
 used for lighting it, can be purchased almost anywhere, 
 and the labor of putting these things together, with a 
 switch and suitable connections, is very slight indeed. 
 A one-half candle lamp requiring 1.58 amperes at 2.5 
 volts is the first requisite; then two cells of dry battery, 
 giving a current with a pressure of about 3 volts will 
 be needed, and last of all a small packing box, that will 
 just receive the batteries, should be selected. If a 
 
344 HOME MECHANICS FOR AT\rA1MajRS 
 
 lain]) of liii>liei* yoltaj^o is ('liosoii, laorc^ (‘(*lls of l)atIory 
 Avill l)(‘ ii(‘(mI(‘(1. a 4-volt, lain]) will IlircM^ (‘(4Is 
 
 of battery. A little mor(Mi<»lit will scxaircMl willi this 
 
 Fig. 221. Battery Box, cover removed. 
 
 Fk;. 222. Temporary Light. 
 
 roiiibinal ion, bill il is nol (l(‘sirabl(Ho iinax^ase tlienum- 
 b('r of ((‘lIs b(*yon(l lliis, as lln* apparatus Ixx'oines at 
 once* loo bulky and loo (‘x jaaisi V(‘. Tli(‘ b(‘st ('oinbiiia- 
 
245 
 
 HOME MECHANICS FOR AMATEURS 
 
 tion is the one-half caudle lamp wih two cells of bat- 
 tery. After the lamp is procured it should be tested mo- 
 meutarily by means of two cells of dry battery, con- 
 nected in series. If the lamp is properly lighted, a 
 packing box which receives the batteries easily is se- 
 
 FiCx. 223. Diagram of Circuit. 
 
 lected, and two small brass hooks, f g, are straightened 
 and screwed into the box near the top. Small copper 
 wires are placed in electric contact with the hooks, f g, 
 as shown in the diagram. At the top of the box is 
 placed a switch, consisting of a piece of spring brass 3 
 inches long and | inch wide held in place by a pivotal 
 screw, c, passing through a central hole in the spring 
 into the box. 
 
 In one of the views the lamp is represented as being 
 supported by a hollow wooden column in front of a 
 clock. In this case one of the lamp wires is incased in 
 a very small rubber tube, to insure insulation; other- 
 wise the construction is similar to that described. 
 
 Two cells of dry battery will light the lamp occa- 
 sionally for a long time, if used only an instant each 
 time; but if the lamp is used continuously, it runs the 
 battery down, so that it will require frequent renewal. 
 
 The wire from the brass hook, f, is placed in electrical 
 
240 
 
 HOME MECHANICS FOR AMATEURS 
 
 contact Avitli tliis screw, c, an<l two brass screws, h c, 
 are inserted in the top of the box, to serve as contact 
 points for tli(“ switcli. 1du“S(‘ sci'ews are connected to- 
 gether and with tlie zinc ])(»!(“ of tlie cell, o', by a wire. 
 The carbon ])ole of the cell is coniu'cled (‘lectrically 
 with the hook, //. The liooks are curved downwai'diy 
 and the terminals of the lamp, a, are wound three or 
 four times around the ends of the liooks, f </, respec- 
 tiveh", so as to support the laniji above and in front of 
 the face of the watch, hanging upon the hook, project- 
 ing from the front of the box. 
 
 The longer arm of the switch is turned uji to form 
 a thumh piece, and is held normally out of contact 
 with the screw, h. Hy pressing the end of the switch 
 doAvu into contact with the screw, h, an electrical con- 
 tact is formed which lights the lamp. By turning the 
 switch on its pivotal screw, c, it is brought into contact 
 with the screw, c, thus forming an electrical contact, 
 which is prolonged until the switch, is returned to its 
 original position. The movement of the switch is 
 limited by the screws, d d. 
 
 AN ELECTRICAL CABINET 
 
 An electrical cabinet is an assemblage of articles 
 which may he combined in various ways to produce 
 pieces of apparatus. By these a large number of ex- 
 jieriments are made accessible to the amateur at com- 
 jiaratively slight expense. 
 
 In Fig. 224 sectional drawings of the essential parts 
 are shown, drawn v(“ry nearly on a third scale. A are 2 
 coils, Avound Avith 8 layers of No. 20, single cotton cov- 
 ered magn<‘t Avir(‘, both Ix'ing Avouud in the same direc- 
 
HOME MECHANICS FOR AMATEURS 24^ 
 
 tion. B, the cores and yoke of an electromagnet, the 
 cores of f inch soft iron bar. C, the frame for support- 
 ing the electromagnet when used as the field coils of a 
 dynamo or motor as in Fig. 237. D, a wooden stand, 
 turned in a lathe, to be used as a support for the com- 
 
 Fig. 224. General View of Parts. 
 
 J1 
 
 
 pass E, to form a galvanometer, as in Fig. 229. F, a 
 permanent horse shoe magnet. G, soft iron wires. 
 H, strips of copper. K, frames for telegraph sounders. 
 
 By the aid of the Figures for the several experiments 
 the practical amateur will have little difficulty in see- 
 
248 HOME ]\IECTIANICS FOE A:\IATEUES 
 
 ills' iiififlc- put tosotlicr. Tlie poritm- 
 
 neiit inas'net and tlio oonpiass can 1)(‘ jmrcliascd to hot- 
 ter advantaso. Tlio rest can ho made witli a lathe 
 and tools. Some No. 28 spring brass wire will he 
 needed for the springs shown on the telegraph sounder 
 
 Fig. 225. 
 
 Effect of Iron on a Magnet. Fig. 226. Decomposition of Water. 
 
 at the left, and some No. 18 spring brass wire to be 
 Avonnd into a close spiral a little less than a half inch 
 in diameter, and cut up into pieces of about 3 turns 
 each to be used as connectors in place of binding posts. 
 
 In describing the several experiments such addi- 
 tional instruction will be given as the case may seem 
 to reipiire. 
 
 The action of iron on a magnet is shown in Fig. 225. 
 Present the end of an iron rod to the compass. The 
 needh* is drawn towards the iron and swings till it 
 points directly towards it. The magnet P may be used 
 for this exi>eriment. The north or marked end of the 
 magnet rejxds the north end of the needle and attracts 
 its south end. As we say, like poles repel, unlike at- 
 tract. Th(* brass and glass cannot stop the attraction. 
 Paper, wood, anything excejd iron, may be interposed 
 
HOME MECHANICS FOR AMATEURS 
 
 249 
 
 between the magnet and the needle without destroy- 
 ing the attraction and repulsion. 
 
 The decomposition of water into two gases, oxygen 
 and hydrogen, by electricity is a very interesting ex- 
 periment. For its best exhibition platinum is required, 
 but as this is a very expensive metal a method is given 
 by which one gas can be produced. Fig. 226 gives the 
 arrangement of the apparatus. The light and heavy 
 parallel lines indicate cells of battery. Two at least 
 are required. A good form of cell is represented in 
 Fig. 229. The glass is a common tumbler. Two plates 
 of battery carbon and one of zinc are clamped together 
 by two bolts Avhich pass through the four strips of 
 wood. Strips of sheet copper or brass, d and e, are 
 included between the strips; d is cut long enough to 
 
 Fig. 227. Galvanometer. 
 
 Pig. 228. Electroplating. 
 
 connect with both carbon plates. Two of the spirals 
 described above are pushed on these strips to receive 
 the copper wires used in forming the circuits. This 
 sort of connector is nearly as good as a regular binding 
 post and costs a mere trifle. 
 
250 
 
 HOME MECHANICS FOK AMATEUES 
 
 The fluid for the cells Is made by dissolving in cold 
 water as much bichromate of soda as the water will 
 take up, and addin"’ slowly and with constant stirrin" 
 one-tenth of the volume of sulphuric acid. The plates 
 should only remain in the solution while they are in 
 actual use. 
 
 The tumbler shown in Fig. 226 is to be filled with 
 water and a little sulphuric acid added. Lacking the 
 acid, vinegar may be used in its stead. 
 
 ^Cith tw'o cells fitie bubbles of hydrogen gas come off 
 slowly from the copper which is attached to the wire 
 leading from th(“ zinc of .the battery and rise to the 
 surface. The o.xygen combines with the copper and 
 do(‘S mtt appear as a gas at all. If platinum were used 
 
HOME MECHANICS FOR AMATEURS 
 
 251 
 
 for the other strip oxygen would be given off from its 
 surface, since oxygen does not combine with platinum 
 under these conditions. This most interesting experi- 
 ment was first performed by Sir Humphry Davy many 
 years ago. 
 
 Fig. 227 shows how to arrange one of the coils A, 
 the compass E, the support D, and the battery as a 
 galvanometer. Place the coil so that its length is east 
 and west and place the compass over the coil. The 
 needle will lie crosswise of the coil. When the current 
 
 Fig. 230. Sucking Coil. Fig. 231. Lines of Magnetic Force. 
 
 flows the needle is turned from its north and south 
 position. The laws and meaning of this is explained 
 fully in the text books of electricity. 
 
 Electroplating has become one of the most important 
 industries. It can be performed with the apparatus of 
 Fig. 228. The arrangement is the same as that of Fig. 
 226, except that the tumbler is now to be filled with a 
 liquid containing the metal with which the article is 
 to be plated. To plate with copper a solution of copper 
 sulphate may be used, though carbonate of copper is 
 better; for nickel a double carbonate of nickel and 
 ammonia is used. The metal will be deposited on the 
 
252 
 
 llOMK MECHANICS FOI! A.M A'l’KU l!8 
 
 strip attaclied to the wire from tlie zinc, tliat one on 
 wliich tlie h.ydrogen appeared when water was d(*com- 
 posed. The other strip must he of the metal with which 
 tlie plating is to be done. 
 
 Fio. 232. Mode of Inducing an Electric Current by a Magnet. 
 
 More instruction and much experience will be re- 
 quired for real work; but much pleasure can be de- 
 rived by watching the process in this simple manner. 
 Three or four cells should be used for depositing nickel. 
 
 If a copper wire is passed straight through the fix- 
 ture D, and the parts are set up as in Fig. 229, it will 
 constitute a detector galvanometer, suitable for large 
 currents, as the arrangement in Fig. 27 is adapted for 
 
 Fici. 233. Mode of giving an Electric Shock. 
 
 fcclile currimts. The wire in all cases must be placed 
 noi-th and south, or lengthwise of the needle when at 
 
 rest. 
 
 vei-y many. It is tli(‘ most imiiortant piece of electrical 
 
HOME MECHANICS FOR AMATEURS 253 
 
 apparatus, aud was iuvented by Sturgeon of England 
 and also by Prof. Joseph Henry in America. Probably 
 neither knew the work of the other. Henry’s inven- 
 tion led directly to the electric telegraph. Fig. 231) is 
 given as an illustration of the power of a helix to draw 
 iron or steel into itself. If a strong battery is used 
 the pen is sucked into the coil with considerable force. 
 A large number of small wire nails may also be held 
 up in the coil without visible support. It is Avizard- 
 
 Fig. 234. Microphone, 
 
 like to see a piece of heaA'y metal hanging in the air 
 upon nothing. Numerous modifications of this curious 
 experiment Avill suggest themselves to an ingenious 
 person. 
 
 With the tAvo coils A, put upon a U-shaped iron 
 rod I inch thick, as in Fig. 231, the beautiful mag- 
 netic phantom or magnetic field of force can be made 
 visible. The wires from the spools are connected to 
 the battery, Avhich is not shoAvn. Join the tAVO spools 
 together so that the outside of the Aviuding of one is 
 
254 
 
 llOMK ME('IIAN1(!S FOlt AMATKUJJS 
 
 coniH’cted to tlio inside of the windin'^ of tlie otlier. A 
 tliin board is laid over the poles aTid iron filin<j;s sifted 
 over the board. Then tap the board <f(‘ntly with the 
 tip of a finger. The filings jump with sudden alac- 
 rity into lines, definite and exact. The figure shows 
 these lines. It means magnetic attraction. Now 
 change the connections. Join the two outside wires of 
 the spools to the battery and the inside wires to each 
 other. The figure changes to one exhibiting repulsion. 
 The lines shun each other. 
 
 If blue print paper be ])inned on the board and the 
 whole exposed in the sunlight, fine photographs may 
 
 Pig. 235. Electromagnet for Lifting. 
 
 be made of these beautiful figures. By using horse 
 shoe and bar magnets, endwise and flatwise, a great 
 variety of magnetic fields may be mapped. 
 
 Next arrange tbe apparatus as in Fig. 232. The 
 compass m-t'dle is strongly deflected from its north and 
 south jmsition. Now remove the battery and close the 
 circuit. Blunge a bar magnet into the right hand coil. 
 1’he ni'edle swings, though not so strongly as before. 
 .An electric curnmt is gmierated so long as the magnet 
 is in motion, (‘ith(‘r in or out of the coil. 
 
 If the cores of tlnj coils in hfig. 232 are filled Avith 
 iron wires a cnrrmit may b(‘ generated by simply tak- 
 
HOME MECHANICS FOR AMATEURS 
 
 255 
 
 ing the right hand coil in the hands, holding it north 
 and south and turning it over quickly. These effects 
 were discovered by Ampere, for whom the unit of cur- 
 rent is named. The student should look up the subject 
 in text books of electricity. 
 
 The giving of electric shocks to one’s friends is al- 
 ways a pleasant pastime. One mode of doing this is 
 illustrated in Fig. 233. Of course no severe shock can 
 be given in this way. The metal handles of Fig. 238 
 should be connected to the open ends of the wires to 
 
 Fig. 236. Electric Telegraph. 
 
 the left. Scrape the ring along the file and a slight 
 shock will be felt by one whc grasps the handles with 
 moist hands. The shock is produced by an induced 
 current. The arrangement is a very simple form of 
 induction coil. As the making of a strong coil is a 
 difficult matter, a special and full description of the 
 coil to be made should be obtained before undertaking 
 such a piece of work. 
 
 Fig. 234 is a microphone. Two bits of iron wire, or 
 bright wire nails, p, are connected to the wires and laid 
 
25(! 
 
 IlOMI-: MKCIIANK'S KOI! AMATKKliS 
 
 oil (lie to]) of a box iiiadc* of fhiii wood as shown. Pine 
 is to be jireferri'd. A slieet of iron is laid njion tb(‘ toj) 
 of the eleetroinasnet. On tajijiinj^- (lie box gently a 
 inneb louder sound will b(‘ beard from the sbeid of 
 
 Fig. 237. Dynamo or Motor. 
 
 of the invention of the transmitter of the telephone. 
 If a telephone receiver is used in place of the electro- 
 magnet and sheet of iron, the feeblest sounds produced 
 on tlie top of the box are greatly intensifled. The 
 microphone box may even be used as a telephone trans- 
 mitter if tlie wires are long enough to permit it to be 
 T;lac(Hl in another room, and all the parts are suffi- 
 ciently delicate. 
 
 Tlie arrangement of an electromagnet for lifting pur- 
 fioses is shown in Fig. 285. By means of a spring 
 balaiic(* oiK^ may find ilu^ ])ull necc^ssary to remove the 
 annatnr(‘ wIkmi 11i(‘ niimbei' of (‘(^lls of the battery is 
 vni'icMl from oik^ (‘(*11 ii]) to ils full (‘apacity. The iron 
 bur iis(*(l as an annatur(^ should always be as large in 
 cross S(*cliou as I Ik* iron coih^ of llu^ magmd. 
 
HOME MECHANICS FOR AMATEURS 
 
 257 
 
 Fig. 236 will guide one in setting up a telegraph line, 
 with a station at each end. The key is simply a strip 
 of spring sheet brass. When not in use it is pressed 
 down and caught under the head of the screw beyond 
 it so as to close the circuit. The construction of the 
 sounder is so simple that it will not be given in detail. 
 The most difficult part to adjust is the vibrating arm, 
 m, whose blows against the slot in the post to the right 
 produce the sound which gives the name to the instru- 
 ment. The vibrating bar should not strike the electro- 
 magnet Avhen it is pulled down, nor have a very wide 
 range of motion. The bar must either he wholly of 
 iron, or better, have a block of iron riveted to it, since 
 brass is not attracted bv a magnet. The tension of the 
 fine wire spring on the left determines the force neces- 
 sary to pull the bar down. 
 
 Fig. 238. Shocks by Rotating Coil. 
 
 To work the telegraph swing tlie key from under the 
 head of the screw which holds it down. This opens 
 the circuit. The bar of the sounder flies up. Now, 
 press the key down till it touches the wires below it. 
 The current from the battery flows and the armature 
 is jerked down, giving a sharp blow on the post Avhich 
 detains it. As the kej^ is moved down and up the arma- 
 
258 liOMP] MECJIANICS FOE AilATFUJJS 
 
 tiire moves down and nj), ])r(»dncinj;' iln* clicks wliicli 
 all have heard in a t(‘l(“i>ra])h <»nic(‘. 
 
 By i’(*ttin,n' a Morse al])liahet and niastcrin_<j tlie art 
 of i)i‘odncin<^ dots and dashes two ])ersons may soon 
 learn to send messai^es to each other. 
 
 A model of a dynamo may he hnilt from the parts, 
 A, B and C, of the cahimd. This is shown in Fiij. 2.37. 
 The electro-maju'net formed hy A and B is fixed upon C, 
 and the circuit completed hy short pieces of ma^^net 
 wire. The open ends to the h‘ft may he connected to 
 the galvanometer, I) and FI, to detect the current. 
 
 The rotating coil, H, and tlie commntator -T, are 
 somewhat difiticnlt of constrnction. The coil consists 
 of about 100 turns of Xo. 20 single cotton-covered 
 magnet wire. The inner end of the wire is soldered to 
 one of the half rings of the commntator, the outer end 
 to the other half ring. 
 
 On whirling the coil rapidly a feeble current will be 
 produced. The current will he reversed, if the coil is 
 whirled in the opposite direction. 
 
 This tiny dynamo may be transformed into a series 
 wound motor hy connecting the battery in place of the 
 galvanometer. 
 
 By changing the connections as shown in Fig. 238, 
 the electric current may be felt in the handles when the 
 armature is whirled rapidly. 
 
 Though the experiments described by no means ex- 
 haust the subject, nor the resources of the electrical 
 cabinet, still they jdace Ixdore the studious amateur 
 enough to em|)loy many an hour most profitably, and 
 to incite him to further study and to higher work. 
 
HOME MECHANICS FOR AMATEURS 
 
 259 
 
 SIMPLE ELECTRIC MOTOR 
 
 Almost every young amateur mechanic is desirous 
 of making sometliing liaving the ability to move and 
 show action. An electric motor does this; and while 
 the mechanic is making a good piece of machinery, 
 he is also learning the principles of electricity. 
 
 The motor we shall describe is intended to turn a fan 
 or light machinerv bv means of a current derived from 
 a battery. It will drive a light sewing machine or 
 other machinery requiring a similar amount of power, 
 and it is so simple as to admit of being constructed 
 with the tools ordinarily possessed by an amateur. 
 
 To begin a motor at the right point is very import- 
 ant. The first thing to be done is to construct the 
 armature — the part which revolves. On account of its 
 simplicity, we have selected the Gramme armature. 
 
 The core of this armature consists of a ring formed 
 of No. 24 sheet iron. A strip f inch wide and 8 feet 
 long (the length of a sheet) is carefully cut from the 
 sheet and wound upon a cwlindrical piece of wood in 
 the lathe or by hand. The wood cylinder is If inches 
 in diameter and 1 inch thick, and in the edge is cnt a 
 shallow notch of a depth equal to the thickness of the 
 sheet iron, as shown in Fig. 240. In the iron, ^ inch 
 from the end is drilled a hole, countersunk to receive 
 a wood screw, which passes through the sheet iron 
 into the wood, and fastens the end in the notch in the 
 wood. The sheet iron thus attached to the wood may 
 be wound closely around the wooden mandrel withoiit 
 a kink being formed by the inner end of the strip, 
 which is in the notch. 
 
 Before beginning the winding, a piece of strong an- 
 
260 HOME MECHANICS EOK AMATEUES 
 
 nc“al(‘(l wire, slovc'-pipe wire for example, is jEaced in 
 a liandy position, and when nine layei'S of Hie iron 
 have been wound tlie striji is ent off and Hie liindini^ 
 wire is wrapped around Hie coil and twisted toiiether 
 at the ends, to keep the sheet iron from unwinding. 
 
 Fig. 239. Electric Motor. 
 
 The wood and tin* coiled sheet iron are together 
 removed from (In* hiHu* (or vis(‘ if it is being done by 
 hand), and placed in a lir(‘, which will h(“at the iron 
 to a cherry red and burn out the wood. The ring is 
 
HOME MECHANICS FOR AMATEURS 
 
 261 
 
 then covered with ashes and allowed to cool slowly. 
 This anneals the iron, and improves its magnetic per- 
 meability. 
 
 After removal from the ashes, and while the binding 
 Avire is still in place, the ends are secured by passing 
 riA'ets through them ; the inner end, which AA’as bent, is 
 cut off, and the ends are beveled Avith a tile, and all 
 the sharp corners are reduced by the same means. 
 
 The core of the armature is then covered with adhe- 
 siAm tape (either electi’ical or bicwcle tire tape), AA'hen it 
 is ready to receiA'e the magnet Avire Avith Avhich it is to 
 be AA’Ound. The ring is diAuded into tiA^e equal sec- 
 tions, and marked Avith a pencil to shoAV Iioav much 
 space each coil of the armature is to occupy. There 
 are five coils on the armature, Avith five laj'Ci’s in each 
 coil. No. 21 single or double cotton or silk coA^ered 
 wire is used. It requires about 28 feet of Avire for each 
 coil. The Avinding is a. sIoav and rather laborious 
 process. The length of Avire for a coil is Avound on a 
 sort of shuttle-stick J inch Avide, 12 inches long, Avith 
 a notch in each end. The end of the Avire is Avrapped 
 twice or three times around the ring over a piece of 
 stout thread, Avhich is tied around the Avires to fasten 
 them together, to begin a coil. Of coiirse, the begin- 
 ning is at one of the marks on the ring. 
 
 Noav the shuttle is passed through the ring and 
 brought back oA’er the outside until one layer covers 
 one space; then commencing the Avindiug oA^er the 
 first layer the second is laid on, then the third, fourth, 
 and fifth; all the layers are AA’ound in the same way. 
 The last three or four turns are mad(? over a stout 
 thread, Avhich is tied Avhen the last convolution is 
 made. 
 
2C2 
 
 HOME MEOTIANICS EOE AMATEUES 
 
 Tlio otlioi' coils of the iiniialnit* ar(^ made in the 
 same way, and wlum tin" winding is all on, the end of 
 one coil is f\vist(“d with Ihe heiiinninn’ of tin* adjac(*nt 
 coil. A piece of well season<‘d hard wood, hai'd mapl(“, 
 for exam])le, is horc'd to rec(‘iv(‘ a ]dece of inch drill 
 rod — Stnhs or sonndhinj;' ecpially n'ood — which consti- 
 tutes the shaft. This rod is 4 inch(>s lon<i'. A iV inch 
 Inde is drilled transversedy thronjih it at or near the 
 center to receive* a short pin which enters a slot in the 
 end of the wooden hnb. 
 
 This i)iece of wood is turned to tit the interior of the 
 armature, and is ent off ahont tin*, same length as 
 the armature. The coils of the armature and the 
 Avooden hnh are now varnished with thin shellac var- 
 nish, and allowed to dry thoroughly. The armature 
 ring is then slipped into its place on the wooden huh, 
 and the hnh and the ring are coated with two coats of 
 shellac varnish, one coat being allowed to dry before 
 applying the other. 
 
 The next thing to claim attention is the commutator. 
 This is a core of wood fitted to the armature shaft and 
 turned to fit a piece of brass or copper tube f or f 
 inch in diameter and f inch long. This tube is divided 
 into five* divisions, and parallel lines, preferably slightly 
 spiral, are drawn from the divisional points marking 
 the ]tlac<*s wh(*r(‘ the tube is to be saAved to form the 
 commutator bai's. But Ix'fore saAving, each end of 
 each s]>ac(* Avhich is to form a bar is drilled, and the 
 hob* is conntei-snnk to rec(*ive a small Avood screAA*, 
 which ]»asses into tin; wood and holds the bar in 
 plac(* when lln* brass tnlx* is saAved on the lines to 
 separa((‘ the bars. After sawing, the commutator is 
 turn(*d smooth and round, or filed in the lathe Avith a 
 
HOME MECHANICS FOR AMATEURS 363 
 
 smooth file. The screws used in fastening the commu- 
 tator bars must not touch each other or the shaft. 
 
 The twisted terminals of the coils are now stripped 
 of the winding at the ends and soldered to the commu- 
 tator bars, having been cut off the proper length to 
 reach to the commutator. 
 
 Before soldering, however, the ends of the terminals 
 and a small portion of each commutator bar are tinned 
 to facilitate the work of soldering. To tin the copper 
 
 Fig. 240. The Armature Core. 
 
 wire, a little pulverized rosin is rubbed on the ends of 
 the wires, and the solder is applied with a soldering 
 iron. 
 
 Tlie commutator bars are tinned for inch at the 
 ends nearest the armature ring in the same manner. 
 
 The terminals of the armature coils are bent so as 
 to touch the commutator bars at the tinned surfaces; 
 the beginning of one coil and the end of the adjacent 
 coil being thus brought into contact with a commutator 
 bar. They are then soldered by applying a drop of 
 solder by means of the soldering iron. The wires are 
 
264 
 
 HOME MI^CMIAN K^S FOl? AMATKUKS 
 
 tlnis made to answer tln^ (loiil)l(^ ])nr])()S(‘ of (*onv(‘vin^ 
 tile enrreiit to the eoiniiiiitalor bars and of (‘ansinu^ tin* 
 eoinnuitalor to revolve with the annatnri*. Arid must 
 not be used in soldering’ (4(‘('tri(‘al eoniuHd ions. 
 
 To rnn smoothly, the armatnr(‘ must be in balan(‘(\ 
 To ascertain Avheth(‘r it is in balam-e, ])lace tin* arma- 
 ture shaft on the (m1il»(‘s of two l(‘V(d straii»ht-(*diL»;(‘s sup- 
 ported about 4 iiK'hes ajiart. If the armature will 
 stand in any position, it is balanccMl. If it rolls so that 
 one side after a few os(‘illations of tln^ aianatnre i»()(^s to 
 the bottom, the to]) must be made heavier to ('onntin'- 
 balanee the bottom. Jb'obably the Ix^st Avay to add 
 weight to one side of the armature is to apply it in the 
 form of solder to a band of wire abont f inch wide 
 wound aronnd the armature. Ilefore this winding is 
 applied, a strip of mica f inch wide must be wrapped 
 around the armature and secured in place by shellac 
 varnish applied to both the armature and to the mica 
 and allowed to become nearly dry. It is not necessary 
 to nse a continnons piece of mica ; it may be in several 
 pieces. When the armature comes to rest after oscilla- 
 tion, solder should be applied to the upper side of the 
 wire band until the armature will stand in any posi- 
 tion. If too much solder is applied, the surplus may be 
 removed by a coarse file. It is important to have the 
 armature as nearly in balance as jiossible. It will then 
 liave \ory little vibration, or none at all, while running 
 at any rc^asonable sjxhhI. 
 
 (Airc^ should Ix^ ns(‘d in all the operations connected 
 with this motor to insure entire siu'cess. 
 
 Th(^ n(‘\t thing to b(‘ done is to construct the field 
 magiK't, which in this motor is in the form of a ring, 
 as shown in hhg. 241. The cor(‘ of the field magnet is 
 
HOME MECHx\NICS FOR AMATEURS 
 
 265 
 
 formed by winding four strips of No. 24 sheet iron f 
 inch wide and 8 feet long upon a wooden core, as in the 
 case of the armature core. The form on which the 
 field magnet is wound being inch larger in diameter 
 than the armature, and as this is variable, it must he 
 ascertained after the armature is wound and balanced, 
 on account of the variation in the winding depending 
 on the covering of the ware and the care with which it 
 
 Fig. 241. Field Magnet Core. 
 
 is wound. In the motor illustrated, the field magnet 
 ring is 2f inches internal diameter and 44 inches ex- 
 ternal diameter. Before winding the field magnet core, 
 the ends of the 8-foot strips are scarfed or beveled off 
 and tinned, and then soldered together and coiled for 
 convenience. 
 
 The strips should be wound upon the form as tightly 
 as possible, and when the last layer is on, a stout wire 
 is wrapped around the outside and twisted together to 
 
2r,r, TTOMP] MECHANICS VOM AAIA^rKlIK’S 
 
 keo]) the sluH^t iron stri]) fi'oin nnwiii(liii^, as in 11i(^ 
 ease of tln^ arinatiire (‘or(‘. 
 
 As it is not nec-essary to ann(‘al th(‘ Ii(‘l(l ina<»:n(‘t, the 
 wooden form is r(miOA(‘d by boring a liole Ilironi»ii it 
 and tlien splitting the wood so that it (*an Ix^ r(miov(xl 
 piecemeal. The coil of she(d iron foimiing iln^ field 
 magnet core is eomposcMl of thirty-thix^e lay(‘rs. 
 
 The ring is divided into four qnartm's by radial lim^s, 
 and midway between two of these lines, on o])])osit(^ 
 sides of the ring, are drilled holes for rivets im-h in 
 diameter, the holes being (*onntersnnk slightly on (‘ach 
 side. These rivets with slight heads are inserted in 
 the holes, with the heads inside the ring. They are 
 then neatly riveted at the outside, leaving the inner 
 side as smooth as possible. To accomplish this, it is 
 necessary to move the binding wire away from the 
 center of the field magnet ring. 
 
 When the two rivets are in the binding wire 
 
 mav be removed; then in the same sections near the 
 ends are placed rivets, one at each end of each section. 
 Tlie sections riveted in this manner form inwardly 
 projecting pole pieces. While drilling* the holes for 
 the rivets, it is necessary to clamp the strips firmly to- 
 gether to prevent the drill chips from working in be- 
 tween the layers of the magnet. Eleven layers of the 
 magnet ring are sawed ont between the pole pieces to 
 make a space for the w'inding of the field magnet; the 
 ends of the ynde pieces are beveled as shown to facili- 
 tate winding. Th(“S(* spaces are covered with adhesive 
 tape and ar(‘ wound with four layers (about 45 feet) of 
 \o. 18 magnet wire, either single or double, cotton or 
 silk cover(‘d. 
 
 One of the y)ole pieces will be at the bottom of the 
 
HOME MECHANICS FOR AMATEURS 
 
 267 
 
 field magnet and the other at the top when the motor 
 is complete; therefore the winding on each side of 
 the field magnet begins at opposite sides of the same 
 pole piece, and is wound in the same direction to bring 
 the wire terminals near the base of the machine, and 
 
 to cause the current in the two windings to unite in 
 producing a north pole at the top of the magnet and a 
 south pole at the bottom, or vice versa. If a mistake 
 is made in the winding, this can be corrected in making 
 the connections. It is not necessary to unwind and 
 rewind. 
 
208 
 
 HOME MECHANICS FOK AMATEURS 
 
 The constniction of tliis inajiiiol is ojxoi lo criticism 
 oil account of the disposition of tin* lainimo, but this 
 constniction is partly or wholly compensated for by tin* 
 large rivets, which bind the jiole pieces and the body 
 of tlie magnet together. 
 
 The holes are drilled in the lower side of the magnet 
 and tapped to receive machine screws, which jmss n])- 
 ward throngh the base of the machine to hold the 
 magnet, which latter sits njion a small wooden saddb^ 
 about ^ inch thick in the middle. The field magnet 
 winding, as well as the iion core, is covered with sev- 
 eral coats of shellac varnish, for insulation and protec- 
 tion. 
 
 The journal boxes for the shaft are simply f brass 
 balls axially bored to receive the shaft, and having an 
 oil hole in the top. These boxes are each held in place 
 by two brass plates bored to receive the sides of the 
 lialls as shown, and attached to the sides of the square 
 wooden standards by screws. The shaft is allowed to 
 project at one or both ends sufficiently to receive a 
 jiulley or fan. The armature is w^rapped around the 
 sides with enough firm paper to cause it to fit tightly 
 into the field magnet, and after the shaft is made level, 
 the journal boxes are placed on the shaft, and the 
 standards which support them are sawed off the prop- 
 er length and secured to the base by screws, one for 
 (‘ach standard, passing upwardly througb the base and 
 iulo the low'(‘r mids of the standard. To the base ad- 
 joining th(‘ standard at tin* commutator end is attached 
 a wooden block, to tin* ends of which are secured light 
 copfier sjirings, which b(‘ar on opposite sides of the 
 commutator and act as brushes for conveying the cur- 
 rent lo the armature. 
 
HOME MECHANICS FOE AMATEUES 
 
 269 
 
 The screws which hold tlie lower ends of these 
 brushes also clamp the wires which extend downward 
 through the base, one being connected with one of the 
 binding posts which receive the battery wires, the 
 other brush being connected with the outside terminal 
 of one of the field magnet coils. The outside terminal 
 of the other field magnet coil is connected with the re- 
 maining binding post. The inside terminals of the 
 field magnet coils are connected together. The con- 
 nections are clearly shown in the diagram (Fig. 242). 
 The upper screws in the commutator brushes are used 
 for varjdng the pressure of the brushes on the com- 
 mutator as may be required; the brushes being bent 
 outwardly to admit of this adjustment. 
 
 If the motor is to be used for driving a fan, the base 
 will need to be set upon legs of some kind. In the 
 motor illustrated, the base is supported upon four in- 
 verted clothes hooks Avhich support it 2 inches from the 
 table. 
 
 The oil cups are made of wood (soft maple or birch), 
 with stems extending down into the fV holes in the 
 spherical boxes; and in the portion of the wood above 
 the journal box is formed a cavity which will contain a 
 few drops of oil. The outside of the oil cup is varnished 
 with shellac except at the end of the stem, before any 
 oil is put in. This confines the oil to the cavity and 
 the interior of the stem and causes it to slowly feed to 
 the journal on which the stem rests. The fan can be 
 purchased for a small sum. It may be necessary to 
 bush it to fit the shaft. Either an 8-inch or a 10-inch 
 fan may be used. 
 
 Of course, a small pulley will be substituted for the 
 fan when the motor is used to drive a machine. 
 
370 HOME MECHAISrrCS FOI? AMATEURS 
 
 If tlie motor wlioii finisliod (lo(*s not run in tlie do- 
 sired direction, this may he chaniLied l)y transposiiii^ tluj 
 wire connections at the hrnshes, so as to cliange the 
 direction of the current in tlie armature. 
 
 SMALL ELECTKIC MOTOKS FOK 
 
 A:MATEUTtS 
 
 Every piece of electric work done hy a student or 
 amateur is of vahn*, not only as an addition to his 
 collection of ap])aratus, but as a means of accpiiring a 
 positive knoAvledge of electricity and of electrical appa- 
 ratus. The following engravings show a simple and 
 easilv constructed motor, which verv fuliv illustrates 
 the construction and operation of the (Iramme motor, 
 and is well adapted to various uses requiring only a 
 small amoAint of power. 
 
 This motor Avas built by ]\Ir. W. S. Bishop, of Ncaa' 
 IlaA'en, Conn., after the general plans of the simple 
 electric motor alreadv illustrated and described in a re- 
 cent Scientific American, but the construction here 
 shoAvn is more simple and more easily carried out. 
 The perspective vieAV here given is tAA'o-thirds the 
 actual size. The front and side eleA'ations and the 
 smaller detail vieAV are full size. 
 
 Th(“ field inagnet. A, is formed of a yoke of NorAA’ay 
 iron inch thick, J inch Avide and 2 ^ inches long. 
 In tin* yok(*, lu'ar its ends and lA inches apart, are 
 <lrilled hoh's for r(“C(uving the (piarter inch Norway 
 in)n cores of tlu' magnet, AAdiich are driA'en into the 
 A’oke. 
 
 Tli(* polar a, of tlu^ field magnet are 
 
 (an‘\(*(l to form a eircailar opeiiiiii;' 2 tV iiu'lies in diam- 
 (*t(*r. Tli(‘ \vindiiii» of the field magnet may be applied 
 
HOME MECHANICS FOR AMATEURS 
 
 271 
 
 to the magnet cores, as shown in the engraving, or the 
 wire may be Avoiind upon spools fitted to the cores. 
 The spools are 1 inch in diameter and 1-J inches long be- 
 tween the heads. Upon each spool is wound 1 ounce of 
 No. 24 double wound, cotton covered magnet wire. The 
 yoke of the field magnet is fastened to the wooden 
 base piece of the motor by screws passing upwardly 
 through the base into threaded holes in the yoke. 
 
 The armature, B, consists of a small Gramme ring 
 mounted upon a Avooden disk secured to the armature 
 shaft. The armature core, c, is a ring formed of a piece 
 of annealed iron Avire, No. 13 B. & S. gauge, hUAung its 
 ends beA’eled and drilled transA^ersely to receiA^e a pin, 
 as shoAvn in Fig. 246. A core of this kind, although 
 theoretically not as efficient as a laminated core, 
 ansAvers every purpose in this A'ery small motor, and 
 greatly facilitates the construction of the armature. 
 The core has an outside diameter of If inches. The 
 outside diameter of the armature is 2 inches, and the 
 inside diameter If inches. Upon the armature core 
 are placed 12 coils, l>, of silk coA^ered, single AAmund mag- 
 net Avire, No. 25 B. & S. gauge, separated by rings d of 
 soft iron Avire No. 13, the rings forming polar exten- 
 sions AAdiich add to the efficiency of the motor. The 
 armature coils are formed in a lathe on a mandrel, 
 separately, as shoAvn in Fig. 247. This mandrel con- 
 sists of a piece of No. 11 Avire liaAdng Iaa’o collars f of an 
 inch apart, one of the collars being fixed and the other 
 being removable. Each coil contains 4 feet 4 inches of 
 wire v.’ound in fiA e layers. 
 
 To facilitate the removal of the coil from the man- 
 drel, the first layer is AAmund loosely. After winding, 
 and before removing the coil from the mandrel, the wire 
 
372 HOMI-] MECHANICS FOR AMATEURS 
 
 is ceiuentcd with paraftiiu'^ or wax iiioltod on ilio coil 
 with a warm iron. After twelve coils have heen com- 
 pleted, they are strung upon the armature* eon*, c, in 
 alternation with the iron wire rings, d, and when the 
 
 Fig. 243. Perspective View of a Small Gramme Ring Motor. 
 
 is fill(*(l, its (^iids arp bioui^ht tojj^etlier and secured 
 hy iiKGUis of tli(^ pin, as sliown. 
 
 Tli(* \vood(‘ii lnd) of t li(‘ arinaiiirc^ is now fitted to the 
 ]‘in^', hat Ixd'oi'e lli(‘ rin<>' is secui'(‘d on tlie linb, twelve 
 
HOME MECHANICS FOR AMATEURS 
 
 273 
 
 equidistant holes are drilled transversely through the 
 huh, near its center, and in each hole is inserted a piece 
 of No. 12 copper wire one-half an inch long. The ends 
 of the pieces of copper wire are allowed to project one- 
 
 Fig. 243 A. Perspective View of Small Gramme Ring Motor. 
 
 sixteenth of an inch beyond the sides of the hub. The 
 ring is placed on the hub, and the ends of the wire pro- 
 jecting from adjacent coils, h, are twisted together and 
 attached by means of solder to the copper wire pins 
 
374 HOME MECHANICS FOR AMATEURS 
 
 (‘xtendinfj tliroufj,!) tlu* hub uiid fonniiiii coimiin- 
 tator bars, tlie cuverins^ bciiiij rciiiuvcd from tli(* cx- 
 tromitios of tlio wire. It will finis Ix' sccui that to <“acb 
 commutator bar is couiiccti'd flic Ix'^iunina; of one coil 
 and the end of the adjacent coil, so that liy means of 
 
 Pig. 244. Sectional Side Elevation of a Small Motor. 
 
 these connections the winding of the armature becomes 
 continuous. 
 
 The ])osls in wliicb tb(‘ armature shaft is journaled 
 are pm forated ni'ar tlnur ujiiier mids with a bole of a 
 size adajiled to ri'ciuve tb(‘ armature shaft, and these 
 holes are countm-horixl from the inner surfaces of the 
 posls, and a win* of ilie same diameter as the shaft 
 
HOME MECHANICS FOE AMATEHES 275 
 
 is placed in the position of the armature shaft, and 
 Babbitt metal or type metal is poured into the open- 
 ings around the shaft, forming the journal boxes. A 
 hole is bored in the top of each post before casting the 
 metal, to form an anchorage for the journal box, and 
 after the casting, the anchorage is drilled through to 
 
 Fig. 245. Front Elevation of Small Motor. 
 
 the opening of the journal box to form an oil hole for 
 the armature shaft. 
 
 The journal box on the side of the commutator is 
 made to project beyond the inner face of the post to 
 receive the disk, f, which carries the commutator 
 springs, g. This projection is made by clamping to the 
 post a piece of wood having in it a hole corresponding 
 
27G 
 
 IIOMK MKCIIAXICS FOIJ AAIATKUKS 
 
 Avitli tliat ill till* ])ost. After tlx* jonrnal hox is cast, 
 file extra jiiocc of wood is rciiiovod, l(‘avinfj; a sloovi* 
 iijioii wliicli to ])laee tlie disk, f. Tliis disk is an iiicli 
 and a lialf in diameter and Vo of an iiieli tliiek. 
 
 Fig. 246. Armature of Small Motor in Process of Construction. 
 
 To tlie inner faee of tlie disk, /, are elamped tlie coin- 
 nuitator sprinj>s, (/. by means of small blocks, as shown 
 in the perspective view, these blocks being held in place 
 by screws passing through the disk into threaded holes 
 
 b 
 
 Fig. 247. Apparatus for Winding Armature Coils. 
 
 in ll)(* blocks. Tli(‘ (‘oiiiimitalor s])riiii»s ai'(^ curved 
 on I ward ly and lh(*ii‘ (aids ar(‘ tnriHal baidcward to- 
 ward IIk^ disk, /, and tlieir (a\treniiti(‘S i'(‘st ii])oii the 
 (‘oiiiimilalor bars, as show n in hd<;s. 243 and 244. 
 
HOME MECHANICS FOR AilATEURS 
 
 277 
 
 The disk, f, and the clanipiiig blocks are made of 
 vulcanized fiber, which is strong and at the same time 
 a good insulator. The commutator springs, g, are 
 made of hard rolled copper, and their inner ends are 
 adjusted so as to touch diametrically opposite commu- 
 tator bars. The best adjustment for the commutator 
 springs is found by moving the disk, f, in one direction 
 or the other. It will he found that the maximum ef- 
 fect is secured when the contact surfaces of the com- 
 mutator springs are nearly in a vertical line. 
 
 The disk, /, is clamped in any desired position by an 
 ordinary wood screw, li, which passes looselj^ thrf)ugh 
 the post and is screwed into a wooden thumb nut bear- 
 ing against the outer surface of the post. The ter- 
 minals of the field magnet. A, are connected directly 
 with the binding post and also with the outer ends of 
 the commutator springs, g, as shown in Figs. 243 and 
 245. 
 
 With one cell of dry battery the motor makes about 
 1,800 revolutions per minute, luit it does not develop 
 its maximum power until one or two cells are added in 
 parallel. Any of the dry batteries will run it for short 
 periods, but if it is required to run it continuously for 
 any length of time, one or two cells of Bunsen or a 
 Fuller battery shoiild be used. 
 
 The motor being shunt wound, is practically self- 
 regulating. Its speed with any amount of battery 
 power does not much exceed 2,000 revolutions per 
 minute. 
 
278 
 
 HOME AIECIIANICS EOE AJIATEUES 
 
 JlOW TO .MAKE A SEWFXO :\FA(''IIIXE MOTOi; 
 
 WITIIOET ('ASTIXdS* 
 
 The acc(»)ni)iniyiiii>’ drawiiijns, lojueilier witli llie fol- 
 lowiiij;: instiaietioiis, will eiiabh* any iiiechaiiic of av<T' 
 af>e ability to build a bi<ildy (‘tticieiit motor that will 
 o])eratc the heaviest of family sewiiij;' machines with a 
 
 Fid. 248. Sewing Machine Motor Made by an Amateur. 
 
 (•()nsinnj)l ion of (‘l(‘(‘ti'i(‘al eiior<>‘v only a trifle ju^reater 
 llnm llial r(*(niir(‘(l lo inaintain an iiu'andesc'oiit lamp. 
 All Ilic! mal(*rials (‘nl(‘riniL>‘ into ili(‘ (*onstrii('tioii of tlie 
 inoloi' may Ix^ pi'ocniXMl in almost any town or small 
 
 * Fy Cecil P. Poole. 
 
HOME MECHANICS FOR AMATEURS 279 
 
 city, and the total cost of the machine, excepting, of 
 course, the labor, should not exceed five dollars. 
 
 The first operation is that of making the magnet, 
 which consists of a bar of ordinary wrought iron, 
 inches square and 19 inches long, bent (while red hot) 
 into a U, as shown by Fig. 248. After bending the iron 
 into shape, cut out two concavities in the limbs, as indi- 
 cated by the dotted lines, to a circle of 4^ inches diam- 
 
 Field Magnet Ready for 
 
 Fig. 249. Field Magnet. Armature. 
 
 eter. The center of the circle of which the concave sur- 
 faces form arcs must be 5^ inches from the short part 
 of the U, known as the magnet yoke, and exactly mid- 
 way between the magnet limbs, so that an equal amount 
 will be cut out of each limb. This cutting can be done 
 by any blacksmith, as it does not need to be precise in 
 the matter of the surfaces of the concavities, the only 
 object being to remove the bulk of metal that is to be 
 cut away in order to form the armature chamber. 
 
 Next smooth up the sides of the magnet on the flat of 
 an emery wheel, rounding off the corners so that a face 
 
280 
 
 IIOMK MI^X'TIAXICS FOIt AM A'l’KUIfS 
 
 view of (lie ends of fli(‘ limbs will be as shown in Fif^. 
 254; the faees, f, f, sbonbl also be snioodied off with the 
 (Miiery wheel, as tliesi' foi-ni (be base of (be niacbine. 
 Then bolt the nia<>net to the fae(“-]ilate of tin* lathe so 
 that the center of the circle, a, to wliicli tla* niafiin-t 
 limbs wei-e cnt away coinciib's with the lathe centers, 
 and bore out the armature chamber to 4^ inches in 
 diameter, leavinj* the ma<;'n(‘t as shown by Fi_i>. 250; 
 the curved surfaces forniinji' th(“ armatni-<‘ chamber arc* 
 known as ])oIe-fac(‘s. If the siib-s of tlie mai>net (by 
 “sides” are meant the ])art facing tin* reader in Fi'is. 
 248, 250, and 253, and the corresiiondiny ])ai-t on the 
 other side of the niaj>net) were not <>round to a true 
 parallel on the emery whe(‘l,and asit is hii>hly probable 
 that they were not, it is advisable to take a sliiiht cut 
 over the whole side exjwsed while the ma'iuet is on the 
 face-plate so as to have it perfectly plane, and also take 
 a cut over the opposite side to insure parallelism. 
 
 The journal ^mkes and boxes come next. There will 
 be two bearings and yokes, one for each side of the 
 machine. Fig. 251 shoAvs the parts necessary for one 
 yoke and bearing; //, y are brass strips 6f inches long, 
 1 inch wide, and t\ inch thick, with rounded ends; 5 
 is the box, made of a piece of round brass rod 1 inch 
 in di.imeter and 2 inches long over all, one end being 
 tui-ned down to f inch diameter for a distance of f 
 inch, a j|-iTich hole being drilled through the center 
 ami a i-itich hole being drilled in one side far enough 
 1o h‘t the point of llu' drill through into the bore of 
 (he box; c is tin* oil r(‘S(‘rvoir, coiisisting of a piece of 
 biass (ubing 1 inch long, inch in diamet(‘r outside 
 and ij inch diamebu- inside, with oiu' end i)ermanently 
 sto|)j»cd by a itlug sold(‘r<*d in and the other end 
 
HOME MECHANICS FOE AJIATETJES 
 
 281 
 
 Hireadecl for a distance of inch. The hole in the 
 side of the box, h, is threaded to match the thread on 
 the end of the tube, c, which is packed Avith lamp 
 wick, filled with oil, and screwed in the box when the 
 machine is completed and ready to rnn. The yoke 
 strips, ,?/, ;?/, haA’e each a ^-inch hole drilled exactly in 
 the center, seA’eral nicks being filed in the edges of 
 these holes. Before putting the yoke together, tin the 
 edges of these central holes and tin the small end of 
 
 
 o 
 
 
 o 
 
 Fig. 251. 
 
 Fig. 252. 
 Parts of Yoke. 
 
 Fig. 253. 
 
 Placing Yokes in 
 Position. 
 
 Magnet with Yokes. 
 
 the box, h; then mount the strips on the end of the 
 box so they will be at right angles with each other and 
 so that the hole in the side of the box comes between 
 two of the legs formed by the strips, and solder the 
 whole at the center. Be sure to fill the nicks in the 
 edges of the holes with solder. 
 
 When both yokes liaA’e been assembled, turn up a 
 block of wood II inches thick to fit closely the armature 
 chamber in the magnet limbs without spreading the 
 
282 
 
 HOME MECTTAXICS EOE A:\IATKUHS 
 
 latter. Tliis block should hav(‘ a i^-iiieh hob* in tin* (‘(‘ii- 
 ter^ and it will b(^ Ixdtia* to di ill IIk^ hob^ fii'st, mount 
 th(^ l)lo(*k on a i]-in(*h inandr(‘l and tnim it np lian* with 
 the (-eiitral hob\ IMit this block in tin* aianatiiix* cham- 
 ber Avith its g-incdi mandixd in tin* ('(*nti‘al hob*, thi'(*ad 
 one yok(^ on om^ (md of the mandrid and the oth(*r on tin* 
 other end, tnrniniij the l(‘i>s of each yok(^ to tlu^ position 
 shown by V\<^. 253. riainj) the Avhob‘ to, 2 ,(‘th(‘i* scxaiixdy 
 and drill four :|-inch holes, //, h, //, //, through the mag- 
 net limbs and both yokes ; ])nnch-mark om^ yok(^ and tln^ 
 fa(‘e of the mai^net limb on whi(*h it r(‘sts so that in 
 reassemblini^ the machine the yarions ])arts will (‘ome 
 back to the ori,i>inal position in Avhich th(‘y w(‘r(^ drilled ; 
 tlien take off the clamps and take off the yokels, r(*moye 
 the yokes and wooden block and anneal the maii^net by 
 heating it to a l)right red and allowing the fire to die 
 ont Ayith the iron coyered np in the coals. 
 
 For monnting the yokes permanently on the magnet, 
 four steel machine scre^ys and eight distance pieces 
 Ayill l)e required. The scre^ys are j inch in diameter 
 and 0:1 inches long under the head, and the head 
 should be slotted. The distance pieces to hold the 
 yokels away from the magnet are made from round 
 l)i'ass rod 1 imdi in diameter; two of them are inches 
 long, two are If inches long, two are 2^ inches long, 
 and the remaining two are 2f inches long. Fig. 254 
 shows one yoke mounted, Avith its distance pieces, c’, 
 cq and .s*, -s, r(q)resent the thread ends of the 
 
 scr(*ws. Tin* yok(‘s should b(^ carcdully fitted or trouble 
 may i‘(*snlt from non-alignment of the Ix^arings. 
 
 Tin.* aianatni'c^ strinduix^ comes mwt hh'om some 
 d(*ab*r in annatni'C stam])ings ])ro(‘nr(^ one hundred 
 1 ‘ings of charcoal iron 4 inches in <liameter outside and 
 
HOME MECHANICS FOR AMATEURS 
 
 283 
 
 3 inches in diameter inside. These rings mnst not be 
 over jV inch thick and preferably about Vt int-li thick. 
 Not all of the one hundred will be needed, but many 
 will be spoiled in drilling. From a dealer in electrical 
 supplies procure two rings of vulcanized fiber, the 
 same diameter outside and inside as the iron rings, and 
 I inch thick. On the face of one ring space off twelve 
 equidistant points on a circle scribed around the cen- 
 ter of the ring's face midway between edges, as shown 
 by Fig. 255, in which the points are indicated by 
 
 Fig. 255. 
 
 Fig. 256. 
 
 Fig. 257. 
 
 Laying Out the 
 Armature. 
 
 Brass Disks. 
 
 Position of Holes 
 for Boits. 
 
 A IM L^ 
 
 Fig. 258. A Trapezoid. Fig. 269. Tie Rod. 
 
 c, c, g, c, c, g.. e, c, g, e, e, g, those marked g being 90 de- 
 grees apart. Take two brass disks 4 incbes in diam- 
 eter inch thick, with a ^-inch boss If inches in diam- 
 eter on one side, as shown by Fig. 250, which may be 
 obtained from any model making establishment, and 
 drill through the center a -f-inch hole, indicated by 
 dotted line in the sketch. Clamp on the smooth side 
 of one of these disks the fiber ring that has been scribed, 
 letting the marked face come uppermost, and drill 
 four f-inch holes at the points marked g, g, g, g, on the 
 
284 
 
 1 1 OM K M K( 4 1 AN I ( K( ) A M .VV Ki: \{H 
 
 ra(*(‘ of file (ln'()UiL>li bolli ili(‘ rini; and llu‘ brass 
 
 disk. Next inoniit on a !|-in(‘li inandKd a block of 
 wood 2| in(‘h(\s tlii(‘k and lar!L;(^ (Mion<»li to |)(*rinit tniai- 
 in<> if down to a rolka* 2 inches in diani(d(a'; instc^ad of 
 tnrniiif; it to nK^asiircincnt, liowcvcr, inak(‘ it tit snniL»iy 
 into tlie intiador of the iron and fibi'(" i inus. Wdnai tliis 
 l)lo(‘k is tnriKMl to siz(^^ tlirc^ad on oik* (*nd of tin* niandrc*! 
 tlie 1)1 ass disk that has only a (‘(nilral hob*, n(*xt ])nt tin* 
 nninark(*d fiber disk on tin* wood(*n bhx'k, down to tln^ 
 brass disk, and follow Avith flu* ii'on rin^s, ])nttin!L» on 
 last the fiber rin:L> that lias b(*(*n drill(*d and th(*n thr(*ad- 
 in^ on tlie mandrel the brass disk that Avas also drill(*d 
 Avith the fiber disk. Turn the disk so that tin* hol(*s 
 near its edf>e ai»T(*e AAitli those* in the fib(*r rini^- under 
 it and compress the Avhole arran<>enient Avith clam])S. 
 If there are so many iron disks that the fiber riiyi;’ 
 cannot be draAvn doAA n oy(*r the end of the aa ooden cen- 
 tering’ block, take off enough to let this lx* dom*, as it 
 is imperatiA^e that all the ring’s and disks should be 
 accurately centered aa itli each other. Then drill }-inch 
 holes throni>li the Avliole mass, entering’ the drill in the 
 holes already bored in the top brass disk and fiber ring. 
 These four |-inch holes are for tie-bolts to hold the 
 armature core together. 
 
 AVhen the drilling is finished, punch-mark each brass 
 disk and fiber ring near one of the |-inch holes (the 
 saiiK* OIK* in (*a(‘h (‘as(*, of course*), remoAX* the (damps 
 and 1h(* bi'ass and fib(*i‘ ])i(*C(*s, run a wire through the 
 hob* in the* iixin rings (*orr(*S])onding' to the one marked 
 on 11k* fib(*i‘s and disks and tic* th(*ni b)os(*ly together 
 nniil lime* 1o ass(*mbl(* IIk* c'orc*. Th(*n cdani]) the tAVO 
 1ib(*r rings 1og(*lh(*i*, wdlh IIk* mark(*d hob*s in align- 
 nK*nt, and di*ill Ihrongh both idngs a iV iaeh hole at 
 
HOME MECHANICS FOE AMATEUES 
 
 285 
 
 each point marked c, leaving each ring as shown by 
 Fig. 257. 
 
 Ne.xt cnt out of hard wood tw'enty-fonr trapezoidal 
 blocks (Fig. 258) f inch thick, f inch wide at one end, 
 -J inch wide at the other, and i inch long. In the 
 center of sixteen of these drill a iV inch hole; in the 
 center of the other eight drill a :|-inch hole. Fin the 
 sixteen trapezoids having small holes to the faces of 
 the two fiber rings, patting the pins throngh from the 
 back throngh the tV inch holes in tlie rings; the pins, 
 which must be of brass, should be a tight driving fit so 
 that the trapezoids will not tend to slip off, and the 
 faces of the latter should be coated with shellac varnish 
 to prevent their turning on the pins. 
 
 The tie-holts, mentioned above, are of brass, fV inch 
 in diameter and 3f inches long, threaded at each end 
 for a distance of tV inch. They mast he insulated where 
 they pass throngh the core by wrapping paper on 
 them, gluing each layer and putting on enough to 
 make the insulated portion fit sniigly in the :{;-inch holes 
 drilled through the rings. Cut a strip of manila paper 
 2| inches wide and wrap it tightly on the bolt, leaving 
 an equal length of uncovered metal at each end. When 
 the right thickness of insulation is obtained, drill two 
 
 inch holes in the holt, exactly 2iV inches from center 
 to center, and equal distances from each end (this dis- 
 tance, if the holt has been accurately cut to the length 
 specified, will, of course, be || inch). Two nuts must 
 he also provided for each holt, and two steel pins which 
 are driving fits in the inch holes,and slightly tapered. 
 One of these tie-rods, without its nuts and pins, is 
 shown by Fig. 259. 
 
 Then assemble the armature core on its wooden cen- 
 
286 
 
 irOMK MECHANICS FOE A:\IATEUES 
 
 terin^ bloc'F^ (‘iioii^li iron disks to immIo* tlio iron 
 
 ])art iiieasiire 1] iiudu^s in tliirkn(‘ss wlnai (*oni])r(‘ss(‘d 
 and beinj>' earofnl to liave tlioso of tlie j-incli liol(*s tliat 
 were marked on tlie fibre ])i(M‘es (‘oine in lim^ witli the 
 liole tlironi>’b wbicdi tlu^ wir(‘ lioldinii; tli(‘ iron disks 
 toi>'etlier was rnn. L(^av(‘ olT 11i(‘ brass disks for tlie 
 ])resent. Tlii*oni>li each J-iindi bol(‘ ])nt a ti(*-]'od, elainp- 
 inji^ tbe strnetnre until tln^ st(‘(‘l ])ins can I)(» i)nt in tlie 
 holes in the tie-rods; enoni>h iron disks slionld lx* jmt 
 in to prevent any looseness when the (damps are rc*- 
 moved. Fig. 2G0 sIioavs the complete structure. After 
 
 Fig. 260 . Fig. 261 . Fig. 262 . 
 
 Armature Ready for The Slitted Tube for Commutator. 
 
 Winding. 
 
 the ti(*-rods are pinned in place the remaining trape- 
 zoids are put on over the ends of the rods; a little 
 groove will have to be cut in the back of the trapezoid 
 to accommodate the steed j)in in the end of the tie-rod. 
 
 Tin* (‘ommutator com(*s next, and while it would be 
 advisable* to buy a com])l(*te commutator, a very serv- 
 i(‘(*abl(* OIK* (*an lx* made with ])roper care in following 
 out 1h(* instructions giv(*n. If the build(*r prefers to 
 buy ih(* comimitatoi', 1h(* dim(*nsions a(‘(X)m])anying the 
 ord(*r must lx* Mi(‘S(‘: I)iam(*t(*r of brush surface, 1 
 imdi; l(*ngth along tin* shaft, 11“ inches; number of 
 
HOME MECHANICS FOR AMATEURS 287 
 
 segments, 12. If the commiHator is to be built along 
 with the rest of the machine, proceed as follows : 
 
 Take a piece of brass tubing, 1 inch in diameter out- 
 side, with a wall about ^ inch thick, and measuring 
 21 inches long. Slit it at twelve equidistant points 
 for a distance of 11 inches from one end, as shown by 
 l^bg. 261, and insert the unslitted portion in a hole in a 
 block of wood that just fits the tubing; the block 
 should be 1 inch thick and nailed to a bench or other 
 support. Then bend outwardly the narrow strips made 
 by slitting the tubing until it looks like Fig. 263 ; the 
 wings shonld be brought to a right angle with the body 
 of the tubing not slitted, and hammered out fiat. 
 Number the “wings” by means of punch marks, from 
 one up to twelve, and then carry the slits along the 
 length of the uncut portion of the tube, cutting it up 
 into twelve pieces like Fi<r. 264. Next turn up two 
 rings of vulcanized fiber 2 inches in diameter outside, 
 1 inch in diameter inside and 1 inch thick, and fit 
 around the circumference of each twelve steel screws, 
 1 inch in diameter and f inch long over all, without 
 heads, as shown by Fig. 265, the screw-holes being car- 
 ried clear through so that the point of the screw may 
 emerge on the inside of the ring. Fut thirty-six strips 
 of oil paper (the kind used with copying books to pro- 
 tect the leaves from moisture) inch thick, inch 
 wide, and 14 inches long. Assemble the pieces of the 
 commutator in numerical order within the two fiber 
 rings, one ring at the wing end and one at the other 
 end of the tubular part, put three slips of oil paper be- 
 tween each pair of neighboring pieces of tube, and 
 draw the segments toward the center by means of the 
 little screws until the oil paper slips are clamped so 
 
288 llOMK MI^](MI AN K^S KOI? AMATKU1?S 
 
 tij»litly between tlu^ brass s(\i>iiu‘nts tliat tluw cannot b(‘ 
 ])nlI(Hl out with tli(‘ iin^(*rs. In ordca' to liav(‘ tin* coni- 
 nintator come toi»(Mli(‘r and foian an ai)])roxiiMat(*ly 
 true (drcle, a saw blad(‘ 3 ^^ iin-lj tliick slionld b(‘ ns(*d in 
 cnttini* tlH‘ sei»in(mts ont of tlie tube. Tlien l)y jiidi- 
 
 Commutator Tube Before it is 
 Cut into Segments. 
 
 Fig. 265. 
 
 Fiber Ring with Screws. 
 
 Fig. 264. One Segment. 
 
 Fig. 266. 
 
 The Commutator. 
 
 cions s(ddin^ np on tlie screws the surface can be 
 liron^lit suftici(mtly m^ar to a true (drcle as to recpiire 
 no truing nj) \u tin* latli(‘. The ])rotrudin<» edf>es of 
 tin* oil-jiapiu' sli])S can b(^ cut off (‘vcm witli tlie brass 
 witli a sliai'|) knife. 
 
 Tin* (‘or(* of tin? commutator may bo mad(i of wood; 
 
HOME MECHANICS FOR AMATEURS 
 
 289 
 
 mount a block on a f-incli mandrel and turn it up to 
 the exact diameter of the interior of the commutator ; 
 then taper it slightly so that it will pass through the 
 commutator before binding, and drive it home as tight 
 as possible without straining the fiber rings that hold 
 the segments. Cut off the block ^ inch beyond the 
 wing end of the commutator and flush with the other 
 end. The complete commutator is shown by Fig. 266. 
 
 The next piece of machine work is the shaft, shown 
 by Fig. 267. It is turned up from a piece of |-inch bar 
 steel 10| inches long. The dimensions are as follows : 
 A, I inch diameter, 2iV inch long; f inch di- 
 ameter, If inches long; C, f inch diameter, 3| inches 
 long; Z), f inch diameter, inches long. Last in the 
 list of machine work on the motor proper are the brush 
 holders, one of which is shown bj^ Fig. 268, the drawing 
 shoAving two views. The holder is a piece of brass 
 tubing, f inch internal diameter and If inches long, 
 mounted on a piece of strip brass f inch wide and A 
 inch thick, the other end of which is bent into a loop, 
 as shown, and provided with an insulating bushing, t, 
 of tV inch fiber. The internal diameter of the bushing 
 is a trifle over an inch when the clamping screw is 
 loose, and the diameter of the loop in the brass strip is, 
 therefore. If inch maximum. This loop is intended to 
 fit around one of the distance pieces, 0 , Fig. 254, from 
 which it is insulated bv the bushing, t. 
 
 The brush is a piece of round carbon, f inch in di- 
 ameter and 1 inch long; it should fit snugly within the 
 tube forming the holder, and a spiral spring, f inch 
 in diameter, made of No. 16 brass wire, must be pro- 
 vided to force tbe brush outwardly on to the com- 
 mutator. One brush holder is attached to the lower 
 
290 TIOMF. MFCJIAXirS FOR A:\IATFIIRS 
 
 left-liand (listaiic*e-])io(‘(‘, c, and lln^ ollua* to tli(‘ ii])])(*r 
 rii»ld-liand ])i(M‘05 tlio tnl)nlai' ])ai'f of tli(‘ liold(‘r s(*l- 
 tiiig Yoi'ti('all y, Ixdwoini tln^ inai»ii(*t ])oI(‘s, witli its in- 
 011(1 not niorc^ tlian J iiK'li from tin* snrfa('(‘ of tin* 
 ('oininntator. F]l(H‘tri(‘al ('oniKH'tion is niad(‘ witli Wni 
 lirnsli arm by moans of a ])ioo(* of tl(‘xil)l(‘ (‘oi'd, snoli 
 as is nsod in ]iani»’ini> in('and(‘S(‘(mt lamjis, on(‘ (md of 
 tlio (‘ord l)oini>‘ soldcnxMl to a (‘0])])(n‘ waslior, wliicdi is 
 olaniiiod nndcn' tlio lioad of tlio sorc^w on tli(‘ brnsli arm. 
 This cord is known as No. IS (‘otton-c'ovorod la.mp- 
 cord, and may bo jirocnrod from any d(‘alor. It slionld 
 bo nntwistod and ono loni>tli iiscmI on (^acli lirnsli lioldor; 
 tlio cord nood not bo mor(^ tlian (> inclu^s lon<>\ 
 
 Wo aro noAv roady to wind tlio nia<>not and armatnro 
 coros. Tho armatnro coro iiinst first lio covorc^d all 
 around tlio ontsido snrfaco with innslin; cut a strip 2 
 inches wide and 25 inches lon^ and, after varnishiiy^ 
 tho porijihory of the coro with shellac, Avind on this 
 muslin strip, being sure that it is tightly wound. If it 
 is iinlled tight, it Avill make two layers; Avhen the 
 strip has been carried once around, A^arnish the surface 
 of Avhat is on the core, and then Avind on the other 
 layer of innslin. Then Amrnish the AAhole outside sur- 
 faces Cut out 24 strips of oil paper, each ItV inches 
 Avid(^ and 2 inches long, and bend np the edges, making 
 th(^ cr(sis(^ j inch from (sicli edge, so as to form shalloAA^ 
 troughs th(‘ Avidth of AAliich aaoII bo tho same as the 
 S])a(‘(‘ l)(dw(Mm lln^ trapezoids on tho end of the coro; 
 apply tAvo of tho troughs to tho inside and ontsido 
 oirch^s of th(‘ cor(‘, as shoAAm in Ffig. 270, and tie tlumi in 
 ])lac(* AA'illi No. 40 or No. 50 soAving (‘otton, ono strand 
 at (sioli sid(‘ of th(‘ 1 rough. Them Avind on an old (‘ot- 
 ton-spool 08 f(*(‘t of No. 20 double cotton-covered mag- 
 
HOME MECHANICS FOE AMATEUES 
 
 291 
 
 net wire, hook the outer end around one trapezoid, as 
 in Fig. 271, and wind into the wiring space between 
 this trapezoid and its right-hand neighbor a coil the 
 full width of the space, which should take 2G turns in 
 
 c 
 
 3 
 
 Pig. 267. The Shaft. 
 
 width, putting five laj^ers in, or 130 turns, to each coil. 
 When the first coil is done twist to the final end the 
 beginning end of the wire which is to Aviud the next 
 coil, and proceed with that one in the same way. Care 
 must be observed to put exactly the same number of 
 turns in each coil and to twist the ending of each coil 
 to the beginning of its neighbor on the right. When 
 the armature is wound, put on the brass disks that 
 were left off when the core was assembled, threading 
 the tie-rods through the holes near the edges of the 
 
 Figs. 268 and 269. Fig. 270. Pig. 271. 
 
 Brush Holders. Section Prepared for Beginning the 
 
 Winding. Winding. 
 
 disks, and putting the boss on each disk outside; clamp 
 the disks hard against the wooden trapezoids Iw means 
 of nuts on the tie-rods. The holes in the disks must 
 be bushed with little pieces of fiber tubing and a fiber 
 
m HOME MECHANICS EO]{ AMA'I’ETIHS 
 
 wjislioi' iiinst uiHl(!r (‘acli luit, in or<l(“i‘ to insulate; 
 the tie-rods from tin* disks; otherwise* the* armature; 
 wemlel run elestrne tively heet. 
 
 Insert the slmft in the e‘e‘nter eef the structure*, ledtinj^ 
 that part marke'd 71 in Fi,u;. 2t)7 e;ome een tlie siele wliere* 
 the ends of tlie armature* wijidim*- are, and ])in the 
 brass disks tee the slmft thi'eeiyuh the be^sse's. The* e*e)m- 
 mutateer ”oes een the* ])ai*t e)f the shaft just referre*el tee, 
 anel it shonlel be a elrivinj; fit, see as to eebviate* leinnin*' 
 en* keying it to the* shaft. The*n ceninect up the enels 
 e)f the armature coils tee the lugs e)f the commutator, 
 le>adiug eaedi enel straight eeut, jearalle*! with the shaft, 
 to the nearest lug. If the ends were twisteel teegether 
 in accordauce with the directieeus, the result will be 
 as shown eliagrammatically by Fig. 272. 
 
 Prepare for wineling the magnet coils by making a 
 winding bobbin as follows : On a piece of board an 
 inch thick and 4 inches square lay out a square meas- 
 uring If inches on a side, the scribed square being 
 symmetrical with the edges of the board; clamp an- 
 other similar piece of board to the one marked, and at 
 the corners of the scribed square drill f-incli holes 
 through both boards; in the center of the square drill 
 a -|-inch hole. Then make a mandrel of 4-inch round 
 iron, the central part being full diameter and 24 
 inches long, and the ends being turned down to pass 
 through the central hole in the board. Moiint the 
 boards on the (*nds of the mandrel and run f-incli iron 
 rods through the corner holes, forming a sort of reel, 
 as shown by Fig. 273. Jam the boards against the 
 should(*rs of tin* mandrel by means of lathe dogs on 
 the outer (*uds of flu* latter, and drive a nail in the 
 face of each board so that the dog will drive the board 
 
HOME MECHANICS FOE AMATEURS 
 
 393 
 
 without slip. The dogs must be so adjusted, of course, 
 as to drive both boards in their proper angular posi- 
 tions, maintaining the parallelism between the ^-inch 
 rods and the mandrel that is necessary to form a per- 
 fect coil. 
 
 Mount this winding frame in the lathe and wind a 
 coil on it of No. 21 double cotton-covered magnet wire, 
 putting as many turns as possible (it should take sixty- 
 six) between the faces of the wooden blocks and mak- 
 ing the coil twenty-seven layers deep. The starting 
 end may be secured to the projecting end of one of the 
 •|-iuch rods to give the necessary tension to the first 
 
 Fig. 272. 
 The Winding. 
 
 Fig. 273. 
 
 Reel for Winding Field 
 Magnet Coils. 
 
 layer of wire, and at least a foot of the starting end 
 should be left free. When the coil is finished, tie it at 
 each of the four corners with strong linen thread, 
 bending the final end sharply backward over one of 
 these corner threads to keep the top layer snug; take 
 the winding frame apart and varnish the coil all over 
 with shellac, setting it aside to dry while the second 
 coil is wound. This is exactly like the one already 
 wound. 
 
 Then take the journal yokes and their bolts and 
 distance pieces off the magnet and wrap the magnet 
 limbs with muslin from ^ inch above the bolt holes 
 up to the bend, putting two layers on each limb and 
 
294 
 
 HOME I^IECHANICS FOR A]\TATETTHS 
 
 \arnisliiTii» it on tlie ontsidc^ of (*a(*li lay(*i\ Wlien tin's 
 is drjj tniai tlie nia^iiet n])sid(^ down, tlii'(*ad on (‘a(*h 
 limb a fiber washer inelies square and i ineli tlii(‘k, 
 tlie hole in the waslnn* fitting the inai»]i(R. limb snn<»;ly; 
 varnish the fa('es of th(^ Avashei's now ni)i)(nanost ami 
 slip the coils on the limbs down on the wash(‘rs whil(‘ 
 the varnish is w(d, so that the lattcn' will sti(‘k to th(‘ 
 coils. In pnttinf>’ on the coils, s(‘e that tln^ b(\i»innin<? 
 end of each coil ^oes on fii'st, so that wlnm tlu^ machine 
 is set rioht side np the final end of each coil will b(‘ 
 nearest the armature. T'ollow (^ach (‘oil with aiiotlnw 
 fiber washer like those first x)nt on the magnet, and 
 then reassemble the journal yokes and distance i)ie(‘es 
 on the niaf>net, this time putting in the armature as you 
 j>‘o along and also putting on the brush holders and 
 f)rushes. Tlie holders should b(‘ so adjusted that the 
 ends of the brush tubes are tV t<> « inch aAvay from th(‘ 
 surface of the commutator. 
 
 The free ends of the magnet coils nearest the arma- 
 ture are connected to the brushes by means of flexible 
 lamp cord, as described in the instructions for making 
 the brush holders, the end of the flexible cord being 
 soldered to the end of the magnet Avire close up to the 
 coil. Th upper ends of the magnet coils go to the ter- 
 minal blo('k, Avhic'h is a block of Avood, 1} inches square 
 and 4 iindn^s long, bolted on the top of the magnet 
 yoke, and caiawing two binding posts, AAhich form the 
 tcaaiiinals of th(‘ machim^ The motor is bolted to the 
 tabl(‘ of th(‘ serving nnudiine, Avith one leg right on the 
 (*dg(‘ of 1h(‘ tabl(‘ and in such position that the pulley 
 of th(^ motor, whi(*h must go on the end of the shaft 
 away from 1h(i commutator, is in line Avith the belt 
 I)idl(w of th(‘ machin(‘. The motor pulley should be 
 
HOME MECHANICS FOR AMATEURS 
 
 295 
 
 one-half the diameter of the pulley on the sewing ma- 
 chine, and be of the same width and depth of groove. 
 
 The regulator is shown by Figs. 274 and 275, the 
 former being the front vie^v and the latter the back. 
 Referring to Fig. 274, A is a wooden arm, 9^ inches 
 long, 4 inch thick, and tapering from 4 inch to IJr inches 
 in width. The narrow end is faced with a thin strip of 
 copper to make contact with the buttons, c, which are 
 simple brass bolts with flat heads; the wide end of the 
 wooden arm is split to straddle the shaft, to which it is 
 pinned as well as clamped. L is the lever controlling 
 
 Fio. 274. 
 
 Regulator — Front View. 
 
 Fig. 275. 
 
 Regulator — Back View. 
 
 the arm, A ; it is made of 4-inch round iron rod, bent 
 to form a right angle; the lever portion is G inches 
 long; the length of the horizontal portion on Avhich 
 the lever. A, is mounted is the same as the width of 
 the sewing machine table on which the motor is to be 
 used. The back end of the shaft is journaled in the 
 base board, C, and the front part in a wooden bearing, 
 li, which is bolted to the under side of the sewing ma- 
 chine table between the narrow drawer and the pan. 
 The baseboard, C, is 0 inches wide (vertically) and IO 4 
 inches long. It is fastened to the under side of the ma- 
 chine table, flush with the back edge. The lever, E, is 
 to be moved by the right knee of the machine operator. 
 
290 HOME MECJlAiNlCS EOU AMATEUKS 
 
 The ariiij is iiornially lield in its lii<»lH‘st i)Ositi()n 
 by the coil spring shown^ in Avhi(‘li position tlie (aii'rent 
 is cut olt* the motor entirely. The conta(*t buttons, 
 are 4 inch in diameter; tlie bolts of which they are 
 tlie liead.s are inch in diameter and loii”- enou<>li to 
 protrude | iiieli on the reversi* sid(‘ of tlie base hoard. 
 This side is shown hy hM<;'. 275. The resistance coils 
 consist of Gernian silver wire, No. 20 B. and H. f^auj^e, 
 wound into coils on a f-inch rod (the rod heinj^ re- 
 moved, of course, when the coil is formed). The jiii'ce 
 of wire forming the niiper coil should he 100 feet long; 
 the next coils contain 90, 80, 70, 00 and 50 feet of wire, 
 resi)ectively, in the order named. The binding posts, 
 7 \ and 7 \, are connected as shown, the connection be- 
 tween 7'i and the iron shaft being made bj' means of 
 flexible cord which will follow the movements of the 
 shaft. On the front the shaft is connected to the cop- 
 per facing at the small end of the arm, .1, by means of 
 No. 10 copper wire. All the connections on the back 
 are made with No. 10 copper wire, preferably but not 
 necessarily insulated. 
 
 The back surface of the base board must be covered 
 Avith a sheet of asbestos over a thin sheet of fiber. The 
 ends of the resistance coils are tAvisted together and 
 soldered, and the connecting Avires should be soldered 
 on at the same time. The coils are held on ordinary 
 poi'celain knobs, fastened to the board by Avood screAA’S. 
 Th(! coniK'cting Avires should be bent into loops Avhei’e 
 they coniK'ct Avilh the bolts, c, and a copper AA’asher 
 shoidd go under each nnt and on top of the loop of the 
 connccling Avire. 
 
 Th(* conneclions betw(‘(‘n Ihe motor and the regulator 
 and the source of curreut sui)2)ly are as follows: From 
 
HOME MECHANICS FOR AMATEURS 
 
 297 
 
 Ti to one binding post on the motor, from to one side 
 of the supply circuit, and from the other binding post 
 on the motor to the other side of the supply circuit. 
 
 The motor above described will run satisfactorily on 
 any direct-current incandescent lamp-circuit of 100 to 
 120 volts pressure. If it is desired to build the ma- 
 chine for use in connection with a batterj^, the Avindings 
 Avill have to be changed as follows : Armature coils. 
 No. 13 wire, 8 turns wide and 1 deep, each coil; field 
 magnet coils. No. 8 Avire, 5 layers deep, 18 turns per 
 layer, each coil; regular. No. 13 Avire, the coils having 
 one-tenth the number of feet specified aboA'e. 
 
 The battery to run such a motor must giA^e 8 volts 
 and from 10 to 20 amperes, according to the load on the 
 motor; consequently four cells Avill be required. 
 
 Should the reader desire to build a standard shunt- 
 Avound motor of i horse power instead of the series- 
 Avound type specified, the same frame may be used, 
 the only variation being in the manner of Avindiug. 
 In order to Avind the machine as a i horse power mo- 
 tor, to AA’ork on a 110 Amlt circuit, the armature coils 
 must consist of No. 27 Avire, double cotton-covered, 
 each coil being 9 layers deep and 28 turns in width — 
 252 turns, total, per coil. The magnet coils Avill con- 
 sist of No. 25 Avire wound to a depth of 39 layers, with 
 as many turns lengtliAvise as can be got in the space of 
 2| inches allotted for the coil length; Avith careful 
 Avinding, 92 turns can be put in each layer, giving each 
 magnet coil a total of 3,588 turns. 
 
 In order to change the design into a | horse power 
 motor, the magnet must be made of iron 2| inches 
 square, instead of 1^ inches, and the armature, shaft, 
 journal-yoke bolts, etc., must be made exactly 1 inch 
 
ucnih] IMKC'lIAxYirS KOI? AMA^I’Ki;i?S 
 
 20<S 
 
 l()iif»(‘r, axially, tliaii tlu^ al)()V(‘ iii(*asni'(*iii(*iils s|)(‘cify. 
 The wiiidiiii^s will 1)(‘ No. 24 wire on th(‘ ariiiatni'(‘, (*ach 
 (‘oil 5 layers (1(M‘]) and 21 turns wid(*; No. 22 wii'(‘ on tli(‘ 
 inai>net, ea(4i (‘oil l)(4niL» .‘>7 laycas d(*(*]) and 74 turns 
 lonj»* (or as many as the 24 inch si)a(‘(‘ will tak(7). 
 The nninlxa' of armature (‘oils and all ()th(a‘ data not 
 s])(H‘iticHl in this ])ara,i>ra])h Avill remain ])re(‘is(4y as in 
 the original instructions al)()V(\ 
 
 A DESIGN Foil AN ELECTKir LAUNCH :\IOTOK 
 
 For the propulsion of an ele(‘tri(‘ lann(‘h a motor 
 must unite elements of efh(‘ien(‘y, (‘()mpa(‘tn(^ss, and 
 strength to a d(\gree scar(‘(4y iie(‘(^ssary in any other 
 situation. The design given luwe is for a motor of un- 
 usual simplicity of construction, Avhi(‘li (‘an (aisily be 
 built by ail amateur at small (‘ost. It is intended for 
 a boat of about 24 feet over all and 4 feet b in(‘hes 
 Ixnim, drawing 18 inches, and is capable of propelling 
 such a (‘raft at a speed of 7 miles per hour. Gearing of 
 all sorts has been dispensed Avith, the motor being 
 a(la])t(xl for direct attachment to the propeller shaft. 
 AAdiile the description below refers primarily to a motor 
 for a (‘raft of this size, dimensions are also given for 
 the (‘onstru(‘ti()n of motors for smaller launches. 
 
 Without going into the details of (‘alciilation, it may 
 b(* slabxl lhat for su(‘h a l)()at the most effi(‘ient service 
 will b(‘ had fi‘()m a four-bla(l(Ml s(‘r(^w, about 14 inches 
 in diani(4(U‘, 12 in(‘h(*s ])il(‘h, Mo p(M‘ (‘(uit. bbuh^ area 
 (by whi(‘h is m(‘ant with blad(‘s having a toLil ])r()je(‘t- 
 ed ar(^a (‘(pial 1o ‘>5 jx^r (‘(uit. of that of a 14-in(‘h disk). 
 
HOME MECHANICS FOR AMATEURS 
 
 299 
 
 Fig. 276. Longitudinal Section of Launch, Showing Interior Arrangements. 
 
300 
 
 Ji()iMi<] MECiiAX'ics F()i{ a:\iateijhs 
 
 at. 880 revolul ions ]»(‘r niiiiuli*. Siicli a screw 
 will aOsorb about 4 boi'S(! power. No very detiiiite fig- 
 ure's of speeds and ])oweis can be* given, as tiu'se de- 
 pend very largely u])on the shape of the boat, its full- 
 ness fore and aft, the luoulding of fhe runs, etc. The 
 motor described Ix'low will give* a sjx'e'el of 7 inib's ])er 
 hour to a ratlu'r full-modeh'd boat of tlu* size iiidicat(*d, 
 when fully loaded to a dis])lac(‘nient of 5,000 jxuinds. 
 This means, assuming that the boat itself weighs about 
 1,000 pounds, a carrying capacity for about ten or 
 twelve passengers. 
 
 The storage battery consists of 24 elements, arrang('d 
 in two series of 12 cells each, each cell being of about 
 80 ]K)unds weight. These cells contains 13 plates each, 
 about 7J inches square, and are about 74x84 inches 
 square by 11 inches in height, these measurements be- 
 ing outside of the rubber containing jars. They should 
 be mounted in two wooden boxes, about 84 inches 
 Avide by 14 inches deep inside and about 7 feet 6 inches 
 long. These make convenient seats in the boat, and 
 their lids mav be coA-ered Avith cushions. Thev should 
 be placed side by side amidships, as low as possible 
 and a little forward of the center of gravity of the boat 
 to compensate for the Aveight of the motor, AAdiich is 
 installed Avell aft. Such cells may be bought from 
 any one of several Avell-knoAvn American makers of 
 accumulators. Elements in glass jars should not be 
 used, on account of the danger of breakage. 
 
 h'or tin* smaller sizes of motor described beloAV, or, in 
 (dh(*r Avords, for smalb'r boats of the same general 
 lype, ilu' number of c('lls remains the same, but their 
 size may be ]»r(q»oi'tioual<'ly r(‘duc(*d. AVith cells of 
 the same type, having plates of the size given, a 3 horse 
 
HOME MECHANICS FOR AMATEURS 
 
 301 
 
 power boat will require those having 9 plates and a 2 
 horse power boat those having 7 plates. 
 
 Terminals for charging should be attached to the 
 boxes containing the cells. It is by all odds the best 
 plan to charge the cells in the boat, and not to at- 
 tempt to remove them for this purpose. 
 
 The capacity of these outfits on one charge is about 
 3 hours’ run at full speed, or about 7 hours’ run at 
 about 44 miles per hour, thus giving the boat in each 
 case a cruising radius of about 30 miles. If a larger 
 
 Pigs. 277 and 278. Section of Coupling. 
 
 cruising radius is desired, it may be attained by the 
 use of larger cells, but, as these are heavier, their use 
 means a corresponding decrease in the passenger carry- 
 ing capacity of the boat. 
 
 The motor illustrated herewith is of a four-pole in- 
 closed type, waterproof and intended to be attached 
 directly to the screw shaft. Some form of flexible 
 coupling is recommended, that shown in Figs. 277 and 
 278 being very simple and easily made. It consists of 
 two cast iron flanges, the larger about 12 inches in dia- 
 meter for the motor to be described and proportion- 
 
302 
 
 IIOMR MI<:CIIy\NlCS FOI{ AJIA'I’FUHS 
 
 alcly .smaller for <li(‘ siiiiillci- iiiolors. Tlu'sc* flanges aro 
 iiiouiiicMl, (»n(‘ on tlie niolor sliafi and llio (OIk'i- on tin* 
 jn-opcller sliaft, so tliat tin* sniallin- runs insick* Uic 
 larnor, Avitli a ck-araina* of about 1 incli all l•onn(l. 
 
 In tlu‘ cylindrical sni-fac(“s of each arc cut ci.nlit \vi!i- 
 dows, the ed,n(‘s of which are rounded off as shown in 
 Fiji'. 278. d'liroui'h these windows a ]»i(“ce of cotton 
 h(‘ltinji', 1 inch wide, is laced as indicated in tlu* fi^ur(‘, 
 its ends being cemented tog(‘ther. Tlu> whole forms an 
 inexpensive and satisfactoiw cou])liTig, which- will 
 largely prewent any strain of tin* shaft dne to the tlex- 
 nre of the boat under loads in a sc-away. 
 
 A thrust hearing, to take np the forward thrust of 
 the screw shaft, is also necessary. A sim])le and satis- 
 factory type is illustrated in h'igs. 279, 280 and 281. 
 Upon the screw shaft are mounted four steel collars, 
 each about three times the diameter of the shaft and 
 about 1 inch thick. These are ])rovided with set 
 screws. A cast iron box contains the brasses against 
 which these collars work. This box, it must be re- 
 membered, receives the whole forward thrust of the 
 scr(‘w, and must not only be made strong enough to re- 
 sist this, but also arranged to communicate the pres- 
 sure to the frame of the boat. A good plan for mount- 
 ing it is to place in the bottom of the boat a stout tim- 
 b<‘i-, long (‘nough to b(“ sciaoved to several of the after 
 frauK'S, and arrange' the thrust bearing with lugs for 
 four or six lag screws so that it may be securely at- 
 lached <o this. In the size of boat described above, at 
 full sjtee-d, I he forward ]»ush of the screw will be about 
 229 pounds, but in a sea, or if th(‘r<‘ is any obstruction 
 in I he way, I his may b(“ <‘asily donhh'd. 
 
 'I'lie b(»x frame of (h(‘ (hrust block, as the illustra- 
 
HOME MECHANICS EOE AMATEUES 
 
 303 
 
 tious very clearly sIioav, is grooved to receive three 
 horseshoe shaped brasses, each about an iuch thick. 
 These straddle the shaft between the collars, Avhich are 
 adjusted to bear ecpially ou the brasses. The box is filled 
 with oil to a level so that the collars ruu iu it, con- 
 stantly lubricating the bearing surfaces of the collars 
 
 and brasses. If one of the brasses heats, it may be 
 lifted out and turned around or replaced with another 
 Avithout stopping the boat. A light hinged cover com- 
 pletes the thrust block. For the smaller sizes of motors 
 indicated three collars on the shaft and tAvo brasses 
 Avill be sufficient. 
 
 The shell of the motor. Figs. 282 and 283 is a cylin- 
 
 
304 
 
 IIOMP] MKCIFANICS FOR A:\IA'rFlM?S 
 
 (li ical iron casting oarryinfj the four polar projortions, 
 A. It is shown in the drawini^s with a perfectly ])lain 
 exterior, bnt it should be ])rovided with feet. Tliese 
 are not shown in the drawinc;, as they slionld he made 
 to fit the shape of the hnll. 
 
 At each end of the heavy field rin," is a cylindrical 
 l)rojection, C, stiffened with four columnar ribs, A', to 
 receive the cap screws which fast(‘n on tlu' (uid plate. 
 The field casfiiii? mav he finished on the lathe in two 
 operations. It should he chucked and the field bored 
 out to a diameter of exactly 6 t\ inches. Upon the ac- 
 curate boring of the field and turning of the armature, 
 or, in other words, upon keeping the air spaces as small 
 as possible, will depend much of the satisfactory per- 
 formance of the motor. 
 
 The end surfaces for the reception of the end plates 
 are trued off at the same time the field is bored, and 
 fhe seat, 8, for the brush holder ring, B, is also turned. 
 There is no necessity for any finish on the exterior of 
 the field cylinder or any other machine work upon it 
 except drilling and tapping four holes in each end to 
 take the cap screws holding on the end plates. After 
 the field is bored all sharp edges and corners left on the 
 polar projections should be neatly rounded off with a 
 file. 
 
 The two end plates are exactly alike, each carrying 
 a hearing IJ inches in diameter by 3 inches long for 
 Ihe armature shaft. They should be cast of bronze or 
 gun iiK'tal, and need not be more than F inch thick. 
 1 ti the one at the commutator end four windoAvs should 
 be cut, opposit(“ the norTual position of the brushes, so 
 thal lhes(“ may lx; observed while the machine is run- 
 
HOME MECHANICS FOR AMATEURS 
 
 305 
 
 Figs. 282 and 283. Longitudinal and Cross Sections of 
 
 Motor Shell, 
 
30G 
 
 llOMK iMKC^IIAMCS FOR AMATEURS 
 
 Tlie briisii holder ring, /^, Figs. 28R and 285, is of 
 brass or bronze, ineli(‘s outside* diain(*t(*r and | ineli 
 tliiek. It earries tin* four biaisli liold(*i's, oiu* of wliiebi 
 is sliown in seetion in fdg. 285 and in (*l(*vation in 
 Fig. 28(). Any design of I'adial brusli liold(*r may be 
 used, but tlie simple foian shown is (*asy to make* and 
 very satisfactory. The body of it consists of a brass 
 box, (‘ast in one piec-e with the stud going through tin* 
 ring, !>, This is tinish(*d out to allow the (‘op])(*r(*d 
 carbon brush, lixlijxf inch(*s in size*, to slide (*asily 
 through it. A forked ])i(*c(* straddling the* n])])(*r cor- 
 ner of this box cariaes a tinger Ayhich is pr(*ss(*d ui)on 
 the butt of the brush by the steel spring and thumb 
 screw arrangement shown. 
 
 The dimensions of the shaft are clearly indicated in 
 tlie drawing. The commutator is by far best bought, 
 though the dra^ying furnishes a sufficient indication of 
 a simple form to enable an amateur to make it him- 
 self if he so desire. It has 48 segments and should be 
 4 inches in diameter, 2 inches face, and bored for a 
 inch shaft. 
 
 The core of the armature is 6 inches diameter and 8 
 inches long. The end plates of steel, inch thick, hold 
 tog(*ther the mass of soft iron disks of which it is com- 
 })os(*d. These should be a little larger than 6 inches 
 diani(*ter in the rough, as the core must finish exactly 
 to this figure. If it comes out a little small, the field 
 boi'(*, which should Acait upbn the construction of the 
 ai'inatun*, must lx* made as nearly as possible inch 
 larg(*r. 
 
 It is us(*l(*ss to japan or insulate the disks. Put 
 1h(*ni log(*lh(*r as lh(*y ai‘(‘, lighl(‘n u]) lln* nut, N, hb’g. 
 2S5, on I ho sliafl and jiin il in place. Th(*ii true oft* the 
 
HOME MECHANICS FOR AMATEURS 307 
 
 surface in tlie lathe by very light cuts with a sharp tool 
 at rather high speed, using au abundance of soapy 
 water on the tool. A mirror-like surface may be at- 
 tained in this way. 
 
 While the armature is in the lathe it should be scored 
 for the binding wires which will hold the coils in place. 
 The grooves for these should be turned, each about ^ 
 inch wide by a scant tV deep, one near each end and 
 one in the middle. 
 
 Fig. 285. Armature Core, Shaft, and Commutator. 
 
 The next operation is milling out the slots for the 
 winding. There are 48 of these, each ^ inch wide and 
 inch deep, equidistantlj" spaced around the core. In 
 milling out armature slots, the tool should turn at a 
 fairl}" high speed, the feed be very slow and the cut 
 light, and an abundance of oil should be used. If no 
 milling machine is at hand, the slots may be planed, 
 great precaution being taken to keep the cut very light 
 indeed. 
 
 The best Avay to line up the frame of the motor and 
 to be sure that the armature is properly centered in the 
 
308 HOME MECIIAXICS FOR AMATEUIiS 
 
 fit'ld bore, is to wrap tbe arinatun* core witli oik* or two 
 layers of thin ])a]K*r, until it tits neatly in the 
 bore, put on the heads at (he ends of the inaehiiK*, and 
 east Hahhitt metal in (Ik* hnsliinus. If tin* (“iid ])lates 
 are mark(“d so that they ean h(> ])nt hack in (Ik* saim* 
 Avay, the armature will h(* found jo he eorreetly cen- 
 tered. Unless this is dom* the electrical balance of tin* 
 motor will he disturbed, and the brushes will probably 
 spark and f>ive trouble. 
 
 The windin'*' to he described is of the sort known as 
 a four-pole lap windinf*', and is one of the simplest and 
 easiest to make of the various forms of interlocked 
 windings. Each of the forty-eight coils used is shaped 
 in the forming apparatus shown in Figs. 287, 288 and 
 289. This is in two parts, a frame for winding the 
 coils and a former for bending them. The frame is 
 simply a piece of hoard with two i inch round metal 
 pins driven in it, these being lOf inches apart, out to 
 out. Around these, as clearly shown in Figs. 288 and 
 289, are wound six turns of No. 14 B. & S. gauge double 
 cotton-covered wire, the starting end of the coil being 
 marked by twisting a loop in it, as shown in Fig. 289. 
 The ends of the wire should he left longer than the illus- 
 tration shows them, say about 6 inches. When this 
 coil is completed, it should he tied in at least four 
 places with small thread to keep it in position when it 
 is removed from the two pins, and it should he well 
 shellacked with rather thin varnish. It is extremely 
 advisable to make up at least five or six of the hoards 
 shown in Figs. 282 and 283, as this enables the winder 
 to allow the coil to dry to the proper consistency of 
 “tackiness” before* it is r(*moved from the frame, and 
 also periuils the* coils to bee made much more rapidly 
 
HOME MECHANICS FOR AMATEURS 309 
 
 than if it were necessary to wait each time for the wire 
 to dry ont before winding the next. 
 
 The correct state of dryness of the shellac for the 
 next operation must be learned by experience. It is 
 when it is at its stickiest. When this condition is 
 reached, the coil is removed from the frame and placed 
 in the apparatus shown in Fig. 287 to he formed. This 
 machine is made of a wooden base hoard, on Avhich is 
 screwed a hard wood shaping piece of the dimensions 
 shown and about | inch thick. Two hinged pieces, as 
 shown, are provided, so that when the straight coil as 
 
 Figs. 287, 288, 289. 
 
 Board for Forming and Bending Coils. 
 
 Fig. 286. 
 Brush Holder. 
 
 it comes from the winding board is laid centrally upon 
 the forming piece, and both the hinged pieces bent 
 over, it will be bent into a form somewhat like a wide 
 inverted U. The illustration shows a coil of only one 
 layer being bent. There will be, of course, six wires in 
 each side of the coil, or twelve in all to be bent. 
 
 When this bending operation is completed, and be- 
 fore the shellac is finallv hard, the bent coil must be 
 pulled apart so that six of its wires, those tied to- 
 gether on one side, may be laid in a slot of the armature, 
 and the remaining six wires, forming the other long 
 
310 
 
 IIOMF. IMFCIIAXK^S KOI? A:\IA30^ri?S 
 
 straif»lit side of ilu* Ixail coil, laid in tin* slot !)() <I(*i;r(M*s 
 away. In otlua' woi'ds, tlie (‘oil, wlnni it is jnit oii tli(‘ 
 arinatiirc', niiist rc^acOi fi'oni slot 1 to slot 0), assnininij;- 
 that tliey are ('onscxait iv(‘ly nnndxn'ed. Tin* ai)])(*ar- 
 anee of tli(‘ tinisluMl (-oil, ix^ady to jnit on tli(‘ armature*, 
 is indicated by 21)0. 
 
 A i>lanee at 21)1, wldi'li shows tin* (*nd of tin* arm- 
 ature partially wound, will make this (‘l(*ar(*r. Tin* 
 
 Fig. 290. Completed Coils, Ready to be Mounted on Armature. 
 
 Pig. 291. End of Core, Showing Arrangement of Coils. 
 
 eoils, if jiropei'ly bent, will lie elose together on the 
 h(*ads of tin* armature and jirodiu'e the very neat and 
 sim])l(' int(*rloek(*d end arrangement shown in the il- 
 Inst rat ion. 
 
 \\ ln*n ail tin* foi*ty-(*ight (‘oils are in ])la(‘e, the arnia- 
 tnF‘(* is i‘(*ady foi‘ banding. In the shallow S(‘()r(*‘S on 
 I In* snrfa(‘(* ar(‘ laid thin strijis of mi(‘a, the armature 
 b(*ing in (‘(*nt(*rs on tin* latln* for this operation, or 
 
HOME MECHANICS FOR AMATEURS 
 
 311 
 
 otherwise iiioniit<‘(l so tliat it can he turned around. 
 It is better to catch tlie niica strips under a cord 
 wrapijed around the core a few turns than to attempt 
 to stick them on witli shellac. On the mica is wound 
 the band, consisting of about No. 24 gauge German sil- 
 ver or hard brass wire wound under the strongest ten- 
 sion it will stand. The band should net be more than 
 t\ inch w ide, tlie number of turns depending, of course, 
 on the gauge of the band wire. Above all, care must 
 be taken not to have this so large or the mica so thick 
 that the bands project above the armature surface, as 
 the clearance space is very small and the bands are 
 liable to injury in putting the armature in place or re- 
 moving it. 
 
 When the band wire is wound on, it is soldered with 
 five or six little dabs of solder, not continuously, and 
 the ends cut off. Three bands will be recpiired, one 
 within about 4 inch of each end of the armature core 
 and the other at the middle. 
 
 The commutator is held from turning on the shaft 
 by a feather (not shown in the illustrations), and is 
 sufficiently held endwise by the ninety-six wires sol- 
 dered into it. To connect these, take the beginning 
 end of any coil, marked by the little loop twisted in it, 
 and solder it and the ending end of the next coil in 
 regular order, either Avay, into the slot in the tail of 
 the commutator bar nearest in line. Proceed around 
 the armature in this regular order, being very careful 
 to bring the ends out neatly and not to pull the head 
 of the winding to pieces in so doing. No acid should 
 be used as a flux in soldering commutator connections. 
 The only safe thing is rosin. A narrow edged solder- 
 ing iron that wall go into the slot in the commutator 
 
312 
 
 HOME MECHANICS FOH .UWTKUPyH 
 
 bar will bo foiiiid vory oonvoiiicait for lliis work. It is 
 woll to wind some tajx^ around tlu^ ininn* Ind) of tln^ 
 (‘oniinntator before l)ei» inning the sol<l(n'in^. \\di(*n it 
 is finished^ a lay(‘r of stout (‘ord sbonld 1)(‘ wound on 
 over tlie bnneb of ends i»()in^ to tlie (‘ominntator to k(x*j) 
 tliese from spreadin<j^ from (*entrifn^al acdion wlien tlie 
 armature is rnnnin<»'. Tlu^se (‘oninintator eoniKM'tions, 
 ready for tlie (‘ord wra])j)inj>:, are shown in Fii». 292. 
 
 The armature is (completed by ladnij^ returmxl to the 
 lathOj where a light out is taken over the commntator 
 
 Fig. 292. End of Completed Armature, Showing 
 Commutator Connections. 
 
 to true it and cut off any straggling wire ends. The 
 armature should be baked over night in an oven to 
 thoroughly dry it out before it is attempted to use it in 
 the motor. 
 
 On each of the four poles of the field is fastened, with 
 small brass angle pieces, as (dearly shown in Figs. 282 
 and 28M, a coii (‘onsisting of twenty-five turns of No. 
 b H.& S. gauge* wire*, arranged in five layers of five turns 
 (*a(di. The*se* e*oils are wound on a Avooden former and 
 tape*d. The*ir inne*r ends should be marked in some 
 conv(*ni(*nt way, and the*y slioulel be connected to- 
 
HOME MECHANICS FOR AMATEURS 
 
 313 
 
 getlier so tliat they magnetize the fields alternately 
 north and south when a current is sent through the 
 four in series. Calling them Aj B, C, and D, this is 
 done thus: Bring out the outer end of A through a 
 hard rubber bushing in the commutator end plate (the 
 end plate at the commutator end of the motor), then 
 connect the inner end of A to the inner end of B, the 
 outer end of B to the outer end of C, the inner end of 
 C to the inner end of D, and bring out the outer end of 
 D through another bushing. 
 
 Two other bushings are provided for bringing out 
 the ends of the wires to the brushes. The four brushes 
 are connected in two pairs, opposite brushes being con- 
 nected together and to one of the leading-out wires. 
 These connections should be made with No. 8 wire and 
 the leading-out wires should be No. 6 flexible rubber 
 insulated cable. 
 
 Should it be desired to construct motors of this type, 
 but of less power, the same general instructions should 
 be followed, the diameter of the armature and casing 
 being the same, but their lengths different. Below are 
 given dimensions and speeds for motors of two and 
 three horse power; where a dimension is not given, it 
 is the same as that described above for the motor of 
 four horse power. The slots for the three horse power 
 armature should be J inch wide and | inch deep; for 
 the two horse power armature, ^ inch wide and tV inch 
 deep. 
 
 The motor now being complete, the next part of the 
 boat’s equipment is the controller. The design shown 
 is exceedingly simple and easy to make. Referring to 
 Figs. 293, 294, and 295, which show it in section, 
 and Fig. 296, which is a diagram of its connections, its 
 
314 
 
 WOUK .MI^:CIIAXICS KOI? AMATKl h^S 
 
 (‘()iistni(4 ion and opca'a! ion will 1)(‘ laanlily niKha'slood. 
 It lias Ikmmi llioniL;lil ))(*st nol to coniplioatc* its (‘on- 
 strnction liy att(an])tini> to coinhiiK* tin* ali(*a(l and 
 astorn (‘ontrolliniL; niovcainaits with thos(* foi' sp(*(*ds, so 
 two liandl(^s ai'(^ ])i()vid(M], om^ .nivint; half th(‘ full 
 s])oods and th(‘ otlna- for i'(*v(‘rsini»' tlu^ boat’s dir(‘(*tion. 
 Th(‘se ar(‘, how(‘V(‘r, foi‘ (*onvcaii(ai(‘(*, nionnt(*d at tln^ 
 two ends of th(‘ eylindi4(‘al (-asc^ of tlu^ (*onti‘oll(a‘. The 
 best material for this is wood. It should lx* about 10 
 or 12 iiudies in diameter outside, and about 1 inch thick 
 
 Fig. 293. 
 
 Cross Section of Speed End 
 of Controller. 
 
 Fig. 294. 
 
 Longitudinal Cross Section 
 of Controller. 
 
 by about 9 or 10 inches long, and is conveniently built 
 11 ]) in the way descallxxl above for the pattern for the 
 ti(4d (‘asting. It should be of wood on account of the 
 insulating jirojauTies of that material. 
 
 In this woodim ('ylinder are mounted two wooden 
 disks, about an imdi l(*ss in diameter than the internal 
 iiK^asurcmient of th(‘ (‘ontaining (‘vlinder. These two 
 disks are turiuMl by th(‘ two handles — the speed and 
 direction handl(‘S — and c'arry on their surfaces copper 
 
sectors which are set into tlie Avood so as to lea\’e a 
 siuootli surface for running under the connecting 
 points. These are aacII shoAA’u in cross section in Fig. 
 293, AA’hich is a partial cross section of the speed con- 
 trolling end of the apparatus. They consist of brass 
 tubes about 1 inch in diameter, 4 inches long, and tV 
 inch thick, containing a spring and a contact piece 
 (brass or copper), fitting the tube neatlj^ and pressed 
 by the spring into contact AA’ith the surface of the disk. 
 Nine of them AA’ill be required. 
 
 Pig. 295. Cross Section of Reversing End of Controller. 
 
 At the speed control end of the apparatus the turning 
 disk carries tAA "0 short sectors on opposite sides, these 
 being connected together as shoAvn, and tAA’O longer sec- 
 tors extending through about 80 degrees of the cir- 
 cumference. These are also folded over on to the hack 
 of the disk, as shoAvn by dotted lines in Fig. 286, so that 
 tAvo of the spring contacts may also bear upon this sur- 
 face. The easiest Avay to make these sectors is to cut 
 the parts out of tV inch sheet copper, and mount them 
 
316 HOME MECTTANTCS FOE AMATEUKS 
 
 on tlio wood with small (*oiint(‘rsunk wood screws. 
 The (‘irenmfer(‘ntial and fiat ])arts of the scM'tors last 
 deseribcnl may well he soldered to.^ethei' aftca* tluw ar(^ 
 in place on the disk. In all (-ases the S(H*toi‘ should Ix^ 
 let into the wood so that there will Ix^ no shoahhu* to 
 (‘atch af^ainst the S])ring’ contact when th(‘ disk is 
 turned. 
 
 At the s])eed (‘ontrol end of the apparatus four of th(^ 
 s])rino* (‘onta('t tubes are mountcxl, hearinii^ u])on th(‘ 
 edf»e of the disk as shown; tlu^ four Ixu'ujlj; in opposite^ 
 pairs ()0 dei>rees apart. Tn the int(U'ioi‘ of the cylin- 
 drical (-ase of the controller are two ])artitions as 
 shown in Fig*. 294, the one nearest the speed control 
 disk just described carrying two of the spring contacts 
 bearing on the flat sectors as shown by the dotted lines 
 in Fig. 293. These bear at points on the same diameter 
 connecting two of the edge bearing contacts. 
 
 At the other end of the controller is mounted the 
 mechanism for reversing, which is shown in partial 
 section in Fig. 295. This consists also of a disk carry- 
 ing on its edge three sectors, two of them only long 
 enough to be entirely in contact with the spring con- 
 tacts as shown, and the other long enough to bridge 
 two of them, about fifty degrees. Three of the spring 
 contacts are mounted bearing on these, 30 degrees 
 a})art. The long sector is connected to the further of 
 the two short on(\s, Avhile the middle sector is connected 
 to th(‘ ])ivot of th(^ disk and thus to the bushing in which 
 it turns. As Fig. 294 shows, this is made quite long, 
 as Ibis (‘ontacl has to (‘ariw large currents. It should 
 not )x‘ l(*ss than 1hi‘(*(‘ incln^s long, the pivot being a 
 pi(x*(‘ of on(‘ inch shaft ing. 
 
 K(*f(u*ring now to Fig. 290, the operations of the (‘on- 
 
, HOME MECHANICS FOR AMATEURS 
 
 317 
 
 troller will be easily understood. It shows the connec- 
 tions for half speed ahead. The diagram shows the 
 two sides of the controller separated, for the sake of 
 clearness, but it is, of course, understood that they are 
 no further apart than the two ends of the wooden box 
 in which they operate. The fuse shown in the circuit 
 between the pivot of the reversing^ controller and the 
 inner spring contact is mounted in the middle division 
 of the box, which should have a door for access. It 
 should be an ordinary single-pole iDorcelain fuse block 
 
 Fig. 296. Diagram of Controller Connections. 
 
 carrying a fuse blowing at about 75 amperes. For 
 the 3 horse power motor it should blow at (>0 amperes, 
 and at 40 amperes for the 2 horse power motor. 
 
 The controller box is easiest made of some soft wood, 
 such as white pine. It should be liberally varnished 
 outside and lined inside Avith asbestos paper, glued or 
 tacked in place. The two disks should be of hard 
 Avood. On the exterior of the box should be marked 
 the positions for the various speeds and directions, or, 
 if the constructor feels so disposed, he can mount a 
 position cam and roller on each pivot. 
 
318 
 
 IlOMl^: MKCMIAXIC'S FOR AMAIO^FRS 
 
 Tlie controller may Re ])la(‘e(l aiiywlHM'e in tli(‘ boat, 
 bnt i)referably \vli(a-(^ it (an inanipnlatcMl by tln^ 
 j)ilot^s left hand whiles In^ stcxn's witli Ins I'i^lit. All tin* 
 wirin<»’ between the batteri(*s, motor, and controlh*i* 
 shonld be run with i»()od ((nality rnl)b(*r (‘ov(*i'(*d win*, 
 No. 4 gani»e, and pr(*f(*rably in iron armor(*d (*ondnit, so 
 that it may not be disturbed by ])ass(*n<>(*i‘s walking 
 on it. 
 
 The 24 (‘ells of battery may In* conyeni(*ntly (*har<»(*d 
 from a 110 volt source of sn])ply by tin* ns(* of a r(*sist- 
 ance. This slnndd be of about 3 ohms and is conven- 
 iently made of iron win^, about No. 14 i>a)ii»e. About 
 350 feet of it will be re(piir(*(l, and this may In* (‘onven- 
 iently coiled u]) in loose coils and hnnj[> in a frame. 
 It shonld not be confined, bnt allowed to have free cir- 
 culation of air, as it Avill warm up (‘onsi(l(*rably. The 
 charsiiis* current shonld be about 20 amperes. Fhill 
 charge is determined either by the voltmeter, which 
 will then read 50.5 volts, or by the ^Omiling’’ of the 
 (‘(*lls. It is a waste of current to attempt to further 
 (‘harge a cell after it begins to ^dioil.’’ 
 
 If the amateur so desires he may make his own cells, 
 bnt he is likely to have more satisfaction with those 
 h(* buys. For the larger size of motor described these 
 c(*Ils shonld be made with plates 8 inches square, 15 
 l(*a(l plates and 10 zinc plates to each cell. 
 
HOME MECHANICS EOK AMATEUES 
 
 319 
 
 THE EDISON DYNAMO OK MOTOK 
 
 It is one thing to make a dynamo or motor from 
 explicit instructions and quite another tiling to design 
 a machine adapted to generate or be operated by a 
 particular current. The former is purely mechanical 
 
 Fig. 297. Small Edison Dynamo or Motor. 
 
 and within the range of most machinists and amateurs, 
 while the latter is entirely tvithin the province of the 
 electrical engineer or electrician. When the tvork of 
 machine building proceeds simultaneously with the 
 
320 
 
 HOME MECHANTCS FOR A]\rATEURS 
 
 study of fundamontal i)i'iTi( ij)l(“S, roal progress is made. 
 For tile benefit of tliose wlio proeei'd in tliis way, and 
 in answer to many imjnirers, w(‘ "ive a detailed deserip- 
 tion of an Edison 0.25 kilowatt maeliine, dc'si^ned for 
 use as a dynamo for siipplyinij a current for five Edison 
 standard lamps, or for use on the PFlison circuit as a 
 quarter horse power motor. 
 
 Before heginninjj; the desci iption of the machine it is 
 hut fair to say that it is thoroughly well made in every 
 particnilar. The insulation in every part is very per- 
 fect, and the whole is so well made that any single 
 machine built by a mechanic or amateur could hut 
 suffer by comparison with it; and furthermore, we 
 doubt if any maker of a single machine could even 
 purchase the materials required for the price asked for 
 the machine by the regular manufacturers. Therefore, 
 if the machine is wanted, we advise a purchase. If 
 experience is wanted, the making of the machine comes 
 first in order, Avith a probable purchase to follow. 
 
 The base, which is of brass, is made hollow, as 
 shown. It is 14 in. long, If in. wide. If in. deep at 
 the ends, with two 1^ in. eleA’ations at the middle for 
 receiving the cast iron pole pieces of the field magnet, 
 Avhich are each secured to the base by two small tap 
 holts extending upwardly through the base and into 
 the pole pieces. 
 
 The upper surfaces of the pole pieces are truly faced 
 for receiving the cylindrical field magnet cores, which 
 are made of Swedish iron, 2if in. in diameter and 44 
 in. long. These magnet cores are each held in position 
 by a threaded stud screwed into the pole piece and 
 entering magnet core. Each core is provided with a 
 vulcanized lilxT collar at each end, Avliich is in. thick 
 
HOME MECHANICS FOR AMATEURS 
 
 321 
 
 and f in. wide. Upon each core, and between the 
 fiber collars, is wound 5^ lb. of No. 24 silk-covered 
 copper wire, with a wrapping of thin varnished paper 
 between the layers. The cores, before winding, are 
 thoroughly insulated with the same material. The 
 
 Fig. 298. Side Sectional Elevation of Dynamo. 
 
 fiber collars are each held in place by three conical- 
 headed screws entering the end of the core, with their 
 heads projecting beyond the body of the core. To the 
 inner and outer ends of the winding of each arm of the 
 magnet are attached pieces of larger wire to avoid 
 
322 
 
 .MKClJAX’K’S KOI? AMA'IMaUH 
 
 breakajic, and the inner ends ai‘<‘ l(>d nut tlironp;!! 
 j>r()()ves in tiie fiber collars. The vok(‘, of Swedish 
 iron, is 2| in. wide, 2^ in. thick and TA in. long. It 
 is held in position on tin* cores by two A bronze 
 stiids, each tlir(*ad(‘d at the iipper and lower ends, and 
 furnished with a collar which tits into the counter- 
 
 Fig. 299. Side View of Field Magnet, Partly in Section. 
 
 bored part of the hole in the yoke. The studs are 
 s<piared sit the upper end to receive a wrench, and a 
 nut is placed on each stud above the yoke for clamp- 
 ing it securely after adjustment. The machine is regu- 
 lated or adapted to any work retpiiring less than its 
 full power by raising the yoke more or less. The yoke 
 
HOME MECHANICS FOR AMATEURS 
 
 323 
 
 is provided with an eye, by means of which the ma- 
 chine may be lifted. 
 
 Front and rear boards of mahogany are arranged on 
 opposite sides of the yoke, and held in place by brass 
 plates at the ends. 
 
 The outside ends of the field magnet coils are con- 
 nected with binding posts on the rear board. 
 
 A variable resistance of ten or fifteen ohms is in- 
 serted between these posts when the machine is used 
 as a dynamo. In the front board, at the right hand 
 side, is secured a bronze casting known as the right 
 hand motor head field magnet terminal. This is 
 
 Fig. 300. Switch on the Edison Dynamo or Motor. 
 
 adapted to receive the line wire, also one of the leads, 
 the upper end of which is screwed to the casting. The * 
 lower end of the lead is secured to a lead terminal 
 attached to a block of wood secured to the right hand 
 pole piece. At the right hand side of the machine a 
 similar arrangement of the lead is found, but the up- 
 per lead terminal is made in two separate parts, one 
 attached to the lead, the other being connected with 
 the line; both being furnished with copper switch 
 tongues. The switch arm turns on a stud projecting 
 from the front board and carries a loose triangular 
 switch plate of copper, having a knife edge which 
 
324 TrOMI<] I\IRCITANFCS FOl? A:\IATKUKS 
 
 readily oidoi-s lK>t\vo(ai tli(‘ swilcli loiioiu-s. Tlie switch 
 has a T-haiidl('' <»f lull'd ruhhia', hy mi'ans of which it 
 is turned. A stoi) ])in ])i'(>j<“ctinf^ fi-oiu llic front hoard 
 limits till' rearward moymiumt of tli(‘ switeli arm. 
 
 The inside end of the I'i^ht mai^md coil is eonneeted 
 with the right hand lead, and lln^ iiisidi^ mid of the left 
 
 Fig. 301. Diagram of Winding of Edison Armature. 
 
 liand magnet coil is connected with the lower half of 
 till* left liand lead terminal. 
 
 At oi)])osit(‘ ends of th<‘ base there are plane surfaces 
 io wliicli are si'cnred tin* self-oiling hearings of the 
 armalnrc* shaft, hlach l)(>aring has a hollow standard 
 fnrnislied wilh a caii, wliich, together with a cross 
 jiieci* in lh(‘ hollow standard, forms a support for the 
 
HOME MECHANICS FOE AMATEUES 
 
 325 
 
 spherical central portion of the bronze sleeve forming 
 the journal box proper. 
 
 This sleeve is shorter than the outer portion of the 
 bearing, and is slotted across the top to allow two 
 brass rings to ride upon the armature shaft. These 
 rings dip in the oil in the hollow standard, and as they 
 
 Fig. 302. The First Two Coils and Commutator Connections. 
 
 revolve carry oil to the shaft in quantities more than 
 sufficient for the purpose of lubrication. The oil is 
 distributed throughout the bearing by means of spiral 
 grooves formed in the inner surface of the journal box. 
 The surplus oil drops back into the hollow standard. 
 A screw plug in the lower portion of the standard 
 allows of the renewal of the oil. The bearings at 
 
326 
 
 HOME MECHANICS ECU AMA'l'EUES 
 
 op2)(»site ends of Hie iiiacliine are alik(‘, exci'pl (liat Hie 
 cast ii'on supiioi-t of Hi(‘ Iiionze joui'iial box, at the 
 coiiuimtator end of Hie armature, is turned on its inner 
 end to receive the hrusli 3’oke. 
 
 Tlie steel armature sliaft is l(i| inches ionj^ and 
 inch in diameter at tlie journals, and incli in diame- 
 ter between the journals. The lari>ei‘ part of the shaft 
 
 Fio. 303. Arrangement of the Layers at End of Armature Core. 
 
 is It] inclii's louo-. Sufficient end chase is allowed in 
 the armature journals to cause the surfaces to wear 
 smooHilj. 
 
 On (he central jiortion of the armature shaft is 
 jilaced a woodmi sl(‘ev(“, liV inch in diameter; on 
 this are moun((‘d Hi(‘ thin sh(‘(‘t iron disks forming' the 
 
HOME MECHANICS FOE AMATEUES 
 
 327 
 
 They are arranged in series of five, with tissue paper 
 betW'een the disks, and between the series of five are 
 placed several thicknesses of paper. Enough disks are 
 clamped together on the shaft to make this portion 
 of the core inches long. The cast iron disks be- 
 tween which the sheet iron disks are placed are | inch 
 in thickness and 2^ inches in diameter. One of them 
 is fixed on the shaft, the other being held in place by a 
 hexagonal nut screw'ed on the shaft. The cast iron 
 disks have their outer corners rounded, and in the 
 
 Fig. 304. The Ends of the Armature Core. 
 
 edge of each are formed thirty-two equidistant radial 
 slits inch wdde. In these slits are inserted slips of 
 vulcanized fiber for separating the different pairs of 
 coils during the operation of winding. 
 
 It is impossible to describe the Edison wunding wuth- 
 out depending mainly on the diagrams. Figs. 301 and 
 302. There are tw’o series of coils ; that is to say, there 
 are tw'o coils in each division of the armature There 
 are thirty-two bars in the commutator, w hich are num- 
 bered consecutively from 1 to 32. 
 
328 
 
 JJOMK MI^XMIANICS FOH A:\IATKT;HS 
 
 The arinatiir(‘ core and sliaft arc^ tlK)r()iii»:lily insu- 
 lated by means of i)a])(n‘ eoated witli an adh(*sive var- 
 nish. Jnte strini*' ril)l)()n is wound on tlie fa(‘e of tlie 
 core as a fiirtluT ])rot(‘(‘tion. 
 
 The wire nsed on the armature is No. 21 (‘ 0 ])i)er wire, 
 double covered; tlie inner eoverinii; beinj>^ of silh, the 
 outer of (‘otton. 
 
 Leavinf»' an end out for connection witli tlie commu- 
 tator (‘oil, No. 1 is bej»un at 1 and wound in four lay- 
 ers, with six convolutions in each layer, the outer ter- 
 minal eominf>‘ out at T. Tlu^se (mds are niarkc^d re- 
 spectively 1 and 1' in such a manner as to avoid any 
 possibility of the detachnumt of the marks. If this 
 caution is observed, much trouble may be avoided. 
 A good Avay to mark them is to jilace a tag of parch- 
 ment, or parchment paper, on each end of the wire, 
 with the number marked on. 
 
 After winding coil No. 1 the armature is turned half 
 way over and coil No. 2 is wound and marked in the 
 same way, with 2 on the inner end of the coil and 2' on 
 the outer end. The coil is then reversed and coil No. 
 3 is wound and its ends are marked in the same way, 
 and so on until the first series of coils is finished, the 
 last coil of the series being marked 16 and 16'. 
 
 The first (-oil of the outer series is No. 17-17'. This 
 is wound on the top of coil No. 1. The armature is 
 turned over and No. 18 is wound on the top of No. 2, 
 and so on until all of the outer coils are in place. 
 
 I>(d‘or(‘ winding, the inner end of each wire is 
 wrapper! in jnt(‘ string ribbon to a point within the 
 (*nd of th(‘ armatnT‘(‘ core, and it is further protected 
 by a wi'apping of Ihin adh(‘siv(" taj)e. The outer end of 
 the coil is (‘ov(*r(Ml in the same Avay. 
 
HOME MECHANICS FOR AMATEURS 
 
 329 
 
 About three pounds of No. 21 wire are required for 
 the armature. The length of wire in the first inner 
 coil is 26 feet 6 inches. The length of wire in the last 
 outer coil is 35 feet. 
 
 The commutator cylinder* is formed of 32 bronze 
 bars having beveled ends and radial arms for receiv- 
 ing the wires. These bars are clamped in position on 
 a sleeve having an under-cut flange, by a countersunk 
 washer and a nut screwed on the sleeve. Mica is 
 inserted between the commutator bars, between the 
 bars and the sleeve, and between the ends of the bars 
 
 Fig. 305. The Armature with Parts Broken Away. 
 
 and the flange and the washer. The radial arms ex- 
 tending from the commutator bars each have a slot in 
 the end for receiving the terminals of the coils. 
 
 The coil terminals are arranged in groups of 16, the 
 wires of each group being parallel. The terminals are 
 carried around and attached to commutator bars 
 which are about 90° from the planes of the coils to 
 which they belong, thus making the winding more 
 symmetrical and at the same time permitting of a bet- 
 ter arrangement of the brushes. 
 
 The coil terminals are inserted in the slots of the 
 arms of the commutator bars and soldered with soft 
 
 * For further points on Commutators, see Supplement 600. 
 
330 
 
 IfOMK MPX:IIAN1CS K()I{ AMA'I'EUKS 
 
 solder, the connections beinij made in accordance Avith 
 the diaj^i'ain, Fio-. 301. 
 
 The wires, where tlu\y cross at the hack and front 
 end of the armature', are separate'd hj sheets of mica. 
 ^yhere the windinij crosse's at the rear end of the arma- 
 ture the wires are spread out so that they are only 
 one layer deep. 
 
 Fig. 306. The Brush Yoke. 
 
 When the winding of a coil is finished, the terminal 
 is fastened by stout threads inserted in the coil before 
 winding the last three convolutions, and tied after the 
 coil is complete. 
 
 A vulcanized fiber collar, a little larger in diameter 
 than the commutator, is slippi'd over the commutator 
 bars and ])laced against the radial arms of the bars 
 as shown. Tin* edgi' of the collar is grooved and a 
 canvas cov(*r is fasti'iied to the collar by tying it in 
 the groove. It is (Ik'u drawn over the terminals and 
 
HOME MECHANICS FOR AMATEURS 331 
 
 fastened by the first ring of binding wire on the arma- 
 ture. At the opposite end of the armature a similar 
 collar and cover are provided. 
 
 Before covering the terminals with the canvas they 
 are wound with twine to give the end of the armature 
 
 Fig. 307. Details of the Brush Holder, the Commutator Cylinder, 
 
 and Brush-holding Jig. 
 
 a symmetrical shape. The winding is varnished with 
 shellac before its cover is applied, and the cover is 
 varnished after it is secured in place. 
 
 The binding rings are formed of brass wire, wound 
 tightly over a layer of mica interposed between the 
 wire and the binding. The binding wire is secured by 
 clips and soft soldering. 
 
 The brush yoke is provided with wooden handle by 
 
:532 HOME MKCIIAXICS FOI? AMA'l’EUHS 
 
 wliich it may be moved and a biiidiiifj; scrc'w by wliicb 
 it is clamped in the position of nse. Jn mortises in the 
 ends of tlie yoke are placed insnlaiin*;; blocks, in which 
 are inserted the brnsbdioldinij studs. These stnds are 
 each provided with a nut for clampiiif^ the brush 
 holder cables which communicate with the leads at the 
 side of the pole pieces. 
 
 On each brush-holdiip" stud is placed a sleeve fas- 
 tened with a set screw, also a loose sleeve connected 
 with the fast sleeve by a spiral spring concealed with- 
 in it. The loose sleeve is furnished with a brush clamp 
 for holding the brush, Avhich bears on the commuta- 
 tor cylinder Avith a yielding pressure. The brushes are 
 formed of spring copper Avires fastened together at 
 their outer ends with soft solder. 
 
 A jig goes Avith each machine for clamping the brush 
 and guiding the file while reneAving the brush ends. 
 
 The speed of the motor on a 125 A’olt circuit is 2,400 
 reA'olutions per minute. The speed at which the arma- 
 ture is to be driven in order to generate a current liaA'- 
 ing an E. M. F. of 125 Amlts is 2,730 revolutions per 
 minute. 
 
 According to the ncAv rating the machine here de- 
 sci-ibed is a 0.5 kiloAvatt machine, Avhich, A\'hen used as 
 a generator for supplying lights, will generate suffi- 
 cient current to bring to full candle power nine 16 C. 
 P. 112 A’olt lamps, and Avhen used for power it is a | 
 horse poAver motor at a rated volt. It is guaranteed to 
 give 0.47 horse poAver at J of its rated volts. 
 
HOME MECHANICS FOE AMATEUES 
 
 333 
 
 THE UTILIZATION OF 110 VOLT ELECTRIC 
 CIRCUITS FOR, SMALL FURNACE WORK* 
 
 It occurred to the writer in wiring up a couple of 
 experimental arc lamps across the feeders of an in- 
 candescent lighting system, that a laboratory electric 
 furnace could be operated on a series carbon plan, 
 Avithout disturbing the protecting fnses of the circnit. 
 This idea of concentrating a pair of arcs within a 
 small crucible or furnace, using only the amount of 
 resistance wire located in the tops of the lamps, proved 
 to be crude, the current taken being excessive upon 
 introducing a charge for fusion, when its character 
 embodied fair electrical conductivity. In order to 
 obviate this difficulty, as well as to compensate for the 
 lowering of resistance due to eddy currents between 
 the carbons, a triple series arc was formed requiring 
 only a short length of German silver wire to steady 
 its action. With this arrangement the most success- 
 ful results were attained, and Avith the furnace, as 
 finally constructed upon this plan, many metallnrgical 
 processes Avere carried on, a 12 ampere fuse placed in 
 each leg of the current supply being snfficient. The 
 little furnace illustrated in Fig. 308 is capable of pro- 
 ducing calcinm carbide in twenty minutes from the 
 time the current is SAvitched on, the fuses remaining 
 intact thronghout the operation, if a short length of 
 resistance wire is introduced into the circnit. With 
 this arrangement it is possible to separate the carbon 
 electrodes 3i inches without extinguishing the triple 
 arc. It is the intention of the writer to describe in 
 detail the construction of this little plant, and fur- 
 
 * By Nevil Monroe Hopkins. 
 
334 HOMJ-: MKCllAxNlCS TOli AMATEURS 
 
 Fig. 309. Plan View of Furnace, showing Connections. 
 
HOME MECHANICS FOK AMATEUES 
 
 335 
 
 nish carefully prepared directions for making small 
 quantities of calcium carbide. This compound is 
 chosen because of its exceedingly useful and interest- 
 ing characteristics, and because of the numerous in- 
 quiries the writer has received in regard to its forma- 
 tion on a small scale. Calcium carbide is a highly 
 refractory body, its preparation requiring the highest 
 temperatures, and its successful production by means 
 of this small electrical equipment urges experimenta- 
 tion with other compounds requiring less energy and a 
 lower temperature. 
 
 Fig. 309 will enable us to understand the mounting 
 and connecting of the carbons, being a plan view of 
 the system. The steps in putting together this little 
 equipment should consist in forming and lining the 
 furnace proper. The shell is made from sheet iron, 
 cut to exactly incase one of the common sizes of fire 
 clay slabs. The exact size and shape of this furnace 
 is, of course, immaterial, provided the length is not 
 over 13 inches from end to end, as shown in Fig. 311. 
 Should the length exceed 13 inches, standard electric 
 light carbons would not prove long enough to meet at 
 the center. As the fire clay slabs adapted to our pur- 
 pose vary somewhat in length, definite dimensions are 
 not given, but those shown in Fig. 310 will be found 
 useful as guides, and are approximately suited to the 
 average sized slab sold for backing up fire places and 
 stoves, which are plane on one side and fiuted on the 
 other. Having procured four of these slabs, the sheet 
 iron (No. 18 or 20 gauge) may be marked off carefully 
 and bent to form the shell. The overlapping sides are 
 drilled through and securely riveted together. One of 
 the fire clay pieces is now placed in the shell on either 
 
336 
 
 .MKCIIAXICS F()I{ AMA'I’l'J IfS 
 
 Fig. 311. Convenient Method of handling Cover. 
 
HOME MECHANICS FOR AMATEURS 337 
 
 side (the fluted surface next to the iron) and a large 
 fire brick dropped in between them. These large fire 
 bricks come with a recess in the top, as represented 
 in Fig. 308, which is desirable for collecting small 
 fusions. If the three pieces of fire clay fit nicely in 
 the shell, the fire brick is removed temporarily, and 
 our attention given to cutting one of the slabs in half 
 to form the ends of the lining. 
 
 In Fig. 310 a section of the shell is shown, where A 
 represents one of the side slabs in position, running 
 from end to end, as illustrated by the horizontal shad- 
 ing. These slabs may be had about 12J inches in 
 length by aboflt 8 inches in width and 2 inches thick, 
 which serve for this lining nicely. The end pieces 
 must be cut off at an angle to form the bottom of the 
 incline leading into the furnace. These are repre- 
 sented in the drawing by section, in oblique lines. The 
 fire clay is cut with a cold chisel and hammer, work- 
 ing slowly with uniform blows, exercising some little 
 patience, until the pieces have the proper shape. The 
 angle must be determined by trial with the shell, which 
 is cut down by means of heavy shears, within 5 inches 
 of the bottom, being about 5^ inches in width. The 
 metal flap, resultant of this cutting down, is sharply 
 bent over and cut off, the edge being smoothed with 
 a large flat file. A band of iron riveted around the 
 top, as illustrated, crowns the opening, and must be 
 adjusted as to height, by the size and thickness of 
 the fire clay lining which has been procured. 
 
 To complete the furnace proper, it is only necessary 
 to put in place the angle pieces, and secure in position 
 temporarily four pieces of glass, in order to form the 
 top of the inclined entrance. The wooden brace, B, 
 
338 
 
 HOME MECHANICS EOl? AMATEURS 
 
 is cut to the proper lenj^th to press the vertical j^lasses 
 (shown ill simple rnliiifi) against tli(‘ eiul pieces of fire 
 clay, and small wooden blocks made to support the 
 o’lass plates on Hie incline', as illnstratc'd, h'aviii" a 
 2-inch space. The hei<ilit of the vertical ,<>lass plates 
 nuist he just eipial to th<‘ lii'i^ht of the side slab, 
 M, and the inclined pii'ces must come nicely in 
 contact Avith them. The two sjiaces foi-im'd, f/ and 
 Z), are now filled in with “stoA’e fix’’ or other fire clay 
 compound made plastic by the addition of a little 
 water. This componnd may be had ready to mix, and 
 is applied with a, trowel. The glass plates must be 
 left in position oi’er night, in order that the material 
 which they support may set. They are then with- 
 drawn together with the wooden brace, and the fire 
 brick dropped into the bottom to stay. An additional 
 quantity of the stove compound is made up, and all 
 cracks and crevices plastered in. When this finally 
 sets, a strong and durable furnace is produced. It 
 should be heated up slowl}' for the first time uncovered, 
 in order to expel all moisture. The top, which con- 
 sists of the fourth piece of slab, is cut through by means 
 of the cold chisel, and is afterward smoothed with a 
 large rasp. 
 
 The method of suspending the cover is illustrated in 
 Fig. 311, the iron bands coming OA’er the fire clay walls, 
 on the inside, being thus protected from the heat of 
 the arcs. Having completed this portion of the Avork, 
 th(' base, platfoians, and scroAV feed must be put to- 
 gether. The base, upon Avhich the entire, plant rests, 
 consists of a h<*aA'y pine board, 4 feet in length by 8 
 inclu'S in Avidth. The furnace is mounted upon three 
 common bricks (2| inches in height) and placed at 
 
HOME MECHANICS FOR AMATEURS 
 
 339 
 
 the center of the board to facilitate the design and 
 construction of the inclines, which must be very ac- 
 curately pitched, in order that the carbons may be fed 
 into the furnace without coining in contact with the 
 openings. Should they touch, however, a couple of 
 mica sheets must be applied as a precaution against 
 short circuits. These inclines are made from 1 inch 
 pine boards, 6 inches in width and 16 inches in length. 
 These boards are mounted upon upright pieces of wood 
 of the same weight for trial, but are not screwed on 
 until the screw feed is put in place, which is attached 
 
 Fig. 312. Sections of Clamp as applied to Screw Feed. 
 
 from underneath. Of course the inclines must be care- 
 fully adjusted to any specific furnace, but the height 
 of the front and back supiiorts will be about 8 and 3:^ 
 inches respectively. These may be attached at once by 
 means of strong angle irons as illustrated in Fig. 308. 
 To form the screw feed, select a large sized furniture 
 maker’s clamp, with wooden screws at least 18 inches 
 long. Fig. 312 illustrates such a clamp, the sections 
 to be sawn through to make the bearings and screw 
 collars being marked in dotted lines. The sections 
 marked 8 8 will be found to contain the screw threads, 
 and serve for the center traveling pieces upon which 
 
340 
 
 IIOMK T\rECIIANI(;S FOI! AMATKl'IJS 
 
 tlie blocks and electrodes are nionnted. The sections 
 1, 2, 8, and 4 s(>rv(* for sini])l<‘ l)(‘arin<>s, after Ixdnii 
 carefully drilled thronf>li with a bit and brac(‘, ex- 
 ercisinjj ^Tcat care in borinj;, to secure centrally located 
 straijjht holes. These are screwed on to the board 
 from nnderneath, and as tbe wood from whicb tbe 
 furniture clam])s are made is Aery hard, <^imlet holes 
 must be proA'ided for tbe reception of the screAvs to ])re- 
 A'cnt splittinj*. These nimbd holes must ha\e consider- 
 able depth. TTpon the traAeliiifj pieces are mounted 
 tAVO blocks (> inches lony, 4 inches Avide, and about 14 
 inches in thickness. Three brass tulx'S are carefully 
 mounted upon each of tln^se, of the ri^ht size to receiA^e 
 electric lijiht carbons (tbe lonf>est kind, copper coated) 
 AA’itli a tijiht tit. These tubes are secured as shown in 
 Fifj. 309 by means of lieavy brass straps. The car- 
 bons are placet in position, about an inch of the end 
 left protruding to alloAV brass spring clips to be pushed 
 underneath. With this spring adjustment, the car- 
 bons can be quickly AAuthdraAA’n or easily regulated. 
 The connections, Avhicli should consist of double in- 
 sulated Avires (No. 10 gauge), are soldered to these 
 clips in the manner indicated. It will be obserA^ed by 
 referring again to Fig. 308 that the carbons may be 
 sloAA’ly AvithdraAAii by turning the scrcAAq or they may 
 be pulled out of the furnace by the handle of the screw 
 when it is necessary to remoA^e the furnace from the 
 base. 
 
 The fiirnace is noAV ready for connecting up and a 
 trial. Adjust all six carbons carefully, making sure 
 tbal ih<*y an* all in contact. When tin* tri]>le arc once 
 forms, th(‘y re(|uir(‘ v(‘ry liltb* attention, aiid, as stated, 
 will conlinm* lo burn wlnm llu* distance betAveen their 
 
HOME MECHANICS FOR AMATEURS 
 
 341 
 
 ends exceeds 3 inches, with a charge of coke and lime 
 as the conducting medium. Fig. 313 shows the scheme 
 of proper connections with a 110-volt electric lighting 
 system. The main conductors, or feeders, are repre- 
 sented at the bottom by heavy horizontal lines and are 
 joined as indicated direct to a porcelain fuse block, F. 
 This connection should be made as near the meter as 
 possible, in order to avoid annoyance from intermedi- 
 ate fuses. In addition to this, the capacity of the meter 
 
 Pig. 313. Diagram of Connections, with Ammeter and Voltmeter 
 arranged for studying the Behavior of Compounds 
 within the Arc. 
 
 should be ascertained, which should allow of a 25 am- 
 pere load. In other words, a 45-light meter will be 
 large enough, a standard 16 candle power lamp taking 
 about 0.6 ampere. Place a 12-ampere fuse in each side 
 of the fuse block, as shown, and join the same to a 
 small knife switch, H. Should the reader possess an 
 ammeter (of fully 50 amperes capacity), it should be 
 included in the circuit, and a voltmeter should be 
 
HOME ]VII^:(UIAXICS FOR A^rATP^URS 
 
 3:t2 
 
 joined across tlie connections of tlie ar(‘S if i)ossil)l(\ 
 Tlie resistan(‘(^, l\, ('onsists of 20 f(M‘t of douRled (Jer- 
 man silver wire, No. 22 ii»an<>e, Brown & Sliar])e.* 
 
 To make tliis resistaiK'e in convenicmt sliape, the 
 wire should be wound about a larm^ fire clav slab, 
 which serves for siiflicaent insulation and resists the 
 effect of the heatinj>* up. This slab witli its wire must 
 not be phu'ed near woodwork. Tln^ furmu'C^ should be 
 run for fifteen or twenty minutes, for the first time 
 without its cover and Avithout a charii^e, movin^e; the 
 carbons back and forth and testing’ their (‘enterinc^, etc. 
 Should the arc i>() out, the fe(Ml is screwed down until 
 contact is again made and the incline rai)ped Avith a 
 mallet in order to cause the ])oints of the carl)ons to 
 Aubrate or rub together. In doing this Avork Avitli the 
 cover off, use strongly smoked glasses to protect the 
 eyes from unnecessary strain. Having mastered the 
 handling of the equipment Ave are noAV ready for 
 experimentation, and Avill proceed direct aa ith the prep- 
 aration of calcium carbide. To produce a laboratory 
 quantity of this compound, folloAV closely the direc- 
 tions given. Weigh out 18 ounces of good unslaked 
 lime (calcium oxide, CaO), and reduce to a granulated 
 form in a large iron or porcelain mortar. Place this 
 portion of the charge on a large sheet of manila paper 
 and })repare for the grinding of the coke. Do not at- 
 temj)t to us(^ (‘harcoal, as it is too light and floury, 
 oxidizing away in the air Avithout combining Avith the 
 ]im(\ 
 
 S(^l(*ct (‘itlnu* good (*oke or procure a lot of broken 
 electric* light carbons, and Aveigh out 1(5 ounces of the 
 
 * "I'his wiro recniires rmich care in handling, and, if allowed to 
 tangle or kink, l)reaks very easily. It is very brittle. 
 
HOME MECHANICS FOR AMATEURS 343 
 
 fragments. These must now be pounded to small 
 pieces and afterward granulated in the iron mortar to 
 about the same size as the pieces of lime. The coke 
 and lime should now be thoroughly mixed together on 
 the large sheet of paper preparatory to grinding in an 
 iron coffee mill. These mills come all of iron, designed 
 to screw up against the wall, and are equipped with a 
 regulating device for grinding coarse or fine. The 
 money put in a mill of substantial character will be 
 well invested, as it will prove of great value in a 
 laboratory or experimental shop for reducing many 
 substances to powder. The granulated lime and coke 
 are poured into the mill and ground to the finest meal, 
 passing the mixture through several times to insure an 
 intimate mixing as well as a fine powder. Should a 
 mill not be at hand, the charge may be reduced to the 
 proper fineness, although requiring much more labor, 
 by means of the large iron mortar. The pestle of the 
 mortar is ground to the right and the mortar rotated 
 to the left with the palm of the left hand. There is a 
 little knack in doing this, and Avith a little practice, 
 but Avith considerable work, the lime and coke may be 
 suitably prepared for fusion. 
 
 The poAvdered charge must be put away in airtight 
 receptacles, if it is not intended for immediate use, as 
 the lime in the finely poAvdered state quickly slakes if 
 left in contact Avith the air. Sliould we use the mix- 
 ture Avithout thoroughly grinding, Avhich is a very 
 dark slate color, it Avill be found a very light gray 
 upon shutting doAA’n the furnace after a run, shoAving 
 that most of the carbon has gone off as carbon dioxide 
 and carbon monoxide, leaving the unfused lime behind. 
 We can noAv start the furnace for actual work and 
 
344 
 
 IIO:\[F. AIFCMIAXK^S FOII A^F\1M^URS 
 
 four or liv(^ ouiu‘(‘s of tlu* cliai^^c' iii llu* arc as 
 soon as well startcMl, ohscu'viiiu^ llu^ voltin(*t(U’ and aiii- 
 lueter, if a study of tlie resistaii(*e of furiiaec^ fusions 
 is to be made. The carbons ar(‘ drawn lijradually a])art, 
 and additional quantities of the charge add(*d from 
 time to time. The cover is kept on as mu(‘h as possi- 
 ble^ only removing it to add more material and to heap 
 
 Fig. 314. Furnace for making Solders and other Alloys having 
 
 Low Melting Points. 
 
 the compound about tlie triple arc by means of a 
 si)atula. Aft(‘r a twenty minutes’ run, during which 
 tiiiK* 11i(* compound is fr(“<piently lieaped about the 
 points of lb<‘ (‘l<‘cli()d(‘s, tlie switch may be opened 
 and the furnace* allowed 1o cool. Should one of the 
 fuses blow out during Ihe run, it should he immedi- 
 ately replac<*d by one of Ihe same cajiacity and a small 
 
HOME MECHANICS FOR AMATEURS 
 
 345 
 
 amount of additional German silver wire added to the 
 circuit, although the 20 feet of the double material will 
 probably afford all the protection necessary and steady 
 the arcs in a very satisfactory manner. 
 
 A variable rheostat of low resistance included in the 
 circuit would be a great convenience, allowing the cur- 
 rent flow to be adjusted to the capacity of the fuse 
 wires to a nicetv. A few runs with the furnace will 
 enable one to become quite expert in forming calcium 
 carbide, working with a 3-inch arc without allowing it 
 to go out. When the furnace has cooled, a number of 
 large masses of the carbide will be found in the bot- 
 tom of the fire brick hearth, which may he thrown 
 immediately upon water to obtain acetylene gas or 
 stored away in airtight cans or jars for future use. If 
 left open in the air, it is slowly attacked by moisture 
 and is decomposed. Before suggesting other work for 
 small preparations, the introduction of a very small 
 crucible furnace may he of interest. Fig. 314 illus- 
 trates the simplest form of crucible equipment de- 
 signed for operation on the 110-volt circuit, Avith six 
 or eight 32 candle poAver lamps arranged in a bridge 
 in multiple as indicated. A large sand crucible or or- 
 dinary floAA'er pot is filled Avith granulated fire clay or 
 other poor conductor of heat, and a smaller crucible 
 placed inside. The AAdiole is stood on a fire brick and 
 the large pot or crucible is provided Avith a clay cover 
 having holes for the reception of tAvo carbon electrodes. 
 The stands sold for supports in chemical laboratories 
 make the most conA^enient holders for the carbon rods. 
 
 The furnace depicted in Fig. 315 is capable of doing 
 more Avork, in fact, as much as may be wished for on a 
 small scale, if the experimenter is so situated that he 
 
346 
 
 HOME MECIIAXICS EOU AilATEUES 
 
 may liave as much cnrront as li(> wants. Tlie small 
 crucible is drilled tliroufjli tlie bottom, and one of the 
 electric lifi'lit carbons c(“m(‘nted iii place, or sim|)ly held 
 in position by a tight tit. The oiiter incasement in 
 
 Fig. 315. Furnace for melting Brass, Copper, etc., for Harder Alloys, 
 and reducing Small Quantities of Metallic Oxides 
 to their Respective Metals. 
 
 tills (lesifi^Ti (‘OTisists of «"i lar<2;o floAver pot, supported 
 on a small iron rinj;- stand, also to be had from cliemi- 
 cnl (h^aha's. This is covered by a heavy plate of mica 
 with a (‘(‘iitral hoh^ for tlu^ (*arbon. I^y puttin<i^ in 
 s(a‘i(*s two or threat i‘li(M)stats the current may be easily 
 
HOME MECHANICS FOR AMATEURS 
 
 347 
 
 controlled, and if heavy fuses are installed, and if 
 there is no fear of injuring any meter, a very fierce 
 and intense arc may be maintained. Use only the cop- 
 pered carbons, and solder their connections to them. 
 The writer suggests experimentation with alloys, in 
 connection with these small crucibles (sand crucibles, 
 plumbago, or graphite), using borax in some cases and 
 charcoal in others (here the light floury charcoal is 
 to be preferred), in order to fuse the bodies in a neutral 
 atmosphere. 
 
 By using an excess of charcoal constantly in the 
 crucible, the inert carbonic acid gas which is formed 
 will expel the oxygen from the crucible and prevent 
 oxidation of the metals experimented with. Nearly 
 all the metallic oxides may be reduced in the presence 
 of carbon with a sufficiently high temperature, provid- 
 ing an interesting field for work. Small masses of 
 aluminum and aluminum bronze may be formed in 
 the crucible furnace illustrated in Fig. 315, or in the 
 large triple arc equipment, although only on a very 
 small scale. Aluminum oxide (ALOa) may be directly 
 reduced in the arc in the presence of carbon by intro- 
 ducing an intimate mixture of the oxide and poAvdered 
 graphite. The aluminum oxide may be bought, or may 
 be prepared on a very small scale from clay or alum 
 as folloAvs : Digest 8 ounces of clay in a mixture of 
 hydrochloric and sulphuric acids in a glass flask (HCl 
 3 parts, H2SO4 1 part) for about an hour. The fluid 
 is mixed Avith four or five ounces of water and filtered. 
 An excess of ammonia (ammonium hydroxide) is 
 added, and the AAdiite precipitate collected on a large 
 filter and alloAved to dry. It is then mixed Avith the 
 graphite and the tAvo ground together. From alum, it 
 
348 
 
 IIOMP] MECIIAXMCS FOR AMATEURS 
 
 is only JU'( (‘ssai‘y to add ilic aniiiionia to a stronjj solu- 
 tion of alnin in \vat(‘r, and treat the r(‘snltant i)re(ipi- 
 tate in a like manner. Of eonise this ])roeess is only 
 a little elieinieal exercise, and is only i>iv(*n for the 
 henetit of those who wish to atteni])t the entire process, 
 althon^'h of no commercial value, the manufacture of 
 aluminum endKxlyiiifi (“iitirely nnlik(‘ methods. 
 
 For the henetit of those who have never experimented 
 with the electric arc, tlu' writer inclmh's in the suj^- 
 fi'estions offered a pair of strongly smoked f];lasses, to 
 he worn whenever the arc is exposed. To work with- 
 out glasses is to eximse the eyes to severe strain and 
 possible injury. 
 
 RECORDING TELEGRAPH FOR AMATEURS 
 
 If the question of utility controls one in making and 
 trying a piece of apparatus, it is useless to expect to 
 realize anything in the way of profit from the record- 
 ing telegraph illustrated and described; but a few in- 
 terested amateurs can co-operate, and with a wire and 
 transmitter for each can secure a practical knowledge 
 of the workings of some of the large telegraph systems 
 and of some of the applications of electricity, which 
 could not be secured in any other way. The expense 
 would be slight, when there is a joining of amateurs 
 for one purpose. 
 
 It is assniiK'd that an ordinary sounder is available 
 for the c<‘ntral ofiice recorder, and that every sub- 
 s(‘ri))(‘r will fiiriiisli a transmitter, a Avire to communi- 
 cate with tli(^ (‘(mtral oftivQ recorder, and battery snffi- 
 ci(ml: to oyxa-atc^ one bran(*h of the centra] office system. 
 
 In makin<» th(^ (*(mtral office recorder, a common 
 soumbn* is j)ress(‘d into service. It is jmovided with a 
 
HOME MECHANICS FOR AMATEURS 349 
 
 stylus-holder which is clamped to the free end of the 
 armature lever. The stylus is a piece of steel wire 
 1-16 inch in diameter and 1 inch long, with a rounded 
 and hardened point. It is clamped in place by a set 
 screw. 
 
 Fig. 316. 
 
 The Receiving Instrument of the Recording Telegraph. 
 
 Under the free end of the armature lever is journaled 
 an arbor, carrying a wooden roller having a V-shaped 
 peripheral groove at the center, exactly under the 
 
350 
 
 IJOMK MI'XJIIANICS F()|,> AMATKUKS 
 
 stylus; so that when a papcu* si rip passes over I lie 
 I'oller, tli(^ stylus eau make a slight <le])T‘essiou iu the 
 ])apei-, when th(‘ soumhu* majuiiet is actuated. 
 
 Th(‘ principal f(*atur<“s of this tel(*!i>ra])h are a sim- 
 ple transmitter for j>ivin<; fixed calls, like a call box, 
 and the meehanism for eaia-yinji the jiajim- taja* over 
 the f>rooved sjiool and under the stylus. The roll of 
 tape as jmrehasial from tin* dc'aler is eariii'd on a 
 wooden read, sujiported hy a standard at the rear of 
 the sounder, ttetween two standards in front of the 
 sounder are journaled two rollers, <i h. The roller a 
 is flanged and jirovided on its perijihery with three or 
 four rubber hands, to give it frictional contact with 
 the paper tape. The lower roller h is covered with a 
 piece of rubber tube and the shaft of this roller carries 
 a small governor c. for regulating the speed of the 
 tape. The tape extends over the roller h, thence down- 
 ward under the flanged roller d, then upward to a 
 fastener. The roller d is ijrovided with a weight which 
 actuates the mechanism. 
 
 It will thus be seen that the paper tape is carried 
 through the machine by the action of the weighted 
 roller d, and its motion is regulated by the governor c. 
 The governor c consists of a slotted hub f, links g g, 
 pivoted in the slots of the hub, a slotted sliding block 
 /(, placed loosely on the shaft of the roller h, weighted 
 arms i i pivotc'd in slots in the block 7t, and pivotally 
 connected to the out(‘r (*nds of the links g g, and a light 
 spring, j, tending to draw tin* weighted arms i i toward 
 each olli(‘r. Tin* block It is provided with a leather 
 washer /, which ])roduc<“s necessary frictional contact 
 with the standai'd, wlnm lh(‘ w(‘iglited arms are thrown 
 out by centrifugal action. The ta])e reel is provided 
 
HOME MECHANICS FOR AMATEURS 
 
 351 
 
 with a slight spring for checking its motion Avhen the 
 paper feed stops. In tlie side of the block which car- 
 ries the stylus is inserted a small stud, in which is 
 clamped a wire m, having its free end near the side of 
 
 the roller a, flattened and turned up at right angles. 
 The flattened end of this wire m lies in the path of a 
 small pin projecting from the roller a, so that when- 
 
352 HOME ]\IECITA.\[rS EOR A^fATETTRS 
 
 ever the aniiatiii'e lever is diawn down h_v (In* inaj^net, 
 the pin is reh'ased, ajid tin* lolha* a is allow<“d to tnrn, 
 hut when no current passes tlie Tnaf>iiet, the armature 
 lever rises and l)rin<>s the fiattfuu'd (uid of tin' wire m 
 into th(‘ path of tlie small pin, and sto]>s tin* movement 
 of the I'oller (i, and (•ons(‘(pientl y arr(‘s(s the proijress 
 of the paper, until the ])in is r<‘l(>ased hy anotlnu’ ac- 
 tion of the armature lever, llindin*- ]tosfs i)lac(‘d at 
 the rear of the sounder ar(' connected with tlu' ma^^net 
 electrically in the usual way. To transmit a signal 
 over a line connected with this instrument, it is not 
 necessary to understand the telei>raph alphabet, nor to 
 know anythinji’ in regard to telegraphy. The signals 
 are pre-arranged, so that the operation of sending is 
 purely mechanical. 
 
 The signal board shown in detail in Fig. 318 was 
 invented and patented ^ears ago bj" William Hadden, 
 but the patent has long expired. This simple device 
 consists of a board, a few inches wide, and perhaps 
 twice the length, depending on the number and length 
 of the messages sent. The board here shown is inches 
 wide, 7 inches long, and f inch thick, with as many 
 longitudinal grooves formed in it, as there are signals 
 to be given. The signal board must be of very hard 
 wood, and the dots and dashes of the signals are formed 
 by sewing No. 30 plain copper wire through holes ex- 
 tending through the board, from the grooves in front 
 to the grooves in the rear. As the signal transmitter 
 is at present constructed, the copper Avire sewed 
 through th(“ first s(‘t of hob's represents the letters of 
 th(‘ .Morse alphabc't from .1 to F, with a dash betAveen 
 each letter. The sewing in the second grooA'e repre- 
 sctits lh(‘ b'iters from (i to -/. Tin* s('wing in the third 
 
HOME MECHANICS FOR AMATEURS 
 
 353 
 
 groove represents the letters from K to M, and so on. 
 All of the wires forming these letters are connected 
 together at the top of the board, by a wire on the back, 
 which is in electrical connection with the binding post 
 seen to the right in onr view of the signal apparatus. 
 The binding post at the opposite edge of the board is 
 
 Fig. 318. View of the Transmitting Apparatus. 
 
 connected on the back of the board with a third bind- 
 ing post, at the lower end of the board. The third 
 binding post is connected by a flexible cord with a 
 wire, having a flattened end, and provided with a 
 wooden handle. Sending a signal consists simply in 
 drawing the flattened end of the wire with a uniform 
 
354 
 
 IIOMK MKClIANK.'S FOIt AMAI’KUIJS 
 
 si)0(“(l down one of tlie grooves. Tlie fii-st two hinding 
 posts, being eonneet(‘d witli tlie binding jiosts of the 
 reeording instrnnient and with a batbaw, wli(*n a signal 
 is sent, the recorder is irb'ased antoniatieally, and the 
 det(*nt is constantly withdrawn from lln* pin in the 
 roller, so long as tin' signal is being s(‘nt, and the ines- 
 
 Fig. 319. How the Board is Wired for the Morse Alphabet. 
 
 sage is thns recorded. When the signaling stops, the 
 recoi-ih'i' is stopjied by the action of the detent. 
 
 S(!V(‘ral transmitters may be connected with the 
 I'ccorder, and om* win* in each case may be dispensed 
 with, by grounding the oth(*r at each end. 
 
 The record(*r will run long enough to record a long 
 signal or sev(‘ral short ones with one raising of the 
 weight cari'ied by the paper tape. 
 
HOME MECHxVNICS EOK AMATEUES 
 
 355 
 
 HOW TO MAKE TELEPHONES AND TELE- 
 PHONE CALLS 
 
 On January 30, 1894, the Bell telephone patent ex- 
 pired and the invention became the property of the 
 public; so that whoever desires to do so can make, 
 buy or sell telephones without fear of infringing the 
 
 Pig. 320. Details of Construction of the Bell Telephone. 
 
 rights of any one. This applies only to the hand in- 
 strument now used as a receiver. Patents for other 
 telephone apparatus still remain in force; but enough 
 is available for actual service. With two hand instru- 
 ments and a suitable call, telephonic communication 
 may be maintained, under favorable conditions, over 
 
356 
 
 HOME MECHANICS FOR AMA'l'EUlJS 
 
 a line eight or ten miles long, no battery being re- 
 quired. 
 
 To avoid the effects of indnetion and to secure the 
 best results, a metallic circuit is re(iuired. It lias been 
 said, on good authority, that with band telephones 
 used as transmitter and receiver, conversation has 
 been carried on between New York and Chicago, using 
 a metallic circuit formed of heavy copper wire and 
 having very low resistance. The words, it is said, 
 were as distinct as where a transmitter is used, hut the 
 volume of sound Avas somewhat less. 
 
 For the benefit of those who are desirous of making 
 telephones for their own use, or for sale, we present 
 perspectiA'e and sectional views of the latest and most 
 improved form of telephone, all of the parts of which 
 are shown in reduced size. 
 
 The handle is made of hard rubber and the cap, 
 which is also the mouthpiece, is of hard rubber. The 
 diaphragm. A, is clamped at the edge between the cap 
 or mouthpiece and the body of the handle. Very thin 
 ferrotype plate has generally been used for the dia- 
 phragm, but thin taggers iron, Avhen protected by a 
 coat of shellac or other suitable varnish, is said to an- 
 swer better. 
 
 The compound magnet, R, used in the telephone, is 
 com]K)sed of four thin, flat bar magnets, a, arranged 
 in pairs on ojiposite sides of the flat end of the soft iron 
 pole i)i(‘ce, c, at one end, and the soft iron distance 
 ])icc<‘, d, at the opposite end, the magnets being 
 clamix'd to flu'se ])i(“c(‘S, with like poles all in one di- 
 recfion. Tin* space in fhe center of the magnet be- 
 f \\(‘en th(^ ])oi(‘ ]»i<‘ce and distance piece is filled Avith a 
 sti-i]), <!, of Avood. 
 
HOME MECHANICS FOR AilATEURS 
 
 357 
 
 The fj’lindrieal end of the distance piece which ex- 
 tends beyond the magnet is bored and tapped to re- 
 ceive the screw by which the magnet is held in place 
 in the handle. The cylindrical projecting end of the 
 pole piece extends to within 1-100 or 2-100 of an inch of 
 the diaphragm. In other words, it is placed as near the 
 diaphragm as possible without being touched by the 
 diaphragm when the latter vibrates. 
 
 On the pole piece, c, is placed a wooden spool, c, on 
 Avhich is wound No. 34 (Am. W. G.) silk-covered cop- 
 per wire. The wire tills the spool, and its ends are al- 
 lowed to project one or two inches. The wire may be 
 Avound on the spool in either direction, and it is im- 
 material Avhich pole of the compound magnet adjoins 
 the diaphragm. 
 
 The resistance of the winding varies from 70 ohms 
 as a minimum to 200 as a maximum. When the in- 
 strument is to be used both as transmitter and receiver, 
 and especially Avhen it is on long lines, the resistance 
 should be 100 ohms or more. No. 36 wire is used for 
 the winding Avhere the resistance is great. Of No. 34 
 wire, 263 feet Avill be required for 70 ohms resistance. 
 For 100 olnns, 373 feet are required. For 150 ohms, 
 343 feet of No. 36 are required. 
 
 In the end of the handle are inserted two binding 
 posts, to which are attached insulated Avires (No. 18), 
 Avhich extend toward the diaphragm, their free ends 
 being soldered to the terminals of the fine wire on the 
 spool, so that when the telephone is connected up in 
 circuit Avith other telephones the current Avill pass from 
 one of the binding posts through one of the coarse 
 wires, through the fine Avire coil, through the other 
 coarse wire to the other binding post. 
 
358 
 
 TTOME MECHANICS I’OIi AMA'I’CriJS 
 
 Tlie Hell teleplione lias a disk of di'xilili* iMiblior 
 sli])])ed over tlie jiole piece and over the ends of the 
 coarse wires as a jiiiard ajjainst shoi-t circuit in, <>■. A 
 screw eje is inserted in the end of the telephone handle 
 for suspendiiii? the instmiinnit when not in nse. 
 
 This telephone, when used in the manner sn''\<iest(“d, 
 requires neither hatterv nor induction coil. It is 
 therefore easily connected up for use hy electrically 
 connectini*’ the binding posts of one instrument with 
 the binding posts of another. Wlnm a number of tele- 
 phones are connected in the same lim*, the niatt(*r 
 
 Fig. 321. Fio. 322. 
 
 Single Wire Circuit. 
 
 is not quite so simple. There are many ways of ar- 
 ranging the circuit; we give diagrams of two, one for 
 one line wire with ground connections, the other for 
 a metallic circuit, Avith a separate circuit for calling. 
 
 In lh(‘ single wire circuit each instrument on the line 
 is pi-ovidt'd with a double switch cut into the line as 
 shown in Fig. ;i21,lh<‘ ])ivots of the switch arm a a', be- 
 iim conn(“cted with the line wire. The switch arms 
 are jiivolally connecl(‘d with a bar of insnlating mate- 
 rial, so I hat they will mov(‘ to,g(‘lher. The arms, <i o', 
 may be bi-onghi inlo coidact with the ])oints, d. <V . e. 
 
HOME MECHANICS FOR AMATEURS 
 
 359 
 
 e', and f. A magneto call box is connected with the 
 points, d d' , and the arms, a a' , are left normally on 
 these points, as shown in dotted lines, so that when 
 any magneto in the line is operated the others will 
 ring. All on the circuit have a special call. 
 
 The one called will know whether the signal comes 
 from the east, west, north or south. Suppose it to 
 come from the east, the switch is placed in the position 
 shoAvn in full lines. This cuts out the magnetos, 
 grounds the western section of the line through the 
 point, c, and connects the eastern section with one 
 
 Fig. 323. Metallic Circuit. 
 
 end of the telephone cord through the point, c', the 
 other telephone connection being grounded through 
 the points, f c, and ground wire. If the call is from 
 the west, the switch arms, a a' , are brought into con- 
 tact with the points, e' f. The arms, a a', are always 
 left on the points, d, d'. Outside the terminal stations 
 the line is connected with the ground or arranged as 
 shown in Fig. 322, with the line grounded through the 
 magneto or telephone. 
 
 In the metallic circuit shown in Fig. 323, the termi- 
 nal telephones are connected with the ends of the line 
 
360 
 
 HOME ]\IP:CHANICS for AMATFUIiS 
 
 wires. Intermediate tcdepliones are cut into the line 
 bj means of a double switcli, as shown in the cut, in 
 Avbich (j shows the intermediate telephone cut out, h 
 shows it connected with the east and i with the west. 
 
 A third Avire grounded at the ends, and including? a 
 magneto for each tele])hone, runs parallel with the 
 metallic circuit. In this case all of the hells ring at 
 once, and individual signals must he agreed upon. 
 
 It is obvious that the information here given in re- 
 gard to the construction of the telephone may he de- 
 parted from in minor points, such as the construction 
 of the handle and mouthpiece, hut eA’erything relating 
 to the magnet, the coil, and the relation of the magnet 
 and diaphragm, should he strictly followed. 
 
 No telephone line is complete without a signal of 
 some kind which will serve to attract the attention of 
 a person in the Aucinity of the instrument. A battery 
 call ansAA’ers A’ery Avell for short distances, but for a dis- 
 tance of from one to tAvelve miles or more, the battery 
 has been found impracticable and the magneto call is 
 generally employed. This instrument not only serves 
 a good purpose in connection with the telephone, hut 
 it answers very Avell indeed for general signaling pur- 
 poses. It is always ready for action, and does not in- 
 volve the care of a battery. 
 
 The line draAvings presented herewith are one-third 
 the actual size (linear measurement) of the instru- 
 ment, and the persjx'ctive vicnv is also one-third of the 
 actual size; the oidy dimension not obtainable from 
 the di-a wings is tlie d(“i)th of tlu' signal box, which is 3 
 inches. As all of the dimensions may he obtained from 
 the eugraviugs, it Avill he unnecessary to repeat them 
 in th(Mlescri])tive matter. 
 
HOME MECHANICS FOR AMATEURS 
 
 301 
 
 The pole pieces, A A', between which armature, B, 
 revolves, are formed of soft gray cast iron, with ears, 
 a a, at the top and the ears, h, at the bottom, separat- 
 ed by bars, C C', of nou-magnetic material, such as vul- 
 canized fiber, hard rubber, or they may be made from 
 hard wood, well varnished or saturated with paraffine 
 to prevent them from shrinking or swelling. The pole 
 pieces, A A', are clamped to the bars, C C', before they 
 are bored out. The3" are bored out to loosely fit the 
 
 Fig. 324. Magneto-Telephone Call. 
 
 armature, R'. The pole pieces are provided with fianges, 
 c, which rest upon the bottom of the casing and are 
 drilled to receive screws, d, by means of which the mag- 
 
IIOMK MKCMIANK^S FOR \^\\TVAl\l^ 
 
 ii(‘i is S(‘(*iir(Ml in ])la('(‘ in ili(‘ ('asini^. In lln* ]K)1(‘ ])i(*c(*s, 
 A A', al)()V(‘ tli(‘ (‘ars, />, ai'(^ diallcMl and ta])i)(*d liol(*s, r, 
 for r(M*(Mvini>’ tli(‘ studs, /, l)y wliirli tln^ li()rs(‘sli()(‘ inaiL>^- 
 nots ar(^ secured lo tlu^ ])ol(‘ ])i(‘(‘(*s. Th(‘ studs, /, ai'(^ 
 drilled for re(‘eivini> keys, by wliieli tlie nny^nets are 
 clamped in ])la(*e. 
 
 The ('oniponnd niai^net, 2, is com])ns(Ml of three Hat 
 steel bars foiininji^- r-shap(Ml nia<;n(ds, //, //', //% with 
 the space between the ])oles ada])ted to receive the pole 
 ])ieces, A A'. The ina<>net Ir^ tits over tlu^ adjoinin^i;- 
 ed!L>es of the nia<>‘nets, li //', and the three inai»n(ds are 
 drilled to receive the studs, /, which (‘xtend thi-ongh 
 the niaf>nets and into the ])ole })ieces, the parts Ixdng 
 clamped together by keys driven throngh the holes in 
 the stnds, as shown in the perspective view. 
 
 The armatnre, R, is the Avell known II type of Sie- 
 mens, made of soft gray cast iron, the sliaft, being 
 cast integrally Avith the body of the armatnre. The 
 part, j, which receives the Avire is narroAA er and shorter 
 than the polar extremities of the armature. The arma- 
 ture is turned so that its convex sides will revoh^e very 
 near but not in contact Avitli the pole pieces. The 
 shaft at the ends of the armature is turned, and to one 
 end is fitted a sleeA^e, k, of insulating material (vul- 
 canizcMl fil)er or hard rubber), on Avhich is placed a 
 l)rass i‘ing, 1. In the inner side of the metallic ring, 
 is insei-tcal a stud, n, to Avhich is soldered one terminal 
 of 1h(* ai'inaturc^ coil, the other terminal of Avhich is 
 sobhaxxl 1o a scr(‘w, ii, inscaded in the shaft, i. The 
 arnialni‘(‘ is wound in th(‘ sann^ manner as an electro- 
 niagmd, I In* wir(‘ b(*ing carri(xl around om^ arm of the 
 araaalnrc* nnlil on(*-half of tln^ Avirc^ is in pla(*e. It is 
 llnm car]‘i(*d across th(‘ c(ai(ral portion of llu^ anna- 
 
HOME MECHANICS FOR AMATEURS 
 
 363 
 
 ture and wound upon the other arm of the armature. 
 The wire used is No. 34 silk-covered wire, there being 
 about 14 ounces of wire upon the armature, or enough 
 to give it a resistance of 200 ohms. 
 
 To the bar, C, is secured a brass plate, E, by means 
 of screws which pass througli the plate and into the 
 bar. In the plate, E, opposite the center of the bore of 
 tlie pole pieces, there is a bearing for one end of the 
 shaft of the armature, and in the opposite or upper end 
 
3G4 
 
 ll():\II-: MKCIIAAMCS F()l{ AJIATJ<:UI{S 
 
 <»f I lie brass plaii*, E, (lua e is a bearin'^ for ibe (Iriviiifi; 
 shaft, b\ To flu* ojijiosite end of tlie bar, C, and to 
 the bar, V/, is seenred a ])lat(‘, E', wliicli is also jiro- 
 A'ided witli b(*arinos for tlie armature shaft and for 
 the drivinij shaft. To tlie bar, C, is seenred a curved 
 spi-inji;, e, wliicb boars uiion the insulated rlufj, ?, and 
 this sprinjj is connected by a wire, />, Avitli a binding 
 ])ost, q, at the top of the casing. 
 
 ITpon the end of the armature shaft, i, outside the 
 plate, E', is jdaced a pinion, r, and upon the shaft, F, 
 is placed a spur wheel, .s, which engages the pinion, r. 
 The shaft, F, is held in place in the machine by a screw 
 inserted in the end of the shaft, and a washer held by 
 the screw against the end of the shaft and bearing 
 against the plate, E. The crank, C, by which the shaft, 
 F, is turned, is screwed on to the end of the shaft 
 through an aperture in the side of the casing. On 
 the stud, f , projecting through the front of the magnet 
 is placed a contact spring, t, which is clamped by the 
 key which holds the magnet in place. 
 
 The mechanism thus described comprises the mag- 
 neto generator which generates the alternating cur- 
 rent reipiired for operating the magneto bell. The 
 machine is held in place in the casing by the screws, 
 (1. as already described, and the back of the casing is 
 cut away to let the magnet, into the back, thus 
 ( conomizing room. To the cover of the casing is at- 
 <acli(‘d the magneto ladl, 11, the magnet and armature 
 of which ar(‘ placed within the door, Avhile the bells 
 are jilaced on tin* outside of tin* door, the hammer ex- 
 t(‘nding tbrongb (he door and between the bells. 
 
 The body of tli<‘ magiK'to call consists of a curved 
 casting, u, wbicli is secured to the inner face of the 
 
HOME MECHx\NICS FOR xVMATEURS 
 
 365 
 
 door and provided with loops, v v' , for receiving the 
 soft iron pole pieces, w w', of the bell magnet. These 
 pole pieces are held in place in the loops, v v', by 
 screws passing through the side of the loop and bear- 
 ing against the pole piece. The convex side of the 
 casting, u, is provided with a rectangular notch, a’, 
 for receiving the L-shaped permanent magnet, 6', which 
 is held in its place by a screw passing through the 
 
 Fig. 326. Details of Magneto-Call — the Bell. 
 
 magnet into the casting. To the L-shaped magnet, h', 
 is secured a plate, c, which is bent twice at right 
 angles, and in the bent ends of which are inserted pivot 
 screws supporting the armature, cl, which extends 
 downward between the adjacent ends of the pole pieces, 
 iv tv'. The armature is covered by a strip, e', of cop- 
 per, and in the end of the armature is inserted a wire, 
 
3G6 
 
 TIOMIO MECHANICS FOI{ AMATI0U1?S 
 
 /, carrying at its cxirciiiity a Ix'll liamiiicr, </'. To tlio 
 outer surface of tlie door, and ou o])])osit(* sides of tlie 
 bell liauiuier, are sup])orted two bells, I, by studs, i', 
 ])rojectiug from adjustable* jelates, /, ])ivoted to the 
 door at one end and ])i-ovid(*d wilb a curved slot at the 
 opposite cud for receiving a claiu])iug screw, wliicb 
 passes tbrougb tin* slot and into tin* door. liy means 
 of this device the bells may be adjusted so that each 
 will receive a stroke of the same power from the bell 
 hammer, //'. 
 
 The spools ou the ])ole piece's, tc ir', emutain abeeut 
 lA ounces of Nee. 34 silk-ce)ve*)'(*et e-opper wire. They 
 are wouuel iii the same dirce-tieeu, and the inside ends 
 are connected together. The eenter end of eene spool 
 is connected with the upper hinge of the casing, which, 
 in turn, is connected with the binding post, (/ ; the 
 outer end of the remaining spool is connected with a 
 strip, of copper attached to the door and connected 
 with a plate, which conies into contact Avith the 
 spring, t, Avhen the door of the casing is closed. 
 
 On the tojA of the casing there is a plug switch, 
 Avhich also answers as a lightning arrester. The rear 
 plate of the SAvitch is provided Avith the binding post, 
 'HI, Avhich is connected Avith the ground. The binding 
 posts, (j (/, receiA’e the ends of the line wire, the con- 
 nections being made as shoAAm in the section on the 
 teleyihone, pages 358-800. 
 
 When the call is placed at the end of the line the 
 call box is grounded by inserting the ping, r, betAveen 
 tin* rear or ground ]date and the front ]>late that is 
 not connected Avith a line Aviri*. When it is desired to 
 cut tin* call box out of tin* line, the plug is inserted in 
 the circular spaci* betw('(*n the two front plates, the 
 
HOME MECHANICS FOR AMATEURS 367 
 
 current passing from one end of the line through one 
 of the binding post to the other portion of the line. 
 When the armature, B, is turned by revolving the 
 crank, G, opposite ends are alternately presented to 
 opposite poles, the consequence, being that the rapid 
 changes of magnetism in the armature induce alter- 
 nate pulsations in the winding of the armature which 
 operate the polarized bell of the instrument, also the 
 polarized bell of the distant instrument, both being 
 normally in the circuit. 
 
 While talking over the line it is important to cut 
 out the magnet on account of its resistance, and while 
 signaling over long distances the signals are more 
 effective if the telephones are cut out of the line. 
 
 These machines can be purchased for |4, and we 
 therefore doubt if it is profitable to undertake to make 
 them ; however, they may be made without fear of legal 
 complications, as they are not patented. 
 
 THE END. 
 

 
 % 
 
 
 « 
 
 
 
 
 
T N I) E X 
 
 Barometer 201 
 
 Bas-Reliefs 69 
 
 Battery, Primary 227 
 
 Brass, Burnished 78 
 
 Cabinet, Electrical 246 
 
 Cabinet, Wall 40 
 
 Caloric Engine 176 
 
 Carving, Wood 26 
 
 Centering 106 
 
 Chasing 126 
 
 Chime, Electric 237 
 
 Chucking 112 
 
 Cutters, Rotary 136 
 
 D 
 
 Brills and Drilling 99 
 
 Dynamo, Edison 319 
 
 E 
 
 Electricity 227-367 
 
 Electric Lighting 232 
 
 Engines and Boilers, Model, 
 
 169-184 
 
 Engines, Running 175 
 
 Pace 
 
 Fluted Work, Turning .... 10 
 
 Frames 36 
 
 Furnace, Electric 333 
 
 G 
 
 Gear Cutting 152 
 
 Glass, Stained 51 
 
 Grilles and Gratings 31 
 
 Grinding and Polishing . . 92 
 
 H 
 
 Household Ornaments .... 31 
 
 Hygroscope 198 
 
 I 
 
 Index Plates 147 
 
 Iron Work 73 
 
 K 
 
 Knives, Moulding 9 
 
 Knurling 126 
 
 L 
 
 Lamp, Electric Night .... 243 
 I^aimch Motor, Electric... 298 
 
 Lathe, Foot 96 
 
 Lathe, Inexpensive 1-7 
 
 Lathe, Woodworking on a. 8 
 
 
Majolica, Imitation 49 
 
 Metal Turning? 119 
 
 Metal Working 89-1 98 
 
 Meteorology 187-205 
 
 Microscoi)e, The 218 
 
 Model Making 155 
 
 Motor, Edison 319 
 
 Motor, Sewing Machine . . 278 
 Motor, Simple Electric . . . 259 
 Motor, Small Electric .... 270 
 
 Moulding Knives 9 
 
 Moulding, Wood 11 
 
 O 
 
 Ornament, Feather 39 
 
 Ornaments, Household ... 31 
 
 P 
 
 Plaster Objects 85 
 
 Portiere 57 
 
 Pseudo-Ceramics 41 
 
 R 
 
 Rain Gauge 193 
 
 Repousse 61 
 
 S 
 
 Sawing, A Wrinkle in ... . 25 
 
 Sawing Metals 89 
 
 Saw, Scroll 12 
 
 Saw Tooth 21 
 
 Saw, Wood 8 
 
 Scroll Snw 
 
 Pack 
 
 12 
 
 ; Silver Work 
 
 94 
 
 Slide Rest 
 
 
 Soldering 
 
 90 
 
 Spinning Metals . 
 
 160 
 
 Stained Glass . . . 
 
 51 
 
 Steadving 
 
 106 
 
 Steam Engine . . . 
 
 169 
 
 T 
 
 Telegraph, Recording .... 348 
 
 Telephone, How to 
 
 Make. . 355 
 
 Telescope, How to 
 
 Make... 207 
 
 Telescopes and 
 
 Micro- 
 
 scopes 
 
 207-225 
 
 Thermometers . . . 
 
 194 
 
 Tooth, Saw 
 
 21 
 
 Turning, Wood . . 
 
 6 
 
 V 
 
 Vases 
 
 41 
 
 W 
 
 Wall Ornaments . . 
 
 35 
 
 Water Motor 
 
 181 
 
 Weather Vane . . . . 
 
 189 
 
 WGiittling 
 
 16 
 
 Wind Pressure Gauge .... 190 
 
 Wire, Things in . . 
 
 75 
 
 Wood Carving . . . . 
 
 26 
 
 Wood Turning . . . . 
 
 6 
 
 Wood-Working . . . 
 
 1-29 
 
 Work Bench 
 
 14 
 
Tools for Home Mechanics 
 
 
 —13 
 1_ C 
 
 ~^QZ 
 
 e 
 
 =Z CS4_ 
 
 -®8 
 
 All Fully 
 Warranted 
 
 04 -- 
 
 Sargent’s Planes 
 
 are first-class goods throughout; well made and nicely 
 finished. 
 
 Sargent’s Screw Drivers 
 
 are superior tools that are appreciated by good mechanics. 
 
 Sargent’s Saws 
 
 are perfect. There are no better saws than these in the 
 world. 
 
 Sargent’s Squares 
 
 are standard goods, carefully made from best steel. 
 
 Sargent’s Steel Hammers 
 
 are made from solid cast steel. They are of the highest 
 grade. 
 
 Sargent’s Augers and Bits 
 
 are branded “ U. S.” They are meant for use day in 
 and day out. 
 
 SARGENT & CO. 
 
 New Haven, Conn.; New York; Philadelphia; Boston; Chicago 
 
OUR Catalog 
 
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 1 METAL WORKING LATHES 
 
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