'♦^ V"^' '^Ml^^^^ "^JU r.^ o.^^M^k'-^ ^^ ^-^ ^^-r. ^AO^ ^^. A' o • » 4 o r-> y > A HISTORY OF THE I PLANING-MILL WITH PRACTICAL SUGGESTIONS FOR THE Construction, Care, and Management of Wood-working Machinery. CI R. TOMPKINS. M.E. C^ ' \ IL^VQ^ \ "Knowledge imparted to others is not lost to him who imparts it." NEW YORK: JOHN WILEY & SONS, 15 AsTOR Place. 1889. So Copyright, 1889, BY John Wiley & Sons. 4 I - Dbummond & NaxT, Electrotypers, i to 7 Hague Street, New York. Pkrhts Bros., Printers, 326 Pearl Street, New York. TC ^n of |«2 jFrCenirs, ESPECIALLY THOSE ENGAGED IN THE MANUFACTURE, SALE, AND USE OF WOOD-WORKING MACHINERY, AND PARTICULARLY THOSE WHOSE LIBERAL PATRONAGE AND FRIENDSHIP HAVE BEEN BESTOWED UPON ME IN YEARS THAT ARE PAST, THIS BOOK IS RESPECTFULLY DEDICATED BY THE AUTHOR. PREFACE. The writer has no apology to offer for presenting to the public this work on the care and management of planing-mill machinery. The forty years or more during which he has been identified with it — for thirty of which he has been actively engaged in its manufacture exclusively — is considered sufficient. In September, 1886, he went out of business as a prac- tical manufacturer ; yet he cannot say that he does not still take an interest in it. The familiar hum of the planing-mill is still pleasant to his ear, and brings up grateful recollections of the past, and reminds him of the many warm friends that he had, and still has, among wood-workers all over the country. Dur- ing that long experience and intimate relation with some of the oldest planing-mill men, a number of whom have long since gone to their rest, he was en- abled to obtain many of the incidents and facts given in the following pages. The long experience of the author in its manufacture, sale, and use forms the basis of those suggestions for the construction, care, and VI PRE FA CE. management of planing-mill machinery; and if they should be found of practical use to those less ex- perienced, then this work, which is dedicated to all users of such machinery, will not have been written in vain. That such may be the case, is the sincere wish of the author. Rochester, N. Y., December 7, 1888. CONTENTS. CHAPTER I. PAGE Early History of the Planing-mill, i Early Inventions in England, 3 Improvements, . 4 CHAPTER II. Automatic Feed-rolls, 7 Wm. Woodworth's Invention, 8 His First Machine, _ . 9 The Commencement of the Planing-mill Monopoly, . . . ii CHAPTER III. Other Inventions, 15 Suits for Infringement, . . 16 The Patent renewed by Special Act of Congress, ... 16 The Norcross Planer, 18 His Patent Sustained, 18 CHAPTER IV. Application for Another Extension, . . . . . . 23 A Formidable Remonstrance, ....... 24 Defeat of the Application, . . . . . . . . 24 Improvements, etc., 27 CHAPTER V. Brown's Extension Gears, . . . . . . . . 31 Other Improvements, 32 Burleigh's Extension Gears, ....... 3^ VI CONTENTS. The Dimension Planer, Gray & Wood's Patent, H. D. Stover's Celebrated Claim, CHAPTER VI. Further Improvements, Patents of Wardwell and others, Wm. H. Doane and others, The Chip-breaker, J. B. Tar's Patent, Early History of the Moulding-machine, CHAPTER VII. Moulding-machine Continued, . The Inside Moulder, . . . ; Introduction of the Resawing-machine, The Crosby Patent, .... Myers & Unison's Claims, . Suit against Messrs. Hawley and Mr. Doncaster, Results, PAGE 33 34 38 38 39 41 44 49 50 52 52 55 55 55 CHAPTER VIII. Abuses of Patent Laws, The Act of 1870, . . The Woodbury Patent, ....... Attempts to Build up another Planing-mill Monopoly, Suits in which the Patent was set aside, .... CHAPTER IX. Construction of Machinery, Quality and Strength of Castings, . . . Care in Moulding, ........ Frames for Machinery, . . . . , CHAPTER X. Care Required in the Construction of Wood-working Tools, Best Proportion for Cylinders, . . . . . Relative Length and Size of Journals, Cast-steel Cylinders, ........ The best Practical Method of fitting them up, . 56 56 57 58 59 70 71 72 76 79 81 83 84 85 CONTENTS. Vll CHAPTER XL Speeding Wood- working Machinery, . Variation of Speed in Different Mills, Centrifugal Force Considered, . Tensile Strength of Bolts, . Pulleys, etc., . . . . . CHAPTER Xn. Importance of Putting Up and Adjusting New Machines, Necessity of Employing Competent Men, . Mistakes often made in the Speed, Anecdote, Mr. A.'s Mistake, Annoyance from Bad Belts, Matcher-belts require Extra Care, CHAPTER Xni. Feed-rolls, Manner of casting them, .... Trouble caused by Imperfect Rolls, . Imperfect Gearing CHAPTER XIV. Lubrication, . . Defective Boxes, The Self -oiling Box described, . Glass-oilers, . . . . Adulterated Oils, The Best Oils for Planing-mills, CHAPTER XV. Hints about Moulding-machines, The most Suitable Size for Planing-mill Purposes, The best Material for Cylinders and their Style, Solid Cutters, Sectional Cutters Useful, CHAPTER XVI. Some of the Difficulties that Manufacturers meet with. Inexperienced Men PAGE 89 90 92 94 95 98 99 102 103 105 106 no III "3 "5 119 119 120 124 125 126 129 130 133 134 135 138 139 Vlll CONTENTS. PAGE Professional Humbugs, * . 140 Carelessness often the Cause of Trouble, 141 The Operator in his Own Estimation never at Fault, . . . 143 CHAPTER XVH. Responsibilities of Foreman, .145 System in Management, 146 A Striking Contrast, 147 Foundations, 149 Levelling from Certain Points Important, . . . . .151 CHAPTER XVni. A Suitable Outfit for a Small Mill described, . . . .154 Machines should be adapted to the Work, 158 A Question of Power, . . . . . . . .159 Economy in Fuel, . 160 Suitable sized Engines, .160 CHAPTER XIX. Advice to Operators, 165 Feeding Crooked Stuff, ........ 166 Setting the Guides, 167 The Use of Springs not recommended, 167 More Experience 168 Causes for Lumber Drawing away from the Guide, . . .169 CHAPTER XX. Artistic Wood-work, 171 Improved Machines for that Purpose, 172 Cutting Tools, . 173 Importance of a Running Balance, , . . . . .175 Hints for fitting up Tools, .176 Their Temper, . 176 Hard and Soft Cutters Considered, 176 Spindles and Collars, . . . . . . . .177 CHAPTER XXI. Friction and the Laws which govern it, . . . . . 180 Sliding Contact, 181 Revolving Contact, .183 CONTENTS. IX PAGE Resistance according to Weight Independent of Surface, . . 184 Its Application to Planing-mill Machinery, . . . .185 CHAPTER XXII. Shafting, 186 Its Proportional Size and Speed, 187 Torsional Strength considered, . . . . , , .188 Method of Testing, 189 Rules for calculating its Strength, ...... igo Table giving Size, Speed, and Power, ..... 197 CHAPTER XXIH. Belting, the Selection of, ... i ... . 198 The Importance of the Mill being well belted, .... 199 Leather Belting the best adapted for the Purpose, . . . 200 Rules for calculating their Power and Length, . . . . 201 Oils not Suitable for Belting, 206 Hints for their Care and Management, 207 Double Belts, Objections to, ...... . 212 Table showing the Power and Speed of Belts, . . . . 215 CHAPTER XXIV. Advice to Young Men, . . , . . . . .217 They should make themselves Proficients in the Business, . . 218 Frequent Changes not Advisable, . . . ... . 219 Proper Studies for the Young Mechanic, ..... 220 Should fit himself for Future Usefulness, 221 HISTORY OF THE PLANING-MILL CHAPTER I. EARLY INVENTIONS, IMPROVEMENTS, ETC. The history of the planing-mill, like many other useful machines, may be traced back in its rudimentary form many years before its individuality as a distinct and complete machine was fully recognized. We find, by a careful examination of old mechanical works pub- lished both in England and France that, many years before William Woodworth made his invention, ma- chines of a similar character were used for working wood into various shapes ; and among these different machines one can readily discover nearly all of the ele- ments from which the planing-machine originated. It is a well-known fact, and one that is recognized by all inventors, that, as a rule, no one man ever originated and perfected an entire machine without embodying in it some of the conceptions of a previous inventor. The first inventor may conceive and carry out, to a certain extent, an idea which to him may appear to be perfect and original in all its parts, and succeed in ac- complishing the object in a manner satisfactory to himself ; but as one idea always suggests another, the 2 HISTORY OF THE PLANING-MILL. second inventor may take the same elements and com- mence practically where the first left off, and not only improve upon that idea, but add other ideas of his own to it which the first inventor never thought of, until finally, by the skill and efforts of a series of inventors, the machine becomes perfected in all of its parts. In some of the earlier inventions in England for the purpose of planing lumber, the stationary knife, in imi- tation of the hand-plane, seemed to be the prevailing idea ; either by a reciprocating motion of the knife, or by forcing the lumber by suitable mechanism under a sta- tionary knife set in an adjustable stock in order to ac- commodate the various thicknesses of the lumber to be planed. As these machines appear to have been ex- perimental, and never came into general use, it is prob- able that there were certain mechanical difficulties at- tending them which could not be overcome so as to render them fit for practical use. In some of the old machines where the rotary cutter- head was used, the head was attached to a mandrel much in the manner as the circular saw of the present time, and the stuff to be planed was pushed by hand, either over or under the cutter-head, and held down to the table by blocks or springs much in the same man- ner as the hand-jointer or buzz-planer of the present time. It seems that this style of planing light stuff was in use as late as 1836, when it was determined to build the great conservatoryat Chatsworth, when Mr. Paxton, the architect and contractor, says, '' he found it desir- able to contrive some means for lessening the great amount of manual labor required in making the im- mense number of sash-bars required for that purpose." EARLY INVENTIONS, IMPROVEMENTS, ETC. 3 On visiting all the great work-shops of London, Man- chester, and Birmingham, the only apparatus which he met with was a grooving-machine. This he obtained, and fitted up at Chatsworth, in connection with a steam- engine, and subsequently so improved it that he could make sash-bars on it complete. This machine, he says, effected a saving of ^^1400 in the expense of the con- servatory. The length of each bar was forty-eight inches, and the original cost of the machine, including the table, wheels, etc., complete, was ;£'20. The attendants re- quired were only a man and a boy. The sash-bars could be made any shape by changing the saws. The bar was presented to the saws below the centre of motion, and to the teeth of the saws which were ascending from the table. " A velocity of twelve hundred revolutions per minute was required to finish the work in a proper man- ner, d^nd, four feet per minute could be produced in this mannen" In 1850, when the great exhibition building in Lon- don was constructed, a similar machine was used by Messrs. Fox and Henderson, the contractors, for form- ing the gutters for the same. Mr. Henderson, however, made some improvements, by adding cutter-heads, so that, instead of using one head and passing the stuff through the machine four times, he applied four heads, so as to finish the work on all four sides by once passing it through the machine. The timber was first squared up to the proper size by a machine invented by Mr. Furness, and known at that time as the Furness plan- ing-machine. In a description of this machine by Mr. Paxton, he says : " In this machine, cutters were attached to the ends of an arm revolving with great 4 HISTORY OF THE PLANING-MILL. rapidity in a horizontal plane. The timber was wedged up in a frame travelling upon rails, and as this was passed under the revolving cutters, the upper surface is planed off, the timber being held down upon the frame by a large iron disk." He does not state whether the frame was moved automatically or pushed along by hand ; but the operation of the cutters and their appli- cation to the work was much on the same principle as the Daniels planer of the present time. In a descrip- tion of the gutter-cutting machine, he says : " Cutters were used instead of saws, and were attached to a cast- iron block by means of bolts and nuts. Four such blocks were required to form the gutter, and were fixed to four separate spindles, and, by the action of drums upon them, were set in rapid motion by means of bands. A piece of timber exposed to the action of these cutters must evidently be scooped out into the form of the outline of the cutters. Any great variety of section can be given to the timber." It would, seem, from a further description of this machine, that some kind of automatic feed was after- wards attached to it ; for further along in his description he says: "The piece of timber is placed upon a roller, and pushed onward until it comes in contact with another roller, furnished with projecting points, which seize it and help to propel it forward, causing the timber to move much steadier than before, the timber at the same time being held down to the cutters by a hold- fast." After all of these improvements were completed, he says : '^By this machine, three feet of gutter would be made per minute. This machine was a modification of the same one which was used by Mr. Paxton at Chatsworth EARLY INVENTIONS, IMPROVEMENTS, ETC. 5 for making sash-bars ; and the improvements were made by Mr. Birch. In Mr. Birch's improved machine, cutter-heads were substituted for saws, and, by the addi- tion of cutter-heads acting on each side of the stuff, all sides of the piece were worked simultaneously. A cut of this machine is shown in TomHnson's " Cyclopsedia," published in 185 1, which, however, only represents one pair of four-sided cylinders, one above the plank and one below it, each having four separate cutters attached, and each cutter having the outhne of that particular part of the sash-bar which it is intended to work ; so that the pieces, when stuck, contained a section equal to four bars. Behind the cylinders were five circular saws, attached to one arbor and placed far enough apart to correspond to the width of each bar and divide it, after passing the cylinders, in just the proper places to form four perfect bars at one operation. This cut also represents two feed-rolls, one on each side of the cylin- ders acting upon the upper side of the lumber ; but whether there were rolls below or not, the cut does not show; but, judging from its appearance, the probability is that there were none, and that the stuff passed over a table and was propelled forward partly by the action of the rolls with some help from the operator. It re- quired about two hundred miles of sash-bars, according to the report, to complete the building; and as the contractors, Messrs. Fox & Henderson, had bound themselves in a contract to complete the building in four months, it was thought by many to be a gigantic undertaking to furnish that quantity of sash-bars in so short a time. The work was accomplished, however, and Mr, Birch obtained an enviable reputation for his 6 HISTORY OF THE PLANING-MILL. skill and energy. The report does not state just how long he was in completing the job, but simply states that the sash-bars were all finished in time. Now, suppose we give him three months, of twenty-six days each, and ten hours to the day : it would then only require a feed of about five feet per minute to complete the work. The report, however, says that " This powerful machine worked with untiring energy night and day until the work was completed." If such was the case, the proba- bility is that the feed did not exceed two feet per minute. . WILLIAM WOOD WORTH'S FIRST MACHINE, CHAPTER II. AUTOMATIC FEED-ROLLS— WILLIAM WOODWORTH— HIS FIRST MACHINE— PLANING-MILL MONOPOLY COMMENCED. Having traced the progress and development of wood-working machinery in England down to the time of the building of the great Crystal Palace, or exhibi- tion building, and noting the machines that were in use at that time, it would seem that, if other and more improved machines were in use or known at that time, Mr. Paxton, the architect, or Messrs. Fox & Hender- son, the contractors, would have called them into re- quisition ; as the immense quantity of material that required to be dressed in so short a time as was allotted to them to complete the work of so large a structure would have warranted them in adopting the latest and most approved machinery for that purpose, which no doubt they did. It is very doubtful whether rotary cutters were known or used either in England or France previous to 1826 ; and even if they were, there were no attempts to combine their use with automatic feed-rolls until long after this time. The first attempt of this kind in this country that we have any record of was a machine invented by Hill ; but, from some imperfections in its construction, after repeated trials it was abandoned and passed into the list of abandoned experiments. About the same time WilHam Woodworth, an old S HISTORY OF THE PLANING-MILL. carpenter residing in Poughkeepsie, N. Y., and who was familiarly known among the carpenters as " Uncle Billy," was experimenting upon the same thing in an old saw-mill situated in the lower part of the town, near the river, and not far from where the old Whaling- dock was afterwards located. The old mill and Whal- ing-dock have long since disappeared, but their loca- tion will no doubt be still remembered by some of the older residents of that beautiful city upon the Hudson. His first machine was patented December 27, 1828. In this machine there was no -other device for holding the lumber down to the bed while being planed except the feed-rolls; but as they were placed very close to the cutter-head, they answered the purpose very well, except upon the ends of the boards as they entered the machine before reaching the second pair of rolls located on the other side of the cylinder. The same difificultywas experienced with the latter end of the board as it passed out of the machine after leaving the first, or leading-in, rollers. This had the effect of causing about six inches upon each end of the board to be planed thinner than the middle ; and in order to use it in laying floors so as to present a uniform, smooth surface, it was necessary to cut about six inches off both ends of the piece. After the side-cutters were introduced and applied to the machine, it became necessary to move the feed- rolls farther apart in order to make room for them ; then the difficulty became so great that it was found necessary to introduce another small roll immediately behind the cylinder, to overcome this defect. It is WILLIAM WOOD IVOR TH' 3 FIRST MACHINE. 9 I quite evident that this small roll was not introduced ; until some time after the patent was granted ; for in the ! original specification and drawings there is nothing shown or described to indicate that this was any part ; of the original invention; and being, as it proved after- II wards, so important an element in the combination, if it 1 had been known at the time it would have been shown in the drawing and mentioned in the specification. In describing his invention he says : " The first i of my invention relates to the combination of rotary cutters and feeding-rollers in such a manner that the ' said feeding-rollers shall be capable of feeding the lumber to the cutters, and also of effectually resisting the tendency of the cutters to draw the lumber up- wards towards them ; the object of this part of my in- vention being to reduce the lumber operated upon to a uniforinity of thickness, and to givQ it a planed and I even surface upon one side thereof. The second part \ of my invention relates to the combination, with feed- ] ing-rollers and rotary cutters, for planing one of the principal surfaces of the lumber ; and of rotary matching cutters so as to form a tongue or groove, or both, upon the edge or edges of the lumber at the same time that one of its principle surfaces is planed." This patent, under the conditions of the old patent law, was granted for fourteen years, and expired December 27, 1842, but was extended for a further term of seven years under a provision of the same law which provides that, upon the expiration of the original patent, if the patentee could show, to the satisfaction of the commissioner of patents, that he had used due diligence in bringing his invention before the public, and that he had not been 10 HISTORY OF THE PLANlNG-MILL. able to realize a sufficient compensation for his time, labor, and expenses in introducing it, he was entitled to a further extension of seven years. It is very doubtful whether William Woodworth had made any money out of his invention up to this time. The feeling among the journeymen carpenters was so strong against it that, when the first machine was put in operation, the old saw-mill in which it was located had to be watched constantly both day and night for several months to prevent them from burning it down. Another reason was the want of means to introduce it. Mr. Woodworth having but little means to begin with, and that had all been spent in perfecting his invention, and as almost every one looked upon it with suspicion, as is often the case with other new inventions, the consequence was that very few planing-mills were in operation at that time. After the patent was extended, finding that he could not interest capitalists into it and obtain the necessary means to successfully introduce it to the public, he determined to sell it out for what he could get. He finally succeeded in selling it out to three or four differ- ent parties, who were each assigned a certain territory. It is not definitely known just what he realized from the sale of this valuable patent, but it was reported at that time that he realized in all about five thousand dollars. The New England States were assigned to Samuel Schenck, the Middle States to John Gibson, of Albany, N. Y.; and the Western States to Samuel Pitts, of Detroit, Mich. These parties were all men of con- siderable means, and at once began to take the proper measures for introducing it among the lumbermen in PLANING-MILL MONOPOLY COMMENCED. II their respective territories. Gibson started a large shop at Albany for their manufacture, and also a large plan- ing-mill where machines could always be seen in suc- cessful operation. The owners of the patent must have discovered some defect or weak points in the original patent, one of which was no doubt the small roll behind the cylinder, which was indispensable for the successful working of the machine. In July, 1845, the original patent was surrendered and a reissue obtained ; and in the reissued patent the small roll is not only shown in the drawings, but is also mentioned in the specifications and claims in combination with the other original elements. From this time, the prejudices of the workmen and their opposition having ceased, the demand for planing- machines increased rapidly, and hundreds of mills were started in different localities, principally, however,- in the cities and large towns. The owners of the patent, it would seem, must have had an understanding with each other not to sell any territorial rights, and only to license a certain number of machines for each city or town, giving each mill- owner the exclusive right for a given amount of terri- tory, for which they were required to pay a certain royalty on each thousand feet planed. They also regu- lated the price to be charged to their customers, bind- ing them in a contract not to vary from that price under penalty of forfeiting their license. The price in the State of New York was fixed at seven dollars per thousand feet for planing and matching, and the royalty for each thousand feet so planed and matched was three dollars. What the prices were and the royalties paid in 12 HISTORY OF THE PLANING-MILL. other territories is not distinctly known ; but probably it did not vary much from the amount just mentioned. Each mill-owner was required to render an account every three months for the amount of lumber dressed,- and verify the same under oath, and pay the royalty thereon within ten days from the date thereof. This, it will be seen, soon created almost a complete j monopoly in the lumber business — at least as far as j dressed lumber was concerned, for every planing-mill owner had a lumber-yard attached ; and, while the cost to him for planing and matching his own lumber was but a small sum over what he paid as royalty, his neigh- bor was shut out from obtaining a planing-machine, and was obliged to pay seven dollars per thousand for all the dressed flooring he sold. In some of the large towns, when it was thought there was sufficient busi- ness to warrant it, two mills would be allowed ; and in that case the monopoly of the lumber trade for that town would be divided between the two. But as the owners of the patent controlled the prices, there was no opportunity for competition between them so far as the price of planing was concerned. This state of things naturally stimulated inventive genius to endeavor to invent devices for accomplishing the same work and avoid the Woodworth patent, which had already become such a monopoly. Among the most prominent of those devices was the machine patented by Joseph E. Andrews, November i, 1845. In this machine, rotary cutters were used, but the orig- inal drawings represent two endless aprons, one each side of the cylinder and working above the lumber for the purpose of holding it down ; while below, another PLANING-MILL MONOPOLY COMMENCED. 1 3 endless apron extended the whole length of the machine, passing under the cylinder, and upon which the board rested. This was intended to evade the patent by dispensing with the feed-rolls, thereby break- ing up the combination. Flat pressure-bars, one each side of the cylinder, were applied to prevent the board from vibrating while being acted upon by the cutters. The endless aprons as a reliable feed proved a failure, and they were abandoned, and feed-rolls were substi- tuted for feeding purposes, retaining the fiat pressure- bars for holding down the stuff. Although Andrews claimed that, dispensing with the roll for holding down the lumber, and substituting the flat pressure-bar, the same elements of the Wood- worth combination were not used, and the ruling of the courts in cases of claims that were combinations was that, in order to infringe a combination claim, precisely the same devices and elements must be used, under these rulings, Andrews claimed the pressure-bar as a new element, and consequently a new combination. Suits, however, were commenced as soon as this machine was put in successful operation, for infringe- ment, which were decided against it in every case. Judge Blatchford, in deciding one case, makes use of the following language : " The substitution of smooth plates of iron, operated by springs or screws, to press down the boards upon the bed while being planed, in place of a pressure roll or rolls, is not a substantial de- parture from the Woodworth device for the same pur- pose " (see Gibson vs. Betts, i Blatchford, 164; N. Y. 1846: also Gibson vs. Harris, i Blatchford, 170; N. Y. 1846). 14 HISTORY OF THE PLANING-MILL. The courts in every suit having decided against the Andrews machine, it was evident that a successful working machine with rotary cutters, without feed-rolls, could not be produced. Inventors then turned their attention to other devices ; and prominent among them was the planing-machine invented and patented by Joseph V. Woodbury in the year 1849. I^^ this machine, the knives were fastened to a stationary knife- stock, placed at about the same angle as a hand-plane and provided with a cap or double iron much in the same manner. The lumber was forced through the machine, and brought in contact with the knives by a powerful train of feed-rolls. In some of them there were as many as six knives, so arranged and set that each knife cut off a certain amount of the stock, the last knife taking a very fine cut, so as to finish the surface and leave it smooth. This machine was quite expensive, and required extra care and skill to operate it. On dry, straight-grained, clear lumber it performed excellent work ; but with cross-grained, knotty lumber the work was not so suc- cessful, and those that were in use were abandoned as soon as the Woodworth planer came into general use without the payment of royalty. MORE SUITS FOR INFRINGEMENTS. I 5 CHAPTER III. OTHER INVENTIONS— 3I0RE SUITS FOR INFRINGE- MENTS—THE PATENT RENEWED BY SPECIAL ACT OF CONGRESS— 7HE NORCROSS PLANER— THAT PA TENT SUSTAINED. The excessive royalty demanded by the owners of the Woodworth patent still acted as an induceraent not only to inventors to discover some machine that would do the work without infringing this patent, but was also an inducement to that portion of the public outside of the -monopoly to encourage them by pur- chasing those machines in order to get rid of the exor- bitant prices demanded for dressing their lumber. In addition to the machines heretofore mentioned, there was the McGregor machine, patented in 1846. The Beckwith and the Gay machines, in Pennsylvania, were gotten up about the same time, besides the Brown machine, in Massachusetts, each with its own peculiar devices, which were supposed to evade the Woodworth patent, — all of which were stopped by in- junctions and declared infringements soon after being put in operation. In the mean time the Norcross machine was put in use ; and this was the first and only machine among the whole number that stood the test of a suit and was decided not to infringe the Woodworth patent. But as we shall have occasion to refer to this machine here- after, we leave it for the present, l6 HISTORY OF THE PLANING-MILL. As the time was drawing near when this patent would expire, and as the owners had all made large fortunes out of it, it was natural to suppose that when the time expired, which would be in 1849, i^ would be allowed to die a quiet and peaceful death, the owners would retire, and the monopoly would come to an end. But the public were doomed to disappointment. The owners, although all of them had made large for- tunes out of the patent, were not yet satisfied ; and, as they were men of considerable influence, their money and influence together had been quietly at work for more than a year previous to this time for a further extension. It was too good a thing to allow it to die a natural death if money and influence could prolong its life for another term of seven years ; and while the public, or at least that portion of it interested in plan- ing-mill machinery, was quietly waiting for its death, the most skilful physicians in the shape of lobbyists were employed and furnished with unlimited means for prolonging its life. How well they succeeded may be found in the special act of Congress which fastened the same monopoly upon them for another term of seven years. There was rejoicing among the monopo- Hsts — not only the owners of the patent, but also the owners of planing-mills which were so situated as to monopolize the lumber trade in certain localities. These men had also liberally contributed, both in money and influence, to bring about this event ; and many were the wine-suppers given on this occasion. There v/as cursing and gnashing of teeth among those outside of the ring, to commemorate this event, also. It was currently reported at that tirne that John Gibson^ MORE SUITS FOR INFRINGEMENTS. 1 7 of Albany, N. Y., who was reputed to have been worth over one million dollars, and who spent nearly the whole winter of 1848 and 1849 ""^ Washington, contributed, in one way and another, over two hundred and fifty thou- sand dollars for that purpose as his share of the neces- sary expenses attending it. And if this was true, and others who were interested as well as himself con- tributed as liberally as he was reported to have done, somebody, either in or out of Congress, must have made " some pin-money for their wives, you know," for of course no one in Congress at that time would be suspected of taking any money to influence their vote. Oh no ! As before stated, from the time of the reissue, in 1845, there had been repeated attempts made to break down the reissued patent ; and many suits were de- fended upon the plea that in the reissued patent there were new elements introduced that were not shown or described in the original patent, one of which was the small pressure-roll behind the cyHnder to hold down the lumber v/hile being planed, especially at the ends as the boards were entering in or passing out from between the feed-rolls. It would seem as if this point should have been a good one fort for the defence ; as the records of the Patent Office, both in the original draw- ing and model, do not show it, neither do the specifica- tions mention it. But notwithstanding this and the plea of irregularity in the assignment which was pre- sented and argued by able counsel in the suits of Brooks V. Becknell in Ohio, Washburn v. Gould, and Woodworth v. Wilson, with several others on record which might be referred to, in every case the claims of 1 8 HISTORY OF THE PLANING-MILL. the reissued patent were sustained and judgments taken against the defendants. The Norcross machine had now made it sappearance; and the owners of this patent were manufacturing this machine openly, and putting it in the market in defi- ance of the claims of the Woodworth monopoly. Suits were, however, commenced against it for infringement at a later date and but a year or two before the ex- tended term of the Woodworth patent "would expire. After a short trial, to the surprise of every one who was any way familiar with planing-machines, it was de- cided that the Norcross machine did not infringe the Woodworth patent. The court which rendered that decision must have looked through something else than his glasses if he examined the machine personally; otherwise he w^ould have discovered in the aforesaid machine more of a direct infringement than many others which had been stopped by injunctions. The claims of the Woodworth patent, it will be re- membered, were for the combination of feeding-rollers and rotary cutters. Both of these elements were used, precisely in the same manner, by Norcross ; the only difference in the machines were, Woodworth's planed on the upper side of the board, while the Norcross cylin- der was below and planed upon the under side of it. But as far as the arrangement of feed-rolls was con- cerned, there was no difference whatever in the two machines. As many of the younger planing-mill owners, as well as operators, may not remember the old Norcross, I submit a brief description of its construction and ope- ration, MORE SUITS FOR INFRINGEMENTS. 1 9 Upon a frame very similar to the Woodworth machine was mounted one pair of feed-rolls somewhat larger in size than those used by the latter machine for the same purpose. Both upper and lower rolls were geared to- gether by the same old-fashioned system of '' star or fin- ger gears," as they were called, and which allowed the rolls to expand or contract sufficient to accommodate the varying thickness of the same lumber, and the top rolls were forced down upon the stuff by the same system of weights and levers. When the machine required chang- ing for the purpose of planing thicker or thinner lum- ber, different-sized gears were provided, and were changed from time to time, as frequent as the thickness of the lumber required it. Behind these rolls, and in as close proximity as possi- ble, was the bed-plate, reaching across the machine, the ends resting upon the frame, to which it was securely bolted. This bed-plate was provided with an opening, or slot, running lengthwise with it across the machine, similar to the bed of the bottom cylinder in a modern- style planer, and the cylinder was placed underneath it, the knives working through the aforesaid slot and act- ing upon the under side of the board substantially the same ; the lumber being held down by a heavy press- plate resting upon it. Instead of the cylinder being fixed to the frame, or permanently attached to the bed-plate, as in the under cylinder of the modern planer, provision had to be made for the varying thickness of the lumber and to re- duce it all to the same thickness. In order to accom- plish this object, the cylinder-boxes were attached to the upper press-plate, which rested upon the upper, or 20 HISTORY OF THE PLANING-MILL. rough, side of the board and was secured to it by means of arms passing down through the main bed-plate, to which the cyHnder-boxes were attached. It will be seen, by this arrangement, that the distance between the upper press-plate and the cutting-edge of the cylinder-knife must determine the thickness of the board after being planed. To adjust the machine for planing the several differ- ent thicknesses of lumber, cast-iron blocks, or, more properly speaking, parallel strips which were planed the right thickness, were furnished and inserted between the points where the upper press-plate was connected to the cylinder-boxes, and the whole securely fastened by bolts passing through the whole; thus forming a strong frame, and, working in heavy, strong uprights, into which they were nicely fitted, left it free to work and allow the cylinder to rise and fall according to the varying thickness of the lumber, at the same time gaug- ing the thickness according to the thickness of the blocks. Here was the direct combination of feeding-rollers and rotary cutters just as perfect as could be found in the Woodworth machine ; and when suit was brought against it, even the parties who had purchased and were using it expected to be stopped by injunctions, and openly expressed their opinion that their machines were direct infringements, and that it would only be a question of time when they would be compelled to stop. But as the owners of the Norcross patent were men of undoubted responsibility, and had bound themselves in a contract, with each party sold to, to guarantee them against all costs and damages in case of suit and they THE NOR CROSS PLANER. 21 were defeated, so the only course for the mill-owners was to run as long as they could and make all they could out of it while it lasted, and then look to the owners of the Norcross patent to indemnify them for future damages. No one was more surprised at the decision of the court than these same mill-owners, many of whom had been estopped by injunction from using the Andrews and other similar machines. It would have been a hard matter to have made some of those old planing-mill men, who were well posted with nearly all such devices, believe that the whole thing was not a put-up job between the owners of the respective patents. The fact was, the Norcross patent had passed into the hands of men who had wealth and influence; and the owners of the Woodworth patent had in contempla- tion another effort for a further extension of their patent, and they feared the influence of the Norcross interest when that time arrived, providing the latter succeeded against their patent. The Norcross owners were secretly in favor of an ex- tension of the Woodworth patent, provided they could be left at liberty to manufacture and sell their own machine. It was admitted on all sides that the Woodworth was far the superior both as to quantity and quality of work, and, while the lumber was planed and matched upon the Woodworth machine at one operation, the Norcross system required two separate machines — one for plan- ing and another for matching. But people who could not procure a Woodworth machine were willing to put up with those inconve- 22 HISTORY OF THE PLANING-MILL, niences rather than pay the exorbitant price of seven dollars per thousand feet for dressing their lumber ; and, further, while the Woodworth patent was in exist- ance there would be a steady demand for the Norcross machine for reasons already given. But if the former were thrown open to the public, so that every one who desired might obtain a Woodworth machine without royalty, every one would prefer that machine and there would be no demand for the Norcross — which subsequent events fully verified. On the other hand, the owners of the Woodworth patent had so many machines in use that were paying them royalty, and would, in all probability, continue to do so after the patent was extended, that the compara- tively small number of machines that Norcross would put into the market during that time would do them but little harm so far as their income^ from royalties was concerned. Besides, as before stated, the Norcross had no matchers attached ; and being only a surface-planer, the lumber, after being planed, required to be cut up and run through a separate machine for matching, thus adding, to the cost of dressing, the expense of twice handling. So it is evident that both parties, each acting from different motives, were in favor of another extension of this great monopoly. FURTHER EXTENSION OF THE MONOPOLY. 23 CHAPTER IV. APPLICATION FOR A FURTHER EXTENSION— FOR- MIDABLE REMONSTRANCE— DEFE A T OF THE ME A S URE—IMPR VEMEN TS, E TC. The public, however, was not to be duped again by resting supinely upon its back until the enemy had a second time bound it hand and foot. The manner in which the Norcross matter was set- tled, with many other things which transpired, created suspicion in the minds of those who were watching the movements of the monopoly ; and when it became def- initely known that they were quietly moving for another extension, by a special act of Congress, ar- rangements were made by the lumber-dealers outside of the monopoly with the publishers of the Scientific American^ a well-k>^own journal with an extensive cir- culation, and well known to the mechanical com- munity, and which was known to be bitterly opposed to the monopoly or its extension, to print and send out to each subscriber a form of protest against any further extension of the patent. These documents were accordingly sent out to each subscriber with a request that they not only sign it themselves, but to solicit all who were in any way interested in lumber to sign it also, and return the same to their office by a certain date. These protests were all arranged and attached to a strong printed pro- 24 HISTORY OF THE PLANING- MILL. test and petition to Congress against any further exten- sion of the Woodworth patent. This formidable docu- ment, containing between fourteen and fifteen thou- sand names, was forwarded to Washington to a trusty member of Congress, who was to present it at the proper time, provided the subject was brought before* that body. Congress assembled December i, 1856, and the ex- tended patent had but twenty-seven days longer to run before it would expire. Gibson and others were ' on hand, backed by a host of the most expert lobbyists and plenty of money, and succeeding so far as to get a bill introduced early in the session to extend the patent for a further term of seven years from December 27, 1856. But when the remonstrance was presented, about the time when it came up for action, which resembled a roll of carpet more than a public document, they con- cluded not to read it, but to unroll and measure it, when it was found to contain two columns of closely- written names fifty feet long. This formidable docu- ment, coming, as it did, from their constitutents in all parts of the United States, without regard to party or politics, was too big a pill for them to swallow, and the result was that the great monopoly was totally routed. And this ended the career of the Woodworth patent. Gibson, who was currently reported to have spent another quarter of a million in his endeavors to pro- long the monopoly, returned to Albany in a frame of mind that can better be imagined than described. He imm^ediately employed an attorney to travel all over his territory and visit every sash, door, and blind FURTHER EXTENSION OF THE MONOPOLY. 2$ factory, besides other mills, which had used anything in the shape of rotary cutters in combination with feed- rolls, whether it be a planer, sticker, moulding-ma- chine, or anything else, and demand a settlement and payment of royalty from the time they had com- menced using the same up to December 27, 1856, or to commence suit against them at once. Previous to this time, no notice had been taken of those small machines for sash and door work. The owners of the patent had confined themselves strictly to planing-mills, and had, by tacit consent, allowed these machines to be run for years without any intima- tion that royalty would ever be demanded from them ; and when it became known that such action was to be taken, it created a profound sensation among that class of wood-workers. Some parties who were timid in the matter were frightened into a settlement ; while others, among whom was the writer, refused, not only to make a set- tlement, but advised him to invite Mr. Gibson to ac- company him to a certain place where the climate was much warmer than Albany. A few suits were com- menced ; but public sentiment had become so strong against the monopoly that I am not aware of any of them ever coming to trial. And it is not known to the writer just how much money his attorney obtained in this manner, — whether enough to pay his travelling expenses or not, — but one thing is well known : that this course of proceedings on the part of Mr. Gibson rendered him so odious in public opinion that, al- though he had a large stock of planing-machines on hand at his factory in Albany, he could not find sale 26 HISTORY OF THE PLANING-MILL. for them, while other shops which had started in the busi- ness were running nights to keep up with their orders. His old customers would buy almost anything rather than have any dealings with him, and he was finally obliged to sell out his business, together with the stock on hand ; and they were purchased by Mr. Daniel Doncaster, a gentleman of fine mechanical abilities, and who had for many years acted as his foreman, and was well liked by his former customers. Mr. Don- caster continued the business successfully for many years after. Gibson afterwards retired to a farm in Steuben County, owned by his wife, and died a few years since, comparatively poor. Mr. Schenck removed his patterns and special tools to Matteawan, N. Y., as early as 1840, and the Schenck machine, as it was called, was manufactured there. But whether there was any arrangement with Gibson for the sale of those machines in his territory does not appear ; but from the fact that there were no Schenck machines met with in this State previous to 1856, the supposition is that they were sold east in his own terri- tory or in territory owned by other parties who did not manufacture. The Matteawan Company, as it was called, continued the manufacture of planing-machines as a part of their business long after the patent expired, and until that company went out of the business by failure. The tools and patterns pertaining to that part of the busi- ness went into the possession of John B. Schenck, and the business was conducted by him until his death, when his sons continued it under the firm name of John B. Schenck's Sons. IMPROVEMENTS, ETC, 2/ Mr. Pitts, of Detroit, Mich., was never engaged in the manufacture of planing-machines personally, but allowed his customers who desired to take a license under the patent in his territory to purchase their machines wherever they preferred ; he simply collecting the royalty on the amount of lumber planed by them. He owned and operated a large mill in Detroit, and, later, started one at Saginaw, Mich. Mr. Pitts, although possessed of a large fortune, was a very liberal-minded gentleman and business man, and died about 1870, universally respected by all who were acquainted with him. The writer had considerable dealings with him in 1863-4 by furnishing him a number of machines, and became personally acquainted with him ; and as those transactions were of the most satisfactory char- acter, they are still remembered with pleasure. Having traced the three original owners of the Wood- worth patent to the end of their connection with it, we now return again to the planer as it was constructed by the original manufacturers. The Woodworth planer previous to 1856, although it had been the bone of many contentions, was still a very crude and imperfect machine, as compared with those of the present time. In fact, there seemed to be no disposition on the part of those engaged in its manufacture to make any improvements : they seemed to carry out the idea that they were good enough ; and, as there was no competition, their customers could take it as it was or do without it. As soon, however, as the patent expired and was open to the public, new manufacturers started, and one improvement followed another, many of which were the subjects of new patents. 28 HISTORY OF THE PLANING-MILL. until the whole machine has become so changed in its appearance and construction that it is a question if William Woodworth, could he return to this earth, would recognize it as the offspring of his original invention. The planing-machines manufactured by Gibson, Schenck, and others previous to 1856 were provided with straight uprights for the cylinder-boxes, and the cylinder worked up and down as it was required to be raised or lowered for the purpose of dressing thick or thin stuff, and worked at right angles to the frame. With this arrangement, it will be seen that if the belts were of the proper tension for planing lumber three fourths of an inch thick, they would be too short when the cylinder was raised sufficiently above the bed to admit of planing two-inch stuff. The common prac- tice was to keep short pieces of belt the right length to make up the difference ; and when it was required to plane thick lumber, these pieces were added to the belts and taken out again when the work was finished and the use of the machine required for thinner stuff. Again, the finger or star gearing that was used to con- nect the top and bottom rolls would only allow of an expansion of about one half an inch, and were not practi- cal to use on different thicknesses of lumber ; conse- quently, whenever a change from one thickness to an- other was required, these gears required to be changed also. There were several sets of them always ready for use, and it was no uncommon thing for the opera- tor to be obliged to change them half a dozen times during the day. The small pressure-roll behind the cylinder was an- IMPROVEMENTS, ETC, 29 other very inconvenient arrangement. The adjustment of it was separate from the adjustment of the cylin- der, and required to be set every time the cyhnder was changed; and frequently the machine would require stop- ping several times before a proper adjustment of this roll would be obtained. The cylinder-belts, also, ran inside of the frame, which required the width of the frame to be from eighteen to twenty inches wider, in proportion to the width of the cylinder, than the modern machine. A modern operator of planing-machines would form rather an unfavorable opinion of a machine so con- structed that, if a job requiring a few hundred feet of thick stuff to be planed, before he could finish that part of the job, would require both cylinder-belts to be taken off and a piece put in each, then change all the gears upon the feed-rolls, besides stopping two or three times to adjust the small roll behind the cylinder, to- gether with all the rods and screws connecting the top feed-rolls with the weighted levers below, spending per- haps an hour or two in order to put the machine in proper shape to do perhaps one half hour's work, he would not only realize that great improvements had been made in the modern machine, but wonder that they were not made sooner. But, as before intimated, the poHcy of the owners of the patent were such as to effectually shut out all improvements as long as the patent was in force. In the machines that were brought out in 1857, the frames were narrowed up so as to allow the cylinder- belts to run outside of the frame, thus rendering them more compact and requiring less room. The uprights which supported the cylinder-boxes were placed at right 30 HISTORY OF THE PLANING-MILL. angles to the driving-shaft, so that, in changing from one thickness of stuff to another, but Httle, if any, dif- ference was noticed in the tension of the belts. The small roll behind the cylinder was attached to the cylinder-boxes, so that it was adjustable with the cylin- der, and, when once adjusted, required no further ad- justment when the cylinder was raised or lowered to accommodate the different thicknesses of stuff. The dif^culty in keeping the small pressure-roll in front of the cylinder free from the small particles of gum which accumulated upon its surface, and which marred the face of the planed lumber, led most of the manufacturers to adopt the flat pressure-bar — an old device, which was used many years previous on the Andrews machine. This device was at first objected to upon the supposition that the friction upon the surface would obstruct the feed ; but subsequent use proved these objections to be unfounded, and soon after 1857 the pressure-bar came into general use upon all first- class machines. BROWN EXTENSION-GEARS. 3^ CHAPTER V. BRO WN EXTENSION-GEARS— THER IMPRO YEMEN TS — B URLEIGH'S PA TENT DIMENSION-PLANER — HENRY D. STOVERS CELEBRATED CLAIM. We stated in the last chapter that, previous to the time when the Woodworth patent expired, very few improvements had been made upon the original ma- chine. With the exception of the Brown extension- gears, which were applied to it a short time previous, and which superseded the star or finger gears, the ma- chine, in its general features, was about the same as when first completed by the original owners. But as soon as the extended patent expired, the inventive genius of the whole country, or at least that portion of it who were in any way interested, seemed to turn their attention in that direction ; and there was no end to the alleged improvements that were brought out and patented within a few years after this event. Some were practical and useful, some really valuable ; but a large portion were of so trifling a nature that they were never heard of afterwards, and probably never known to any one but the inventor and the examiner at the Patent Office. The examiners at the Patent Office at that time seem to have granted about everything that was applied for, without giving themselves the trouble to look up and ascertain whether the thing appHed for was new and 3 2 HISTORY OF THE PLANING-MILL. useful, or whether it had been patented previously or not ; as we find, in the time between 1856 and i860, several patents granted for the same thing, and dated so near the same time that they all must have been pending in the Office at the same time. One of the earliest patents we notice that came into use was one which was granted to James A. Woodburg, of Boston, Mass:, for a plan for moving both matcher- heads by means of two separate screws. As the old Woodworth machine moved one matcher-head by a screw, the simple fact of attaching another screw to the other head for the purpose of moving that also was a mere duplication of parts, and, under the present ruling of the Patent Office, would not be considered an invention, and, consequently, not patentable. The improved extension-gears invented by Charles Burleigh, of Fitchburg, Mass., and assigned to the Putnam Machine Co., was really a good invention, and was an improvement over the Brown gears, and over- came certain objections to that device. „, It consisted in forming one end of the links that confined the idle or loose gears to those attached to the roller-shaft in the form of the segment of a circle of the same radius as the idle gears, with teeth or cogs formed upon the out- side circumference so as to engage each other; and, when confined in this position by the cross-strap that kept them in gear, when the top roll was raised or lowered to accommodate the varying thickness of the lumber, those links worked together upon the same centre as the gears, thus always keeping them in the same relative position to each other, no matter what the position of the rolls might be. HENRY D. STOVER'S CELEBRATED CLAIM. 33 The dimension-planer known as the Gray & Wood planer was patented January 24, i860, just about one month after the celebrated Stover patent was issued, which we shall soon notice. The Gray & Wood planer is so well known among wood-workers that a descrip- tion of it is deemed unnecessary, except so far as to illustrate the loose manner in which the business of the Patent Office was conducted at that time. The Gray & Wood planer, as is well known, is a modification of the old Daniels planer, which had long been in use ; and their improvements consisted in the application of a Wood- worth cylinder to plane the lumber lengthwise of the grain, instead of the arms of the Daniels, which worked crosswise, using the same sliding table as the Daniels. They also applied feed-rolls so that the lumber could be fed through the machine while the platen remained stationary, or the feed-works could be readily removed and the platen used in their stead when it was desirable to take the lumber out of wind. Their claims were few, and appear to be confined to just what they in- vented and-nothing more. Now, just about one month previous (December 18, i860) the Patent Office had granted to Henry D. Stover a patent for the same thing ; which not only covered everything which he had invented but every- thing which others had invented or could invent — principally the latter : and these two claims must have both been pending in the Office at the same time. While Mr. Gray is somewhat modest in his claims, and seems only to cover what he invented, Mr. Henry D. Stover goes in for the " whole hog." As this patent is such a remarkable one, and deserves to go into the 34 HISTORY OF THE PLANING-MILL, history of planing-mill machinery, we give the claims in full, as a historical curiosity. In the specification he say : " The claim and engravings will explain the nature of this invention. [No one will doubt that fact when he has read them.] " First, I claim the combination of cutting-cylinders {p) and cross-head {in), with two or more screws (e) for raising and lowering the cutting-cylinders evenly and parallel to the face of the platen. " I also claim to so pocketing or encasing the raising and lowering screws {e) in the uprights {c) that dust and shavings will be effectually excluded, whether the ma- chine is in operation or not. " 1 also claim so constructing the cutting-cylinders {o) as to receive four or more cutting-blades (Pj, each im- parting a shearing or drawing stroke or cut ; and, at the same time, for convenience in construction and ease in sharpening and securing the blade to the- head. " I also claim forming the portion of the cutter-head immediately back of the edges of the cutting-blades, — an angle varying from 5° to 45° from the face of the cutting-blades, — to constitute a solidly, variable, and efficient cap to the cutting-blades. " I also claim so constructing, connecting, and arrang- ing the sliding journal-boxes (T) with cross-head {111)^ which carries the cutting-cylinder (^), by means of rods {it\ that, when the cutter-head is raised or lowered, these journal-boxes will move so as to always retain a pre- cisely equal distance between the driving-pulleys and the driven pulleys on the cutter-head for equal tension of the belt. HENRY D. STOVER'S CELEBRATED CLAIM. 35 " I also claim feeding the platen back and forth by friction-sHde {A), and wheel (/?), and rack (^), and pinion (6^), for the purpose set forth. '' I also claim reversing the movement of the platen by means of screw {iri) and wheel (., "the matcher don't work." I was well satisfied that the ma- chine was all right and that the trouble was, " The man did not work." However, I took the train the next morning and ar- rived at the station, and procured a horse and buggy and drove out to the mill, which was eight or ten miles in the country. I met one of the proprietors in the yard, and inquired what the trouble was. He replied he did not know : but one thing he did know, that l68 HISTORY OF THE PLANING-MILL. they had spoiled 400 or 500 feet of lumber in trying to match, and the boards ran off so that some of them were only about half as wide at one end as the other ; and that finally they had concluded to give it up and shut the machine down. I accompanied him into the mill and asked the fore- man if he had a square and monkey-wrench ; he had, and got them. I put the square against the front roll and found the long guide about one inch out of square the wrong way. The guide had plenty of draught, but it was not the kind of draught required. I took the wrench, and loosened the nuts and set the guide back to its place, giving it about one half inch draught in its length, and requested him to start up. He did so, and every board after that hugged the guide so that there was no further use for the hand-spike that he had rigged up. The proprietor at first was inclined to give the fore- man a raking down for his ignorance ; but I calmed him down by telling him that mistakes would some- times happen in the best-regulated families. He then invited me into his office and inquired how much my bill would be, as they had made such fools of themselves that it was no more than right that I should be paid for my time and expenses. I told him if he felt disposed to pay my expenses, I would accept that ; but for the time, I would say nothing about it, as the joke on him was sufficient compensation. Another cause for the lumber drawing away from the guide is in not having the pressure-bar behind the cylinder properly adjusted. If the end of the bar next to the guide presses hard on that edge of the board it is sure to draw off. While it is very essential, in THE USE OF SPRINGS NOT NECESSARY. 1 69 order to make smooth work, that the pressure-bar should rest upon the whole width of the board, yet the side opposite to the guide may be a trifle closer without any detriment to the work or the machine, and helps to keep the board from drawing off without the use of levers or springs. Where the machine is fed by a boy, who may be sometimes careless in placing the board against the guide, a light spring placed close to the front roll may be of advantage for that purpose ; but if a machine is properly constructed, with the rolls square with each other and in line, then, if the guides are properly set, there is no use of the clumsy, heavy devices that are found attached to many planers for keeping up the boards, that require all the strength of the operator to push the lumber by them before entering between the rolls. Some operators seem to think that everything must be screwed down as tight as possible in order to make smooth work, so that it requires all the power that is in the feed to force the lumber through. This is bad practice : the unnecessary pressure on the bed soon wears it away, so that it will require frequent planing off in order to be true enough to work all widths of lumber in a satisfactory manner. The slipping of the rolls when the pressure-bars are screwed down so tight also wears them away, so that they soon become im- perfect; besides the extra wear and tear upon the gearing. It is astonishing to note the difference in planing-ma- chines, and, in fact, all other wood-working machinery, after a few months or years in use, when put in the 170 HISTORY OF THE PLANING-MILL. hands of different operators. I could point out a large number of different machines, that have been in use five or six years in the hands of careful operators, which show but little wear and are practically as good as new ; while others, which have run less than half that time, are, from careless usage and neglect, nearly used up. If the bottom rolls are attended to and kept in line with the bed, there is no necessity for setting the pressure-bars so tight upon the stuff. If they rests upon the board just sufficient to keep it from vibrating with the cut, it is just as effective as it would be if the press- ure were increased to a ton ; and just as smooth work will be done, with much less wear and tear of the ma- chine. When the work comes out wavy, it is not always be- cause the pressure-bar is not down tight ; the fault may be in the cylinder-boxes or some other part of the machine. And the careful operator, who understands his business, will ascertain where the difficulty lies before he moves a screw ; and then he will be sure to move the right one the first time. ARTISTIC WOODWORK. I/I CHAPTER XX. AR TIS TIC WOOD WORK— IMP IW VED MA CHINES— CUT- TING-TOOLS—IMPORTANCE OF A RUNNING BAL- ANCE—HINTS FOR FITTING UP TOOLS— THEIR TEMPER — HARD AND SOFT CUTTERS CONSID- ERED. The increased demand for artistic woodwork with- in a few years past has led to the introduction of many new, compHcated, and useful machines. Intricate carved work and irregular formed mould- ings of the most elaborate kind, which were formerly worked by the slow and tedious process of hand-labor, are now produced by special machines invented ex- pressly for the purpose, which not only performs the work more accurately and in less time, but materially decrease the cost of production. This change has not only demanded more accurate and skilfully constructed machines, but a more skilful and intelligent class of mechanics to operate them suc- cessfully. In mouldings especially, there is a great change, as compared with those stuck at the present time and those stuck a few years ago. Architects and builders are far more exacting now than they were at that time, jjuilders then were satisfied with mouldings if they were the correct shape and of an even thickness ; and if the surface required smoothing down by the liberal use of sand-paper, or sometimes the moderate use of a hand- 1/2 HISTORY OF THE PLANING- MILL. plane, there was nothing said, because it was the best they could get, and was far better than the laborious process of working them entirely by hand, as they had been accustomed to do in former years. The competition among the manufacturers of those machines, and the desire of one to excel the other in the quality of their work, together with the increasing demand of the 'builders and architects for better ma- chine-work and less hand-labor has brought the mould- ing-machine to such a state of perfection that the most intricate designs in mouldings are now made, both in hard and soft woods, so perfect and smooth that even the use of sandpaper is dispensed with. This of course requires mechanical skill, in order to keep those machines in a perfect state of adjustment and the cutting-tools in perfect order, as the quality of the work depends entirely upon these conditions. The extra care required in fitting up a pair of cutters so that each may be the exact counterpart of the other and perform its part of the work, has led some opera- tors into the pernicious practice of using one cutter, and counterbalancing it with a piece of iron, or an- other cutter of a different shape. If this was a prac- tical thing, and the feed regulated accordingly, there is no doubt but just as smooth work might be done; but a cutter-head can never be balanced in that man- ner. It is true a standing balance in this way may be ob- tained, i.e., the head, when placed upon the balancing- bars, may remain at rest at any point, this showing a perfect standing balance. But there is a vast difference between this and a running balance ; and unless the CUTTl[NG-TOOLS. 173 counterbalance is of the same weight and thickness in all of its parts, and every part of it revolving in the same circle, a running balance cannot be obtained. It must be remembered that the centrifugal force of all bodies moving with different velocities in the same circle is proportioned as the square of their velocities ; and a body revolving lOO revolutions per minute has 4 times the centrifugal strain as one moving 50. Again, the centrifugal force of two unequal bodies moving with unequal velocities, and at unequal distances from the centre are in the compound ratio of the quantity of matter, the square of their velocities, and their dis- tance from the centre. Now, in order to illustrate this, suppose two cutters, each weighing one pound, were attached to a head 5 inches in diameter, and describing a circle of that di- ameter at the rate of 3600 revolutions per minute : by the rules given in another chapter for calculating cen- trifugal force, the strain upon each side of the head would be equal to 77-55 pounds; but as a portion of each cutter must necessarily project beyond the diam- eter of the head to correspond to the depth of the moulding, the strain would be increased just in propor- tion to the weight of that part of the cutter, and its distance from the centre. Now, suppose only one cutter were used, and, in place of the other, a piece of iron were fastened to the op- posite side to form a balance. Although it may be of the same weight, and the head, when tested upon the balancing-bars, may show a perfect balance, yet when put in motion, those parts of the cutter which project beyond the head will present exactly the case just 174 HISTORY OF THE PLANING-MILL. mentioned. There would be two unequal bodies mov- ing with unequal velocities, and at different distances from the centre ; and the difference in their centrifuga strain would be in the compound ratio of the quantity of matter, the square of their velocities, and their distance from the centre. So it is evident that a cutter-head cannot be balanced in that manner so as to run smooth and accurately. Some operators claim this may be compensated for by making the counterbalance a trifle heavier than the cutter; but this is only guesswork, and the result cannot be relied upon : and the result is, the machine goes on rattling and jarring until every bolt and screw in it has worked loose. But this is not the worst feature of it. One side of the journal is constantly pressed against the box in its efforts to find its true centre of gravity, and soon that side becomes worn flat or egg-shaped, so that it will be impossible to run it until it is taken to the machine-shop and turned off. A few turnings so re- duces the size that it soon becomes worthless. If I were asked to express my opinion as to the best and surest way to use up a moulding-machine in the shortest time, I would recommend the use of one cut- ter, balanced with a piece of iron. Notwithstanding some operators claim that it is a difficult matter to fit up two knives and keep them in shape so that each part will make the same cut, there is no difficulty whatever with proper facilities, except it may require more care. A very convenient tool for this purpose may be con- structed, with but little expense, that will easily enable one to accomplish this object. Get a couple of pieces IMPORTANCE OF A RUNNING BALANCE. 1/5 of hard wood — one say about twelve inches long and the other six, and about one and a half inches thick and six or eight inches wide. After dressing them up perfectly straight and square, firmly attach the short piece to the long one, about three inches from one end, so that the two faces will make an angle of 45° to each other. On one side of the upright piece attach a guide parallel with its side and square with the bottom. Now if a piece of moulding the exact pattern of that which is to be stuck be bevelled on one end so as to fit closely to the bottom of the upright piece and fastened to the bottom of the form parallel with its edge, and then if the cutter is placed with its back against the upright and its side against the guide, when the edge is let to drop upon the pattern, and fitted to it and set accurately upon the head, there will be no danger but every part of one will be the exact counterpart of the other, and each perform its part of the work. With standard cutters, which are much used, the patterns should be cast of soft brass or babbitt-metal, to prevent them from becoming marred and losing their shape. As certain parts of all moulding-cutters wear away faster than others, they should always be dressed to this pattern in order to preserve their shape. The proper temper for a moulding-cutter is a subject upon which there is a variety of opinions : some con- tending that they cannot be too hard as long as they stand ; while others contend that very little temper is necessary. Wishing to satisfy myself and be able to advise oth- ers understandingly, I made a series of experiments 176 HISTORY OF THE PLANING-MILL. with cutters of different tempers. My experiments were conducted in the following manner: A three-winged cutter-head was selected and bal- anced, with great care ; three knives were prepared. One was given a light straw-color ; the second a medium temper, so that it could be cut with a fine, sharp file ; while the third was drawn down to a blue, with very little temper. These cutters were tested upon hard and soft woods ; and in each case, after running a short time, the machine was stopped and the edge of each one examined with a strong magnifying-glass. The edge of each knife presented the same round appear ance that all rotary cutters have after being used. If there was any difference at all, it appeared to be in favor of the knife with the medium temper. As each test gave the same results, and the advantages being in favor of the knife with the medium temper, the conclu- sions were that the fine, thin edge of the hard knife crumbled off, while the very soft one wore off ; so that after running for one hour, neither had any advantage over the other. With all the improved machinery at the present time, the practical wood-worker is frequently obliged to resort to his own ingenuity in order to get out some of the crooked and odd-shaped work that is required. With straight work, no matter how complicated, tools can always be adapted for the purpose. Where the work is to be done on the edge, no matter how crooked or complicated, the upright shaper — or variety moulding- machine, as it is sometimes called — is admirably adapted to this class of work and saves an immense amount of hand-labor. SPINDLES AND COLLARS. 1 77 In order to adapt it to all kinds of work, that portion of the spindles which projects above the table should be made so as to allow the cutter-heads to be as small as possible, in order to work in small circles. The cut- ters are bevelled upon both edges and fit into corre- sponding grooves in the collars ; the lower one being stationary and revolves with the spindle, while the top one is loose and held down upon the cutters by means of a nut attached to the upper end of the spindle. The lower or stationary collar, as it is called, is made deep enough to allow the pattern to which the work is at- tached, to work against it. In this manner, it will be seen that, if a piece of stuff be fastened to this pattern by screws or otherwise, and kept constantly pressed against it as it is fed towards the cutters, it will follow the shape of the pattern and be worked to correspond with it. With some of the earlier machines this difficulty presented itself. If the spindles and collars were small enough to ad- mit of working in very small circles, when heavier work required large collars and longer cutters they were found too light ; so that heavy and light work could not be successfully run on the same machine. This difficulty was met by some of the manufacturers and obviated by making the main part of the spindles, as far as the top of the upper bearing, sufficiently heavy to admit of being bored into and tapped ; so that the part which projected above the table, and carried the collars and cutters, could be screwed into it. In that way, they were detachable, and any sized spindle or collar could be used. This improvement had not only the advantage of 178 HISTORY OF THE PLANING-MILL. allowing different-sized collars and spindles to be used upon the same machine, suitable for heavy or light work, but duplicate sets could be kept on hand ; so that, instead of changing and setting the cutters for every different style of work which presented itself, and which required considerable time to adjust the cutters, one set with cutters attached could be readily removed and another substituted in a few minutes: and in this manner, heads and cutters for ordinary work could be kept constantly on hand all set up and ready for use. The manner of raising and lowering the spindles so as to adjust the cutters to the work, in some of the earlier machines, was awkward and inconvenient. The workman was obliged to get under the table and screw them up from the bottom, which placed him in such a position that he could not see the work, and conse- quently had, in a great measure, to work by guess, which frequently involved the necessity of making sev- eral such attempts before the object was accomplished. Now all first-class machines of this kind are provided with hand- wheels at the side, within easy reach of the workman, where, by means of bevel gears and -screws, the spindles are readily adjusted to any point desired, the workman having his work and the cutters con- stantly in sight. The best and most practical machines of this kind have two spindles working in opposite directions and furnished with duplicate cutters, so that, if a piece of circular work is being stuck, one half may be worked upon one head and the other upon the opposite one ; thus enabling him to always work with the grain, and avoid slivering. As soine portions of the cutters for certain work HARD AND SOFT CUTTERS CONSIDERED. 1^9 necessarily project some distance beyond the collars, it requires considerable care in giving them a proper temper, so that they will stand. If too hard, they are liable to snap off; if too soft, they will be liable to bend : and in either case, they become useless until re- paired or replaced by new ones. A good medium temper is indicated by heating the tool slowly over a clean fire or a piece of red hot-iron, after being hardened and scoured bright, until the color changes to dark purple with a slight tinge of green. This has been found to be the best temper for this class of tools. If the steel is of a good quality and has not been over- heated, it will give it not only a fine cutting edge, but the greatest lateral strength. When mouldings or other irregular shapes are to be stuck on the face of irregular or crooked pieces, the operation is more difficult. With segments of circles of not too small a radius the most convenient way is to work them upon a common sticker. This may be accomplished by first dressing the outside to the circle required, and then attaching to the table of a common sticker a reversed form corresponding to its shape, so that, instead of being fed by the rolls in a straight line, the work will be forced to conform to the circle of the guide, and follow it in a curved line, instead of a straight one. If the form, as it is called, is so placed that the radius of the circle which it represents is par- allel with the line of the cutter-head, the moulding may be stuck with the same cutters, and will corre- spond in shape with those which are straight. l8o HISTORY OF THE PLANING-MILL. CHAPTER XXI. FRICTION— THE LA WS WHICH GO VERN IT— SLIDING CONTA CT— RE VOL VING CONTA CT — RESISTANCE ACCORDING TO WEIGHT, INDEPENDENT OF SUR- FACE IN CONTACT— ITS APPLICATION TO WOOD- WORKING MACHINERY. Friction is the resistance arising from one surface coming in contact with another and rubbing against it. It is the only force in nature which is perfectly inert, its tendency being always to retard motion. In some respects, it may be considered as an obstruction to the power of man and an obstacle in carrying out mechani- cal designs. But, like every other force in nature, it may, if properly managed and understood, be turned to advantage. While it may be an obstacle in the running of machinery, yet it is the chief source, after all, of the general stability of everything that requires to remain in a state of rest. The experiments of Rennie and M. Morin — the latter under the direction of the French government — have demonstrated certain fixed laws which govern it : First, when two flat sur- faces are pressed together without any lubricant, the amount of friction is in every case the same, and wholly independant of the extent of the surfaces in contact, so that, the force with which two surfaces are pressed together being the same, their friction is the same, whatever may be the extent of their surfaces in contact ; second, similar bodies excite a greater de- THE LAWS WHICH GOVERN FklCl'ION. l8l gree of friction than dissimilar ones ; third, with all hard substances, and within the limits of abrasion, fric- tion is in proportion to the pressure, without regard to time or velocity. All moving bodies in contact with each other are subject to three stages or conditions with regard to fric- tion : One is a state where there is no lubricant used ; another is a state in which a lubricant has been used but pressed out, so that the two surfaces come in inti- mate contact with each other ; and, lastly, where the pressure is Hght and the lubricant is sufficient to keep the surfaces entirely apart by a stratum of the same interposed between them. There is no rule established whereby the exact amount of loss by friction can be estimated, as the dif- ferent kinds of metals used in the construction of machinery all produce different degrees of friction ; be- sides, the great difference in the quality of the lubri- cant used often renders the loss double with one kind to what it would be with another. M. Morin estimates that, with' suitable metals in contact, and with a good lubricator, the loss is from 20 to 25 per cent of the force by which the bodies are pressed together ; or, in other words, if 2 sliding surfaces were pressed together with a force equal to 100 pounds, it would require from 20 to 25 pounds of power to put them in motion. And, according to the laws established by those tests, it would make no difference whether the bodies in con- tact have a surface of i square inch or 20; for with the same load and velocity, the friction would be the same, regardless of the surfaces in contact. , If a force or weight of 100 pounds be placed upon a 1 82 HISTORY OF THE PLANIMG-MILL. surface containing 20 square inches, then the pressure would be only 5 pounds to the square inch and the friction upon each square inch of surface would only be the one twentieth of what it would be provided the whole 100 pounds were placed upon i square inch. Again, if the 100 pounds were placed upon a surface containing but i square inch, this, h-r.ving to sustain 20 times the load of the former, will consequently have to overcome 20 times the resistance by friction ; and if moved at the same velocity, the liability of heat and abrasion would be increased 20 times. And when this condition commences, the loss by friction is indefinitely increased ; besides, the surfaces are rapidly cut away and the parts soon destroyed. In view of these facts, it is one of the most import- ant duties of the designer of machinery — and one that cannot be neglected — to so apportion every wearirig part of the machine, whether it be a sliding contact or a revolving one, that the surfaces in contact shall be in such proportion to the weight to be sustained that there will be no danger from heat and abrasion. So far reference has only been made to such parts or devices which produce a reciprocating motion. But the same laws are applicable to revolving bodies ; as, the journals and boxes upon which each part of a machine revolve. There is, however, a slight difference in the conditions under which a sliding and a revolving surface may work, which may produce different results. In a slid- ing surface, the power is supposed to be applied in a direct line with the two surfaces in contact ; so that in every case the power to move it is in proportion to the RESISTANCE ACCORDING TO WEIGHT. 1 83 weight — the friction being the same, without regard to the extent of the surfaces in contact, or the velocity with which they are moved. But this rule will not hold good with revolving shafts under the same conditions. For instance, if a shaft 2 inches in diameter, revolving in a bearing 6 inches long, sustaining a weight of 100 pounds, and driven by a 4-inch pulley making 1000 revolutions per minute, requires 25 pounds of the power applied to overcome the friction, no more power would be re- quired to overcome the same friction if the speed were increased to 2000 revolutions. Neither would the fric- tion be increased provided the box was increased to 10 or 12 inches in length; for it will be remembered "that with all hard substances within the limits of abrasion, friction is as the pressure, without regard to surface or velocity." Now, if the shaft were increased to 3 inches in diameter, with the same weight, and driven the same speed by the same sized pulley, the conditions would be changed, and more power required to overcome the resistance. While the frictional resistance would be the same in both cases unless the diameter of the pul- ley were increased in the same proportion, more resist- ance would be offered to the driving power in order to overcome the same friction and maintain the same speed. Hence, we say that with all revolving bodies, in order to comply with the laws of friction the power must in all cases be applied at the same proportional distance from the centre of that body. Long bearings, then, require no more power to drive them with the same load than short ones, as long as the same diameter of shaft is retained. But if the 1 84 HISTORY OF THE PLANING-MILL. diameter is increased in size, then a larger pulley will be required in order to retain the same leverage from the centre. This being the case, it is much more economical to use long bearings ; for the more space or surface that the weight is applied to, the less the pressure upon any one place and the more surface to wear upon. For instance, if a box has a superficial area of 8 square inches, and the weight of the body resting upon the shaft revolving therein is i6o pounds, it is evident that each square inch of surface between the shaft and the box will be pressed together with a force of 20 pounds. If the length of the box be increased with the same shaft so as to contain i6 square inches, then with the same load the two surfaces would be pressed together with a force of lo pounds to the square inch instead of 20 ; and as only one half of the pressure is brought to bear upon each square inch of surface, and there being just twice the number of square inches to sustain the whole pressure, it is evi- dent that, without any more loss by friction, the long box will wear just twice as long. Again, if, instead of lengthening the bearing, we shorten it so as to diminish the area from 8 square inches to 4, then each square inch of surface would be required to sustain a pressure of 40 pounds ; and if the same speed was maintained with the same load, the chances of injury arising from heat and abrasion would be increased in the same proportion. Builders of machinery are becoming aware of this fact, as may be seen by the increased length of the journals both in shafting and nearly every kind of RESISTANCE ACCORDING TO WEIGHT. 1 8$ machinery where there is any amount of work re- quired. Wood-working machinery is of that class in which, under its conditions of work and in the most favorable circumstances, the wear and tear is greater than in any other class of machinery. It is not only the high rate of speed that it is required to run but the dust and grit with which most of the lumber is covered, is a con- stant source of annoyance to the most careful opera- tor. Wood-working machinery requires to be stronger and more accurate than any other class of work. A slow-running machine may have a number of little im- perfections about it that may not manifest themselves for a long time ; but with a planing-machine or moulder, if there is any imperfections in the bearings or boxes, they will manifest themselves in a very few minutes after it is started. Perfect bearings and long boxes are requisite to a well-running and durable ma- chine ; and that manufacturers as a class begin to under- stand this, is evidenced by the improved condition of the journals and boxes of all modern-made wood- working machinery. 1 86 HISTORY OF THE PLANING-MILL. CHAPTER XXII. SHAFTING— ITS PROPORTIONATE SIZE AND SPEED— TORSIONAL STRENGTH CONSIDERED — METHOD OF TESTING — RULES FOR CALCULATING ITS STRENGTH— TABLE OF SIZE, VELOCITY, AND PO WER. The necessary shafting and pulleys also enter into the items of planing-mill machinery, and much depends upon the selection of the most suitable size, the proper speed for utility and convenience, and the economy of power. Some are partial to large shafting and moder- ate speed, while others go to the opposite extreme of very small shafting and high speed. Now there is always a medium which is best adapted to all cases. A line of shafting for planing-mill purposes should always be adapted to its work, and in a great measure depend upon the size of the mill and the number of machines to be driven from it. For planing-mill purposes, as all machines run at high speed, it is more economical to use a lighter shaft and run at high speed, as this enables each machine to take its power direct from the line without the use of large, cumbersome pulleys or intermediate counter- shafts, which are both expensive and objectionable. It is a well-known fact that speed is power ; and if a shaft 2 inches in diameter will safely transmit 15 horse- power at 100 revolutions per minute, that same shaft, if the speed were increased to 300 revolutions, would, with the same torsional strain, safely transmit about 43 horse-powen SHAFTING— ITS PROPORTIONATE SIZE, ETC. 1 8/ Taking the first cost of heavy shafting and pulleys into consideration, the extra labor in handling, with the wear upon the boxes caused by that extra weight, and there is no doubt but medium-sized shafting with light' pulleys running at a moderately high speed is the most economical in the end for planing-mill purposes. Some object to high speed on account of the fear that it might shake the building; but in the present advanced state of mechanical science there is no more necessity for shaking the building with a shaft running 300 or 400 revolutions per minute than there would be at 100, providing the shafts are straight and true, and the pulleys well balanced ; and no machinist at the present time who makes any pretensions to mechanical skill, or who values his reputation as such, would send out anything that was not so. In selecting the shafting for a mill or factory, the millwright or mechanical engineer who may be in- trusted with that part should have a thorough knowl- edge of the torsional strength of iron in order to make a proper and judicious selection. The amount of twist- ing strain that can be sustained by a shaft of a given size without permanent injury or displacement of the particles composing it have been variously estimated. Trautwine says, *' To compute the size shaft to trans- mit a given number of horse-powers, multiply the num- ber of horse-powers to be transmitted by 300 and divide the product by the number of revolutions per minute, and the cube root of this quotient will equal the size of the shaft." According to this rule, then, in order to transmit 50 horsepower from a shaft making 125 revolutions per 1 88 HISTORY OF THE PLANING-MILL. minute, it would require a diameter of 4^^7}- inches, thus: 300X50 -r- 125=120; the cube root of which is 4.93 inches. By the rule given by Scribner, the same shaft would require a diameter of 4j- inches. He says : " This rule comes from the highest authority and will give per- fectly safe results." There is no question, so far as the safety is con- cerned, for by this same rule a shaft 2\ inches in diame- ter would not be able to transmit but a trifle over 15 horse-power at a speed of 100 revolutions per min- ute. It would be a difficult matter to make any practical machinist or millwright, in the present state of the art, believe that this rule is anywhere near cor- rect, or that a shaft 2\ inches in diameter, at 100 rev- olutions per minute is not able to transmit with perfect safety from 25 to 30 horse-power. Being fully satisfied that those rules were not reliable, and desiring to arrive at some correct basis, a series of tests were instituted by the author, which were conducted in the following manner: Several pieces of iron were cut from the same bar, and a space 12 inches long turned on each one i inch in diameter. One end was secured in a strong vice, while the other was supported upon a centre so as to allow it to move freely. To this end was attached a lever, having a notch cut in it just 12 inches from the centre of the shaft. A suitable box for holding the weights was suspended from the lever at the notch by a bail provided for the purpose. The weight of the box be- ing known, the weights were carefully placed in the box so as not to produce a shock, and the deflection of TORSIONAL STRENGTH CONSIDERED.' 1 89 the lever carefully noted at each increase of the weight until the bar began to show a permanent set. By means of a cord and small pulley attached to the floor above, the box could be gently raised so as to re- lieve it from the weights, and note the deflections of the lever. With 400 pounds the deflection of the lever at the notch was i|- inches. But when relieved from the weight it returned to its original position. The load was then increased in the same manner to 420 pounds. The deflection of the lever was then nearly 2 inches, and when relieved of the load again it showed a permanent set in the bar of 4°. Tests were then made with other bars of the same size and length by applying the load suddenly. It was found that when 100 pounds were dropped suddenly upon it, the same deflection of the lever was shown that 400 pounds pro- duced when let down carefully and without any shock. Over 100 pounds applied with a shock produced a per- manent set in the bar. From these tests we arrived at the following facts : That where shafting is subjected to sudden shocks, as all shafting is liable to be by the throwing on of heavy belts in starting machines, one fourth of its ultimate strength is all that can be safely relied upon in practi- cal use. To reduce this to foot-pounds, or to a given number of pounds moved at the rate of I foot per minute, suppose the lever i foot long to represent a pulley of I foot radius or 2 feet in diameter ; and sup- pose I revolution per minute is taken for the unit of speed. Now the circumference of a pulley 2 feet in diameter is near enough to 6 feet in circumference for all practical purposes, so that the 100 pounds at each 1 90 HISTORY OF THE PLANING-MILL. revolution would be carried through a space equal to 6 feet per minute, which would be equal to 600 pounds carried through a space equal to i foot in the same time. Thus we find that a shaft i inch in diameter re- volving at the rate of i revolution per minute will transmit 600 pounds per minute, no matter what the., distance may be from the centre at which the power is applied in order to communicate it. For example, if the power be applied to a pulley 4 feet in diameter instead of 2, at each revolution of the shaft the load, whatever it may be, will be carried through double the space in the same time, and conse- quently requires but one half the force to produce the same effect. Therefore we divide this 600 pounds by the circumference of the pulley to find the force to be applied once every minute to obtain that result. Thus if the pulley were 12 feet in circumference, 600 -M2 = 50 pounds. So that 50 pounds applied to a pulley 4 feet in diame- ter making i revolution is equal to 100 pounds applied to a pulley 2 feet in diameter at the same speed. Again, if it were required to find the number of rev- olutions per minute that a shaft i inch in diameter should make to transmit a given power, divide the number of pounds contained in that power by the number of pounds which the shaft is capable of trans- mitting at I revolution per minute. If it be required to determine the number of revolu- tions per minute that a shaft i inch in diameter should make in order to transmit 2 horse-power, take the value of 2 horse-power and divide it by 600 ; thus : 33000 X 2 = 66000^600 =110 revolutions. TESTING TORSIONAL STRENGTH OF SHAFTING. I9I When the speed of a shaft i inch in diameter is given, to find its power multiply the speed of the shaft by its size and by 600, and divide by the value of i horse-power. Example : what power will be transmitted from a shaft I inch in diameter revolving at the rate of no revolutions per minute ? I X 1 10 X 600 -^ 33000 = 2 horse-power. The foregoing examples and rules are applicable to shafts I inch in diameter exclusively ; but now to apply the same rule to other sizes other conditions must be complied with. It is well-known to mechani- cal experts that the torsional strength of all round bars of iron of different diameters are to each other as the cube of their respective diameters ; but as the cube of I is I, there is no necessity for a proportional state- ment, and all that is required to apply the foregoing rules is to use the cube of the diameter instead of the real diameter. Hence, to find the power of any sized shaft when the size and speed is given, multiply the cube of the diameter by the number of revolutions per minute and that product by 600, and divide by the value of I horse-power. Example : What power may be transmitted from a shaft 2 inches in diameter at a speed of 1 10 revolutions per minute ? First, the cube of 2 is 8 ; then 8 X no X 600 = 528000 -=- 33000= 16.3 horse-power. When the diameter of the shaft and the power re- quired are given to find its speed, first multiply the given power by the value of i horse-power to obtain the number of foot pounds required per minute, and 192 HISTORY OF THE PLANING-MILL. then divide by 600, (the unit of foot-pounds for i inch), and the cube of the diameter of the shaft the quotient will equal the number of revolutions per minute. Example : At what speed should a shaft 2 inches in diameter run in order to transmit 16 horse-power? First, 16 X 33000 = 48000 foot-pounds per minute re- quired. Then as 600 is the unit for i inch, 48000 -^ 600 = 880 pounds, the strength of the shaft, or the num- ber of foot-pounds which it is able to safely transmit. Now if the last number be divided by the cube of the diameter of the shaft the quotent will equal the speed — 88o-r-8=iio revolutions. When the power and speed are given to find the size of the shaft, first asertain the number of foot- pounds which are required in order to obtain that power. This is obtained by multiplying the given power by the value of i horse-power ; then this product divided by the number of revolutions per minute given represents the number of foot-pounds that may be transmitted at each revolution, and as 600 pounds to the revolution is the unit, by dividing by this num- ber we obtain the cube of the diameter of a shaft capable of transmitting that power at the given rate of speed the cube root of which is the diameter required. Example : The diameter of a shaft is required which will transmit 16 horse-power at a speed of 100 rev- olutions per minute: 16x33000=528000-^-110=: 4800 -^ 600 = 8 cube root of 8 = 2 inches. From the foregoing tests and examination of this subject, we have been able to formulate the following rules: Case i. When the diameter of a shaft is given, HOW TO CALCULATE STRENGTH OF SHAFTING. 1 93 and the power it is required to transmit to find its speed. Rule : Multiply the given power by 33000 and divide that product by 600; this quotient divided by the cube of the diameter of the shaft will equal the speed in revolutions per minute. Case 2. When the diameter and speed of a shaft are given to find its power. Rule : Multiply the cube of the diameter by 600, and that product by the number of revolutions per minute and divide by 33000 : the quotient will equal the number of horse-power. Case 3. When the power required and the speed of a shaft given, to find its diameter. Rule: Multiply the given power by 33000; divide this product by 600 and the speed of the shaft in rev- olutions per minute. The cube root of this quotient will equal the diameter. To familiarize the reader with the foregoing rules, the following promiscuous examples are given : What power may be transmitted from a shaft 2^ inches in diameter running at a speed of 300 revolutions per minute? The cube of 2^ is 15.6; then 600 X 15.6 X 300 -^ 33000 = 85 horse-power. Required the power that may be transmitted from a shaft 3 inches in diameter at 150 revolutions per min- ute. 3 X 3 X 3 = 27 (the cube of the diameter) ; then 27 x6oo X 150-r- 33000 = 73.63 horse-power. How many revolutions per minute must a shaft 3 inches in diameter make in order to transmit 90 horse- power? 90 X 33000 -^ 600 -i- 27 = 183.33 revolutions. How many revolutions per minute should a shaft 2 194 HISTORY OF THE PLANING-MILL. inches in diameter make in order to transmit 25 horse- power? 25 X 33000 -^ 600 ^8 =: 171.87 revolutions. What is the required diameter of a shaft that will transmit 180 horse-power a speed of 120 revolutions per minute? 180 -J- 33000 -^ 6oo -H 120 =: 82.5, the cube root of which is 4 35 inches. What sized shaft would be required to transmit forty-eight horse-power at three hundred and thirty revolutions per minute? 48 X 33000 -\- 600 -^- 330 = 8 cube root of 8 = 2 inches. In the application of the foregoing rules, torsional strength is all that has been taken into consideration. There are, however, other things to be taken into con- sideration in connection with this subject, before de- ciding upon the most suitable sized shafting for a mill. It often becomes necessary to place a pulley or gear that may be required to transmit a large portion of the power to another shaft, and that pulley or gear may be required to be placed in the centre of the shaft between the bearings ; and while the torsional strength maybe amply sufificient to perform the work, the trans- verse strength may not be sufficient to prevent it from springing sidewise. This, however, may always be remedied by either using a larger piece of shaft at this particular place, or by adding another bearing close to the pulley or gear, as the case may be : but the latter is always preferable when it can be conveniently done. One of the mistakes often made in arranging for shafting is a proper distance between the bearings. Cases are often met with in the same mill where there may be two or three lines upon different floors, each HOW TO CALCULATE STRENGTH OF SHAFTLNG. I95 of different size, yet the distance from centre to centre of the bearings are all about the same. This is not good practice ; for while the sizes of the different lines may be in good proportions according to the amount of labor they are required to perform, the distance from centre to centre should also be in proportion to the size : otherwise they will be deficient in laterall strength. The transverse strength of all-round bars of iron of different sizes, but of the same length, is in proportion as the square of their diameters ; consequently shafts of smaller diameter require less distance between bearings, in order to retain their lateral strength, than larger ones. The most practical rule that can be adopted and coincide with this is to take three times the diameter of the shaft in inches for the same number of feet between the centres of the bearings. Thus a shaft three inches in diameter would require nine feet from centre to centre of the bearings, while one of two inches diameter would require six feet — and so on. The proper length of bearing is another con- sideration, and in ordinary practice should not be less than three diameters of the shaft. In special cases, where there is an unusual stress, the length may be in- creased to four diameters. A large amount of power is frequently lost in many mills by the use of imperfect shafting. To run well and economize power, a Hne shaft should be perfectly straight and true ; all pulleys (and gears, if any are used) should be perfectly balanced, so that when the whole is put up and the bearings oiled, a line 100 feet long should be readily turned by hand by taking hold 196 HISTORY OF THE PLANING-MILL. of one of the pulleys. But if put up imperfect, out of line with pulleys, not well balanced, several horse- power will be required to overcome the frictional resistance. The following table shows the number of horse-power that may be safely transmitted by shafts from one inch to six inches inclusive, at speeds from 100 to 300 revolutions per minute, compiled from practical tests by the author. SIZE, VELOCITY, AND POWER OF SHAFTING. IQ/ TABLE I. Number of Revo- lutions. lOO "5 H. P. 150 175 200 225 250 275 300 Diameter of shaft in inches. H. P. H. P. H. P. H. P. H. P. H. P. H. P. H. P. I i.8i 2.27 2.72 3.18 3-63 4.09 4-54 5.00 5.45 li 2.58 3.22 3.87 4-51 5.16 5.80 6.45 7.10 7-74 li 3.54 4-43 5-31 6.20 7 09 7-97 8.86 9-74 10.39 I| 4.72 5-90 7.09 8.27 9-45 10.63 II. 81 13.00 14.18 li 6.12 7.66 9.19 10.72 12.26 13-79 15.32 16.85 18.39 If 7.80 9-45 11.70 13-65 15.60 17-55 19.50 21.44 23.40 If 9-74 12.17 14.61 17.18 19.48 21.91 24-35 26.78 29.22 I| 12.53 15-62 18.75 21.87 25.00 28.12 31-25 34.37 37-50 2 14.50 18.12 21.75 25.37 29.00 32.62 36.25 39.87 43.50 2i 17.40 21.75 26.10 30.45 34-80 39-15 43.50 47.85 52.20 2i 20.70 25.87 31.05 36.22 41.40 46.53 51.75 56.92 62.10 2| 24.30 30.37 36.45 42.52 48.60 54.67 60.75 66.82 72.90 2i 28.40 35-50 42.60 49.70 56.80 63.90 71.00 78.10 85.20 2f 32.80 41.00 49.20 57.40 65.60 73.80 82.00 90.20 98.40 2f 27.80 47-25 56.70 66.15 75-60 85.05 94.50 103.95 113.40 2l 43 -20 54- 00 64.80 75-60 86.40 97.20 108.00 116.80 129.60 3 49.00 61.25 73-50 85-75 98.00 110.25 122.50 134.75 147.00 3i 62.40 77.90 93.60 109.20 124.80 140.40 156.00 171.60 182.20 3i 77.90 97.37 116.85 135-32 155-80 175.27 194-75 214.22 233.70 3f 95.80 119-75 143.70 167.65 191.60 215.55 239-50 263.45 284.40 4 116.30 145-37 174-45 203.52 232.60 216.67 290.75 319.82 348.90 4i 139-50 174-37 209.25 244.12 279.00 313-87 348.75 388.62 418.50 4i 165.60 207.00 248.56 289.80 331.20 372.60 414.00 455.40 496 . 80 4f 194.80 243-50 291.20 340.80 389.60 438.30 487.00 535-70 584.40 5 227.20 284.00 340.80 397.60 454.40 511.20 568.00 640 . 80 681.60 5i 302.00 377.50 453- 00 528.50 604 . 00 679.50 755-00 830.5o'9o6.oo 6 392.00 490.00 588.0 686.0 784.0 892.0 980.0 1078.0 1176.0 198 HISTORY OF THE PLANING-MILL, CHAPTER XXIII. THE SELECTION OF BELTING— THE IMPORTANCE OF THE AIILL BEING PROPERLY BELTED— LEATHER BELTING BEST ADAPTED FOR 7 HIS PURPOSE- RULES FOR CALCULATING THEIR POWER— HINTS FOR THEIR CARE AND MANAGEMENT— OILS NOT - SUITABLE — DOUBLE BELTS; TABLE SHOWING THEIR POWER. Much of the comfort and economy in the manage- ment of planing-mill machinery arises from having a mill properly belted. With the high speed at which they are required to run, and the liability of becoming saturated more or less with oil and often subjected to chafing more or less, leather has been found the only practical material that should be used for this purpose. Oak-tanned leather belts, cut as near the back of the hide as possible, should be selected ; they should have short laps and be strong, and of even thickness and well put together. While almost everything pertaining to machinery has fixed rules whereby the strength and power may be calculated, it is a fact that there are no reliable rules whereby the power of a leather belt may be cal- culated with any degree of certainty. We would not wish to be understood as saying that there are no rules : on the contrary, there are plenty of them. Every belt-manufacturer who publishes a catalogue of his work has a set of rules of his own ; but the trou- IMPORTANCE OF PROPER BELTING. 1 99 ble is, no two agree upon the same thing : according to one, a belt six inches wide, with a given speed and stress, should transmit eight horse-power; while another would give to the same belt, under the same condition, ten. We have endeavored to harmonize these rules, and, if possible, discover some true bases to work upon, but confess we have failed to do so. Being con- vinced that the power of a belt is simply a question of friction between the under side of the belt and the face of the pulley, produced by the tension or stress upon it, it would seem that all that was required was to de- vise some plan whereby, with a certain stress and under certain conditions, that friction could be meas- ured and then reduced to some fixed rules that would be at least approximately correct. For the purpose of making these tests, two iron pul- leys twenty inches in diameter and of 4-inch face were selected. These, after being bored and turned both to the same size, were balanced and fitted upon a shaft and secured by keys. This shaft was then suspended upon centres prepared for the purpose, so as to be free to turn with the least amount of friction. One end of a strap was fastened to the face of one pulley, and passed around it, while to the other end a bucket was attached and suspended to receive whatever weight might be required. A piece of leather belt of the average thickness, one inch wide, was secured to the floor by one end, while the other was passed over the pulley in the opposite direction, so as to embrace just one half of the circumference, and a similar bucket at- tached to it. One hundred pounds, including the weight of the bucket, was then applied. Weights were 200 HISTORY OF THE PLANING-MILL. then placed in the first-mentioned bucket until the fric- tion of the belt was overcome and the pulley began to slip under it. This was so regulated by small weights that after repeated trials the descent of the bucket would average one foot per minute. This was quite a delicate matter, and only accomplished after repeated trials. The first bucket, containing the weights, was then detached and weighed, with its contents, and found to equal 40 pounds. A piece of 2-inch belting was then substituted for the i-inch, and, with the same weights, gave the same results. The weight in the first bucket was then increased to 200 pounds and the friction arising from the second overcome, as be- fore, by adding weights; 80 pounds were then re- quired to produce the same result. Tests were then made in the same manner with 3 and 4-inch belts, and all gave the same results, viz. : that the fric- tional power of a leather belt embracing one half of the circumference of a cast-iron pulley is equal to y^o^ of its stress, regardless of its width. Tests were also made with new belts which had been used but a few days, as well as those which were old and filled with grease. The new ones, when first applied, gave a trifle less than 40 per cent ; those which had been used a few days gave a small fraction over, while the old ones showed considerable over that amount, but broke so frequently that their real frictional value could not be obtained with any degree of certainty. Those tests established this fact : that if the fric- tional power of a leather belt moving at the rate of i foot per minute is 40 per cent of the stress, with a stress of 100 pounds, moving at the rate of i foot per HOJV TO CALCULATE POWER OF BELTING. 201 minute, 40 pounds of efficient force is all that can be realized from it. But if the stress be increased to 400 pounds and still moving at the same rate, 160 pounds of useful effect will be returned. Again, if the stress remains the same and the speed be increased to 2 feet per minute, then the power re- turned in frictional force per minute will be doubled. Hence, with equal stress, the frictional power per minute increases directly as the speed, and with equal speed it increases directly as the stress. From these two propositions we are able to adduce the following rule : When the stress is known, to find the power multiply the speed of the belt in feet per minute by .40 of the stress in pounds, and divide by 33,000. Example : Assume the stress upon a leather belt to be 600 pounds and the speed 2,000 feet per minute. First, 40 per cent of 600 is 240 \ then 240 X 2,000 = 480,000 and 480,000 -j- 33,000 = 14.28 horse-power. Now, this power may be obtained from a belt 8 inches wide, or from one 12, provided the stress is the same, and the belt strong enough to withstand it ; for the resistance of belts to slipping, with equal stress, is independent of their width, and there is no advantage, in a frictional point of view, derived from increasing the width beyond that which is required to resist the tension without material injury. It must not be as- surfied, however, that, because a belt i inch wide may sustain a weight of 350 pounds, it would be good prac- tice to run a belt of that width at any such tension, for the reason that the fibres of the leather would soon 202 HISTORY OF THE PLANING-MILL. become detached from each other by the continued strain, and thereby become worthless. Durability must always be taken into consideration, as well as quantity of work to be performed in a given time. A small horse may be compelled for a short time to draw a heavy load : but by constantly over- taxing his abilities, his enegies soon become exhausted and render him worthless ; while a much heavier and stronger animal would perform the same work from day to day without material injury. So with a belt : the wider it is with the same stress the less the strain upon each inch in width. If 1200 pounds stress were put upon a six-inch belt, each inch would be required to sustain 200 pounds ; whereas, if the whole stress was 600 pounds, then there would only be loopounds to be sustained by each inch in width ; and it needs no argument to show that with a stress of 60 pounds or 100 pounds to the inch, that the belt would last much longer than it would with double that strain. Therefore within reasonable bounds the wider the belt the longer it will last. There is one difificulty that presents itself in calculat- ing the power of a belt, and that is to determine just what the tension is, or what it should be. Some claim that the average tension should be 200 pounds to the inch in width, but it is very doubtful whether driving, belts as a rule are ever submitted to any such tension, or more than half of it. If so, a belt 12 inches wide should be constantly submitted to a strain equal to 2,400 pounds, or nearly \\ tons weight : it is a ques- tion of considerable doubt whether it would stand a weight of that amount suspended from one end of it now TO CALCULATE POWER OF BELTING. 203 for any length of time without permanent injury to the fibres of the leather. From extensive observation I am led to believe that the average stress upon driving belts as a rule does not exceed lOO pounds to the inch in width. It is true that when running a large portion of the stress is upon the driving side ; but even then, except under peculiar conditions, I doubt whether a strain of 200 pounds to the inch in width is ever attained. The stress of a belt may be approximately obtained, however, by calculating the stress required to give a frictional force equal to a given power, and by assum- ing a certain width ; then if the belt, when put to use, performs the work in a satisfactory manner without slipping, it is reasonable to suppose that the tension is not less than a given number of pounds. Practical experience has proved that if a belt will perform the required work when running slack, it will last much longer than one of less width with double the tension. Extremes in this as well as in every other case' should be avoided. If a belt is run so slack that it is constantly flapping about, the sudden jerks are not only detrimental to the belt itself but to the machinery and shafting attached — especially so with planing-mill machinery. In selecting a driving-belt, and determining its width, there are always certain conditions to be con- sidered and complied with: First, the amount of power to be transmitted ; second, the speed of the line shaft and size of the pulley required. This, when the power is steam, must be determined by the speed of the engine and size of the band-wheel. When these 204 HISTORY OF THE PLANING-MILL. points are settled, the width of the belt may be determined according to the diameter of the pulley : a small pulley at the same speed requires a wider belt in order to obtain the necessary frictional surface. In ordinary practice it is well to run the line-shaft about 300 revolutions per minute in order to avoid loading it down with large heavy pulleys, and also to enable those machines which have counter-shafts at- tached to be driven direct from the line, thereby avoid- ing the use of intermediate shafts as far as possible. At 300 revolutions per minute, with good bearings and well balanced pulleys, there is no objection to that speed, or even more, if necessary. Suppose after all these points are settled the result should be as follows : An engine of 60 horse-power is required, the band-wheel of which is 8 feet in diameter, and is required to make 150 revolutions per minute. To accommodate the greater number of machines, the line-shaft is required to run 300. From this data the diameter of the driven pulley for the line-shaft and width of the belt must be calculated. As the size of the main pulley must be in proportion to the band-wheel, as its speed we have this proportion : 300 : 150 :: 8:4; consequently the diameter of the main pulley must be 4 feet. Now as the circumference is equal to the diameter multiplied by 3.1416, in order to find the speed of the belt in feet per minute the diameter must be multipHed by this number, and the speed or number of revolu- tions per minute ; for it is evident that the belt must pass over the whole circumference of the pulley 300 times per minute in order to make 300 revolutions in SELECTION OF BELTING. 20$ that time; then 4 X 3.1416 X 300 = 3769.92 feet per minute. Now the tension of the belt to produce a frictional force upon the face of the pulley sufficient to equal 60 horse-power must be computed. As the unit for i horse-power is a force equal to 33,0CXD pounds, moved at the rate of i foot per minute, 60 horse-power must be multiplied by that number; then 33,000 x 60 = 1,980,- 000 pounds of frictional force, which must be applied once in every minute. The stress upon the belt, as we have already found, is proportional to the frictional power as 100 is to 40 ; so that in order to find that stress we say 40 : 100 :: 1,950,000: 4,950,000 pounds : then 4,950,000 -~ 376.992 (the speed of the belt in feet per minute) ==1313 pounds, which must be constantly applied; or, in other words, 13 1 3 pounds is the whole stress that is constantly applied to the belt, and without any allowance for ex- tra shocks in starting, etc., a belt 13I- inches wide would give that power by the foregoing rules already given. But to allow for this and other contingencies which are liable to arise, one of 16 inches would be preferable. In selecting belts, those of even thickness, with mod- erately short laps, and well riveted, should be chosen. A good way to test the quality of the leather is to bend it short towards the flesh side. If the material is poor or been injured in the process of tanning, it will show fine cracks when submitted to this test. If the material is good, it should be soft and pliable and bend short without showing any signs of cracks in the grain. Some manufacturers recommend running the grain 2o6 HISTORY OF THE PLANlNG-MILL. side next to the pulley, thereby claiming a much greater percentage of power with the same stress. While there is no doubt that this is the proper way to run a belt, the tests made do not warrant any such results. The reason for running the grain side next to the pulley is, there is more strength in the flesh side than there is in the grain; and that part of the belt which possesses the greatest tensile strength should be sub- jected to the least wear. This may be demonstrated by splitting a piece of belt leather exactly in the centre and submitting each part to a breaking strain, when it will be found that the part next to the flesh side will require nearly double the strain to part it as the other. So that a belt run with the grain side next to the pulley, when worn down to nearly one half of its original thickness will retain more than three quarters of its original strength, unless otherwise injured ; while the same belt run with the flesh side to the pulley will give out and break long before it reaches that condition. Another reason is that the best of belts, and those that are soft and pliable when new, after being used and exposed to the fine dust that is constantly settling upon them, soon absorb the oil, rendering them hard and dry ; then if run over small pulleys with the grain side out, they become filled with fine cracks, which ma- terially impair their strength. When belts become hard and dry,' they are not only more liable to crack, but as they do not adhere to the pulleys, and are constantly slipping more or less, the heat generated by the friction burns them so as to im- pair their strength, and in a short time renders them \ CARE AND MANAGEMENT OF BELTING. 20/ worthless. When such is the case, it is the common practice in many mills to pour on any kind of oil, rub on soap and rosin, or, in fact, anything convenient to prevent them from slipping. This is all wrong. If the belt is too slack, stop and take it up ; for it is much cheaper to stop for half an hour than to spoil a belt worth forty or fifty dollars. Lubricating-oils such as are in general use contain more or less mixtures of hydro-carbon, which is detri- mental to leather. Lard-oil is also injurious, from the fact that it contains a large percentage of margaric acid. There are also many patented articles under various names of stuffing, for softening and preserving belts, which are advertised and hawked about ; and if mill-owners would believe one-half the stories which are told by drummers for those articles, they would believe that a belt would never get old, wear out or break as long as they continued the use of their prep- aration. Now, the basis of nearly all of these compounds — all, so far as they have been examined is — either petroleum in some of its numerous forms, or some other hydro- carbon mixed with neatsfoot oil or something worse, and totally unfit for this purpose. Tallow seems to be the only material that is natural to leather, but should never be applied to a belt when dry and covered with dust, for this reason : The solid fats of all animals are composed of three elements, viz ; stearine, margarine, and oleine. Margarine contains a large percentage of margaric acid, which must be kept out of the belt as far as pos- sible, The proper manner to tr^at a belt when it be- 208 HISTORY OF THE PLANING-MILL. comes hard and dry, and to exclude the greater por- tion of the margarine, is to take it off and lay it upon a clean floor ; then, with soap and warm water, thoroughly cleanse it, and, if necessary, scrape it until the surface on both sides is perfectly clean ; then prepare some clean tallow by melting it, and, with a brush, apply a thick coat upon the flesh side while it is just soft enough to spread well and while the belt is wet, and then leave it until it becomes perfectly dry. The stearine and margarine are both insoluble in water, and will not enter the pores of the leather while it is wet. Margarine has a greater affinity for stearine than it has for oleine ; consequently, it remains on the outside and becomes hard before the leather becomes dry enough to absorb it ; while the olein, which has a greater affinity for the leather, seperates from the other ingredients, and, as the water evaporates gradually, as- sumes its place, leaving the other two on the outside in the form of a white substance much harder than tal- low, which may be readily scraped off. Belts treated in this manner about once in six months will be as soft and pHable as new, and retain their strength until worn out. Many object to this process of taking off their belts and wetting them, because they shrink up so that it requires an unreasonable tension to replace them. This may be avoided by fastening the belt to the floor by means of clamps before washing it. To formulate rules for determining the length of a belt may to some appear quite superfluous. This may be the case in many instances — perhaps so in the nia- CARE AND MANAGEMENT OF BELTING. 209 jority which come within the range of ordinary prac- tice. When everything in the mill is favorable, — the coun- ter-shafts, if any, all up, and the pulleys on the line- shaft, together with all the machines that are to be driven from it in their respective places, then with a good tape-line, the length of each belt, whether crossed or straight, may be easily obtained by measurement. This condition of things, however, does not always exist. It is sometimes necessary to determine the length of some of the belts, especially the large drivers, before the shafts and pulleys are in position. The distance between centres, and the size of the pulleys may be obtained from the drawings. Much time may be saved in this way, especially if the belts are made to order and shipped from a distance. Crossed belts should be avoided as far as possible, especially if there is considerable difference in the diameters of the pulleys and the distance between centres limited to a short space. In such cases the cross will' occur so near the small pulley that the ten- dency to run off will require the constant use of a belt- shifter or some other device to keep it on the pulley, The chafing upon this, with the friction upon the belt where they cross each other nearly edgewise, under such conditions will soon destroy it. When pulleys are nearly of the same size and the distance between centres considerable, the cross will occur nearer the centre of the space between them, and the two surfaces cross each other nearly flatwise and with but little friction. Under such conditions, a cross-belt is not so objectionable. 2IO HISTORY OF THE PLANING-MILL. The rule for calculating the length of an open belt when the distance between centres and the size of the pulleys are known, is very simple : To twice the distance between the centres, add one half the circumference of each pulley, with three times the thickness of the belt. Example : Suppose the distance between the centres of two shafts is 14 feet, the diameter of one pulley is 8 feet and the other 4, and. the thickness of the belt is \ inch. Then one half the circumference of the 8-foot pulley is 12.5664 feet. One half the circumference of the 4-foot pulley is 6.2834 feet. Three times the thickness of the belt is f inch, or .0625 feet ; then 28 -|- [2.5664 4" 6.2834 + .0625 = 46 feet \o\\ inches. To find the length of a cross-belt, the rule is more complex, and when the pulleys are in position and can be conveniently reached, it is much easier to determine their length by the tape line. If not, the following rules are applicable and will give correct results. First, the distance from the centre of each pulle}^ to the centre of the point where they will cross, must be obtained. If both pulleys should happen to be the same diameter, the cross will occur exactly in the centre of the space between them. If not, then that point will be in proportion to their respective diam- eters, and may be found by the following rule : Divide the diameter of the larger pulley by that of the smaller, and add one to the quotient. This will represent the number of parts into which the distance between centres is supposed to be divided into. Then as the whole number of parts is to the number of parts taken by the larger pulley, so is the whole distance RULES FOR MEASUREMENT OF BELTING. 211 between the centres to the point where the cross will occur. Example : A pulley 8 feet in diameter is to drive one of 4 with a cross-belt i inch thick, the distance between centres being 14 feet ; required, the distance to the point where they will cross, and the whole leno-th of the belt. First, find the point where they will cross, by the fore- going rule : 8-^-4 = 2+1 = 3. This represents that the 14 feet are supposed to be divided into three parts ; and as the diameter of the small pulley is contained in that of the larger one twice, it shows that two parts of the three must be taken by it : then, 3 : 2 :: 14 : 9^4'' Now as the whole distance is 14 feet, and the large pul- ley requires 9 feet 4 inches, the distance from this point to the centre of the smaller pulley will be 4 feet and 8 inches. So that the distance from the centre of the large pulley to the point where the belt will cross is 9 feet 4 inches, while the other from the same point will be 4 feet 8 inches. If a horizontal Hne be drawn through the centre of each pulley, extending from one to the other, and a perpendicular one also drawn through the same points, intersecting it at right angles, there will be two right, angled triangles formed— the base of one being 9 feet 4 inches, with a perpendicular equal to the radius of the 8-foot pulley, or 4 feet, while the other base will be equal to 4 feet 8 inches with a perpendicular equal to the radius of the 4-foot pulley, or 2 feet, the belt in each case representing the hypothenuse ; and as the square root of the sum of the squares of the base and perpendicular of any right-angled triangle equals 212 HISTORY OF THE PLANING-MILL. the hypothenuse, it is evident that the hypothenuse of these two figures must represent the length of belt between these two points. The operation perhaps will be more simple and easier understood if the whole be reduced to inches. Then 112 x 112 == 12544 inches ; and 48 X 48 = 2304 inches being the square of the base and perpendicular in inches, then 12544 -|- 2304 = 14848, the square root of which is 121.85 inches. With the other proceed in the same manner : 56 x 56 = 3136 and 24 x 24 = 576, and 3 1 36 -|- 576 = 3712, the square root of which is 60.92 inches. Now if each of these sums be doubled, and one half the circumference of each pulley with three times the thickness of the belt be added together, their sum will be equal to the whole length of belt required in inches, which, when reduced to feet, will be found to equal 48 feet and ij- inches. Much has been said in favor of double belts, convey- ing the idea that they are not only stronger, but will transmit more power with the same stress. That there is more tensile strength in a double belt if made of equally good stock than in a single one, there is no doubt. But as far as frictional power under the same stress is concerned, the tests which have been made with both do not show any difference worth speaking of. In certain cases a douHe belt may trans- mit more power than a single one, but it is owing to the greater stress put upon it, either directly or by the extra weight — especially if running horizontally, or nearly so, with the slack side running towards the top DOUBLE BELTS. 213 of the driven pulley. The sag causes it to embrace a greater arc and cover more surface of the pulley. . There are objections to double belts which more than counterbalance their advantages. One is, that the stock generally used is apt to be thin and soft, and of an inferior quality. But the greatest objection is that even if they are made of good, solid stock, the uneven strain upon the two thicknesses which compose it has a tendency to tear them asunder. When two pieces of leather of even thickness and length are cemented and united by rivets, if strained around the surface of a pulley they cannot remain so : the outside piece must stretch' or the inside one contract. In either case the tendency is to separate. To illustrate this : Suppose a pulley 4 feet in diameter, the circumference of which would be 150.734 inches. Now if this pulley were entirely surrounded by a single piece of leather -f^ inch thick, it would require 151.734 inches in length to surround it ; and the diameter of the pulley, including the leather, would be increased by twice the thickness of it, and the circumference would be increased to 152.76 inches. Now surround this again by another piece of the same thickness, and it will require 153.69 inches; so that the difference in length of the two pieces of leather would be equal to 1.96 inches. But as the belt is supposed to embrace only one half of the circumference of the pulley, the real difference would be about one half, or one inch ; but if the same belt passed over another pulley, — ^.hich is al- ways the case, — then the difference would r mount to 2 inches, provided the pulleys were both the same size. Now it is evident that if these two pieces were cut 214 HISTORY OF THE PLANING-MILL. the same length and riveted together, when strained around the half-circumference of each pulley one piece must contract or the other stretch sufficient to make this difference in the length. If the belt remained at rest after being bent around the pulley, it would be dif- ferent. But this is not the case. As soon as it leaves the pulley and becomes straightened out again both parts must resume their former relation to each other, and become of the same length. This constant unequal strain must have a tendency to break the cement and tear out the rivets in a short time, which is usually the case. If it is absolutely necessary to use a double belt, it is better toiise two single ones, one running outside of the other, with independent lacings, and having no con- nection with each other. When run in this manner, it will be noticed that the position of the outside belt with reference to the other will be changed at every revolution, and in a short time it will make a complete revolution around it. Belts run in this manner will work better, last longer, and give as much power, with no more trouble, as a double belt made in the ordinary manner. The following table shows the horse-powers belts are capable of giving at a stress of lOO pounds to the inch, in width from i to 24 inches inclusive, and at speeds from 100 to 3000 feet per minute. The ratio of f'-iction is taken at 40 per cent of the stress. This tabic is calculated from tests made by the au- thor, and intended expressly for this work ; VARIOUS HORSE-POWERS OF BELTS. 215 TABLE II. Feet Width in inches. per min. I in. 2 in. 3 in. 4 in. 5 in. 6 in. 7 in. 8 in. g in. 10 in. II in. 12 in. H. P. H. P. H. P. H. P. H. P. H. P. H. P. H. P. H. P. H. P. H. P. H. P. 100 .121 1 .242 .263 .484 .606 .727 .848 -969 1.09 1. 21 1-33 1-45 200 .242; .484 .727 .968 1. 21 1-45 1.69 1-93 2.18 2.42 2.66 2.90 300 ■363 .926 i.oS 1-45 1. 81 2.18 2-54 2.90 3-27 3-63 3-99 4 35 400 .484 .768 1-45 1-93 2.42 2.90 3-39 387 4-36 4.84 5-32 5.80 500 .605 1. 21 1. 81 2.42 3-03 363 4.24 4.84 5-45 6.05 6.65 7-25 600 .726 1.40 2.17 2.90 3-63 4-36 5-o8 5.81 6.54 7.26 7-98 8.70 700 .847 1.69 2-54 3 38 4.24 5.08 5-93 6.78 763 8-47 9-31 10.15 800 .968 1-93 2.90 3.87 4.84 5.81 6.78 7-75 8.72 9.68 10.64 11.60 900 1.08 2.17 3.26 4-35 5-45 6.54 7-63 8.72 9.81 10.89 11.97 13-05 1000 1. 21 2 42 3-63 4.84 6.06 7.27 8.48 9.69 10.90 12.10 13-30 14.50 1100 1-33 2.66 3-99 5-32 6.66 7-99 9-32 10.65 11.99 13-31 14.63 15-95 1200 1-45 2.90 4-35 5.80 7.27 8.72 10.17 11.62 13.08 14.52 15.96 17.40 1300 1-57 3-14 4.71 6.28 7.87 9.44 1 1. 01 12.59 14.17 15-73 17.29 18.85 .1400 1.69 3-38 5.08 6.76 8.48 10.16 11.86 13-56 15.26 16.94 18.62 20.30 1500 1. 81 3-69 5-44 7-25 9.08 10.89 12.71 14-53 16.35 18.15 19-95 21-75 1600 1-93 3.86 5.80 7.62 9.68 11.62 13-56 15-50 17-44 19.36 21.28 23.20 1700 2.04 4.10 6.16 8.22 10.39 12.35 14.41 16.47 18.53 20.57 22.61 24.65 1800 2.16 4-34 6.52 8.70 10.90 13.08 15.26 17.44 19.62 21.78 23-94 26.10 1900 2.29 4-59 6.89 9.19 II. 51 13.81 16.11 18.41 20.71 22.99 25.27 27-55 2000 2.42 4.84 7.26 9.68 12.12 14-54 16.96 19.38 21.80 24.20 26.60 29.00 2100 2-54 5-o8 7.62 10.16 12.72 15.26 17.80 20.34 22. 8g 25.41 27-93 30-45 2200 2.66 S-32 7.98 10.64 13-32 15.98 18.64 21.30 23.98 26.62 29.26 31.90 2300 2.78 5.56 8.35 II. 12 13.89 16.71 19.48 22.24 24-77 27.83 30.59 33-35 2400 2.90 5.80 8.70 II 60 14-54 17.44 20.34 23.24 26.16 29.04 31.92 34.80 2500 3.02 6.04 9.06 12.08 15-14 18.16 21.18 24.21 27-15 30.25 33 25 36.25 2600 3-14 6.28 9-4'2 12.56 15-74 18.88 22.02 25.18 28.34 31.46 34-58 37.70 2700 3-26 6.52 9-79 13.04 16.35 19.60 22.87 26.15 29-33 32.67 35-91 39-15 2800 3-38 6.76 10. 16 13-52 16.96 20.23 23-72 27.12 30-52 33-88 37-24 40.60 2900 350 7.07 10.52 14.01 17-56 21.05 24-57 28.09 31.61 35-09 38-57 42.05 3000 3.62 7-38 10.88 14.50 18.16 21.78 25-42 29.06 32.70 36.30 39-90 43-50 2l6 HISTORY OF THE PLANING-MILL. TABLE II.— Concluded. Feet ! Width in inches. per min. 13 in. 14 in. 15 in. 16 in. 17 in. 18 in. ig in. 20 in. 21 in. 22 in. 23 in. 24 in. H. P. H. P. H. P. H. P. H. P. H. P. H. P. H. P. H. P. H. P. H. P. H. P. 100 1-57 1.69 1. 81 1.94 2.06 2.18 2.30 2.42 2-53 2.66 2.78 2.90 200 3-14 3-38 3.62 3-87 4.12 4-36 4.60 4.84 5.06 5.32 5-56 5.80 800 4.71 5-07 5-43 5.82 6.08 6.54 6.90 7.26 7-59 7.98 8.34 8.70 400 6.28 6.76 7.24 7.76 8.24 8.72 9.20 9.68 10.12 10.64 11.12 11. bo 500 7-85 8.45 9-05 9.70 10.30 10.90 11.50 12.10 12.65 13-30 13.90 14-50 600 9.42 10.14 10.86 11.64 12.36 13.08 13.80 14.52 15.18 15.96 16.68 17.40 700 10.99 11.83 12.67 13-58 14.42 15.26 16.10 16.94 17.71 18.62 19.46 20.30 800 12.56 13-52 14.48 15 52 16.48 17.44 18.40 19.36 20.24 21.28 22.24 23.20 900 14-13 15.21 16.29 17.46 18.54 19.62 20.70 21.78 22.77 23-94 25.02 26.10 1000 15.70 16.90 18.10 19.40 20.60 21.80 23.00 24.20 25-30 26.60 27.84 29.00 1100 17.27 18.59 19.91 21.34 22.66 23.98 25-30 26.62 27.83 29.26 30.58 31.90 1200 18.84 20.28 21.72 23.28 24.72 26.16 27.60 29.04 30-36 31.92 33-36 34-80 1300 20.41 21.97 23 -53 25.22 26.78 28.34 29 90 31.46 32.89 34-58 36.14 37-70 1400 21.98 23.66 25-34 27.16 28.84 30.52 32.20 38.88 35.42 37-24 38.92 40.60 1500 23-55 25-35 27-15 29.10 30.90 32.70 34-50 36-30 37.95 39-90 42.70 43-50 1600 25.12 27.04 28.96 31.04 32.96 34-88 36.80 38.72 40.48 42.50 44-48 46.40 1700 26.69 28.73 30.77 32.98 35-02 37.06 39.10 41.14 43 01 45.52 47.26 49-30 1800 28.26 30.42 32.58 34-92 37.08 39-24 41.40 43-56 45-54 47.88 50.04 52.20 1900 29.83 32.11 34-39 36.86 39-14 41.42 43-70 45.98 48.07 50.56 52.86 55-10 2000 31-40 33-80 36.20 38.80 41.20 43.60 46.00 48.40 50.60 53.20 55.68 58.00 2100 32-97 35-49 38.01 40.74 43.26 45-78 48.30 50-82 53-13 55-86 58.42 60 90 2200 34-54 37-18 39 82 42.68 45-32 47.96 50.60 53.24 55.66 58-52 61.16 63.80 2300 36.11 38.87 41.63 43.62 47-38 50.14 52.90 55-66 58.19 61.18 63.94 66.70 2400 37.68 40.56 43-44 46.56 49.44 52.32 55-20 58.08 60.72 68.84 66.72 69.60 2500 39-25 42.25 45-25 48.50 51-50 54 50 57-50 60.50 63.25 66.50 69.50 72.50 2600 40.82 43-94 47.06 50.44 53-56 56.68 59-80 62.92 65.78 69.16 72.28 75-40 2700 42-39 45-63 48.87 52.38 55-62 58.86 62.10 65-34 68.81 71.82 75.06 78.30 2800 43-96 47-32 50.68 54-32 57.68 61.04 64.40 67.76 70.84 74.48 77.84 81.20 2900 45-53 48.01 52.49 56.62 59-74 63-32 66.70 70.18 73 37 77-14 81.62 84.10 8000 47.10 50.70 54-30 58.20 61.80 65.40 69.00 72.60 75.90 79.80 85.40 87.00 ADVICE TO YOUNG MEN. 217 CHAPTER XXIV. ADVICE TO YOUNG MEN — THEY SHOUID MAKE THEMSELVES PROFICIENTS IN THEIR BUSINESS —FREQUENT CHANGES NOT ADVISABLE— PROPER STUDIES FOR THE YOUNG MECHANIC IN ORDER TO FIT HIM FOR FUTURE USEFULNESS, ETC. In conclusion, a few words of advice to young men may not be amiss. The question is often asked why it is that planing- mill operators as a class are not as competent men as may be found in other mechanical businesses. There is scarcely an accident or a breakdown but may be traced directly or indirectly to carelessness or neglect on the part of the operator. To a close observer this question can be satisfactorily answered. In the first place, comparatively few young men adopt this as a regular business or permanent occupation, and do not serve the necessary apprenticeship to qualify them for the duties and responsibilities devolving upon them. In the second place, men who have served an appren- ticeship and thoroughly fitted themselves for the duties and responsibilities of the position cannot afford to give their time and energies to a business that in the past has offered so little inducements in the small salaries that most planing-mill proprietors are willing to offer ; consequently many abandon this business for something that may offer them better inducements. In fact, it would seem as if a large majority of plan- 2l8 HISTORY OF THE PLANING-MILL. ing-mill operators adopt this business as a sort of makeshift until they can find something better. Such men are not expected to devote their mind and energies to a business that they expect to remain in only a few months. A young man, for instance, gets tired of farming, and makes up his mind to try something else. He goes to the nearest town and applies for a job in a planing-mill ; works around a few months ; watches the men who are running the machines : it all looks simple enough to him, and after awhile he makes up his mind that he can do that work just as well as anybody. He goes to the next town, and obtains a situation in some mill as a competent operator ; works until he has a breakdown, or the machine gets in such a condition that the customers complain of bad work and threaten to leave ; when, if not discharged he will pick up his traps and try something else. So he floats around between planing- mills, saw-mills, and logging-camps ; and if he should happen to continue around planing-mills long enough he may pick up sufficient knowledge in time to become a second or third class operator : but the chances are that one or two seasons will wind up his career, and he will either return to the farm, which he should never have left, or try some other business, with like results. There is a class of planing-mill operators, however, who have learned this business in the regular way, and have become experts in their chosen profession, many of whom I have the pleasure of being personally acquainted with. Such men are ornaments to their profession, and profitable to their employers at any THE YOUNG MECHANIC. 219 salary; and there are planing-mill proprietors who appreciate such men, but I am sorry to say that they are not as numerous as they should be. To this class of operators I have no reference — their own work and the efficiency of their machines are a sufficient recommendation ; but 1 do contend that a man, to have the care and management of wood- working machinery, should be a proficient at the business. A young man starting out in life, who in- tends to make this his business and profession, should go into some first-class mill, and, under a competent foreman, serve a regular apprenticeship, and devote all the energies of his mind to the business unreservedly, until he has mastered all the principles and details of the different machines that may come under his charge in after years. It is by this means only that he can make a success of it and command the highest price for his labor and skill, and superintend with intelligence and authority the workmen under his charge. He should not only aspire to become a good operator, but should endeavor to become a master-mechanic in his chosen profession. He should devote his leisure time to the study of such mechanical works as relate to his business, instead of throwing it away, as many young men do, in reading the trashy literature of the day in the shape of dime novels, which impart no useful information, or in attend- ing variety shows — both of which are a total loss of time. He should remember that '* time once past never returns : a moment lost is lost forever." He should also study mathematics, philosophy, and the natural sciences ; thereby not only fitting himself to 220 HISTORY OF THE PLANING-MILL. discharge his duties in a more intelligent manner, but also for any other useful occupation in after life in case of accident or disability. By making himself master of those principles of science — more particularly those which are most in- timately connected with his business, he may be laying unawares the foundation for future discoveries in mechanical improvements that may be a source of great benefit to the public and profit to himself. Benjamin Franklin, when learning the trade of a print- er and devoting all his leisure time to the study of philosophy and the natural sciences, probably never dreamed of the brilliant discoveries that he would make in after-life, or the fame that would attach itself to his name and descend as a living monument to generations yet unborn. Elihu Burritt, the learned blacksmith, who com- menced learning his trade when quite young and with a very limited cornmon school education, at the age of forty was master of fifty-two languages, and wrought at his anvil during all that time, only devoting his leisure time to study until the demands of the public called him to a more public, beneficial, and profitable occupation. I could name a large number of men among my per- sonal acquaintances who commenced their apprentice- ship poor, and with but little education, but who by devoting their leisure time to study, have ascended to the top of the ladder, and are now filling places of re- sponsibility and trust, and have secured, many of them, a large competency ; while others, from the same shops, who devoted their leisure time to novel-reading and THE YOUNG MECHANIC. 221 attending places of amusement that were no benefit to them, are now, in their dedining years, still working as common hands, and for wages that no more than enables them to eke out a bare existence. Such ex- amples are to be found in every shop and in every line of mechanical business, and should be a living example to young men not to go and do likewise. When a young man decides to learn a trade or pro- fession, whether it be the care and management of wood-working machinery, the charge of a lumber-yard, or any of the mechanical trades, he should cultivate a spirit of contentment, and realize that when he is work- ing for the interest of his employer he is working for his own. I do not mean that he should content him- self to always renjain in just the same position he may fill at the time, but by study and perseverance fit him- self for advancement to the higher and more responsi- ble positions that the same line of business may afford. It is a well-known fact, that may be demonstrated by numerous living examples, that some of the largest and wealthiest lumber-dealers in the country began life as common laborers in the yard, and by energy, strict in- tegrity, and careful attention to business in time suc- ceeded in rendering themselves almost indispensable to their employers, and finally became partners, and lastly proprietors themselves. The young man who is satisfied with his business and adheres to it, and endeavors to make himself useful in whatever position he may occupy, presents a much more respectable figure in the eyes of the public than one who is constantly changing from one thing to an- other and undertaking hazardous enterprises^ which 222 HISTORY OF THE PLANING-MILL. often end in debt and ruin. A man who has been en- gaged in a mercantile business all his life will not be apt to succeed well as a manufacturer ; neither would a blacksmith be apt to succeed as a merchant. There is an old saying that is applicable to every one who has been brought up to a regular trade or profes- sion, and that has more truth than poetry — " Keep to your shop, and your shop will keep you." I admire the old English style. If a man is a suc- cessful manufacturer or mechanic, no matter how wealthy he may become, his sons and grandsons are not too proud to be known as manufacturers and mechanics themselves, and write themselves with pride as the successors of the old firm. For honesty, integrity, and genuine respectability, commend me to the intelligent, hard-working mechanic. 1 r\ V \. 53 «4 <^ .• -U *""* '^^ ^ "^ k"^ Ho^ 6^^ ^o ■JJ .*<' s^ »'»^3^.* ._ _ _. _ J DOBBSBROS. I' * LiailARV BINOINO