THE LIBRARY OF THE UNIVERSITY OF CALIFORNIA DAVIS ;v THE CONSTRUCTION OF MILL DAMS COMPRISING ALSO THE BUILDING OF RACE AND RESERVOIK EMBANKMENTS AND HEAD GATES, THE MEASUREMENT OF STREAMS, GAUGING OF WATER SUPPLY, &0. Illustrated by numerous Full-Page Plates. SPRINGFIELD, OHIO: James Leffel & Co., AUTHORS AND PUBLISHERS. 1874. UBRARY Entered According to Act of Congress, in the year 1874, by JAMES LEFFEL & CO., In the Office of the Librarian of Congress at Washington, D. C. PREFACE. PREFACE. A considerable portion of the matter contained in this work has appeared in a serial form in the monthly issues of Leffel's Illustrated Milling and Mechanical News, but has been carefully revised and corrected for republication in this form ; while the remaining chapters and illustrations are entirely new, being now printed for the first time. While the series of articles on this subject was in progress in the monthly journal referred to, the degree of interest with which it was received by the milling public was indicated by frequent requests from all parts of the country for files of the paper containing the complete series. The number and the urgent character of these applications, with most of which the publishers were unable to comply, the earlier editions of the paper being soon exhausted, suggested the expediency of publishing the series entire, in a form which would admit of fully supplying both the present and future demand. It may also be said, in further justification of this course, that in view of all the circum- stances of the case and the amount of labor and outlay required in the preparation of these articles with the illus- trations accompanying them, it seemed desirable that the results attained should be put in more permanent shape than it is possible to give them in a periodical publication. The collection of materials for this work occupied a period of over three years, and the facts embodied in it were gathered from all sections of our country, so that for Amer- ican readers at least we may venture to hope that it will not be found wanting in comprehensiveness and variety. 4 PREFACE. Abstract and technical features, it will be observed, have been uniformly avoided, our object being to make this volume useful in the highest possible degree to every per- son owning water power or interested in any way in its utilization. To this end we have chosen the presentation of the subjects discussed in this volume in the most direct and practical form ; and whatever may be its deficiencies in other respects, we trust that by minuteness of detail and distinctness of description it may be rendered service- able to the class of readers to whose favor it is respectfully commended. JAMES LEFFEL & CO. Springfield, Ohio. CONTENTS. CONTENTS. Introduction, - 7 Material and Form of Dams, ---.._ 9, 12 A Beaver Dam, -- 16 Log Dam for Soft or Sandy Bottoms, - . . _ 21 A Safe and Economical Dam, - 26 Hollow Frame Dam, __-..-. 32 Rip-Rap Dam, 39 Crib Dam, - - 45 Dam for Rock Bottom, -__-.-_ 51 Pile Dam, .--._-_.- 57 The Housatonic Dam at Birmingham, Connecticut, - - 62 Plank Crib Dam, ---.--.. 7I The Moline Dam, 78 Boulder Wing Dam, -__-.._ 34 Brush, Stone and Gravel Dam, ----._ 89 Curved Plank Dam for Rock Bottom, _ _ •. . j)4 Construction of Dam Between Coffers, . - . - 100 Stone Dam near Frankfort, Kentucky, _ . . . 106 An Iron Dam, - 111 Pile and Boulder Dams, -- 116 Stone Dams, -._- 121 Dam at Lawrence, Kansas, (3 plates) _ . _ - 126, 131, 136 Dam on the Tassoo River, Hindostan, _ . - . I43 Lock and Dam at Henry, Illinois, 148 Crib Dam with Plank Covering, ------ l.~>7 Plank Dam at Gilboa, Ohio, 162 6 CONTENTS. PAGE. Frame Dam at Clifton, Ohio, Ifjg Timber Dam at New Hartford, Connecticut, (2 plates), - 175, 179 Log Dam for Narrow Streams, -----. 184 Frame Dam on Mad Kiver, - 191 Dam at Osborn City, Kansas, .-.._, 19 j Stone and Timber Dam, 202 Dam for Quicksand Bottom, 208 Overhung Apron Dams, --.-... 214 273 Stone Dam with Plank Covering, ------ 219 Timber Dam at South Hadley Falls, Massachusetts, - - 224 Stone Apron Dam, -.--___. 228 Pile and Frame Dam, ----_.. 233 Pile and Brush Dam, --.--.._ 240 Log and Plank Dam, --- 245 Frame Dam with Sheet Piling, ...... 252 Double Crib Dam— Trestle Dam, - - - _ . 9-g Light Frame Dam, -------- 9^2 Dam for Rock and Sand Bottom, 269 Race and Reservoir Embankments, . _ . . . 276 281 Head- Gates lor Races and Canals, - - - . . 091 Gauging the Supply to Water Wheels, 297 Weir Dam— Measurement of Water, - . . . ^q^ To Measure Water More Accurately, 3q8 Measurement pf Large Open Streams, - , , , 311 INTRODUCTION. INTRODUCTION The household proverb that '' Fire is a good servant, but a bad master," is true in an almost equal degree of water, its opposing element. Under the intelligent control of man, the power of water is one of the chief instrumentalities in promoting human comfort and spreading the blessings of civilization. The uses to which it may be turned are so various, and the products for the manufacture of which it is a serviceable agent are of such manifold forms and min- ister to so many wants of our nature, that the country which is possessed of abundant water power is looked upon as especially favored by Providence. But this invaluable servant, if once it bursts over the bounds which have been set for its action, becomes a destructive scourge, laying waste the very fields whose tillage it had made profitable and bringing to poverty, in an hour as it were, a whole community, whom until then it had sustained in prosperous industry. More than one such instance occurs in our own memory and doubtless in that of every reader, where an insignificant stream along whose banks thousands of men, women and children have earned for years a secure liveli- hood, has risen in its might and swept away with its swollen torrent all the fruits of those years of labor, often not sparing even the life of the laborer himself, and in a single day inflicting damage which a generation may not see repaired. As the first step in the improvement of a water power is the construction of the dam, so the first consideration in that work is strength and durability. While the builder of a mill is bound to consult economy in the means he g INTRODUCTIOII. employs in obtaining a sufficient fall for the purposes of bis business, and diverting from its natural channel that por- tion of the stream which is to be made directly available, the economy which does not provide a sure resistance to sudden floods is very apt to prove the worst form of ex- travagance in the end. The tremendous power which a stream acquires in time of high water is seldom properly estimated when it is seen moving tranquilly within its usual bounds. When the day of disaster comes, the trifling neglect which brought it on is regretted, but too late for remedy. Our object in the present volume is to ofi'er a few suggestions which may be of practical value to our readers, in regard to the methods by which a dam may be economi- cally built and yet be of efl'ectual service and the greatest attainable durability. The power of water being by far the cheapest motive power which can be applied to manu- facturing purposes, it is important to inquire how it may be employed with the least expense, without sacrifice of strength and utility. We may perhaps safely venture the assertion that in this volume is presented a larger number and greater variety of dams of different styles, materials and methods of con- struction than can be found illustrated in like manner in any other work upon the subject; for although a vitally important branch of the business of milling, it has generally been suff'ered to pass with comparatively slight attention. The building of the mill itself, the application of the mo- tive power and the con-struction of the machinery for its transmission, are matters upon which innumerable author- ities may be consulted ; but for the erection of the dam, which may be justly regarded as the very foundation of the enterprise, the mill-owner has been left in a great measure to his own devices, aided by such conflicting counsels as he can obtain from his neighbors and his mill-wright. It has been our aim to supply in some degree this manifest deficiency in the literature of the milling business, and to present the results of a somewhat extended experience and observation in a form which will render them of service to others who are seeking information on this subject. The Construction of Mill Dams. CHAPTER I. MATERIAL AND FORM OF DAMS. The weirs or dams thrown across the beds of rivers have been constructed in a great variety of shapes and of different materials, some of them too costly for general use in a coun- try where small mills are chiefly needed. In cases where the supply of water is large and a high fall is not demanded, a temporary dam composed of boulder stones is sometimes thrown across the stream in a diagonal or slanting direction, and of length considerably greater than its breadth. The water is thus partly forced into the conduit or race above the dam, and the remainder passes over the surface of the dam in a shallow sheet. Being hastily and cheaply built, a dam of this kind may be repaired without much outlay, but the inconvenience of doing this after every heavy rise of the stream is a material drawback on its value. In contrast with this comparatively rude species of dam are those of more solid structure, substantially built of stone, and stretched across the river in the form of a bow, the curve being against the current — the middle of the dam, in other words, being higher up the stream than the two ends. A dam of this sort, if provided with massive stone abutments, presents a firm resistance to the onset of a flood, and will stand any test ordinarily experienced. It may be made with 10 MATERIAL AND FORM OF DAMS. a gentle slope from the crest both up and down the stream ; or with a steep descent on each side, making its walls almost perpendicular ; or again with either a steep or sloping front on the upper side and on the lower a curved apron, the wall rounding downward from the top like the lower half of the letter 0, by which arrangement the fall is made gradual and its force abated. In a stream of moderate size, a form of weir has sometimes been adopted resembling the letter Y, with the apex or point directed up-stream. If built upon piles, with a frame of tim- ber forming an inclined plane upon the face of the dam, and filled up with gravel surmounted by a mass of boulder stones well packed in, the dam will be nearly impenetrable by water. The position of the two arms of the V distributes the force of the water in passing over, and as the currents descending from either side tend toward the centre of the stream, the banks are less liable to be washed away. If tim- ber is abundant, the frame, instead of having a uniform slope downward on the face of the dam, may be made in a series of steps like a wide stairway, breaking the water into cascades. The piles for such a dam may be placed at right angles with the current, stayed and covered with plank, and made watertight with sheet piling supported by foot piles. Constructed in other respects like the one last described, a dam of this kind will possess great durability and admit of no leakage. An undue accumulation of water above the dam may be remedied by a channel and sluice gate in one of the side walls, by which the surplus water may be drawn off before reaching the crest of the dam. A self-adjusting dam of heavy planks strongly framed together is sometimes stretched across the stream, connected by hinges to the crest of the permanent dam, and held in an upright position by weights passing over wheels on the abutments. In case of a flood the weights give way partially to the increased pressure and the auxiliary dam is let down toward a horizontal posiiton, allowing the water to pass unobstructed. In place of an appendage of this kind, movable flash boards are often used, being held in place by pins and other supports along the MATJlRiAL AKD FORM OF 1)AMS. 11 brink of the dam, and tightly fitted to each other. In time of low water, the flash boards are of important service in obtaining sufiicient head. When the stream rises, the boards are removed (though the supports may often remain) and the crest of the main dam being below high water mark, the surplus water escapes freely. In the following chapters the varieties of dams more prac- tically adapted to the wants of mill-owners in our own coun- try will be mainly considered — including log and frame dams, embankments, crib-work, and their various combina- tions. We accompany each chapter (with the exception of the 1st and 2d) with a full-page engraving, in order to present to the reader more clearly the suggestions we desire to off"er. The methods of construction above described are chiefly useful for large establishments and corporations, with whom the matter of expense is not a vital considera- tion. Our next inquiry will be how the same practical re- liability may be obtained, on a smaller scale and with the most moderate outlay. 12 MATERIAL AND FORM OF DAMS. CHAPTER II. MATERIAL AND FORM OF T>AM^.— Continued. In many localities where stone is not readily obtained — which is the case in a large portion of the Western States — frame dams are the cheapest substitute, and if properly constructed serve their purpose in the most satisfactory manner. If the stream has a firm and level bottom, the frames, which are made in a triangular shape, resembling a harrow, may be placed directly on the bed of the river, without any intervening foundation. The narrow end or apex is of course laid up the stream, and the frames placed in a line extending from bank to bank, with a space of three or four feet between them. The upper side being then planked the whole length of the dam, an inclined plane is presented to the current on the up stream side, and if the frames are substantially built the pressure of the water will be firmly resisted. On a soft or irregular bottom, where a heavier foundation is required, the following plan is the most economical, and requires comparatively little labor. Three tiers of timbers running parallel to each other across the stream are placed at the foundation of the dam, one tier at the lower side, one at the upper side, and the third midway between them. Posts are then framed into the lower and middle tiers of timbers, those on the lower tier being of a hight nearly equal to the top of the rafters at the crest of the dam, and the top of those in the middle tier being in range with the former and the foot of the rafters. Two upper tiers of tim- bers are framed upon the posts thus erected, and the raft- ers, which should be slightly notched at the point where they rest upon the timbers, are thus firmly supported at the head and foot and in the middle ; and the planking being well fastened to them, a strong and serviceable dam is the MATERIAL AND FORM OF DAMS. 13 result, with but moderate outlay either of money or labor. The best form of dam, whatever be the material of which it is constructed, is that resembling a bow, with the arch up-stream, as described in Chapter I; but this method of construction is seldom followed in frame and log dams, the straight line calling for much less labor and care, as well as less material, the distance being of course less than when a curve is made. A clieap and substantial dam may be made, where timber is abundant, by laying a foundation of logs of considerable size, which are placed lengthwise of the stream and close together, forming a sort of corduroy road, extending from bank to bank. If the bottom is soft, tlie logs should be carefully fitted down and adapted to the inequalities of the bed, and if placed as deep as possible they will be less lia- ble to decay by exi)osure in time of low water. The breast- work of the dam is built near the up-stream side of this foundation, the logs extending from under it down-stream, and serving as an apron to receive the waste water as it comes over. The rafters and coverings of the dam form an inclined plane on the up-stream side, and extend over Ihe upper ends of the logs, protecting the foundation from be- ing undermined by the water working beneath it. In a region well timbered, and where the stream has a rock or other solid bottom, a log dam of the following de- scription has advantages in point of cheapness, strength and durability. A series of large logs are placed in line, one at the end of another, at the down-stream face of tlie dam, the loose rubbish being carefully cleaned out, and hol- low places filled with short logs to support the main founda- tion firmly. The logs used for the foundation tier should be as long and large as can conveniently be procured. A se- ries of short logs are then laid upon this tier, with their butt ends resting on the foundation logs and their top ends on the bed of the river, pointing up stream, the distance be- tween them being six or eight feet. Upon these a second tier of long logs is placed, parallel with the foundation tier, but a little farther up stream. A second set of ties is laid with the butt ends on the second tier of logs and the top 14 MATERIAL AI^D FORM OF DAMS. ends on the ground beside the first set. This second set of ties being a trifle shorter than the first, room is left to place a log of moderate size across the ends of the first ties. This will serve as a support for skids upon which to roll up the third tier of large logs. The logs should be notched where they cross and the ends resting on the ground firmly secured in order to impart the necessary strength to tlie whole structure. If properly built, the front of the dam will rise considerably faster than the rear, and will at the same time incline up stream, so that its form will resemble a portion of an arch, the foot of the ties being the center and the breast of the dam the circumference. Beside the series of large logs in front, a second and even a third series of smaller size, running parallel with it across the stream, may be placed in the angles formed by the ties, which should be notched where they cross the logs ; and the three series of logs should range in hight so that the covering of the dam will form an inclined plane — not too steep for the length of the incline, or the whole fabric may slide down stream when the pressure of the water is brought to bear. Either logs or rafters may be used in constructing the covering. If the former, they should be close together, and chinked with moss, pounded cedar bark,*or other suitable riiaterial. If rafters are used, they may be placed about three feet apart and planked crossways, the thickest planks being used at the bottom and at the crest of the dam. Many other varieties of dams remain to be more fully noticed in the succeeding chapters of this work — as every section of country calls for new adaptions of the material and shape of the structure to the peculiar surface, soil and resources of the region. As a matter which may interest the reader, we give, before closing this chapter, a brief ac- count of the method in which a broken dam in the western part of Indiana was repaired some time since, after repeated unsuccessful attempts. The dam referred to was built of logs, brushwood, &c., and the bed of the stream was a treacherous quicksand— perhaps the most difficult kind of bottom upon which to obtain a secure foundation. The breach was nearly in the center of the dam, and not less MATERIAL AND FORM OF DAMS. 1 5 than forty feet wide ; and the deep and swift current which rushed through it defied every efi"ort to gain a point of sup- port from which to work. Various expedients were tried, even to throwing huge boulders into the stream, which were carried along by the force of the water and rendered of no avail. Several millwrights and engineers coasted in skiffs about the place for two or three days, looking for some base of operations, but entirely without success. At length one of them, having pushed his explorations along the banks a mile or more up stream, discovered a huge tree, with an ex- traordinary breadth of branches, near the water and lean- ing toward it in such a way as to suggest that it might pos- sibly be launched into the stream. Other trees near it were felled and leaned against standing trees so as to serve as a kind of skids, and by dint of two or three days' patient toil, in which the use of windlasses was found necessary, the tree was at last guided down the stream butt foremost, and lodged in the gap at the broken dam. The expedient proved completely successful, for although a mighty cracking and splintering of boughs ensued, the stout branches held fast on the sides of the dam, and a beginning was thus made from which the necessary repairs were effected with com- parative ease. 16 A BKAVER DA3r. CHAPTER III. A BEAVER DAM. We depart in this chapter from the line of discussion pre- viously laid out so far as to substitute, in our illustration, a dam constructed under the guidance of instinct for one in which human reason and the rules of mechanical science are the directing agencies. The art of dam-building as prac- tised by beavers may be said to possess novelty rather than intrinsic value to the mechanical reader, and we offer the accompanying view of it as matter of interest and amuse- ment to such readers, affording a perhaps not unpleasing variety, in connection with the strictly practical details to which our previous as well as our succeeding chapters are confined. It may be said, indeed, that an examination of the science of constructing mill dams, intended to cover as nearly as possible all the principal branches and phases of the question, would be grossly incomplete if we failed to take notice of the fact that this most useful art has a plain foundation in nature and was practised, in what approaches very closely to an intelligent method, by other animals than man, long before civilization had built its first mill and set its first rude water-wheel in motion. The ingenuity of these untaught workmen furnishes, moreover, a striking argument in favor of the theory, of late a very popular one, that man- kind are not a wholly distinct order of beings, but possess a comjnon origin, however remote it may be, with what is con- ventionally termed the brute creation. This is a matter, however, into which the purpose of the present work does not permit us to enter; especially as it leads to no definite conclusions, but launches the inquirer on a vast field of speculative controversy with no apparent prospect of use- ful results. The American Beaver, a specimen of whose skilled labor A BEAVER DAM. 19 is shown in our engraving, is remarkable as being the only quadruped known to naturalists whose fore parts resemble those of a land animal, while their hind parts are adapted to aquatic habits, having membranes between the toes. The beavers begin to congregate for theix season's work in June or July, on the shores of a lake or river where they design making their abode. They gather from all directions, to the number usually of two or three hundred. They frequently establish themselves in the standing waters of a lake or pond, if of sufficient depth, and in this case no dam is re- quired ; but a running stream gives them the advantage of a current by which to transport their supply of wood, which they invariably cut at points farther up the stream than the locality of the dam, being thus enabled to float it down. They use chiefly the trunks and branches of small birch, mulberry, willow or poplar trees, beginning the work of cut- ting timber early in the summer. The building of the dam and houses is not generally commenced until some time in August, being finished just as the cold weather sets in. The trees are cut so as to fall into the water if possible, although small shrubs at some distance from the stream are dragged to the bank and launched. The strength of the beaver's teeth and the industry he displays are strikingly shown by the size of the trees, reaching sometimes twelve and even eighteen inches diameter, which he cuts down; and this in such numbers and with such regularity that his clearing might easily be mistaken for that of an enterprising settler or backwoodsman. More surprising still than their sagacity in floating their materials to the proper place is the intelligence shown by the beavers in adapting the shape of their dam to the character of the stream. If the current is gentle, the dam is built nearly straight across ; if it flows swiftly, a curved dam is made, arching up-stream. The trees, branches, &c are simply allowed to rest upon the bottom, and mud and stones mixed in, to which the stream itself makes constant additions. The dam thus acquires great solidity and strength, and in some instances the willow or birch trees take root, so that a sort of hedge is at length formed. An old dam which 20 A BEAVER BAM. has been often repaired is found to possess remarkable power of resisting the current and the broken ice driven against it. The main object of the dam is to produce sufficient depth of water to cover the entrances to the beavers' houses, thus enabling them, in the winter season, to pass in and out under the ice. The houses are built of the same material as the dams and are very strongly constructed. Each lodge usually contains four old beavers and six or eight young ones, though double this number are sometimes found in a single dwell- ing. LOG DAM FOR SOFT OR SANDY BOTTOMS. 21 CHAPTER IV. LOG DAM FOR SOFT OR SANDY BOTTOMS. In a country where timber is abundant, a log dam is the most economical, affording, if properly built, an ample de- gree of strength and durability at comparatively small cost aside from the labor involved. This is of course a consider- able item, but as the work can be performed by ordinary laborers chiefly, it is of a less costly nature in proportion to its amount than the construction of a frame dam or the building of a solid stone wall, requiring the services of a carpenter and a stone-mason. We give with this chapter an illustration showing with some minuteness the construction of a log-dam which may be relied upon to resist almost any conceivable pressure from the current, and which is in very little danger of be- ing undermined. It is adapted, moreover, to river beds which are of too yielding a character to afi'ord a solid found- ation for a stone dam. Our engraving reproduces in all its essential features a drawing lately made in our office for the construction of a dam in the State of Texas. It is adapt- ed to all localities where timber is not too costly, and espe- cially to streams which have soft and sandy bottoms. In the engraving the dam is shown as if cut into at the middle of the stream, the further half being represented, with the crib or pen built into the opposite bank. The dam here represented may be literally described as a " brush and timber dam," though it comes under the gen- eral head of log-dams, the main portion of its structure being of that character, while saplings of any size may be used in making it compact, and brush, clay and boulder stone for filling on the up-stream side. The process of con- structing this dam is essentially as follows : Cut trees of eight or ten inches in diameter, lopping off the limbs on 22 LOG DAM FOR SOFT OR SANDY BOTTOMS. what will be the top and bottom sides, when the logs are placed in position. Start the first layer (forming the found- ation and front of the apron of the dam, and projecting down stream as shown at the extreme left of the cut) plac- ing the logs side by side with the tops up stream, the lower or butt-ends being about fifty feet below the point where the dam is to be raised. Having completed this, fall back about twenty-five feet and place a second layer of logs side by side as before, the limbs being carefully lopped off" on the under and top sides. Having now two layers or courses of logs reaching from side to side of the stream, start a third layer twenty feet back of the second, and carry it across the stream in the same manner as the others. The fourth course, five feet back of the third, completes the se- ries of successive and overlapping tiers of logs constituting the foundation of the dam and forming the apron. With this last course, you begin raising the dam, using for the purpose trees and saplings of any convenient size, and all the while filling in compactly, especially toward the up- stream extremity of the dam, with brush and clay. If boul- der stones are readily accessible they should be thrown in along with the clay. The successive courses of logs should now be laid on in such a way that the face of the dam will present a steep slope, the crest being about two feet farther up-stream than the point at which the dam rests upon the apron. At nearly every course it is well to lay binders lengthwise across the stream, pinning them to the largest logs beneath them. The ends of these binders, which may be three or four inches in diameter, are shown in the cut. They should be placed from two to four feet back of the face of the dam. Having reached the crest of the dam, a top binder is pinned on as solidly as possible, a pin being driven wherever there is a chance for it to hold. If convenient, two or even three binders may be employed, in which case they should be firmly secured to each other and to the upper tier of logs. The dam should be filled in on the surface, from the crest back to the extreme up-stream tips of the trees, with fine brush and clay. For this purpose, trestle work may be built LOG DAM FOR SOFT OR SANDY BOTTOMS. 25 out over the stream and planks laid on to serve as a track on which to wheel the dirt out upon the dam. Throughout the whole work, care should be taken to lop the branches from the top and bottom sides of the trees, and the butts of the trees should invariably be laid down stream. The dam should be made in the form of a semi-circle or half-moon, arching up-stream. To secure the ends of the dam, a log-pen should be built at each bank, (one of which is shown in the cut,) extending back into the bank as far as it can conveniently be carried. Each pen should be chinked from the inside and filled with clay ; or if stone is plenty it may be used instead of clay for filling the pens, which will not then require to be chinked. If clay is used it should be packed in as tightly as possible to prevent it from working out. It has been found that a dam of this kind will settle about eighteen inches the first year, for which due calculation and allowance should be made. After that time, it will remain nearly stationary. It is cheaper, in a favorable locality, than a frame dam, and has an important advantage in the fact that it will hardly ever wash out. It is almost impossible to build on a quicksand bottom a frame dam that will stay in, as the experience of many mill-owners has shown. The use of piling cannot be recommended, as the water forms small whirlpools around the piles, and will in time wash out the earth clear to their bottoms. It should be remarked that in building a dam of this kind, unless the stream is nearly dry, it will be well to leave a passage through which the water may escape while the building is going on. This need not usually be done until the apron is completed, and perhaps one or two courses of the upright part of the dam laid on ; but after that it will be expedient to leave a space or channel near the middle of the dam for the water to pass through until the rest of the dam is finished, when the gap may be closed up. A SAFE AND ECONOMICAL DAM. CHAPTER V. A SAFE AND ECONOMICAL DAM. Although the material and method of construction of a dam should generally be determined by the character of the stream and its bed and the supply of timber or stone to be found in the vicinity, there are many cases in which the natural resources of the country are not specially abundant in either respect, and the most economical method is the best, whether the dam be of logs, frame-work, or stone. It is understood, of course, that strength is under all circumstances the first consideration, and there is no true economy in a plan in which it is not so regarded. The cost of rebuilding or repairing a dam will usually be sever- al times greater than the additional outlay which would have been required to make it proof, in the first place, against sudden floods and the action of frost, floating ice and driftwood. We give in connection with this chapter an illustration representing a style of dam which can be confidently rec- ommended for its durability, and which involves no excess- ive outlay either of money or labor. It has some points of resemblance to the log dam described in our last chapter, but the dam referred to is particularly suited to a region where timber is abundant, while the one here shown does not require so ample a supply of that material. The abut- ments of this dam, it will also be observed, are built of stone, instead of crib-work as in the former case. Crib- work, however, can be substituted if more convenient ; or if stone is used, cap-rock or rubble will answer the pur- pose, if compactly laid and filled in with earth solidly in the rear, nearly as well as more costly building stone. The construction of this dam is shown very thoroughly in A SAI'E Aln) ECONOMICAL DAM. 27 the cut, and only a brief explanation is necessary. Its qual- ities of firmness, compactness and durability adapt it to any sort of bottom, whether it be sand, soft mud, gravel or rock ; and in either of these cases it would take a more vio- lent pressure than most dams are subjected to, to move it from its foundation. The first step in the process of build- ing it is to la^^ the foundation logs A A, which extend across the stream, being spliced if necessary, to obtain the requisite length. They should be imbedded in ditches crossing the stream transversely, and of sufficient depth to bring the upper surface of the logs nearly on a level with the bed of the stream. One of these logs is laid at the foot of the apron, another at the point where the dam is to be raised, and the third, fourth and fifth farther up stream, as shown in the cut, the distances between them being six or eight feet. The ends of these logs should project some dis- tance from the sides of the dam into the bank or under the abutment. The weight of the abutment resting upon them will have the efi'ect to hold the dam in its place and pre- vent it from being lifted or moved forward by the force of the current. The second series of logs, B B, are laid across the first course, lengthwise of the stream, and about six feet apart, the butt ends resting upon the lower log of the first course. The dam is then raised at the second log of the foundation, which is six or eight feet from the front log, the intervening space being occupied by the apron of the dam. A log of considerable size is laid down directly above the foundation log, and notched to the logs B B wherever they cross. A smaller log may be laid in like manner above the third foundation log, and also at the fourth if desired ; as these cross-logs or binders, which should be put in with considerable regularity, especially at the face of the dam and near it (as shown at D D) will serve to support and hold together the whole fabric. The alternate courses of logs having been carried up to the height of about five feet at th-e face of the dam (which should be nearly perpendicu- lar) and sloping back gradually as shown in the cut, the crossing of the logs will form cribs or chambers, as at C, S§ A SAt'E AiTD ECOKOMIOAL DAM. which are to be filled with stone or gravel. Stone is to be preferred if conveniently at hand, but gravel answers the purpose nearly as well. The binders on the top of the dam, crossing the stream, are to be firmly fastened to the logs upon which they rest — those at the crest of the dam and at the lower edge of the planking being secured by bolts, which pass through all the successive logs, below them to the very foundation of the dam. Except at these points it will be sufficient to fasten the binders with long pins to the logs beneath them. The planking E already referred to ex- tends from the crest of the dam about twelve feet toward the up-stream end, and serves to protect the front of the structure from damage by ice or driftwood. The spaces at H, at the rear of the dam, below the planking, should be filled with stone or gravel. The abutments F (only one of which is here shown, as our engraving comprises but half of the dam, giving a front, top, and sectional view) are built, as already stated, upon the ends of the foundation logs projecting from the sides of the dam, aiding thereby to hold the structure in its place. The abutment represented in the cut is of solid ma- sonry, good building stone being the material employed ; but it may be more cheaply constructed, either of rough stone or crib work, as described in the introduction of this chapter. The apron of this dam should be planked between the pro- jecting logs, as shown at G, the planks extending back under the first transverse log which begins the face of the dam. It will be manifest from the nature of its construction that no part of this dam can be moved from its place without the entire fabric going with it. The diff*erent portions being firmly connected and secured to each other, the structure must go out bodily or not at all. The great breadth of the dam at its base is one of its strongest advantages, prevent- ing it from being undermined by the current — a danger which constantly threatens a dam with a narrow foundation, let it be ever so strongly built. It is also to be observed that the amount of timber required in building by this plan is very moderate, being much less than is often used in A SAFE AND ECONOMICAL DAM. 31 dams which do not possess nearly so much actual strength as is here afforded. As a practical example of the reliable character of this dam, we may here remark that one of the publishers of this work, having had two costly dams of cut stone carried away from the same site by high water, finally built one according to the plan here described, at a total cost of $700, and has found it perfectly safe, the floods of four successive years, some of them extremely violent, having failed to carry away any part of it, or inflict any material damage. Neither of the two stone dams which preceded it stood over eighteen months, the bottom being of the sandy and treacherous nature to which a great part of the difficulty involved in the science of dam-building is to be attributed. 32 A HOLLOW FRAME DAM. CHAPTER VI. A HOLLOW FRAME DAM. Having treated at some length on the subject of log-dams, especially for soft or sandy bottoms, and with particular reference to the means at command in a region moderately well timbered, we present in this chapter an illustration of a hollow frame dam which we can safely recommend for a country where economy in timber is necessary. It offers an equal degree of security with the log dams previously described, at the same time requiring far less material in its construction. A good, reliable dam, in fact, can hardly be built with a more economical use of timber than is shown by the plan here given. Our artist has presented very clearly the peculiarities of construction, leaving it nec- essary to supply little more than the figures, dimensions &c., to give the reader a clear idea of the design. The dam here represented is built upon a solid rock bottom, but with slight modifications is adapted to streams with a soft or san- dy bed, as hereafter explained. The first step in the construction of this dam is to lay the foundation blocks A A, each of which is a stick of timber ten inches square and about four feet in length. Three rows of these blocks are to be laid across the stream, one at the face of the dam, one at the up-stream extremity, and another midway between them. The distance between the centers both ways — across the stream and from one row to another — is eight feet, giving three blocks or bearings to each bent of the frame- work. Three additional blocks are placed in the front row and twelve in the rear row to re- ceive the bolts by which the dam is fastened to the rock. Upon these blocks are now laid the mud-sills B B, which form the immediate foundation of the dam, consisting of logs about sixteen inches in diameter, hewn on the upper A HOLLOW FRAME DAM. 66 and under sides so as to give a thickness in that direction of thirteen inches. These are laid across the bed of the stream in three tiers, one for each row of blocks. Where joints occur, a two-feet splice should be made, and the two ends firmly pinned together. The end of the front sill at each bank should project into the abutment about fifteen inches ; while that of the second or middle sill projects an equal distance just behind the up stream wall of the abut- ment, the center of which is near the front sill, bringing part of the abutment against and the other part below the dam. The front sill has three bolts passing through it, one at each splice, an extra block being placed underneath as already stated. The up-stream sill has twelve bolts, under each of which is a block, in addition to the blocks on which the bents of the frame-work are to rest. The bolts should be If inches in diameter. Each one of them passes through the sill and block down into the rock, which it penetrates about three and a half feet, making the total length of the bolt five and a half feet. The bolt is made after the hole has been drilled, the necessary length being ascertained by careful measurement. A " stoved head " as it is called, is given to the bolt, and a washer placed underneath the head, which is drawn tightly down by the tapered shape of the head. In order to prevent any possibility of the bolt working loose, the lower end is split five or six inches up, and an iron wedge inserted. When the bolt is driven down, the wedge, coming in contact with the rock, is driven up, and spreading the point, holds the bolt firmly in its place. Fine wet sand afterward put in will make it perfectly tight and solid, being as eff'ective for this purpose as lead or ce- ment. In drilling the hole in the rock, an ordinary stone drill slightly smaller than the hole to be made, is employed, and is put down through the sill and block, which are previously bored and placed in position. The bents of which the framework of the dam is con- structed, and which come next in order, are built throughout of timbers ten inches square — the same size of material being used in the lower horizontal pieces C 0, the uprights 34 A HOLLOW PKAME DAM. D D, and the upper pieces E E, which form the slope of the dam. The length of the lower timbers is sixteen feet, and that of the upper timbers the same, the effect of which is to give the face of the dam a slight inclination up stream. The lower timbers are framed into each sill, a gain being cut two inches deep, and the timbers secured with a dove-tail key- driven to the side of each bent. The upright posts connect- ing the upper and lower timbers of the bent have a length of two feet three inches in the clear at the face of the dam, and half that length at the middle sill ; and they are to be mortised into the upper and lower timbers in the same man- ner as in the framing of a house. The bents are the same distance apart between centers as the blocks under the sills — eight feet, and the distance from the front to the middle upright is the same. The upper and lower timbers of each bent are hewn obliquely or beveled at the up-stream end so as to fit snugly together and give a combined thickness at the extremity equal to one piece. The last step in the building of the frame is placing the ties F upon the top of the structure, extending transversely across the stream in the same direction as the sills. There are five series of these ties, one over each sill and one be- tween. They should consist of timbers 4 by T inches and lie on the narrower side. Each tie is let into the upper or in- clined timber of the frame wherever it crosses, the depth of the gain being one and a half inches, giving the tie five and a half inches thickness above the frame. The gain is cut into the frame at right angles with the upper timber, the ties being thus slanted slightly upstream and presenting a level surface for the planking. The forward tie is let into the frame piece about four inches from the end, in order to give sufficient strength to the gain to prevent it from breaking out. The whole upper surface of the frame is now planked over. The planking, which is strongly spiked to the ties? should be one and a half inches thick, and the wider the better, as the fewer the number of joints, the more secure from leakage will be the covering of the dam. A greater thickness of plank than that given will increase the liability A HOLLOW FRAME DAM. 37 to rot, as the wood is wet on one side and dry on the other. The abutments, as already stated, extend but half way from the face to the up-stream end of the dam. To protect the exposed portion of the sides, the dam is enclosed with stout upright planking from the middle sill to the upstream end, the ends of the planks resting on the rock bottom. In like manner, the rear of the dam is closed with sheet piling extending from bank to bank, closely matched and of suffi- cient hight to meet the planks which cover the top of the dam, the lower ends of which are footed by the piling, which extends to their upper side and is flush with the sur- face of the dam. The abutment is built of timbers fifteen to eighteen inches in diameter and is eleven feet square. The logs are hewed on one side to give a face to the abutment. The first or foundation timbers are laid in the same direction as the sills of the dam, transversely to the stream, the lower one about three feet below the face of the dam, and the up- per one just below the middle sill, which it touches and helps to hold in i^osition. The first cross piece on the side toward the dam is laid over and across the end of the front mud-sill, which extends beneath it, as already stated, about fifteen inches into the interior of the crib. The up-stream end of the cross-piece reaches to the middle sill of the dam. The timbers of the crib are notched and saddled where they rest upon each other, and the structure is thus firmly held together. The ends of the first two ties on the surface of the dam extend to the crib, and the third tie passes directly behind it in the same manner as the center sill below. The crib is filled up with rough stone or coarse gravel, and cov- ered with upright planking on the upper side and on the side against the dam. A joist, I, two by ten inches, is spiked against the crib along the top of the dam from its crest to the up-stream corner of the crib. The dam here shown is ninety-three feet long and its total hight from the rock bottom to the surface of the plank- ing is six and one-half feet. There are eleven bents in the complete dam, only half of which is shown in our engrav- ing. The dam here represented was built by Messrs. Book- 88 A HOLLOW FRAME DAM. waiter & Olaypool of Attica, Ind., to furnish power for a large iand very complete flouring-mill just erected by them, in 'which three Letfel Double Turbines were placed, with all other necessary machinery, lurnished by the same establish- ment. The design of the dam-, which was drawn in the office of James Leifel & Co., can be adapted with some alterations to a stream having a soft instead of a rock bottom. For that purpose, it would be necessary to lay a foundation of two and one-half inch plank, instead of the blocks, for the sills to rest upon. These planks should be laid lengthwise of the stream, and project ten or twelve feet below and an equal distance above the dam, making a total distance of about forty feet. As it is difficult to obtain planks of this length, the foundation may be laid in two sections, the planks in each having a length of twenty feet. About midway between the breast and the* up stream end of the dam, where, if the planks are twenty feet long, a joint will occur, a wide sill should be placed beneath them, upon which the ends of the planks can be firmly spiked. At the down-stream end of the planks, constituting the edge of the apron, a light sill or binder should be placed underneath — not to support, but rather to hold together the planks. At the up-stream end, the planks will be simply imbedded in the soil, and the planking at this point, and the whole back ol the dam, cov- ered with gravel, sand and dirt. A layer of brush at the bottom of this covering will make it hold all the more firmlv to the bed of the stream. A RIP-KAP DAM. 39 CHAPTER VII. A KIP-RAP DAM. The conditions of cheapness in the construction of a dam are changed by every change of locality. In one section, where material of a suitable kind may be comparatively abundant, while labor is scarce and commands high wages, economy is consulted by making the work of building as short and simple as possible, even if the material used is not the cheapest which could be found. In another district, or under different circumstances, workmen may be easily obtained at a very moderate rate, and the mill-owner may in this case save money by putting an extra proportion of labor in- stead of expensive material into his dam. Our engraving herewith given illustrates a kind of dam wholly distinct from any which we have before presented. In some por- tions of the country it would be difficult to find stone enough for its construction at any price — and it is not in- tended, of course, for the demands of such 1 calities. In other sections, the earth and stone of which it is composed would cost almost literally nothing, and it has the further advantage of requiring no skilled labor in putting it up, except in building the chute and waste gate, and in the lay- ing out and general superintendence of the work. The construction of a " rip-rap dam," which is the term commonly applied to a dam of the description here shown, is begun by throwing an embankment of earth across the stream (space being left in the middle of the stream for the waste- way or chute) carrying it up to a hight of about eight feet in the center and sloping it as shown in the cut, quite steeply on the down-stream and more gradually on the up-stream side. The dam here illustrated has an ex- tent between the foot of the up-stream and that of the d6wn-stream slope, of from thirty to forty feet, and from 40 A RIP-RAP DAM. one bank of the stream to the other of a little over seventy feet. Of the latter distance, twelve feet in the middle of the stream is occupied by the chute (in which the waste- gate is placed as hereafter described) leaving a distance of thirty feet on each side, froni the frame-work of the chute to the bank. It is not intended, of course, that the water should at any time flow over a dam of this sort, the escape of surplus water being provided for by the chute. The two slopes of the embankment do not meet at the top in such a way as to form a sharp ridge or crest, but the summit is leveled off so as to give a nearly flat surface about four feet in width, extending the whole length of the dam irom each bank until it reaches the chute. In constructing the embankment, the framework of tlie chute is to be set in position and strongly planked on the interior side, where the water is to pass, before the earth is filled in at that point — except that a All about two feet in depth is made on which the floor of the chute is to rest. This floor is laid upon a frame of heavy sills and cross-tim- bers, the planks of which it is composed extending length- wise of the stream, and projecting at the down-stream end some eighteen inches beyond the face of the dam, in order that the current of water, as it issues from the chute, may be carried beyond and clear of the embankment beneath. The tendency of the water to wash away the foundation of the dam is thus avoided. This is an important point, as the result of neglect in this particular will be the speedy under- mining of the chute and caving in of the wall of earth and rock on either side. The earth-work having been completed, the dam is now to be "rip-rapped" from end to end. This process consists in lay- ing two courses of stone, one above the other — ordinary cob- ble-stones being a suitable material for the purpose — over the whole surface of the embankment. The stones are placed on their edges, in the manner in which a gutter is paved, and laid as compactly together as possible, so as to give the entire dam a strong and durable face on both slopes and along the crest. The united depth of the two courses of stone will be about twenty inches. If three instead of two courts A RIP-RAP DAM. 4^ are laid, additional strength will be gained, and the dam will be all the more secure from the effects of any accidental inroad of water. The rip-rapping should not be confined to the dam itself, but extend along the banks on both sides of the stream, a short distance above and below the dam, as shown in the cut. This will prevent the banks from being worn away or washed out, and protect the dam from injury, to which it would otherwise be constantly liable. The up-stream slope of the dam is covered with earth from the base about two feet upward, reaching to the floor of the chute. Our engraving rei)re8ents, in addition to the dam, the in- let and part of the channel of the mill-race, on the further bank of the stream. The corners of the banks at the point where the water enters the race should be rip-rapped in the same manner as the dam, to secure them from being washed away and caved in by the continual action of the current. The exact distance to which the sides of the race at this point should be covered with stone will be determined by the shape of the bank, character of the soil, swiftness and force of the current, and other considerations which vary in different localities. The matter will be easily regulated by the exercise of a fair degree of judgment; but in general it is best to err, if at all, on the safe side. A little extra pre- caution, resulting in perfect security, is better than a falling short which may lead to damage and destruction in time of flood. The construction of the chute and waste-gate is a matter in which, of course, some measure of skill in the carpenter's and millwright^s trade will be in demand. The heavy tim- bers required are the sills and cross-timbers of the floor, the upright posts, the inclined or slanting beams which fol- low the direction of the slope of the dam up and down stream, and the timbers connecting them at the top, which will be as long as the crest of the dam is wide. The posts are mortised into the sills below and into the beams above, and their lengths are so arranged as to give the proper slant to the inclined beams, parallel with the face of the dam. For the construction and operating of the gate, a number 44 A RiP-RAP DAM. of methods are in use. A very simple arrangement is that in which the gate is raised and lowered by the use of a lever inserted into holes in the standard to which the gate is at- tached. A chain and windlass may also be used, the man- ner of their application being so obvious as to require no minute description. Still another form of gate is found very useful, in which the gate is made in sections, each sec- tion swinging on a horizontal axle resting on journals near the bottom of the gate, so that it can be let down like the tail-board of a cart when desired, and raised with equal ease whenever necessary. The division of the gate into sections, or as it were' into several narrow gates, each acting independently of the other, is found expedient on account of the great force it would be necessary to apply to raise and lower the entire gate in the manner described. The gates fall in the up-stream direction, their own weight as- sisting the process when they are lowered, and the force of the current helping to raise them — sometimes more power- fully than is desired — when the chute is to be closed. In future chapters of this work, descriptions and illustra- tions will be given of one or more varieties of head gates, which with some modification might be applied to a case of the kind above described. A CRIB DAM. 45 CHAPTER VIII. A CRIB DAM. We present in this chapter an illustration of a dam peculiarly adapted to streams which have a comparatively narrow channel, with a high bank on each side — although the latter condition is not indispensable, as any deficiency in this respect, if the shape of the country is not extremely unfavorable, can be made up by constructing an artificial levee or embankment. The structure of this dam is of the nature of crib-work throughout, logs being the material used in every part, although stone, gravel, clay and brush are employed in filling at various points, as hereafter de- scribed. The dimensions of the dam shown in the cut are nearly as follows : length of span, fifty feet, the logs in each of the two sections being about thirty feet long, giving ample mar- gin for notching at each end ; cribs on each side twenty feet square, the logs of which they are built from twenty-two to twenty-five feet long and the hight of the cribs from twenty- five to thirty feet. The dam itself is twenty-five feet high, the cribs being carried up three or four logs above the top of the dam. In building a dam of this description, the whole struct- ure, including both the cribs and the V shaped connection between them, are begun and carried up together. The apron, however, is first put down, consisting of a layer of logs placed closely side by side from bank to bank, with the butt ends down stream, and the limbs lopped off" up to the point where the dam is to rest upon the apron. Above this, the limbs may be left oil the trunks, as they extend into the earth which is filled in above the dam. The front of the apron should extend three or four feet forward of the cribs, as shown in the cut. The logs used in building the 46 A CRJB DAM. apron, and also the cribs and the dam itself, should be, if possible, at least one foot in diameter, in order to give the proper degree of weight, strength and solidity to the fabric. Having completed the apron, the next step is to lay the foundation of the wings and central portion of the dam. The first log of the crib on each side should be firmly pinned to the apron ; or the foundation of the crib may be laid two or three feet deeper than the apron, in which case it will not be necessary to fasten them together. The cribs are each to be set into the bank, which will thus enclose them on three sides, as appears in our illustration. Thus situated, it is scarcely within the bounds of possibility for the cribs to be moved from their position ; and if their con- nection with the dam is made firm and secure, the strength of the fabric, aided by the peculiar shape which it presents to the current on the up-stream side, will resist almost any conceivable pressure of water. In building up the cribs and the dam, the logs are to be notched and saddled wherever they meet^ — that is, at the four corners of each crib, at the points where the timbers of the dam enter the crib, and at the middle of the dam where the two sides of the angle or V intersect. This an- gle is of course pointed up-stream, the proper distance from the centre or place of intersection to the down-stream edge of the apron being about twenty feet. The pressure of the current upon the harrow-shaped structure thus presented to it will of course tend to spread the two wings or cribs apart; but if the latter are well grounded, filled and supported, and the logs in every part of the dam carefully notched upon each other, the force of the current will have no per- ceptible effect. Binders are to be inserted in each half of the dam as the work progresses, one for every second course of logs being sufficient, although one for each course is still more effect- ual. Small trees or saplings may be used for this purpose with the limbs and brush left on, the butts resting between the logs of the dam and the tops forming a part of the fill- ing on the up-stream side. In the engraving, the ends of these binders may be seen between the courses of logs A CRIB DAM. 49 forming the V, the tops of course being covered up and in- visible. The cribs are to be filled with stone and gravel, and if these materials are scarce, a moderate proportion of clay may also be introduced. The up-stream side of the V is to be covered with upright planking, which will extend from the top log down to the apron. Planks ten inches wide and two inches thick are suitable for this purpose, and they should be placed close together and either pinned or spiked to the logs, as convenience may dictate. The planking is cut away at the points where the binders occur, sufficiently to admit the ends of the binders, which rest upon the hori- zontal logs and are notched to them as already described. The filling on the up stream side, against the planking, completes the building of the dam. For this purpose, any convenient material may be used, whether stone, gravel, clay or brush, or all together. The filling should slope gradually from the crest of the dam, extending up stream a distance of not less than twenty-five feet, in order that all risk of the washing or undermining of the dam may be avoided. If the banks of the stream are too low to enclose the cribs to a sufficient hight to make them secure in their position? an artificial embankment must be constructed, covering three sides of the crib and extending from the stream unti it reaches ground of the same hight as the top of the dam- This embankment should be made wide and substantial, and compactly built of stone or earth. It is important that the material should be of such a nature that the water will not penetrate it, as the destruction or serious injury of the dam may occur in consequence of a very small outlet. The main force of the stream is brought to bear, of course, upon the dam itself; but in time of high water there will be more or less pressure upon the levee, which should accordingly be made as secure as circumstances will allow. Our illustration shows, also, the entrance of the race above the dam, on the left bank of the stream. The dam above described is adapted to any sort of river- bed, whether it be rock, sand or clay. The shape of the banks is a more material point than the nature of the bot- 6 50 A CRIB DAM. torn, especially if it is desired to raise the dam to a hight equal to that shown in our engraving. DAM FOR ROCK BOTTOM. 51 CHAPTER IX. DAM FOR ROOK BOTTOM. Under favorable circumstances and with plenty of mate- rial of the right kind conveniently at hand, a dam may be built of a character which will do excellent service and withstand the most sweeping freshets, without requiring the exercise of much mechanical skill on the part of the builder. Among this class are several of the dams already illustrated in this work ; such, for example, as the log dams shown in our fourth and fifth, and the rip-rap dam in our seventh chapter, all of which might be constructed, with the exception, perhaps, of the chute in the rip-rap dam, with such means and experience in the carpenter's or mill- wright's trade as are possessed by nearly every mill-owner of average capacity. It often happens, however, that a moderate amount of skill in the use of carpenter's tools and in the putting together of frame-work will enable the builder of a dam to accomplish his object with far less ma- terial than he would otherwise be compelled to use, thus reducing very greatly the cost of the undertaking. His head and hands, in other words, will save his pocket, if he is so fortunate as to know how to use them with due effect. For this reason, it is of prime importance to every owner of a water power which is to be utilized by the erection of a dam, to be able to economize and turn to the best possible account the means which nature has placed at his disposal. Our illustration herewith given presents a description of dam specially adapted to streams which have a solid rock bottom. It is entirely different from any which we have laid before our readers in preceding chapters, and de- pends for its strength and security mainly upon the thor- oughness with which it is put together. With proper care 62 1)AM FOR ROCK BOTTOM. in this regard, intelligently exercised, it may be relied upon as a perfectly safe and permanent structure ; this fact hav- ing been proved by as severe tests as are generally exper- ienced in the way of sudden and violent floods. The general construction of this dam is plainly shown in our engraving. The posts A A are supported by the braces B B, and have the horizontal timbers D D gained into them, the upright planking being nailed to the horizontal timbers on the up-stream side. The posts A A should be sixteen inches square, and in the dam here shown are eight feet long above the rock, in addition to which they should extend Irom twenty-two to twenty-eight inches into the rock, thus giv- ing them a firm foundation and foot-hold. The braces should be twelve inches square, and a 2^ inch shoulder should be made in the post to receive their upper ends, which are beveled to fit the notch in the post. Each brace is secured with a thin key at the top where it encounters the post, and a piece of 1^ inch plank is inserted at the foot of the brace between the end of the brace and the rock. The brace is let into the rock ten inches, the end being left square, and resting in an angular hole or notch ten inches deep and fourteen inches wide. The horizontal timbers are six by ten inches square, and the gains cut in the posts, in which they are placed, are 2^ inches deep. They may be fas-tened either by spiking or keying until the upright planking is nailed on. This plank- ing should be two inches thick, and the upper ends of the planks should project one or two inches above the upper horizontal timber or tie. The lower ends should be care- fully shaped to fit the uneven surface of the rock with which they come in contact, so that the escape of water beneath them may be prevented as thoroughly as possible. The upper part of each post is beveled in the down-stream direction to enable the water to run off freely, and also to prevent it from going down the grain of the wood and thus causing it to decay. The holes for the posts are drilled in the rock in dovetail shape on the upper side. The end of the post is cut to fit this dovetail, a shoulder being made on that side two inches DAM FOR ROCK BOTTOM. 66 deep. For the admission of the post it will be necessary, of course, to make the hole somewhat larger than the end of the post. For the purpose of securing the post firmly in its place, a long, wide key, about 2| inches thick, is inserted on the lower*side of the post, holding it snugly and strongly against the dovetail side of the hole. This key should be so made as to fit the full depth of the hole against the rock on the lower side. It is of vital importance that the dovetail should be made on the up stream side. Experience has shown in the most striking manner the necessity of this ar- rangement. A dam in one instance within our knowledge was built on the general plan here described, but the dove- tail and key placed in contrary order to that here given — the dovetail being on the down-stream side and the key put in on the up-stream side. This dam went out when a flood came upon it, the keys, which perhaps were not fitted with sufficient accuracy, working loose so that the posts lifted out. When re-built in the same manner, except that the dovetail was placed on the upper and the keys on the lower side, the dam stood firm, resisting up to the present time every freshet that has occurred. The length of span of the dam here illustrated is about sixty feet, the distance between the posts being twelve feet. On the up-stream side of the dam a fill should be made against the planking, extending up from the rock four or five feet and sloping off* gradually. For this fill coarse gravel or small stones may be first used, immediately against the bottom of the planks, finer material being afterward thrown in. For the upright planking, it is well to use seasoned and green planks alternately. If all are seasoned, they are lia- ble to swell in such a manner as to burst them off" of the ties. If all are green, exposure to the air will cause them to shrink and leave wide cracks. The planks should be champered or half-beveled on the up-stream edge (the down-stream edges being brought together perfectly close) in order to catch the loose earth which may drift against them. , On the left of our engraving is the race H, and an eleva- 66 DAM FOR ROCK BOTTOM. ted wing of the dam, the post G being about five feet high- er than those in the main portion of the dam. The cap E extends into the rock on that side of the stream and is there firmly secured. The planking F is nailed to this cap below ; and in this wing of the dam is the head-gate, which does not appear in the cut, but the position of which is clearly indicated. A PILE DAM. 57 CHAPTER X. A PILE DAM. The dam which we illustrate in this chapter is adapted to a mud bottom or to any kind of river-bed which will afford a firm foothold for piles, and into which they can be driven to the necessary depth. The first step in the process is the preparation of the piles, which should be of oak if conve- nient, ten or twelve inches in diameter, and from twelve to twenty feet in length, according to the hight it is intended to give the dam, the nature of the bottom, and consequent- ly the depth to which it is necessary to drive the piles. The taper at the lower end should begin two or two-and-one- half feet from the point. In using the pile-driver in setting the piles it Avill be found that the iorce of the successive blows will after a time have the efi*ect to split the pile at or near the top; and to prevent this a ring should be placed over the top of the post. This ring is made of bar iron three-fourths of an inch thick and from two and a half to three inches wide, the ends where they meet to form the cir- cle being welded as strongly as possible. It is also expedi- ent to champer or bevel the inside of the ring so that it will go on with the wider opening downwards, the object being to make the ring compress the top of the pile in such a manner that when it is desired to remove the ring it will come ofi" easily. Care must be taken not to champer it at too great an angle, or the post will act upon it like a wedge and the ring will burst before the driving is comple- ted. As this accident is liable to happen in spite of every precaution that can be taken, it is well to have several rings made before beginning the work, so that while one is taken away for repair another may be used and the driving go on without interruption. For a dam like the one here illustrated, the piles are driven eight or nine feet into the ground, leaving from six 58 A mle dam. to eight feet above for hight of dam ; but where the'bottom is sound and firm the posts need not go in to so great a depth. There are three rows of piles shown in our engrav- ing, the two front rows, A and B, being close together, but alternating so as to " break joints," and the second and third rows, B and C, being far enough apart to admit a hor- izontal layer of logs E E between them. A dam may be built with but two or even only one row of piling, and possess suificient strength for any ordinary test. If only one row is planted, logs and brush should be piled up behind it on the up-stream side so as to make the dam tight and break the immediate pressure of the current. The liorizontal logs E E should be of about the same diameter as the piles; and between them, at intervals, are inserted the butt ends of the binders G G, which are logs or poles from thirty to forty feet in length, extending from the piles up stream and be- ing covered with the filling. The upper horizontal log E is pinned, as will be seen in the cut, to the end of the binder belcw it; and this should be done at frequent i)oints along the whole extent of the span. The apron H has a foundation of heavy sills D D, for which large logs should be selected, laid transversely across the stream, and spliced and firmly pinned where two ends meet. Cross logs F F are laid upon these, extending up-stream be- tween the piles, and having a length of from ten to fifteen feet, or whatever may be necessary to prevent the water, as it comes over the dam, from striking beyond the ax)ron and washing out the river bed. The planks H are laid parallel with the cross-logs F and firmly spiked to the sills D D. The crib I is a hollow square comjDosed of piles driven down in the same manner as those of the dam, but of greater length above the bed of the stream, making the top of the crib from two to four feet higher than the dam, according to the hight and nature of the bank. These piles, as will be seen, are placed close together; and the dam should meet the crib at a point a little farther up-stream than the center of the crib. At K is shown the water-line when the dam is full to the crest; and at L is indicated the filling, for which gravel, dirt and stones may be used, the slope extending A f»tLE BAM. 61 from the crest of the dam thirty or forty feet up-stream. The same material is used for the filling of the cribs or abut- ments, of which but one is shown in our engraving, which represents the dam as if cut in two, lengthwise of the stream. It is of special importance that the dam should be made as nearly water-tight as possible in every part. For this purpose stones may be used in filling the holes, the size SI > Z 01: ?^ 5' B' M. i (7 in i!!; / / / / i^ Vl ^if^'li,lflir STONE DAM J^EAR FRANKFORT, KY. 109 Size and built up in the manner above described, and the back orjup-stream side is composed of loose flat stones laid up without much regularity, the work being finished by filling with earth and small stones, making a tolerably gradual slope on the up-stream side and giving the dam a wide and substantial base. The face of the dam, composed of the solid tier of masonry, inclines slightly up-stream, varying but a foot or two from a perpendicular. The length of the dam here shown is about 300 feet be- tween the towers. Its width at the base is 8 feet and at the top 5 feet, and its hight about 12 feet. The towers are each IT feet high, 18 feet square at the base, and 12 feet square at the top. The number of courses of stone in the main dam is six, the stones being, as already stated, two feet thick. From the tower at the right of the picture a wing or con- tinuation of the dam runs out, keeping the same general direction as the dam itself, its purpose being to keep the earth from washing out, the bank being common soil and very low on this side of the stream. On the other side the bank is of sufficient hight to require no protection of this kind. The dimensions of the wing wall are less than those of the main dam, as it has much less pressure to resist. From the same tower with which the wing wall connects, a side wall of somewhat greater width and hight extends up the stream, along the bank to the entrance of the race, pro- tecting the bank from being overflowed or worn away by the stream. A similar wall also extends a short distance above the race, and both sides of the race are in like man- ner strengthened against the action of the water, their walls being somewhat lower than those along the banks of the stream. At the entrance of the race are placed head-gates, which are not represented in our engraving. A tablet on the face of one of the towers bears the name of the owner of the dam, date of construction, &g. Our illustration gives a view of the dam by which the power is furnished for the extensive flouring mill of Mr. Geo. B. Macklin, four miles from the city of Frankfort, Ky. The course of the stream at this point is such (making what 110 STONE DAM NEAR FRANKFORT, KY. may be called a "horse-shoe" bend) that by running the race from 200 to 300 yards a fall of 21 feet is obtained. The firm of James Leffel & Co. have put in three of their im- proved Double Turbine wheels in this mill, from which fact an idea may be formed of the amount of business it is de- signed to maintain, and which fully justifies the thorough and durable manner in which the dam has been constructed. The dam was completed about four years since, and is one of the most substantial structures of the kind to be found in the West or South. ,\N IRON DAM. Ill CHAPTER XIX. AN IRON DAM. Iron is now so common a material for building, and enters so largely into the construction of edifices of every class, that it would be a matter of surprise if it did not prove adaptable as well to the erection of dams. It possesses the advantages of great strength in small compass and of being more conveniently handled than the cumbrous materials required in building many other classes of dams. We illustrate in this chapter the first dam in our whole series thus far of which iron has formed a part otherwise than in the shape of bolts or spikes. We do not now present it as possessing practical merit superior to that of many other dams already represented, but rather as an interesting novelty, and an example of what may be done in the erec- tion of a substantial and reliable dam, with iron as the almost exclusive material. The dam shown in our engraving is particularly suited to a rock bottom, or can be placed on a solid earth bottom by putting under it a substantial foundation of timbers. It consists, as to its general construction, of upright sections or panels of boiler or cast-iron, built in zig-zag or " worm " fashion, after the style of the "Virginia fence," and sup- ported at each bank by stone towers. The hight of the panels is six feet, in the dam here represented, and the hor- izontal length of each the same, so that the distance be- tween the extreme ends of the two panels forming an angle will be ten or eleven feet, the width of the " worm " being three feet. The total length, therefore, of the dam shown in our cut is about 120 feet. Its course across the stream is straight, there being no advantage gained, in a dam of this 112 AN IRON BAM. construction, by giving it the arch or curve formation which has been shown in previous chapters. The panels, as alreaiy staled, may be made either of boiler-iron or cast-iron. If of boiler-iron, each panel is com- posed of two plates of equal size, lapped and riveted to- gether. If of cast-iron, three plates are used in each panel, filleted together and ribbed on the back. The panels in this case should be about one inch thick. The posts to which the panels are bolted may be of either cast or wrought iron, and are shaped to suit the angle made by the corners. They should be about one inch thick, and contain recesses to re- ceive the ends of the plates. At the bottom of the post is a flange or foot-pad, through which the bolts are driven by which the post is secured to the rock. The braces supporting the posts are of wrought iron. They are bolted to the posts on the down-stream side, and have a cast flange at bottom through which they are bolted to the rock in the same manner as the posts. The brace should meet the post within six or eight inches of the top of the latter. The stone towers shown in the cut at the extremities of the dam are about 12 feet high, 12 to 14 feet square at the base, and 10 to 12 feet square at the top. The relative dimensions and manner of construction of the walls en- closing the race will be sufficiently understood from an ex- amination of the cut. The race is provided at its entrance with a head gate of the usual description, made in two parts for convenience of operation. If a protection is required for the dam, on account of ice or driftwood passing over, a timber may be laid lengthwise along the top of the dam, and rafters placed against it, which when sheeted over will form a sort of inclined apron The ice or other substances calculated to injure the dam if allowed to pass over with a perpendicular fall, will thus be safely conveyed away on a gradual slope. As the " worm " of the dam is three feet wide, as already stated, three tim- bers instead of one aiay belaid along the top, placed snugly side by side and constituliai^ a still more reliable covering. This portion of the work may be varied in many ways, ac- 14 Aif IROK DAM. Il5 cording to the judgment or preference of the builder of the dam, and will of course depend greatly upon the peculiar circumstances of the case, the nature of the stream and the country, and the materials most readily at command. In many localities, the dam itself may be all that is required, no covering or shield being necessary if it is subject only to the pressure and spill of water. It should also be remarked that this is but one of a great diversity of iron dams which it would be practicable to con- struct, and any one of which would doubtless be equally serviceable with this. In fact, if iron is the sole or chief material employed, it may be put up in any shape or on any system the buildei may select, it being in this respect more adaptable to circumstances than any other material. Stone can only be used for laying in a wall, filling cribs, or rip- rapping an embankment; and logs and timbers are subject to a variety of limitations arising principally from the fact that they possess the necessary strength only when in con- siderable bulk. With iron, on the other hand, the maximum of strength may be attained with the minimum of dimen, sions. It affords more liberty in the selection of plans and mode of construction than the more bulky substances which are generally used, and which, it must be admitted, have undeniable advantages on the S( ore of cheapness and the ease with which they can often be turned to account with- out the employment of skilled laborer expensive manufac- turing processes. 116 PILE Aim BOULDER DAMS. CHAPTER XX. PILE AND BOULDER DAMS. A point of vital importance in the construction of a dam is to provide against the effects of the overflow, which has a constant tendency to undermine the foundation of the dam by gradually washing out or wearing away the bed of the stream at the point where it strikes. This is in fact one of the chief difficulties to be taken into account in building a dam, and it is at this point, perhaps, as I'requently as any other which can be named, that they prove to be defective. The working of the water in the manner described is often so gradual and insidious that its effect is unobserved until made apparent by the giving way of the foundation at one or more points, and this very probably at a season of high water, when even an attempt to repair the mischief is scarcely possible and is apt, if made, to prove ineffectual. The location of the breach, moreover, being at the very base of the dam, where the weight of the structure and the piessure of the water bearing upon it is chiefly felt, renders the task of making good a defect of this kind after it has thus betrayed itself an exceedingly arduous one. In many instances it has been found impossible to perform the work successfully, and the loss and entire rebuilding of the dam has proved the necessary consequence of the neglect to make it in the first place secure against this particular dan- ger. In this matter, as in a thousand others,experience has repeatedly shown that an ounce of prevention is worth a pound of cure. A due regard beforehand for the known conditions of the case and the well understood action of water in flowing over a dam will save many hundreds of dollars in subsequent repairs and rebuilding, as well as in PILE AND BOULDER DAMS. 119 the incidental losses which attend a breakdown of this kind. The methods of construction adopted to prevent this de- structive action of the water are various, and some of them have already been illustrated in this volume. In some cases the horizontal apron projecting from the foot of the dam down stream is found sufficient; while in others an apron is made forming a gradual inclined plane from the crest of the dam to a point some distance down stream, thus permitting the water to escape in a swift current in- stead of a heavy perpendicular fall. This is an excellent method of breaking its force, provided the inclined plane is itself strongly constructed with a firm foundation and with no liability to leakage. We illustrate in the engraving here presented two forms of construction for a dam by which the prevention of injury by underwash is effectually attained. A glance at either of the two figures in the cut will show that there is scarcely any possibility of the water wearing either downward in the bed of the stream or backward under the foundations. Both th'»se methods of construction partake of the nature of the inclined plane, it being so modified in the second as to constitute a series of steps by which the force of the water is broken and it is carried in successive easy stages from the top to the bottom. The strength of the materials used and of the method in which they are employed will also be observed. In Figure 1 an open frame of timber is represented, into which are inserted large boulder stones, forming a compact mass of boulder sheeting resting on gravel, and nearly impervious to water. The timbers here used should be large, say a foot square, and firmly pinned together. The hight of the dam in Figure 1 is about eight feet, and the bents, each consisting, as shown, of the three uprights, the inclined rafter and the intermediate brace, should be placed at intervals of six or eight feet along the face of the dam. A stringer is bolted to the top of the second upright, under the rafter, as shown in the cut, and one end of the brace is let into this stringer, the other end being pinned to the highest upright. At the top of this 120 PILE AND BOULDER DAMS. upright, also, will be seen a heavy stringer bolted on each side in such a way as to form a level surface at the crest of the dam and protect the structure at that point. In addition to the brace shown in the engraving others may be put in in a similar manner, giving additional strength to the frame- work. In Figure 2, the same principle of construction will be observed, with modifications suited to a region where tim- ber is plentiful. This structure is composed of piles driven at right angles with the direction of the stream and placed in rows, properly stayed and covered with planking firmly nailed to the horizontal and vertical timbers. If it is de- sired to have the structure perfectly water-tight, a line of sheet piling may be driven in, in the line of the dam across the whole breadth of the stream, and this being again sup- ported by foot piles and stays at diflerent distances, a tight and very durable dam is the result. The water falls in cascades over the series of steps, and any injurious elfect on the foundations is prevented. The method in which the horizontal timbers are pinned to the uprights and the stringers bolted to the top of each upright will be readily understood by a glance at the cut. The timbers in this dam need not be so large as in Figure 1, six or eight inches square being amply sufficient. The bents in this, as in the other dam, may be put in at intervals of six or eight feet. The construction of both these dams, aside from the framework, is very simple, and presents a safe and substan- tial resistance to the pressure of the water. The rip-rap of the embankment on the upper side may be carried farther, if desired, than is shown in the cut; and the proportions and extent of the layers of boulders may be varied in any direction according to the judgment of the builder and the circumstances of the case. STONE DAMS. 121 CHAPTER XXI. STONE DAMS. Whatever may be said in favor of other descriptions of dams, whether they be frame, crib, log, pile, earth, brush or iron dams, it must still be admitted that stone is on many accounts the most suitable material for a barrier against the pressure of water, and the one which will naturally be se- lected where the circumstances do not make it too costly, or where the object in view cannot be as effectually accom- plished by more convenient methods. Stone possesses more of the qualities which are valuable in a dam than any other substance. Its weight, though it renders the work of build- ing more arduous, is a source of strength when it is once in position, such as can hardly be given to any other material ; it is subject to neither rot nor rust, and unless undermined or caved, in consequence of the weakness of some other part of the structure, it is not liable to yield to any of the ordinary forces which a dam is intended to resist. When prop- erly guarded from the gradual inroads of the water through apertures or crevices, or in the form of underwash by which the foundations are sapped, a stone dam is an immovable bulwark and will withstand the heaviest freshets, saving in the long run, in many cases, by the avoidance of any outlay for repairs, many times the difference between its cost and that of cheaper but less reliable structures. We illustrate in this chapter two different forms of a stone dam, both of which have the attributes of strength and per- manency, the choice between them depending on the char- acter of the stream and the means of the builder. Figure 1 is a sectional view of a dam constructed in England by the celebrated engineer Smeaton. It has, as will be seen, a long inclined slope on each side, above and below, and the 15 122 STONE DAMS. extent of base in proportion to the hight is such as to con tribute immensely to the stability of the dam. At the crest of the dam and inclined downward, will be observed the ends of two courses of flag stones, which are so laid as to break joints, footed ux3on grooved sheet piling with bearing piles and stringer, and supported by a thick and wide layer of " rubble " or small boulders underneath the flags. Live moss is packed between the flag stones to prevent the silt being driven through. At the foot of the dam is another row of sheet piling, similarly supported, and protected by a fir plank at top from the action of the water. Over the layei* of rubble is placed a row of regular stones, laid end- wise and leaning, so as to be perfectly secure from derange- ments by floods. In the up-stream direction from the crest of the dam is also placed a layer of rubble with a tier of flat stones above it and at the up stream end of the dam is a single course of large flags reaching from the surface to the base of the dam and held down by a filling of small stones. A dam of this kind is adapted to a stream having a soft bottom either of loam or clay; but if there is a sandy bottom the piles must be driven to such depth as will give them a firm hold, and special care must be taken to guard against underwash at the foot or down-stream extremity of the dam. In Figure 2 is shown a dam built upon a somewhat dif- ferent principle, composed of solid masonry instead of rub- ble and flags, and having a curved or concave apron instead of a gradual slope on the down-stream side. On the up- stream side the construction is very similar to that of the dam in Figure 1, except that stones of more regular shape are used; and in all parts of this dam reliance is placed up- on heavy and compact stonework instead of piling. The water has at first a nearly perpendicular fall, but is carried away in such a manner by the curve of the apron as to en- tirely lose the direction which would give it an injurious eff*ect upon the foundation. The construction of this dam throughout is so distinctly shown by thesectiona*l view here given that it requires no further explanation. An English writer on the subject of the construction of AU A* LAWRElfCE, KANSAS. 13d described, are laid down to complete the foundation, and each succeeding course is drawn five feet up the river, as will be seen by the appearance of the butts of the trees in the cut. As each course or platform, or part of a platform, is sunk, it is thoroughly weighted, and all interstices in the brush or between the trunks are carefully filled with rubble, so as to form a solid concrete. The frame consists of eight platforms of timber, composed of two main sills 12 by 14 inches, laid flatwise, halved together where the ends join, and bolted with drift bolts of inch iron. The main sills are held in place by means of cross-ties 8 by 8 inches, the ends of which are dovetailed into the sills. The ties are put in at intervals of eight feet, and spiked to the sills with | inch drift bolts. The first platform, forming the base of the dam, is twenty-four feet wide from out to out, and is gained into the upper platform of trees so as to receive a uniform and level beiring, and each succeeding course is thoroughly se- cured with iron bolts to the course below, receding on each side one foot. The breasts of the dam are thus given a slope of 45 degrees, and the top is finished with a level sur- face eight feet in width. An open platform twelve feet in width is also firmly attached to the* lower sill of the upper slope of the dam, which practically makes the base of the structure thirty-six feet in width. As each platform is laid and adjusted, it is carefully filled with rubble rock of large size, all interstices being packed with spawls so as to form a solid body. The frame being completed and filled with rock as above described, the outer corners of the sills are trimmed off* so as to present a bearing surface of four inches, and the whole is covered with plank 2^ inches in thickness, placed in line with the current of the stream, and firmly spiked on with six-inch boat spikes. The dam having been built and com- pleted in sections, as each section is planked over, a protec- tion is placed on the up-stream side, extending thirty feet up the river, having a thickness of fully four feet on the open pilatlorm, and extending at least half way to the top of the dam on the ujjper slope. This protection is composed of large stones, all the interstices being filled with spawls. liO DAM AT LAWRENCE, KANSAS. After a row of tongued and grooved sheet piling has been driven at the lower ends of the tree foundation, a large amount of rubble rock is placed upon the lower ends of the logs and in the bed of the river below. The plan contem- plates the use of 10,000 yards of rubble stone, which is be- ing quarried out of the south bank of the river, immediately below the dam. The head gateway and canal on the north side, which are represented in the engraving, rest on ten rows of piling driven closely together, up and down the river. The piles^ after being sawed off two feet below low water mark, are capped by timbers 10 by 16 inches, laid flatwise, upon which is laid a close floor of ten-inch timbers; and this timber floor is covered with a floor of three-inch planks, laid in line with the stream and firmly spiked down with six-inch boat-spikes. On this platform the masonry is laid, each pier resting on three rows of piling driven twenty-tive feet to the bed rock. Sheet piling is driven to the clay, from the bank in front of the head gates, and along the base of the inside pier to the lower end of the tree foundation, thence under the canal to the river bank, and along the bank out- side of the round piling, to prevent any washing of the bank by the discharge of the water from the water wheels. Sheet piling is also driven along the lower ends of the tree founda- tion to the intersection of the rock bottom. The canal below the tree foundation is constructed the same as immediately below the head-gates, excepting that the sand and gravel is washed out from among the piling to a depth of about five feet, and then riprapped thoroughly with stone to prevent any further washing. Water wheels may be located on either side of this canal by merely cut- ting a hole in the floor to receive the tube of the wheel, and the water is discharged under the canal into the channel ol" the river below the dam. The outside or bank walls below the piers are six feet thick at the base, battered on the out- side to three feet on top, are eighteen feet high above low water, and will serve as a foundation for buildings their en- tire length, as power can be taken at any point along the canals. The piers in which the headgates are placed are DAM AT LAWRENCE, KANSAS. 141 six feet thick, without batter on either side, by eighteen feet in hight. The inside or river walls are six feet thick without batter ; and, as already stated, are nine feet high, being only two feet higher than the dam, and thus serving in time of flood as an overfall for the water. The head-gate piers or walls on the south side of the stream are similar in construction to those above described, except that they have a foundation of solid rock instead of resting upon piles. The floor of the south canal is also the same in general construction as that of the north canal, ex- cept as regards the foundation, the posts or piers supporting it being placed on the excavated rock bottom of the canal. The manner in which the water is discharged from the wheels has been fully illustrated, archways being provided for its escape from the south canal, while from the north canal here shown it has free passage outward both at the lower end and at the side, between the piles by which the flooring is supported. The great work which has been thus minutely described and illustrated in three consecutive chapters is expected to reach its completion in the coming autumn (1873). We have already acknowledged our indebtedness for material for our account to Mr. Orlando Darling, the enterprising contractor, undei- whose immediate supervision the work is carried on, and by addressing whom at Lawrence, Kansas, any particulars which we have omitted to give, or informa- tion in regard to the leasing of power, can be obtained Lawrence is at present a flourishing city of some 12,000 in- habitants, and has been built up to its present proportions chiefly by the excellent trade, which by its central location in a country of unsurpassed fertility, aided by its ample railroad facilities, it has been able to command. It may be for this reason that its people have hitherto been content to allow its magnificent water power to remain so long unim- proved ; but they have now resolved to make their town the manufacturing center of Kansas. Railroads already run out from the place in six diff'erent directions, and two more are being built into the city. The wool of California and New Mexico and the cotton from the Red River bottoms and lis hAU At LAWRENCD, KANSAS. Northern Texas pass through Lawrence on their way to an eastern market, to be manufactured and returned, laden meanwhile with numerous profits and transportation charges. Nowhere, it is said, can black walnut lumber for furniture be bought cheaper than at Lawrence ; and timber for agri- cultural implements can be obtained at moderate prices. Paper materials are abundant and cheap ; yet for hundreds of miles no paper-mill is found. Few points, therefore, offer more attractive inducements to manufacturing enterprise than the beautiful and thriving city of Lawrence. PAM ON THE TASSOQ RIVBR, HINDOSTAN. 143 CHAPTER XXV. DAM ON THE TASSOO RIVER, HINDOSTAN. The utilization of water power for manufacturing pur- poses is the ordinary, in fact the almost universal object of the construction of a dam ; and it has been with reference to this leading purpose that our illustrations thus far have been designed. There are, however, other useful ends for which a substantial and durable dam is sometimes requisite ; and among these is the provision of the necessary supply of water for the daily use of the inhabitants of a large city. Structures of this kind and for the object indicated are to be found in various localities in our own country; but the one we have chosen for our present illustration belongs to a remote quarter of the globe and is the work of a foreign nationality ; and it may possess the greater interest to many of our readers from the fact of its distance and novelty, as well as its great magnitude and the special necessity which it is to meet — that of furnishing to the people of Bombay, one of the largest cities of Hindostan, an abundant and un- failing supply of water. The city and island of Bombay, which have nearly 800,000 inhabitants, are supplied with water from Vehar, an artificial lake in the hills of the neighboring island of Salsette. The Vehar reservoir, which was constructed by the Government of Bombay about thirteen years ago, passed into the hands of the municipality of Bombay in 1863. It is nearly sixteen miles from Bombay Cathedral and has hitherto amply sup- plied the wants of the island ; but the rainfall of 1871 being very small, the lake, at the end of the "monsoon,-' (the periodical wind which blows half the year in one direction and the other half in the opposite, and which in the Indian Ocean blows from the southwest from April to October, 144 DAM ON THE TASSOO RIVER, HINDOSTAN. bringing heavy rains, after which it changes to the north- east for the rest of the year) was nearly ten feet lower than usual. Attention was thus drawn to the possibility of a short rainfall in the ensuing year, 1872, from which a deficiency of water would result, with all its consequent evils. To prevent so great a calamity it was decided by the municipality to make a new lake at Toolsi, to supplement Vehar. The valley of Toolsi is 112 ft. above the top of the Vehar lake, and is divided from it by only a slight ridge of hills. Hitherto the waters flowing from the hills into the Toolsi valley have found their exit by the river Tassoo, the eource of which is at the end of the valley opposite to the ridge dividing it from Yehar, whence it flows past Kennery to the sea. By damming up the source of the Tassoo, the water is impounded in the Toolsi valley, and by tunnelling through the ridge between Toolsi and Vehar, a passage is made for it into the latter lake. Of course, the supply of water into Yehar from Toolsi can be controlled, and, if not wanted, can be kept impounded in Toolsi lake till it is re- quired, any surplus flowing over the dam across the Tassoo, and escaping by the old route. The view given in our illus- tration is of the dam across the Tassoo, as it now appears, 30 ft. high, with the water overflowing. This view shows but a very small portion of the intended lake, the greater part of which lies behind the low ridge stretching across the picture. It is intended to raise the dam to a height of 71 ft. The lake, which is but an auxiliary supply, has an area of 300 acres of water, containing 1,451,000,000 gallons (besides as much of the available rainfall of Toolsi as can be turned into and stored in the Yehar lake.) All this water, except a few gallons, can be made, by opening the penstock in the tunnel in the ridge dividing Toolsi from Yehar, to flow into the latter lake, and thence through the main to Bombay. Yehar, when full, covers an area of about 1,400 acres, and has 2,550 acres of gathering ground, and contains 10,650,000,000 gallons, giving a daily supply of 10 gallons a head, and Toolsi will increase it by 4| gallons per head. This additional cheap water supply, which will probably last Bombay for twenty or thirty years, is expected 18 Bii DAM ON THE TASSOO RIVER, HiJfDOSTAN. 147 to cost only four lacs of rupees, a sum equal to about $220,- 000 in United States currency. The construction of the dam is not shown in detail in our engraving, but a sufficient portion of the structure is visible to give a very clear idea of the plan upon which it is built. The main feature of the work is the broad and solid wall of masonry, of which most of the lower or down stream face is shown. The up-stream face of this wall is covered and protected by strong piers of timber, between which are up- right planks, closely fitted and strongly secured; the top of this part of the dam being finished with horizontal stretchers extending between the piers. Midway of the stream a space is provided for the overflow of the surplus water, which afterwards falls over the stone work of the dam into the chasm below. On the upstream side of the timber face of the dam is a filling of stone and gravel sufficient to pro- tect the timbers and the foundation from undermining or leakage. These extensive and admirably constructed works wore designed and carried out by Mr. Kienzi Walton, an associate member of the Institute of Civil Engineers, who is the act- ing executive engineer of the municipality of Bombay. 148 LOCK AJiiD 1)AM AT HENRY, ILL. CHAPTER XXVI. LOCK AND DAM AT HENRY, ILL. We have described in preceding chapters the construction of dams for the utilization of water power, for the measure- ment of streams, and ior the provision of a supply of water for the use of the inhabitants of a populous city. We now give illustrations and a general descriptive sketch ol" a dam, the object of which is to improve the navigation of one of our Western rivers and afford, eventually, a channel of traffic between the lakes and the Gulf of Mexico, which will be of immense value to the people of our great grain growing States. The most urgent need of the agricultural popula tion of the Mississippi and Ohio Valleys is cheap transporta- tion for their products, by which the value of their wheat and corn shall not be wholly absorbed by the charges paid in getting it to a good market. As the case stands, the railroads do not afford this indispensable means of convey- ance at a reasonable cost ; and without discussing the ques- tion where the fault, if any exists, is to be found, we may safely say that no greater blessing could be bestowed upon the people of the West than direct communication by water with the great centres of commerce. With a view to securing this most desirable end, the State of Illinois has undertaken to improve the Illinois river so as to make it navigable for the largest class of steamers that traverse the Mississippi river at all navigable seasons of the year, from the mouth of the Illinois uptoLasalle, the point where the Illinois and Michigan canal enters, 100 miles southwest from Chicago. The distance thus comprised is 230 miles. The improvement is to be made by the construe tion of locks and dams, lorming a slack water navigation. The locks are to be 350 feet long between the gates, and 75 feet wide, and the dams are to .be raised so as to make a LOCK AND DAM AT HENRY, ILL. 151 uniform depth of 7 feet of water for the entire distance at all seasons. At present, during low water, there is less than three feet of water on many of the bars in the river, and on one only 16 inches. For the entire improvement, from Lasalle to the mouth of the Illinois river, five locks and dams will be required, the total cost of which is estimated at $2,200,000, being less than $10,000 per mile for the 230 miles comprised in the work; and this certainly appears a moderate expenditure for the facilities of transportation which will be secured. One lock and dam was finished some time since, at a cost of $400,000. This is the work illustrated in our engravings, its location being at the town of Henry, 28 miles below Lasalle and 32 above Peoria, the second largest city in the State. The lock is on the north side of the centre of the river. The dam connects with an outside protection wall, about 100 feet above the upper gates, and a short distance above the bridge erected not long since at this point; and joins the south bank midway between the bridge and the mouth of Sandy Creek. The two smaller engravings of the three which we here present, give front and sectional views of the dam, the top of one end of which may also be seen at the right of the larger cut. The dam is built of timber cribs filled with loose stones. It is 35 feet wide, 11 feet high, and 540 feet long, and is raised 6 feet above low-water mark. On the upper side of the crib-work sheet-piling is driven into the bed of the river to a depth of about 5 feet, and on the lower side piles 12 inches square are driven close together, 10 feet into the bottom of the river. Twenty feet of the width of the dam has a coping of timber, sloping up-stream, 8 inches thick at one end and 4 inches at the other. There are two drops (;f 3 feet each on the lower side, with solid timber aprons twelve inches thick, and 7^ and 8| feet width on which the water falls. Below the lower apron and the square piles, stone and brush are extended 20 feet on the river bed, and above the dam for 50 feet it is filled in with brush and gravel, tapering over on to the upper slope of the tim- ber coping. The dam is securely bolted at every crossing of 152 LOCK AND DAM AT HENRY, ILL. timber, and there were used in its construction more than 20,000 lbs. of wrought-iron bolts, generally | inches square and 14 to 22 inches long. In our illustrations. Fig. 2 gives a sectional view of the dam, showing distinctly all the parts as above described. In Fig. 3 is given a front view of the dam, such as would be obtained by standing midway in the stream below the dam and looking up-stream. By comparison of the two figures, the different parts will be readily identified. The lock is built entirely in the bed of the river. In com- mencing the work, an area of a little over seven acres was Fig. 2. inclosed by a coffer-dam substantially built of piles with cap timbers, and of sheet piling driven outside from 6 to 10 feet into the bed of the river, and protected with gravel on the outside of the piling from the bottom of the river, with a suitable outside slope. The water, which averaged only 4 feet in depth over the whole area at low water, was removed by a rotary clam-shell pump, with an iron delivery pipe ^ inches in diameter, and driven by a 15 horse-power steam- engine. The area of pit to be excavated for the foundation of the lock was 485 by 115 feet, and averaged 6 feet deep, requiring the removal of 13,000 cubic yards of earth. After the excavation was made,'';3,200 bearing piles of hard wood, from 12 to 25 feet long and 12 inches in diameter at the large end, were driven over the bottom. On these piles eleven rows of square timbers, 12 by 12 inches, were placed longitudinally, each row extending 477 feet, and secured to LOCK AND DAM AT HENRY, ILL. 153 the piles with bolts 22 inches long and | in. square. On these timbers cross timbers 12 inches square were placed 6 inches apart, covering two thirds of the whole area, and bolted to the piles and the longitudinal timbers at every crossing with bolts I in. square. All the spaces from the top of the cross timbers to 3 inches below the bottom of the longitudinal timbers — a depth of 27 inches — were filled with concrete. The whole of this foundation was covered with 2^ inch planking secured to the timbers. On this substantial foundation the side walls of the lock were commenced, extending 476 feet on each side, with a mitre sill wall under the upper gates, and a breast wall at the head uniting with both side walls, which are 73 feet apart at foundations through the lock chamber. For 176 feet from the head of the lock the walls are 30 feet high, and for the remaining 300 feet 24 feet high ; the upper end of the lock being 6 feet higher than the lower end, on account of the extreme depth of the water in time of floods. The main walls of the lock, where the hight is 30 feet, are llffeet thick, while those 24 feet high are lOf feet thick at the foun- dation. The breast wall is from 7 to 8 feet thick and 7 feet, 8 inches high. The mitre sill wall is of the same hight, and from 10 to 15 feet thick; and in this wall are eight arched culverts 5^ feet wide and 3^ feet high, through which water is admitted into the lock. Below the lower gates the main walls extend 20 feet, with wing walls 40 feet long on both sides, flaring 10 feet each at the lower end. The water is dis- charged from the lock through semi-circular arched culverts 5 feet wide, with abutments 6 feet high, and connected at the top with an arch of 2^ feet radius. The masonry is com- posed of magnesium limestone and is very substantially put up, laid in the best quality of hydraulic cement mortar; and amounts in all to 10,328 cubic yards. The entrance to the lock is formed by heavy rubble walls extending up from the head of the lock on each side. On the north or shore side it turns with a curve towards the shore, and joins a slope wall protection to a guard bank, which extends 350 feet to connect the lock bank with the shore. On the south, or river side, this wall extends 100 feet, flaring out from the 19 154 LOCK AND DAM AT HENRY, ILL. line of lock walls ; then, forming a circular pier-head of 8 feet radius, it extends down parallel with the lock walls (the faces of the two walls being 50 feet apart at bottom) to 100 feet below the end of the lock, where it forms a pier- head similar to the one at the upper end, and returns to join the wing wall of the lock. The entire length of this wall is 900 feet on the river side, forming the abutment to the dam and the river protection to the lock. It is from 20 to 29 feet high, 7 to 8 feet thick at bottom, and 3 feet thick on the top, with a stone coping 9 inches thick. At the foot of the lock, on the shore side, is a similar wall extending down 50 feet and then curving towards the shore. This \ss^\:uivt»xs Fig. 3. wall is but 15 feet high. The rubble walls are all on a foundation of piles, timber and planking, there being 860 piles, from 12 to 19 feet long. There are 5,560 cubic yards of rubble wall, of which 5,300 cubic yards are laid in hy- draulic cement, and 250 cubic yards are laid dry. The filling between the outermost or river wall and the wall of the lock with its wing extension, is not shown in our engraving, the space being represented as if hollow, thus showing the interior or bank side of the wall, as it appeared before the filling was put in. The lock-gates are of massive proportions, 24 feet high and 43 feet wide, each gate containing over 20,000 feet, board measure, of the best white oak timber, and 27,000 lbs. of wrought and cast iron (including the anchor irons by which the gate is secured to the lock walls) weighing over LOCK AI^D DAM AT HEl!TRY, ILL. 155 60 tons, and costing, with the hanging fixtures, $4,000 each. The mechanism for operating the gates and for admitting and discharging the water is all of the strongest and most complete description, and the balance of the gates is so perfect that, ponderous as they are, two men can open or close them in four minutes with ease. The lock can be filled or discharged in three minutes, moving at its maximum lift 172,000 cubic feet of water. A single boat can be locked through in about fifteen minutes, a fleet requiring more time, as the boats have to be got into position in the lock. The capacity of the lock is equal to 12 canal boats at one timo, of the size of those on the Erie or the Illinois and Michigan Canal. This extensive work was completed Jan. 11, 18T2. It was prosecuted under the official charge of Messrs. Joseph Utley, Virgil Hickax and Robert Milne, canal commis- sioners, the designing and construction being the work of Daniel C. Jenne, chief engineer, assisted by Geo. A. Kee- fer, John S. Butler and Chas. 0. Upham ; and the details were faithfully carried out by the contractor, William Johnson. The stone was obtained from the Semont and Joliet magnesium limestone quarries, the oak and pine timber from Michigan, and the other timber and piles from the immediate vicinity of the work. By the building of this lock and dam, 60 miles of good navigation, is added to the Illinois and Michigan Canal. It is intended eventually to extend this work to Chicago, by improving the river in a similar manner 60 miles to Joliet, and enlarging the Illinois & Michigan canal to the Chicago river for 86 miles. It is estimated that this will cost over $16,000,000, but the money will be well invested in an enterprise so vastly beneficial to the people of the west and southwest, giving to them, as it will, direct communication I'rom Chicago by large steamers to New Orleans and to all points on the Mississippi river and its chief tributaries. A total of 1,500 miles of navigation will thus be secured, and :i cheap channel of commerce opened for an almost boundless agricultural region, which needs for its complete development only the means of transporting its products at 156 LOCK AND DAM AT HENRY, ILL. small cost to the distant points where a remunerative market awaits them. CRIB DAM WITH PLANK COVERING 15T CHAPTER XXVII. CRIB DAM WITH PLANK COVERING. Crib-work, when properly constructed, with suitable fill- ing and secure fastening of the timbers where they cross, IS as reliable an arrangement for a dam as any that can be mentioned. It of course requires the use of a considerable amount of timber, there being, from the nature of the structure, no chance to economize in this respect ; but as crib-work can be put up in a thorough manner with the employment of but very little skilled labor, the saving in this point is often much greater than the reduction in cost of material would be by adopting any other plan. Moreover, even in a country not heavily timbered, there is apt to be in the vicinity of a water-course a sufficient amount of such timber as will answer for crib-work, with a little manage- ment; and the builder need not therefore, in most cases, resort to an unsatisfactory style of construction, or pay high wages to expert professional workmen, unless an unusual scarcity of timber prevents him from adopting such a method as is described in the present chapter. The plan of dam here illustrated is suited to compara- tively narrow streams, not exceeding 100 feet in width, and where not over 10 feet head of water is to be afforded. The material used is timber, brush and loose rock, with an admixture of fine or coarse gravel or coarse sand and dirt. The crib is a contmuous one, from bank to bank, the tim- bers crossing the stream being spliced together where required. At intervals of 8 or 10 feet timbers are placed crosswise of the dam, in the directio'n of the stream, their purpose being to bind the frame together. They are firmly secured to the longitudinal timbers with either pins or spikes. They diminish in length from the base to the top 168 CRIB DAM WITH PLANK COVERING. of the dam, as the up-stream and down-stream sides of the dam have each a slope which brings them nearly together at the top. The filling may be of brush and clay, though gravel is preferable to clay under all ordinary circumstances. In this case, as the dam is intended to be as nearly water tight as may be, the clay will serve very well to give weight and solidity to the crib-work. For the purpose of exclud- ing the water, the dam is covered tightly with plank on both sides and on the top ; and an apron of planks, supported on logs, is also placed in front of the dam down stream. For abutments, square cribs are built, of the same general nature as the dam, but of somewhat greater width and hight. The cribs should be filled with stone and gravel, and thus made as heavy and substantial as possible. It is an excellent plan, also, to give the dam a curve up stream, as shown in several preceding chapters, its strength being thus considerably increased. The dam in our engraving is supposed to rest on a hard bottom ; but should the bed of the river be soft, it would only be necessary to put down in the first place a founda- tion of logs, laid close together, lengthwise of the stream, and projecting beyond the base of the dam down-stream. Should leaks occur in the plank covering of the dam, it may be made tight by stirring saw-dust or fine tanbark into the water above the dam. A small leak at the bottom may be stopped by crowding straw or fine brush into the hole and covering it with earth. The exact locality of such a leak may be found by stirring a little saw-dust into the water near the bed of the stream and observing where the current carries it through. For a larger leak, the best plan is to put in first a stone nearly large enough to fill the hole, following it with smaller stones and finally gravel and loam. This has the advantage of being more durable than the straw filling, which will rot in time. Although relating to a different style of construction from that above described, we may venture to add in this connec- tion the following letter on the subject here treated of, received some time since by the publishers of this work : Editor Leffel News : My model of a dam is a common CRIB DAM WITH PLANK COVERING. 161 barn roof placed across the stream ; the eaves — the upper one especially — sunk to a solid foundation, the peak or ridge extending level from bank to bank across the creek. Or the half of the roof down the creek may be omitted, and let the surplus water drop perpendicular on an apron. (I adopt the roof as an illustration as being so easily understood, the bearers being in place of the rafters, and the planking in place of the roof boarding.) The bearers should be sup- ported by plates running across the stream, except at the foot, where they should be beveled and rest on the bed of the creek. The plates may rest on stone walls, log cribs, or posts standing on mud-sills that have been well bedded and in the direction of the stream. The strength of timber and distance apart must be in proportion to the height of the dam. There are dams near here in rapid streams, the foundations of which have been in for over one hundred years. WM. C. CRAWFORD. MiLFORD, Pike Co., Penn. We think a sloping face on the downstream side of the dam, with an apron to carry the water fairly away, is pref- erable to allowing the water to drop perpendicularly on the apron. It is at the foot of the dam, in front, that undermining, wearing and washing out very frequently occur, by eddies and reacting currents of water. If the water comes down in a sloping directiion to the apron, as in the dam which we illustrate, or as in the "roof" con- struction suggested by our correspondent, the danger re- ferred to is almost entirely removed. 20 162 PLANK DAM AT GILBOA, OHIO. CHAPTER XXVIII. PLANK DAM AT GILBOA, OHIO. In the dam which we illustrate in this chapter, a combi- nation is presented of the plank construction with stone and dirt, or gravel, for the interior filling, the latter giving the dam its requisite weight and solidity. In the Plank Dam illustrated in Chapter XVI, only a single tier of plank was laid, the main reliance for sustaining the pressure of the water being the curve of the dam up-stream, and no filling, even, being required, except a little on the upper side of the dam to keep it tight. The dam thus built, however, was suitable only for a rock bottom. A nearer approach to the construction here shown was that of the dam described in Chapter XII, in which two tiers of plank are erected ; but the manor of laying them is materially different from that here represented, as in this instance the wide base and nar- row top, or the pyramid construction, so to speak, add very greatly to the firmness of the structure, rendering it hardly possible for any direct pressure to force it from its foundation* Our engraving does not represent a merely theoretical style of construction, but is a view of a dam in process of erection for supplying the power to a Leff'el wheel running the grist and saw mill of A. D. McClure, Esq., located on Blanchard River, in the town of Gilboa, Putnam Co., Ohio. The stream at this point is 250 feet wide and has a rock bottom. The perpendicular hight of the dam is six feet It is shown in the cut as if cut across in the direction of the stream, showing the* ends of each tier of plank, the cross- ties connecting them, and the filling between the tiers. The planks used in the construction are 10 inches wide, 2^ inches thick, and of any convenient length; care being taken in laying them up to break joints. The cross-ties extending from one tier to the other are planks of the same r'M iilliiiiiiiil!!iii%iiiiiiii. PLANK DAM AT 6ILB0A, OHIO. 165 thickness as those in the two walls, but may vary in width, while their length is of course determined by the distance between the tiers. They are put in at every 8 or 10 feet, or thereabout, ol" the length of the dam, their ends coming out between the ends of two planks which meet in the tier, and flush with the outer face of the dam. Their thickness being the same as that of the other planks, a close joint is hus made and the dam remains tight. The planks in each tier are so laid as to fall back two inches at each successive course or layer, a continuous slope thus being given to the face of the dam, at an angle of about forty-five degrees. This falling back does not begin, however, on the up-stream side, until about half the hight of the dam has been reached, the first three feet of this tier being perpendicular. The slope then commences and con- tinues at the same angle as the down-stream face, each layer of planks falling back two inches, until the crest is reached, where the top layers of each tier are placed side by side, as shown in the cut. It may be well to surmount these with a single plank as a cap or cover, so that there will be no open joint along the crest of the dam. Built in this manner, the entire width of the base of the dam, from out to out, will be about ten feet, of which six feet or more will be on the down-stream side of a point directly under the crest of the dam, the continuous slope being on that side. For fastening the planks either pins or spikes may be used, but pins are preferable, ks, being of wood, they admit of the planks being readily sawed out when repairs are required. The planks in the down-stream tier are of oak, while in the up-stream tier sycamore and elm are used below water, and oak above. Sheeting, or even round poles, may be put on the top of the dam on the up-stream side, if desired, to guard it from ice and driftwood. The whole upper side of the dam, indeed, may be covered with cement to make it perfectly tight. Mr. McOlure, who is erecting the dam here described, proposes to build without putting on either the cement or the sheeting, but will add them afterward if found expedient. Still another additional 166 l>LANk DAM A* GILBOA, OHIO. means of protecting the up-stream tier of the dam is to build a wall directly against and of the same hight as the perpendicular portion of that tier, which in the dam under consideration is the first three feet of the tier. This may be done if stone is abundant and easily obtained in the locality where the dam is built, but the necessity for it is not suf- ficiently urgent to warrant any heavy outlay, such as would be required if the stone were to be brought a considerable distance. The dam built by Mr. McClure is abutted at one end against the stone wall of the mill ; the other end extending into a square crib about ten feet high and built of the same material — 2 or 2i inch planks — and in the same manner in all essential respects as the dam itself. It is about twelve feet square, and filled with stone. The crib in our engraving is shown as projecting considerably beyond the base of the dam, as we regard it very desirable that a crib should extend two or three feet beyond the dam on both the up-stream and down-stream sides, li' the dam, therefore, has a width of ten feet at the base, as in the case here described, we would give the crib a width of at least fourteen feet, thus allowing a projection of two feet beyond the dam in both directions. Care should be taken to make the dam as tight as possible on both sides, avoiding any cracks or gaping joints in the tiers of plank or at the points where the ends of the cross-ties occur. The filling between the tiers, in Mr. McOlure's dam, is stone and dirt. Gravel, either fine or coarse, may be used instead ; or stones of irregular size, from boulders down to small cobble-stones, mixed with loam and a moderate amount of clay — the more stone and the less clay, the better. We have shown in our engraving a filling of stones, earth and brush against the up-stream side of the dam. If sheeting, cement, or a breast work of stone is put on this side of the dam as above suggested, the filling will not require to be so heavy or so carefully put in as would be necessary if the dam were in no other way protected. The construction thus fully described is intended for streams having a rock bottom. If the bottom is soft, a PLANK DAM AT GILBOA, OHIO. 167 foundation must first be laid, for which purpose logs placed close together, side by side, lengthwise of the stream, con- stitute the most reliable material. They should be long enough to project beyond the base of the dam both up and down the stream, but especially down-stream, in which direction they should extend far enough to form an apron to the dam ; and this apron may be covered with plank to render it still more secure against the undermining action of the water. It will be observed, however, that the con- tinuous slope of the down-stream face of the dam has a very advantageous effect in preventing the reacting, eddy- ing and undermining tendency of the water, thus making it much less destructive to the apron and foundation of the dam. The filling or other protection for the up-stream side and upper slope of the dam would be substantially the same for this as for the dam on rock bottom. 168 FRAME DAM AT CUFTON, OHIO, CHAPTER XXIX. FKAME DAM AT CLIFTON, OHIO. A description of a dam actually erected and in use is of more value than any theoretical plan of construction can well be. not only because it has been proved by greater or less leu^^lh of service to be adapted to its purpose, but also because the difficulties to be overcome, and the demands of the situation in every particular, are realized and can be pointed out, whereas in a proposed method which has never been verified in practice, many of these important details are liable to be overlooked. We illustrate in this chapter a dam which has been for some time in use, located on the Little Miami river, near the village of Clifton, in Greene County, Ohio. The course of the Little Miami in the region of Olifton,as many tourists from distant States are well aware, is remarkable for the picturesque scenery which it presents. The towering cliffs, deep gorges and shadowy ravines which have made this locality a favorite resort of pleasure-seekers for many years, fall short of actual gran- deur and sublimity only when compared with the bolder natural features of the Eastern or far Western portions of the continent. In the absence of mountain ranges, which are necessary tr the display of such bights and depths as are sufficient to strike a travelled observer with awe, this charming spot is as well entitled to be called a Switzerland in miniature as any thing which Ohio or the prairie States can boast. At the point where the dam here illustrated is built, the stream has a much wider bed than immediately above or below, so that the length of the dam is about 100 feet. The bottom is solid rock, and the cliffs on either side rise to a hight of 70 or 80 feet. A rock against which the dam abuts on the right bank is itself nearly 40 feet high. The foundation of the dam consists of six sills, 10 by 14 21 FRAME DAM A* CLIFTON, OHIO. iTl inches, crossing the stream, and placed from 6 to 8 feet apart, being somewhatnearer together under the apron than beneath the main structure of the dam. The ends of the sills are mortised into the rock at each bank, the sill farthest up-stream being also imbedded in the rock for its entire length. Across these sills are laid timbers 10 by 14 inches and about 40 feet long, the distance between centers being about 6 feet. They are secured to the lower or foundation sills by li inch barbed iron bolts, 2 feet long. Both these courses or layers of logs are squared on the top and bottom. The two center sills running lengthwise of the stream, and situated at the angle of the dam, are bolted together. The breast of the dam is raised at the fourth foundation sill, counting from the up stream side. The upright posts constituting the front of the dam are 12 inches square, about 15 feet long, and have an inclination from perpendicular of nearly 3 feet up-stream. The posts at the center or angle of the dam, like the two upper sills at that point, are set close together and bolted to each other. The whole num- ber of posts is the same as the number of upper sills, and they are placed the same distance apart, each post resting on a sill, into which its lower end is mortised. Upon the top of the posts, crossing the stream, is a' cap timber 12 by 14 inches. This cap timber is in four pieces, each 25 feet long, spliced where they connect, and mortised into the rock at each bank. The upper ends of the upright posts are mortised into the cap-timber. The rafters composing the up-stream slope of the dam are 10 inches square and some 25 feet long, and equal in num- ber to the posts — each rafter, with its corresponding post and the interior braces, constituting a '' bent.'' The rafters are mortised into the cap-timber, and between them are short cross-timbers or ties, 10 inches square, mortised into the sides of the rafters, and flush with their upper surface. The same description of ties are placed between the up- right posts. The purpose of these ties is to give firmness to the frame, and prevent any tendency of the bents to sway or spread to or from each other. There are three of these ties between each pair of rafters and two between 172 f-llAME ©AM At CLIFTON, OttlO. posts, SO that each bent is connected with the next by five ties, the distance between the ties being from 6 to 8 feet. The foot of each rafter rests upon one of the upper sills, and a bolt is driven through the rafter and upper sill to the foundation sill of the dam. This slope of the dam is covered with two coats or courses of 2-inch oak planks, jointed in the usual manner, the first course being laid crosswise of the stream, and the second or top course lengthwise, in the same direction as the raf- ters. The planks are secured by spikes, and the top course footed at the lower ends of the planks against a sill running across the stream the whole length of the dam. In the interior of the bents are braces 10 inches square. Fig. 2. mortised into the posts, sills and rafters, in the manner and position indicated in Fig. 2 of our engravings. The apron is constructed by placing transverse or cross sills upon the longitudinal or upper sills of the dam, these cross sills being three in number and about 6 feet apart. Upon these sills are laid timbers of the same size, length- wise of the stream, hewed on two sides and laid close together. These logs, forming the apron, are 17 feet long. At their upper ends, where they meet the breast of the dam, a cross-timber is laid on, running the whole length of the dam, and beveled on its front so as to leave its top only 2 inches wide. The cap-timber at the top of the posts also projects 2 inches, and the 2-inch planks constituting the face of the dam, which are spiked in an upright position PRAME DAM At CLlPtOlJ, OHtO. 173 upon the posts and cross-ties, make with the 2-inch projec- tions at their top and bottom, against which they rest, a continuous smooth face to the dam, giving the water an unbroken and even fall. All the sills, rafters and ties composing the frame work of the dam are of white oak, secured by iron bolts. The interior of the crib-work composing the apron is filled comi^actly with stone. The interior of the dam is also filled with stone, about half-way to the top ; and against the up- stream slope of the dam is a filling of gravel and clay, extending from some fifteen feet above the dam to a point half-way up the slope, thus covering the entire lower part of the planking. The ground plan of the dam is such that it makes an angle with the apex up-stream, instead of the arch or curve often used. The angle is but a moderate one, the center of the dam being but about 4 feet farther up-stream than the ends, while the entire length, as already stated, is about 100 feet. As will be seen by the dimensions already given, the base of the dam, inclusive of the apron, has a total length of about 40 feet. Near the center of the dam is a waste-way regulated by a sliding gate on the upper side of the dam. The door of the waste-way is indicated in the cut near the base of the dam close to the center posts. The hight of the dam from the apron up to the crest is about 14 feet, the 15 feet posts having a slight inclination as already stated. The hight from the rock bottom to the top of the dam is 17 feet or thereabouts, the top of the apron being 3 feet or more above the rock. The water enters the forebay behind the large rock on the right bank of the stream, and only a portion of the forebay, consequently, is shown in our engraving. The race passes through an opening in the rocks, and the frame- work of the head-gates is mortised at both ends into the solid rock. This dam was built nearly three years since by Messrs. King & Hagar, at that time proprietors of the Clifton Paper Mills, now carried on by Col. David King. A general view 174 FRAME DAM AT CLIFTON, OHIO. of the dam is given in our principal engraving, and in Fig. 2 is represented a cross-section, showing the upright post, rafter and braces constituting a bent, the two courses of plank on the up stream slope, the end of the timber against which the upper course is footed, the upright planking on the face of the dam, the ends of the cap-timber above and the beveled timber below, and also the ends or sides of the various sills composing the foundation and the crib-work of the apron. As the region in which this dam is situated is visited every year by large numbers of tourists, many of our readers may already have examined the structure above described, or may have opportunities of doing so in future. At a favorable season of the year, a more attractive spot can hardly be found, though there are many of wider reputation and more favored by the patronage of the wealthy and fashionable. TIMBER DAM AT NEW HARTFORD, CONN. 175 CHAPTER XXX. TIMBER DAM AT NEW HARTFORD, CONNECTICUT. The durability of the dam which we illustrate in this chapter has been proved by a period of service dating back farther than the birth of many of our readers. It was built in 1847, and has therefore stood over 26 years, requiring in all that time but little repair or alteration. It belongs to the Greenwoods Company, of New Hartford, Conn., and extends across the Farmington river at that place. The dam, as will be seen by our engraving, is built of timber, no other material being used except that required for filling' or staying the structure, and for the abutments as will be hereafter described. The timbers used are from 9 to 12 inches in thickness, the first or foundation tier being laid crosswise, the second tier lengthwise of the stream ; and this arrangement is continued throughout, the alternate layers crossing each other until the work is brought to the desired hight. When complete, it has the form of a pyra- mid, the sides presenting an angle of 27 degrees with the horizontal line or bed of the stream. This angle of the sides gives the base such ample width in proportion to the hight that, taking this in connection with the pyramidal form, the dam has a degree of solidity and strength in its very shape which ensures its durability. The timbers are fastened, at each point where they cross, with a spike of |-inch round iron, 20 inclies long. The water side is covered with planking of 3-inch oak and chestnut, jointed, and put on with 7-inch cut spikes. The timbers running lengthwise of the .stream are placed 6 feet from center to center, the ends coming out flush with the face and back of the dam. The timbers running crosswise of the stream are so placed as to give from two to three feet I'T^ TIMBER DAM AT NEW HARTFORD, CONN. in the clear; and all the spaces -ire filled with stones, from the foundation up to the cap-log. On the lower or down-stream side of the apron, piles are driven and securely fastened to the lower mud sill, on which the apron partially rests. The apron is composed of tim- bers 12 inches thick, placed close together. In order to attach the apron firmly to the main structure of the dam, the following plan is adopted : once in every six feet of the apron a timber longer than the others is put in, extending up-stream under the dam a distance of 25 or 30 feet, while the other apron-timbers run only 2 or 3 feet under the first timber of the dam proper. By this means, without putting more timber into the apron than is absolutely required, it is nevertheless held so firmly to the main structure of the dam that no danger of separation exists. The entire length of the ^^rollway" is 232 feet. The hight of the dam, from the bottom of the mud-sills to the top of the cap-log, is 21 feet. The width at the bottom, from the foot of the dam to the up-stream side, is 68 feet ; and the apron projects 14 feet beyond the foot of the dam. The river bottom at this point consists of cobble-stones, gravel and quicksand. The banks are gravel and sand. The gravel is of the kind known as " washed," it being devoid of all the fine admixture which renders a bank tight against water. On the upper side of the dam is a filling of gravel to within 4 or 5 feet of the cap-log. It is not uncommon for the stream to rise to such a hight as to give six feet of water on the cap-log ; and a depth of even 10 feet at that point has been known, but is of rare occur- rence. The capacity of the river at this place is stated at 14,525,000 cubic feet of water every 24 hours during an ordinary drouth. Our present illustration gives a perspective view of the exterior of the dam, showing also one of the abutments, which are of solid masonry, and pyramid-shaped, like the dam itself. In our next chapter we shall give a sectional view, showing more clearly the interior structure of the dam, with some additional particulars required to complete the description. TIMBER DAM AT NEW HARTFORD, CONN. 179 CHAPTER XXXI. TIMBER DAM (Continued,) In our last chapter we gave a perspective view and gen- eral description of the dam of the Greenwoods Company at New Hartford, Conn., comprising the dimensions of the dam, the material used, size of timbers, and the manner in which they are put together and secured. We now present a sectional view of the same dam, from which the arrange- ment of the timbers will be still more clearly perceived. In this engraving, also, a full view is given of several portions not shown in the perspective cut, such as the apron in front, composed of twelve-inch timbers placed close together; the piles driven on the down stream side of the apron, and fastened to the lower mud-sill, extending into the bed of the stream to a depth of 15 feet ; and the form of the abutment, the face or front portion of which also rests upon piles. Our present engraving shows but a small part of the dam, the entire length of which, as already stated, is 232 feet. In the yiew it is represented as if cut transversely, in the direction of the stream, showing the internal frame- work, but not the filling of stones in the interior, or that of gravel in the upper side of the dam. The strength and stability afforded by the pyramidal shape of the dam will be readily seen in this illustration, the only real source of danger being from the washing out of the gravel, especially on the lower side of the dam, which is liable to occur at a time of very high water. This difficulty did in fact present itself in the case of the dam here described, during a very heavy flood some fifteen years ago. The water acted with such effect at the lower side of the apron that a considerable quantity of gravel was washed away ; to remedy which the proprietors built cribs of poles ISO TIMBER DAM AT NEW HARTFORD, CONI^. and logs, and filled them with large rocks, weighing two to three tons. These cribs were then sunk to the bottom, and the whole chained to the piles at the foot of the apron ; since which time no trouble from washing out has been experienced. About three years ago, some repairs of the dam were found necessary, and nine or ten feet of the top was taken off, the timbers having become rotten. The cause of the rotting was ascertained to be that the dam, when originally built, was planked tight on the lower side as well as on the water side, leaving no avenue of escape for the hot steam which gathered inside the dam in hot weather. The face of the dam being to the south, the heat of the sun had a pow- erful effect in generating this steam in the interior, with the injurious results to the timbers above indicated. All the planking on the lower side was therefore removed, and for the last three years, consequently, this side has been in the condition shown in our engraving in the last chapter. It is proposed to raise the dam six feet in the course of next summer, making with the present hight of 21 feet a total hight from bottom of mud-sill to top of cap-log, of 27 feet. It has already been mentioned that the stream fre- quently rises to such an extent as to give six feet of water, and in rare instances even ten feet, on the cap-log of the dam as it now stands. The increase of hight will therefore afford the means of a corrosponding addition to the amount of power held in store, the present structure being hardly in due proportion to the capacity of the stream. Our en- graving shows the wall as already raised. The dam or " rollway " will be raised by placing at every 6 feet of the length of the dam a frame or trestle resting, as it were, astride of the crest of the dam and very firmly secured on both the upper and lower slopes of the present structure. The water side of this additional framework will be covered tightly with 3-inch jointed plank. Upon the lower side will be placed 3-inch planks, 2 incTies apart, the object of this arrangement being to ventilate the interior and give free escape to the hot steam generated as already described. It is believed by the proprietors of this dam that it will 183 compare favorably with any other structure of the kind in the country as regards the quantity of water held in reserve by it, for the amount of money invested. It certainly possesses great merit in the plan of construction, and has been found to possess, in practice as well as theory, the prime essentials of a good dam, — strength and durability. 184 LOG DAM FOR NARROW STREAMS, CHAPTER XXXII. LOG DAM FOR NARROW STREAMS. The description and illustration which we present in this chapter were elicited by an inquiry on the subject of Mill Dams published in Leffel's Illustrated Mechanical News for February, 1873. In order to present more clearly the sug- gestions embodied in the ensuing article, we first reprint in full from the Mechanical News the inquiry alluded to, (and also the comments editorially made upon it) as follows: '' Messrs. James Ldffel & Co. :— I desire to build a mill- dam a(?ross a hollow about 60 feet wide. Will have a slate rock foundation all the way across, and the hight of dam will be 15 feet. I have two plans for building the dam. The first is to dovetail posts in the rock about four feet apart, straight across the hollow, and nail two-inch planks to the posts, setting the posts 12 inches in the rock, and having them 15 feet high. My second plan (I think the best) is the following: Get me a sill 14 by 14 and lay on the rock across the hollow, and then put iron stirrups across the sill about 5 feet apart, placing the ends of the stirrups about 1^ feet deep in the rock and running Babbitt metal in the hr.les around the stirrups. Then place my posts about four feet apart, letting them about one foot deep into the sills, and having a brace running from top of post down stream, lower end on a sill. Stone is too scarce to build a stone dim. The stream of water is only from a large spring (no creek) only 100 yards from the dam. The water, when running on mill, is about 6 inches deep in a fore-bay 3 feet wide, afi'ording enough water to run a set of 30 inch wool cards and a grist-mill? rocks 30 inches in diameter. The fact is this : we want to build a good dam, without a great expense. I would say that the hollow is wider between r d > > H PI > LOd^ DAM FOR NARROW STREAMS. 187 the spring and dam than it is at the point we wish to put the dam. I desire you to answer this in the next number of the News. Tell us which is the best plan, and if you can let us have a better plan, please give it in your paper. You may put me down as a permanent subscriber. Enclosed find money. Trusting you will comply with my request, I am Fraternally yours W. H. W- Flyntville, Tenn." " [We do not agree with our correspondent in thinking his second plan the best, but should give the preference to his first, provided certain important amendments are made to it. The posts should be let into the rock a depth of at least two and one-half feet, and three would be still better; and they should have one or if possible two series of braces if the dam is to be 15 feet high. The general plan of the dam, as we would build it, is similar to that described in our issue for November, 1871, except that the posts in this case should be nearer together than in the dam illustrated. The reason for this is, first, that the hight of the dam is much greater, and second, that slate rock is peculiarly liable to wear away under the influence of either sun, air, frost or falling water. We shall be glad to hear from other correspondents in re- gard to W. H. W.'s inquiry. Ed. Leffel News.] " In a subsequent issue of the Mechanical News appeared a communication from another correspondent, in Wabash, Ind., over the initials " R. S.," giving a full description of a dam which he has found by practical experience specially adapted to narrow streams such as are here referred to. He also furnished a pencil sketch of a dam of this character of which he is a joint proprietor, located on Treaty Creek, Wabash Co., Ind. ; and from the sketch thus supplied we have produced the engraving here presented. Referring to the plans submitted by "W. H. W.," the Wabash correspondent remarks : " I do not like either of them ; and as the editor stated that he ' would be glad to hear from other correspondents in regard to these inquiries,' 1 will, as an old hand at building mills and dams, suggest 1S8 LOG DAM FOR NARROW STREAMS. my plan of building dams across narrow streams, or ' hol- lows 60 feet wide' as he says his is. The motto of B. Franklin has ever been mine, viz.: ' What is worth doing at all is worth doing well.' Even should my plan cost a little more at first than his, it will be the cheapest in the end. " Here it is. If the banks are stone, and have no natural jut or projection sufficient to abut the ends of the dam against, and are not too hard to cut, cut a groove in the stone embankments where the ends of the dam are wanted, about 12 inches wide, and a few inches deep, from the bot- tom up, and as high as the dam is to be built. Take round logs and face two sides straight and nice, large enough to measure a foot thick when faced. Cut the logs long enough for two lengths to make the dam. Square the end that is to go in the groove at the abutment, or shape it to fit. Lay the log not at right angles across the ravine, but put the ends which meet in the middle nine or ten feet up stream above a straight line, so as to form the dam that much in the shape of a horse shoe, or rather in the form of two panels of rail fence with the lock up stream ; then halve together the ends which meet, putting the faces of the logs together as the dam is raised so as to hold the filling of gravel or dirt. Continue to so notch the logs together in the middle until the dam is the desired hight, filling up at the same time with gravel and stone if plenty; if not, dirt will do, provided the logs fit well enough to hold it. Thus we see, to build a dam in this way supersedes the necessity of any posts or braces, for it braces itself. And the harder the pressure of water and filling above, the tighter it will press the ends of the dam against the abutments, so that it can neither push out, wash round the ends, nor wash or un- dermine if stone bottom, and the bottom log well fitted* This plan supersedes, also, the necessity of cutting any post-holes or mortices in the bottom of the stream, or of bolting down the bottom log to keep the dam from pushing down stream." " If not stone bluff's, then of course, abutments of either good stone or timber must be made, projecting into the LOG DAM FOR NARROW STREAMS. 1S9 banks. They should be notched up as the dam is raised, and all well filled as it goes up." "If the bottom is slate, or any material that will not stand the force of water pouring over for many years, it should be leveled a sufficient distance up and down the stream, clear across, to receive a log apron. Face the logs on three sides, putting the square edge down. Cut them 16 feet long, and cut a gain on the top of each one 6 feet from the end that lies up stream, 4 or 5 inches deep, to lay the bottom log of the dam in, thus letting the apron extend about 10 feet be- low the dam, and 5 above. The apron logs notched in this way and the dam built on them, and they fitted up together, will prevent the bottom from wearing as long as they last. And having them 12 inches thick (which they should be for 15 feet fall) they will last, if water is kept over them, many years, for they cannot wash out put in in this way, nor raise at the lower end in case of a flood of water rising over them below the dam." " This plan of building dams is not only applicable to W. H. W.'s ' hollow,' but to all streams that are not too wide for two logs to span in a bracing way. And it makes no difference how high the dam is built, it cannot push out if the logs are stout enough not to bend edgewise and come out like a spring-pole." " We, of the firm of Small & Son, have a log dam 1.5 feet high, about 60 feet whole length, built precisely as I have directed, and it has been in use some twenty-seven or twenty-eight years, and not a log amiss yet; though the top is getting a little tender, and wants a new top-log. Ours are stone bluff's and solid limestone bottom, all the apron it needs. Our filling is mainly shelly limestone with some gravel and dirt ; not even sheeted on top, but would be the better of it, for the stone and gravel washes off" some.'' " I give a rough sketch of our dam, which is so simple that any ten-year-old boy of common mother wit can see into the philosophy of its strength and durability." '' In 1846 I helped put a log dam across the Missisinewa River, nearly 200 feet long. In 1854, 1 think, I put in, or rather spliced the same kind of a dam on Deer Creek, to 190 LOG DAM FOB NARROW STREAMS. run a saw and grist mill. And about 1858 or '59, 1 put a log dam in to run two 4 feet burrs; all in Grant county, Ind. Not one of these dams has gone out yet, unless they went this winter. Though these dams were all straight, the breast is logs, and a log laid in the stream a few feet above, with dove-tail ties in it and the breast logs, as they were notched up, all tied to the single log above, filled with stone and gravel, then sheeted with 2 inch plank, and graveled on the upper end of the sheeting; and with good abutments and aprons, I consider the log dam the cheapest yet" FRAME PAM ON MAD RIVER. 191 CHAPTER XXXIII. FRAME DAM ON MAD RIVER. We add in this chapter another illustration and description of a dam which has the advantage, over a merely theoretical plan, of being verified by actual construction, so that every detail has been worked out and may be relied on as prac- tical, and duly adapted to the circumstances of the case. The dam here represented is built across Mad River, in Clarke County, Ohio, and is 165 feet long. The stream at this point has a mud and clay bottom, upon which is a coating of sand and gravel, washed down from above. The founda- tion of the dam consists of sills 30 feet long, hewed flat on the top and bottom to a thickness of ten inches, and laid lengthwise of the stream, about 8 feet apart. Upon the top of these sills, at their up-stream ends, and running across the stream, is bolted a timber 8 inches square, 16-inch bolts being used to secure it to the sills. The breast of the. dam is raised to a hight of 30 inches above the apron, and is made by first laying a timber, 5 by 14 inches in size, across the stream on the foundation sills. On the top of this 5 by 14 inch sill are eight tiers of joists 3 by 10 inches, which are laid flatwise upon each other and spiked together with 6-inch iron nails. The face of the dam, composed of these joists, is battered or inclined up stream 5 inches. At a point five feet up-stream from the cross-sill on which the joists rest is laid across the stream, and bolted to the foundation sills, a timber 8 inches square. From this sill to the top of the breast- work of joists, or crest of the dam, are laid rafters 6 by 8 inches, 6 feet long, and 3 feet apart from centre to centre. The cut required at the upper extremity of each rafter to give it a secure hold upon the breast of the dam, is made about 3 inches from the end of the rafter, which therefore projects that distance in front of the tier of 192 FRAME DAM ON MAD RIVER. joists, and by this means the rafters are, so to speak, hooked over the crest of the dam. The depth of the cut is about half the thickness of the rafter, and the width 10 inches, the same as that of the joists. The rafters are pinned to the crest of the dam, and also to the sill at their lower ends? with wood pins 1| inches in diameter. For the covering of the dam there are laid, crosswise of the stream upon the rafters, 2| inch planks, which are fas- tened to the rafters with 6-inch nails. From the foot of the rafters, also, to the up-stream end of the foundation-sills, a covering is laid consisting of planks 2 inches thick, running cross-wise of the stream and nailed to the foundation-sills. Upon the plank covering of the mud-sills, and extending some distance up the covering of the rafters, is a filling of gravel about 2 feet in depth; and the space under the rafters, from the mud-sills up to the plank covering, is also filled with sand and gravel. The apron of the dam is made by laying three sills across the sfe-eam, resting on the foundation sills, and secured to them with 16-inch bolts. Upon these cross sills and the projecting edge of the 5 by 14 inch sill under the breast of the dam, are spiked planks 2i inches thick, 12 feet long, and running lengthwise of the stream, as indicated in the engravings. At the down-stream end of these planks^ against the side of the apron-sill and the ends of the foundation or mud sills, are driven spiles 3 by 6 inches, reaching to a depth of five feet. The same is done at the up stream end of the dam, where the extremities of the mud-sills and the side of the cross-sill at that point rest in like manner against the spiles. The spiles at both the up- stream and down-stream extremities of the dam, are placed close together, forming a continuous sheet across the stream. The abutments of the dam are of solid masonry, laid up with cement, and are 21 feet in length of face, 5^ feet in hight, and 6 feet thick. In addition to this are the wings? each 10 feet long, and of the same hight as the face wall The tops of the abutments are at about the same level as the earth banks of the stream. They rest on the foundation 24 FRAME DAM ON MAD RIVER. 195 sills of the dam, three of which are under the abutment. The filling of the space enclosed by the face and wing walls is entirely of gravel and sand. E. B. Harvey, of Miami county, is the builder of this dam, which is located near Enon, Clarke County, Ohio, and is owned by Martin Snyder. It supplies the power to run a flouring mill, propelled by Lef- fel Double Turbine water- wheels. Our large engraving gives a perspective view of the dam, showing both the abutments and also a portion of the race, with the head-gates, three in number. In the smaller illus- tration is presented a sectional view, showing a foundation sill fr; lengthwise of the stream ; the ? end of the cross-sill at the up- ^ stream extremity of the dam, and also of the cross-sill at the foot of the rafters, the one on which the breast-work rests, and the three sills of the apron ; the ends of the eight tiers or layers of joists, and of the planks covering the rafters and the up-stream portion of the mud-sills ; the side of one rafter, showing the cut at one end for the foot-sill and at the other end for the crest of the dam ; the plank covering of the apron, the spiles at the upper and lower extremities of the dam, and the line of the gravel filling. By the clearness with which every detail is shown in this cut the whole construc- tion of the dam will be accurately understood. We may here state that for the purpose of keeping the water from interfering with the work upon the dam, a cofi'er 196 FRAME DAM Oif MAD RIVEft. was built at a point 5 or 6 feet up stream from the upper ends of the foundation sills, extending from one bank nearly across the stream, and thus protecting one-half of the dam while the building was going on. To protect in like manner the other half of the dam while in process of construction, it was only necessary to remove the upper part of the coffer above the finished part of the dam, letting the water flow over both coffer and dam on that side of the stream ; the material thus taken off being used to extend the remaining part of the coffer to the opposite bank, and a barrier being also built from the coffer to the inner or midstream end of the finished half of the dam, keeping the water from that part of the dam on which work was still in progress. [Since the foregoing was put in type, we have received information that the work upon this dam, just as it was ap- proaching completion, was interrupted in the following manner. The dam on one side of the stream having been finished, and work on the remainder being in progress un- der the protection of a cofier, a channel was cut from the head race through the bank behind and around the finished abutment, to carry off the water. A flood occurring, the swollen stream poured through this channel and caused great damage to the abutment and the completed portion of the dam. We presume that parties on the spot were best qualified to judge as to the course proper to be pursued; but from what data we possess, we are inclined to believe that by first putting in a head-gate at the race, and allow- ing the water to pass over the completed portion of the dam, the disaster might have been avoided.] Dam at osborn cMy, kai^saS. 197 CHAPTER XXXIV. DAM AT OSBORN CITY, KANSAS. The dam herewith illustrated is constructed on the same principle, in many respects, as several which have already been described ; but the plan here shown will be found in some localities to possess advantages in point of simplicity and strength which will justify its adoption by the mill- owner. It cannot be accurately classified as regards the kind of material employed, as stone, logs, sawed timbers, boards, rock, gravel, sand and hay are used in its construc- tion, their proportions and arrangement being such as to afford, without very heavy outlay, a satisfactory degree of firmness and durability. Our engraving gives a perspective view of the dam built by Messrs. David Milne & Son, at Osborn City, Osborn Co., Kansas, furnishing power by which their saw-mill and grist-mill are run. The width of the river at this point is 64 feet, and its bottom consists of a layer of sand about 3 feet in depth, resting on a bed of solid slate and shale. In preparing for the erection of the dam, the first step was to scrape the sand away until the solid bottom was reached. The mud-sills were then put down, consisting of logs from 14 to 18 inches in diameter, and from 20 to 28 feet long, their direction being lengthwise of the stream. Brush was also put in to aid in making the sills as firm and solid in their positions as possible. In scraping away the sand, a hollow of considerable depth was of course made ; and after the sills were put down, the sand washed over the mud-sills, which thus became imbedded in sand and brush, and have thus far shown no indications of giving way. The distance between the sills is about 6 feet from center to center. It should be stated, before proceeding further, that the 198 KANSAS. body of the dam is supported at each end by wing walls, as shown in the cut, these walls being 3 feet in thickness and built solidly along the face of each bank for a considerable distance both above and below the dam. After laying the mud-sills, as described, the next stage of the work is the erection of the crib, which is composed of sawed timbers, and rests upon the sills, extending from bank to bank, and forming, as will be seen in the engraving, an obtuse angle with the vertex up-stream. The width of this crib is five feet and its hight 8^ feet. The timbers run- ning across the stream are 6 by 6 inches, while the cross pieces are 4 by 6 inches, placed flatwise, from 5 to Y feet aparl , and spiked to the main or longitudinal timbers, which are therefore 4 inches apart, one above the other. These 4-inch spaces are covered by nailing boards upon them, thus rendering the up-stream and down-stream walls of the crib sufl&ciently tight for all practical purposes. The 6 by 6 inch timbers are pinnod together with 2-inch oak pins, 16 inches long. In the engraving, the dam is shown with a part of the filling on the down-stream face cut out, giving a view of a portion of the crib in the interior. The main or longitudinal timbers, the ends of the cross-timbers, and one of the foundation sills, are thus shown, and also the level top of the crib, 5 feet wide, forming the crest of the dam. The ends of the foundation sills are likewise seen, project- ing down-stream from under the filling. Each end of the crib, at the point where it joins the wing wall, is let into the wall for a depth of 3 or 4 inches, giving it a firm and solid bearing, and rendering it, in connection with the angular direction of the two halves of the dam, abundantly strong in its position, so far as regards any direct pressure from the water above. The filling of the inside of the crib consists of broken rock, gravel and hay, arranged in the following manner : a layer of rock, finely broken, is first put down, having a depth of 10 inches ; a coat of gravel is then put on, leveling up the surface of the rock ; then follows a layer of hay, then another layer of rock, and so on with alternate coats of rock, gravel and hay up to the top of the crib. The rock k I $ i^ 1^ "i DAM AT OSBORN CITY, KANSAS. 201 used is a kind of flint found in the vicinity, and very heavy. Above the crib is a filling of broken rock, gravel, hay and sand. The width of this fill at the base is 12 feet, sloping to the top of the crib. Below the crib, on the down-stream face of the dam, is a fill of rock and brush, sloping to the top of the crib, and the whole dam has thus the shape of the roof of a house. The crib is located a^ a point on the mud-sills about two-thirds of the distance from their down- stream to their up-stream extremities, and the front of the crib is just above the projecting corner or vertex of the angle formed by each of the wing walls. These distances and proportions are distinctly shown in the engraving. This dam has been doing service for some time, and as yet has shown no signs of settling, or of deficiency in any respect. We are of opinion that the plan of dam above described, which is an excellent one in most respects, would be still further improved by bolting the mud-sills in a few places to the rock bottom. If they were surrounded and covered by a good depth of mud, this would be less important. A mix- ture of sand, in liberal proportions, with the gravel in the crib, to pack and tighten the whole mass, would also be useful ; although this point is very well provided for by the board covering on the side of the crib, especially if a con- siderable amount of fine sand and gravel is thrown against it. As for the use of hay, either in the crib or above it, we have small faith in its utility, as it will rot out after a time and require refilling. There is, in fact, nothing better than heavy gravel and sand for all kinds of filling about dams, head-gates, races, &c. — and nothing poorer than clay. Of the light rocks and brush forming the inclined apron below the dam, a considerable portion will wash away in case of a flood; but if there are also plenty of heavy boulders, these will maintain their position, and no material damage will be done. 26 202 STONE AND TIMBER DAM, CHAPTER XXXV. STONE AND TIMBER DAM. In the present chapter we describe and illustrate a stone and timber dam which was erected in 1873 by the owner, Hamilton B. Lawton, at East Brunswick, Rensselaer Co., N. Y. Its method and material of construction are such as to adapt it to a region where stone is abundant, as this, with a moderate amount of timber, is the article principally used in its erection. This dam is built on a rock and " hard-pan " bottom. Its length is 150 feet, and its hight 22 feet, from the level of the water to the top of the upper plate. The base of the dam, measured on a horizontal line from the up- stream to the down-stream extremity, is 23 feet in extent, being nearly the same as the hight; and the up-stream side of the dam, therefore, slopes at an angle of 45 degrees. This form of construction gives the necessary degree of sta- bility, and also affords ample room for filling in between the rafters with rocks and small stones, thereby rendering the mud-sill and plate very secure in their position. Our principal engraving shows the face of the dam and abutments, the upper and lower plate and the posts being the only timbers visible. In the smaller cut is given a com- plete representation of the framework, in which A is the upper plate and E the mud-sill at the up stream extremity of the dam. The rafters B are fastened to the plate and sill with strong spikes. It will be observed that midway of the rafter B is a timber D, parallel with the plate and mud-sill ; and that to this middle plate are attached short rafters C, alternating with the main rafters and having their lower ends secured to the up-stream mud-sill in like manner with the main rafters. The purpose of these short rafters is to STONE AND TIMBER DAM. 205 give a more firm support to the plank covering of the dam at this point, where the pressure of the water is heaviest. The main rafters, reaching from the up-stream mud-sill (which is bolted to large rocks) to the upper or cap plate of the dam, may consist of timbers unhewn except on their upper faces, where they should be made flat to admit of the laying of the planks, and give an even surface to the water side. The main timbers of which this frame is composed are 12 by 14 inches. The bottom plate or sill F lies upon a series of rocks arranged, as indicated in our first illustration, so as to form an apron to receive the overfall of water and pre- FiG. 2. vent the washing, wearing and undermining of the base of the dam. The posts G are framed into the upper and lower plates as shown in both the cuts, and serve to support the upper plate, in case the wall should settle in course of time, as it is liable to do to a very small extent. The ends of the dam, on each side of the frame-work, are compactly built up with rocks and small stones in the rear, and in front square rocks are carefully laid up to present a smooth front and a permanent wall ; thus allowing the tim- ber work to be taken out and renewed, should it be necessary at any future period. The filling in the interior of the framework, as already mentioned, is composed of rocks of irregular size, from heavy boulders down to cobble-stones ; and the dam is 206 STONE AKD TIMBER DAM. covered with planking in the same manner, substantially, as described in lormer chapters relating to dams of this general nature. The builder of this dam is confident that it will last a life- time, and that very little expense will be required in repair- ing the wood-work. The other portions of the structure should of course demand no outlay whatever after having been once completed. As an appropriate addition to the account above given, we may here describe briefly another dam of very similar nature to the one already shown, although in quite another section of the country. The dam to which we now refer is built across the Des Flaines river at Joliet, 111. It is the lowest dam down the river in the city, there being two State dams above it; and is owned by Messrs. Wm. Adam & Co. of the " City Mills." The bottom of the river at this point is lime- stone. The dam has an extent across the stream of 160 feet. Its lace is composed of masonry, with the addition of a mud-sill and cap-sill, the whole corresponding almost pre- cisely with the lace of the dam already described, except that there are no upright posts connecting the upper and lower sills. The mud-sills, which cross the stream, are 12 by 14 inches being of the same size as those in the other dam. The first mud-sill, at the face of the dam, is laid on the rock, which is leveled ofl' as smoothly as possible to receive it; and 40 feet up-stream from this is placed another 12 by 14 inch sill, parallel with it, the two being bound together with timbers 6 by 8 inches, running lengthwise of the stream, and placed at intervals of 12 feet for the whole width of the stream. Around the first mud-sill a stone wall is laid in water-lime, and on the foundation composed of this wall and sill the face of the dam is built, consisting of solid masonry, 30 inches in thickness. On the top of this wall is placed the 12 by 14 inch cap-sill. This cap-sill or plate is kept in its place by means of binders 6 by 8 inches, which extend from the plate to the up-stream mud-sill. These binders are fas- tened to the timbers which tie the two mud-sills together (as already described) by iron rods, and are also supported STONE AND TIMBER DAM. 207 by posts to give them the necessary stability. Furthermore, across these binders, which run lengthwise of the stream, smaller timbers, 4 by 6 inches, are framed, parallel with the face of the dam, to keep the binders from spreading apart. All the timber work in this dam is dovetailed where cross-timbers are met; and in fastening the framework to- gether, ten kegs of 8-inch spikes were used, from which it will be seen that it is not likely to become separated by any strain it is liable to undergo. Back of the face of the dam a layer of clay was filled in, clear up to the face of the cap-sill ; back of this, brush, rub- ble stone and gravel were put in ; and on top of this was spread a coat of clay. A covering of two inch planks was then put on, the whole length of the dam, for a distance of 20 feet from the crest toward the up-stream extremity, com- prising, in other words, the upper half of the up-stream slope, next to the face of the dam. Finally, a covering of gravel was spread over the entire up-stream slope, with the exception of about six feet along the cap-sill. The banks of the stream are faced with a wall of masonry, connecting with each end of the dam and forming the abut- ments. There is certainly no lack of strength and solidity in the dam, and its manner of construction and selection of material appear to be, for the region in which it is located, of a very judicious character. If we were to take any ex- ception whatever, it would relate to the use of clay as one of the materials for filling, our own experience and observa- tion having convinced us that it is less reliable for this pur- pose than any other substance used, whether it be gravel, loam, sand or brush. Undoubtedly, in the case here de- scribed, the other sources of strength and compactness in the structure of the dam will preclude any danger of in- jurious results from the presence of the clay ; and when thus protected by better material, it may answer as well as any to a limited extent; but in cases where it is expected to resist of itself the inroads of the water, we should not re- gard its use as safe or profitable. DAM FOR QUICKSAND BOTTOM, CHAPTER XXXVI. DAM FOE QUICKSAND BOTTOM. In the issue of Leffel's Illustrated Mechanical News for November, 1873, appeared the following inquiry from a Kansas correspondent, over the initials " D. P. " : ^' How can a dam be put in with 10 feet of sand or quicksand at the bottom?" In this inquiry is presented one of the most formidable di^culties with which the builder of a dam has to contend ; and he is therefore fortunate if the nature of . the river-bed on which he is to place his foundation is not of the character described in the question above stated. The trouble is not so much in devising a theoretical plan to meet the conditions of the case as in the lack of due con- sideration, in many cases, on the part of the builder, re- sulting in insufficient provision for the peculiar dangers to which the structure will be exposed. There is no case, in the prosecution of enterprises of this kind, where deliberate forethought, and careful study of all the circumstances and necessities of the situation, are more essential to ultimate success, than in the one which we have now in view. For this reason, it is especially desirable that the teachings of experience, rather than of mere theory, however plausible, should be consulted for the guidance of the builder ; and we will not pause, therefore, to discuss on abstract grounds, the principles which should be followed in a case of this nature, but proceed at once to describe a dam in the erec- tion of which the obstacles referred to were encountered, and which has shown by its permanence that it possesses all the necessary elements of durability. Our engraving gives a general view of the dam to which we allude, viz.: the "Hydraulic Dam" across the Tippe- canoe Kiver at Monticello, White Co., Ind., which was built BAM FOR QUICKSAND BOTTOM. 211 in the year 1849, under the direction of Mr. E. A. Magee, for the Hydraulic Co., of that place. This dam rests upon a quicksand foundation, and the banks of the stream on each side are also of sand. The length of the dam between the abutments is 340 feet, its width from up-stream to down-stream extremity (exclusive of the apron in front) is 24 feet, and its hight 5^ feet. The abutments, only one of which is shown in the engraving^ are each 30 feet long, 12 feet high and 12 feet wide, and are composed of timber and rock as hereafter described. The foundation of the dam, part of which constitutes the apron, is laid as follows : commencing with the down-stream tier of the apron, the lower extremity of which is 18 feet from the down-stream edge of the main portion of the dam, poles or small trees from six to eight inches in diameter at the butt and from 40 to 50 feet in length, with all the brush left on at their upper ends, are laid lengthwise of the stream as close together as possible, and rock enough placed on them to hold them to their position. A second tier of the same kind is then laid, the ends of the trees being six feet back of those in the first tier ; and a third tier follows in like manner, falling back from the second tier six feet as before. Six feet up-stream from the ends or butts of this last tier of trees is commenced the base of the dam itself, which is thus already provided with a secure foundation, composed of the upper portions of the three tiers. As the entire dis- tance from the up-stream extremity of the 24 ft. dam to the down-stream edge of the 18 ft. apron is but 42 feet, and as the trees in the three foundation tiers are 40 to 50 feet long, their upper portions will of course extend under the whole base of the dam. The weight of the dam serves to hold them securely in place, and they in turn give the dam a hold upon the bed of the stream of such breadth and strength that it is practically immovable. For the first course at the base of the main dam, seven sills or stringers are laid, cross-wise of the stream, the one farthest down stream being, as stated, six feet from the ends of the uppermost tier of trees in the apron. The ends of 212 DAM FOR QUICKSAND BOTTOM. these sills are seen in our engraving. They are 14 by 16 inches in size, and their distance apart, between centers, is 4 feet, dividing the width of the whole base into 6 equal parts. They are lapped on each otherwhere two ends meet, and fastened together with two-inch pins. Their upper sides are counter-hewed to receive the cross-timbers, which are put in at intervals of 10 feet for the whole length of the dam. These cross-timbers, whose direction is of course lengthwise of the stream, are 12 inches square, and those in the first course are 24 feet long, being equal to the width of the base of the dam. They are counter-hewed and let down evenly on top of the first course of stringers or sills. The second course of stringers, which are five in number, are 12 inches square, and counter-hewed on top like the first or bottom course, upon which they rest solidly, making, with the cross timbers, a "water-joint." Next comes the second course of cross-timbers, 12 inches square and counter- hewed, but shorter than the preceding course, the width of the dam being less as it approaches the top; then -the third, fourth and fifth courses of stringers, alternating with the third, fourth and fifth courses of cross-timbers, all of which are 12 inches square, and counter-hewed so as to form the " water joint" by their contact wherever they cross. The fifth or last of the courses of stringers consists of a single timber 12 inches square, laid solidly on the center tier as shown in the engraving. The outsides of the outer stringers, and the ends of the cross-timbers, are beveled so as to present a smooth and even inclined face, which is planked on both the up-stream and down-stream slopes of the dam, as shown in the cut. The planks used are 2^ inches thick, and are fastened to the timbers with 6-inch spikes. By the crossing of the sills and transverse timbers in the frame, with water-joints as above described, a large number of cribs are formed ; and these are filled with rock up to the comb of the dam. The abutments, the dimensions of which have already been stated, are composed of timbers 12 inches square, counter-hewed and laid solidly one upon the other. They are lapped at the ends and pinned with two-inch pins. DAM FOR QUICKSAND BOTTOM. 213 Through the interior of the crib thus formed extend two courses of ties as shown in the cut, dividing it into three smaller cribs, all of which are filled with rock to the top. Outside of the abutment, both up and down the stream, for a distance of three feet, the bank is excavated, and the sand thus taken out is replaced with fine gravel and clay and sand puddle. On the side and end next to the water above the dam, sheet piling is driven, and the abutment is planked up and down with 2-inch planks. On the upper side of the dam and on the brush of the tree-tops projecting above, a coating of gravel two or three feet thick is placed. It will be observed that this dam by its construction forms an angle across the river, with the point or vertex up-stream, thus giving it to some extent the elements of strength per- taining to the arch, but requiring less care in the framing than if a regular curve was made across the stream. It should be here stated that the engraving is in some respects an imperfect one, as it does not .show the planking on the abutment ; and in the cross section of the dam in the front of the picture, the shape and arrangement of the counter- hewed sills and cross-timbers are not accurately represented. The cut is, however, sufficiently correct to enable the reader, aided by the minute description we have given, to form a clear idea of the manner in which the work is done. In building this dam, 15,000 feet of hewed timber, 26,000 feet of plank, and 1,575 poles or trees were used. The total cost at that time (1849) was about $4,500, but would be greater now, as labor and materials are both more costly than 25 years ago. The durability of the structure, with its broad base and the pyramidal form of the main dam, are sufficiently manifest, the strength of the abutments and the weight of the filling both in abutments and in the cribs of the dam, being such as to give abundant stability, in spite of the unfavorable nature of the river-bed. The fact that the dam has stood for over 24 years, and that the main body of it is still perfectly good, is conclusive testimony on this point. For a period of 15 years it required no repairs; but afterward the abutments above the water were rebuilt, and some repairs have recently been made on the dam itself- 214 OVERHUNG APRON DAMS. CHAPTER XXXVII. OVERHUNG APRON DAMS. Dams of several different kinds, adapted to streams having a hard bottom, have been illustrated and described in pre- ceding chapters of this work ; and as the one of which we now propose to speak does not dilfer greatly from some al- ready shown as regards the material used and the general principle of construction, we have given only an outline sec- tional view of it, which will, however, present with sufficient clearness all the novel features contained in it. The apron, in fact, is the only point in which there is any radical de- parture from the system laid down in former chapters. In this respect, the dam here shown is quite peculiar; but as it has stood the test of practical service for a number of years, we must conclude that for the locality and the kind of foundation on which it is built, it is a reliable structure^ at least under any but the most extraordinary circum- stances. This dam was built in 1867, Mr. C. Goodnow of East Sulli- van, N. H., with other parties, performing or supenntending the work. Its hight is 13 feet, and its length about 60 feet across the bed of the stream, at the point where the founda- tion timbers lie ; while, measuring on the cap or top of the dam, the distance is 80 feet. One end of the dam rests against a ledge, while at the other end is a steep gravel bank. In the cut, (Fig. 1) A A represent the foundation -sills extending across the stream, which consist of whole trunks of trees, some 24 inches in diameter at the butt. These sills are made flat on their upper surface to receive the OVERHUNG APRON DAMS. 216 cross-sills B, which are 12 inches square and locked on the top of the sills A, as shown in the cut, the gains being two inches in depth. The spaces between the sills are filled with rocks. The rafters are 28 feet in length, 12 inches in diameter at the lower end, and 10 inches at the upper end. They are notched upon the up-stream sill A, and at the other end upon the cap-timber F. The posts D are 10 inches in diameter, with a 3-inch tenon at each end, one be- ing inserted in the cap-timber F, and the other in the cross- sill B, which runs lengthwise of the stream and resting on Fig. 1. the foundation-sills A. The length of the posts D is suffi- cient to give the dam, at the crest, a hight of 13 feet, as al- ready stated. The distance between the rafters is 4 feet, from center to center. The manner in which the apron is framed is plainly indi- cated, and will attract the particular attention of the reader. The sills B project down-stream beyond the front founda- tion-sill A far enough to receive the posts E, which incline somewhat down-stream from the front of the dam. At the upper end of the posts E they are framed into the cap- tim- ber G, from which short timbers extend to the top of the cap F, meeting there the upper ends of the rafters. The projection thus formed, which we have called the apron, 216 OVERHUNG APRON DAMS. (although it bears but little resemblance to that portion of the dams hitherto described) serves to carry off the water from the dam, the overflow in floods being frequently 20 to 30 inches deep on the crest. Of course, on any other than a rock or very hard gravel bottom, an apron of the usual kind, and of considerable extent down-stream from the base of the dam, would be required to prevent washing and un- dermining; but there appears to have been no necessity for it in this case, as the builder of the dam states that it has Fig. 2. withstood all the floods which have occurred in the period — reaching nearly seven years — which has elapsed since its erection. It should be further stated that the rafters of this dam are covered with planks 2^ inches thick, which are secured to the rafters with 5-inch spikes. The total amount of lumber used in building the dam was 25,000 feet. Another dam, strongly resembling this in its method of construction and in the kind of apron attached, but of a still simpler form in many respects, is in use at Millbrook, Dutchess Co., N. Y. We give in Fig. 2 a representation of the manner in which it is built, from which it will be seen OVERHUNG APRON DAMS. 217 that nothing more simple or economical in the way of frame- work can well be devised. The particulars in regard to this dam are furnished to us by Mr. V. Anson of Millbrook, who states that the stream on which it is built has a rock bottom and sides, the river bed being quite steeply inclined, as in- dicated in the cut. No mud-sills are laid, and no timbers are required to rest the braces or studs A A upon, as they are footed directly into steps or notches in the rock. The distance between these studs is 5 or 6 feet, or whatever space may be adapted to the hight it is desired to give the dam. In framing the studs into the rafter B, the builder of this dam states that he found it much better not to make long tenons, secured with pins, as the timber would give out in and around the tenons. He therefore made them quite short, just enough in fact to keep them firmly in their places, and omitted the pins ; and the results were entirely satisfactory. The studs A and the rafter B constitute (aside from the apron) one bent of the dam; and these bents are placed side by side in a direct line across the stream, with intervals of 2 or 3 feet between them. Having been set perfectly plumb and properly stayed, they are covered with planks two-inch pine being considered sufficient for this purpose At the foot of each rafter, up-stream, an iron rod C, li inches in diameter and 2 feet long, passes through the rafter and into the rock for a considerable distance. It is manifest from the position of the rafter and direction of the rod that the pressure of the water from above the dam will tend to keep the rod in its place rather than to withdraw or loosen it ; and it will have a like eifect to preserve the foothold of the studs in the notches cut for them in the rock bottom. The cut shows very clearly the construction of the apron, the timber D having a slight incline from the horizontal, and being halved on to the end of the rafter and secured by pins or otherwise ; while near its outer extremity it is supported by the brace E. One end of this brace is tenoned into the timber D and the other into the stud A, as shown. It will be observed that the stud A at the front of the dam 27 218 OVERHUNG APRON DAMS. is not parallel with the others, but is drawn in at the foot — the object being to avoid the fall of water from the apron upon the foot of the studs, which would in time loosen them and weaken the entire structure. The studs and rafters are \'2 inches square, and the tim- bers of which the apron is made 4 or 5 inches square. It is unnecessary to remark that while this form of dam may be entirely reliable on a rock bottom, with banks of the same character, and other circumstances of a favorable descrip- tion, it would be impossible to give it the requisite strength and firmness, on the majority of streams, without mud-sills, and also an apron at the front of the foundation, such as we have illustrated in former chapters. STONE DAM WITH PLANK COVERING. 219 CHAPTER XXXVIII. STONE DAM WITH PLANK COVERING. It will be perceived on a very superficial examination of the dam illustrated in the present chapter that it is of an extremely substantial nature, and presents no weak point in any part of its structure to lead to a destructive inroad of the current. The plan of the particular dam shown in our en^^raving is taken from drawings furnished us by Messrs. 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OJ l-K >-( 00 On 4=^ 1 00 ON t 4^ ON to 00 to ^ On 01 1 to 00 to -S vO 00 On 00 OJ .1-, J ON 4» to O 00^ Ui 4*. to I i-i bib to ' ool -I- 4.1. ^4 ;oj 1^-1 On • r» ^ i r- i i-w ( J. M. WaUGH Frank A. Gilbert,; ?«"'<=«• Equal Owners, | ^; ^gY,*"/;!;,: MANSFIELD MILLSTONE DRESSER. -OWNED AND MANUFACTURED BY — GILBERT. OGDEN &l CO., Mansfield, Ohio. We claim the MANSFIELD MILLSTONE DRESSER to be the best and most complete machine ever invented for cracking and facing a Millstone. i^We use the common hand pick — grinding pick without removing it from the head — it makes a perfectly clean track in a right line. NEW REVISED EDITION. Entirely rewritten bj- the ablest writers on every subject Printed from new type, and illustrated with Several Thousand Engravings and Maps. This work is sold to Subscribers only. It will be com- pleted in sixteen large octavo volumes, each containing about 800 pages. PniCT.TER You. :— Extra Clofh, $5. Library Leather, %^. Half Turkey Morocco, V%. 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"By the use of one of these a builder, mason, carpenter or other worknuu, can always have in his pocket the most valuable of his apparatus used in construction, combined in a portable, useful, and cheap form " -From the Scientific American. We are extensive manufacturers of BOX-AA^OOD and IVORY RULES, And would not hazard our reputation by advertising a mechanic's tool which is not just what we represent. Send for Book of Explanation and Terms. STEPHENS & GO., Riverton, fLitchfield Co.,) Conn. BELT'S PATENT SHEET IRON ROOFING. CHEAPEST and BEST IRON ROOFING MADE This roofing having received, by practical test, the unqualified indornement. and approbation of all who have used it, for its ease and simpUcity of appli- cation, by any ordinary mechanic or laboring man, embracing an extent of territory in its adoption almost imparalleled in the history of any Metal Roof ever placed before the pubUc. Combining in its superiority of merit and worth, CHEAPNESS and durability, with all the desired qualities of a FIRE, ^VATER AND WIND-PROOF ROOFING, Resisting and withstanding perfectly harmless, its test in the frigid regions of Minnesota and Northern Michigan, the windy passes of the Rocky Mountains, the torrid /one of Southern Texas, and many seaboard States, East and South, and in every Western State, between Lake Huron and the Gulf of Mexico, making an array of practical and testimonial merit, that must carry confidence and conviction to the minds of aU, as to its superiority and worth. Highly commending itself to the attention and examination of all interested, and de- siring a superior roofing. For circulars, references and other information Address W. S. BELT, Patentee and Manufacturer, Nos. 56 & 58 E. Thibd St., CINCINNATI, O- 328 Bookwalter Engine. LOOK AT THESE PBICES — MANUFACTURED BY- JAMES LEFFEL & CO., Springfield, Ohio. LKFPEL^S DOUBLE TURBINE WATliR WHEEL. 329 James Leffel's Improved Double Turbine W^ater Wheel. There is perhaps no surer evidence of practical merit than success long established and widely extended, and based upon repeated trial upon the most exacting conditions. An invention of but little real utility may obtain a temporary reputation by means of shrewd management in bringing it before the public ; but its deficiencies will inevitably come to light, and a final verdict will be pronounced upon it in accordance with the facts. Cases in point are of almost daily occurrence, in which a transient popularity is gained by a device which will not endure the test of experience, and which speedily disappears from the market. It is therefore hardly too much to say that the fact that some seven thousand of the James Lefi'el Double Turbine water wheel are now in successful operation, under heads varying from 1^ to 240 feet, and that the demand for them is larger to-day than at any previous period, constitutes the strongest possible evidence that it is what it is claimed to be by its inventor and manufacturers — the most perfect water wheel ever off'ered for sale. HOW THE WHEEL HAS BEEN BROUGHT TO PERFECTION. No machine, however simple, durable and perfect in appearance, will in every respect prove satisfactory, when first put into operation ; many parts will require perhaps a change of form, strengthening, or may be an entirely difi'erent arrangement, upon application to the work to be performed, and a trial of two or three years. In fact it requires years of diligent study and practical experience, 41 JAMES LEFFEL'S Improved Double Turbine Water Wheel leffel's double turbine water wheel. 331 particularly with a water wheel, to so perfect all of its parts, as to make it successful under all circumstances, even though it be sound and practical in principle ; of course many of them never can, by any amount of labor or attempted improvement, be made to operate all species of machinery, and must always remain but little better than worthless. To the general principle first stated, the Leffel Double Turbine has perhaps been no exception ; during its introduction for the first four or five years, many of them were, no doubt, imperfect and not so durably made, as all newly introduced machinery is necessarily. Yet it has been our constant aim and design, to study and know its faults, which so large an experience with it would enable us to discover, and to the proper remedies and improvements we have directed our attention with the most gratifying results. A number of parts have been strengthened, others changed, and some added, all of which we could point out and de- scribe, stating the object, purpose, &c., if we thought it desirable. Among the most noticeable modifications and additions made, (some of which are patented) are the im- proved link for operating the gates ; the process for lining the iron plates with brass or any anti-corrosive metal (ap- plied only when specially ordered) ; the combmation of the toothed segment with the gate-arm in such a manner that the segment can be removed when the teeth become worn, and a new one supplied ; the spherical iron penstock ; and the improved method of casting solidly in one piece both wheels, by means of which the edge of the diaphragm can be made much thinner and yet stronger, assisting also to separate more perfectly the due proportion of water to each wheel. Half the buckets being made of good boiler iron, and the fillets retaining them being improved both in form and strength, it is impossible to break or tear out any of them ; as a result of which, out of the last 4,000 wheels put into operation not one has lost a single bucket. One set of buckets can easily be bolted or riveted to the wheel flange, if it were considered advisable. All such buckets are, however, liable to frequent derangement, by working loose and striking the inside of casing and end of guides often dropping entirely loose and breaking others; subject- ing the parties to the expense and inconvenience of taking the wheel from the casing to replace the broken ones. We prefer and recommend only those cast solidly into the wheel, thus enabling them to withstand the shock of blocks, stones and other rubbish to which they are so often sub- jected, and avoiding also the annoyance of removing the wheel from casing. Practically, the wheel itself is perfect. In fact the durability of the entire wheel and casing is such that the entire amount of repairs called for at all the shops of the firm, per annum, is covered by a sum so extremely small, in view of the fact that about 7,000 wheels are in operation, as to be scarcely worth estimate. The firm have within the last two years so arranged and syste- matized the process of manufacture that if any part is accidentally broken it can at once be duplicated, another being supplied by express on receipt of the necessary information. In short, the Leffel Improved Double Turbine has kept pace, from its first introduction, with the most advanced developments of mechanical science ; and for any purpose for which the power of water is employed, it may be safely guaranteed as having no equal in utility, economy and durability. DOUBLE WHEELS. An idea exists to a considerable extent, that water wheels may be so constructed, with two or more sets of buckets, in such a manner that each set of buckets may form a separate wheel, and that the water maybe received first by one set of buckets, or one wheel, and after passing from the first, then to operate on a second arrangement of buckets^ or wheel, and so on with as many sets or wheels as there may be, or until the last one is passed or operated upon ; thus in their opinion, obtaining a much greater percentage of the power of water, than is ordinarily utilized by the use of well constructed wheels of other kinds. , In fact a much greater power is often claimed for them than can possibly exist in the quantity of water used. Again, there is another class of wheels claiming to be double wheels, leffel's double turbine water wheel. 333 which are in reality and principle, but single wheels ; their builders believing by such representation that the reputa- tion and popularity of our wheel, (so celebrated for its truly double character) may thus directly benefit them. A single wheel, either a central or vertical discharge wheel, is commonly used, with a partition through the middle of the tier of buckets, thus only dividing the wheel, without in the least changing the action of the water on the buckets on either side of the partition or division, and without any modification of the principle of construction. The Lefi'el Double Turbine should not be confounded with either of these classes of wheels, as it is constructed, and acts, upon entirely and essentially difi"erent principles, which are peculiarly characteristic of it as a water wheel. There is in it a combination of two independent sets and kinds of buckets, one a vertical, the other a central dis- charge, each entirely different in its principle of action upon the water, yet each wheel or series of buckets receiv- ing its water from the same set of guides at the same time ; but the water is acted upon but once, since half of the water admitted by the guides passes to one wheel, and the other half of the water to the other wheel ; the water leaving both wheels or sets of buckets at the same time and as quickly as possible. These two sets of buckets are so combined as to make really but one wheel ; that is both are cast in one piece and placed upon the same shaft. By this arrangement there is admitted the greatest possible volume of water, consistent with its economical use, to a wheel of any given size, and at the same time the greatest area for the escape of water is secured. The surface in the wheel is thus reduced to minimum as compared with the quantity of water used, avoiding a very material loss by friction, which otherwise seriously diminishes the working power of a wheel. The value of this arrangement will be fully ap- preciated by those who who understand the practical effect of the frictional surface in a water wheel. JAMES LEFFEL & CO. Springfield, Ohio. 334 leffel's improved patent globe casino. Leffel's Improved Patent Globe Casing, The plate on page 335 represents our New and Improved Patent Globe cast iron Penstock, or Casing, which we are making, and in which many of our wheels are now placed. The form being that of a Globe or Sphere, it at once secures the greatest strength, with the least weight, and at the same time affords the largest space for the water to circu- late above and around the wheel ; while it also admits of the smallest exterior dimensions, and therefore occupies less space, than any other form or shape that can be adopted. As none of the parts are subject to wear or breakage, it never requires replacing, and of course its durability is beyond question. It is, as the plate represents, two hemispheres bolted together, thus enabling it to be easily taken apart, if at any time it should become necessary. There is a movable cap or cover, 0, bolted on the top of the casing, which can at any time be removed, (when the head of water is not standing in the case) and the wheel lifted bodily out of the casing, the opening in the top of same being amply large for that purpose, though it is seldom necessary to remove the wheel from any cause. There are two large man-holes on the sides, also a hand-hole B on the top cover, through which any obstruction can be removed, that may by care- lessness or accident get into the casing ; through these holes the wheel can also at any time be examined. On the top of cap C is bolted firmly a bridge-tree, carrying a good, broad oil bearing, for the support of the upper end of the water wheel shaft, to which a clutch coupling D is at- tached, immediately above said bridge-tree. In the cover or cap are arranged neat, snug and tight stuflSng boxes through which the gate rod. A, and water wheel shafts pass, and by which any water is prevented from discharg- ing ; they are supplied with tightening bolts by which they LEFFEL'S IMPROVED PATENT GLOBE CASING LEE'FEL^S IMPROVED PATfeNT GLOBE CASING. can be tightened down, should the packing at any time become worn or loose. In fact, the whole affair, when well set and arranged, is perfectly water tight, not leaking a drop, and could be located upon a floor near to any of the machinery if desired. They cannot be frozen up, since the iron is thick, and the circulation of water always sufficient to prevent freezing. A short tube or cylinder is attached to the bottom, which is intended to be slightly submerged under standing tail water ; it has a flange with its face turned and with bolt holes, to which an iron draft tube can be attached, and by a little care a perfectly air-tight joint can be made ; in cases where such draft tube is used of course the entire casing can be set higher, and sometimes in a more convenient location. We cannot say too much in praise of this casing, particu- larly for high falls ; being made strong and water tight it will always remain so. It has been fully tried and tested under almost every circumstance, and has proven in the highest degree satisfactory ; some of them are under heads from 80 to 240 feet, and stand the tremendous pressure admirably. In fact almost all of our small wheels up to 20 inches diameter are now ordered by our customers to be encased in this manner, such has been the satisfaction they have given. Of course it is not absolutely necessary to use it, except in particular instances, where a want of space or other circumstances would prevent the erection or use of a wood flume or box in which to place the wheel; but at any time and under almost any condition it is preferable and makes a number one arrangement, especially in any case whatsoever where the power is taken off' below the level of head water. But its greatest convenience is in locating wheels under mills, and in other difficult places, where posts, foundations, walls, &c., cannot be removed ; such difficulties being obviated by the compactness of its form, and the ease with which it can be connected to the head water by a pipe of suitable size. JAMES LEFFEL & CO. Springfield, Ohio. THIS BOOK IS DUE ON THE LAST DATE STAMPED BELOW BOOKS REQUESTED BY ANOTHER BORROWER ARE SUBJECT TO RECALL AFTER ONE WEEK. RENEWED BOOKS ARE SUBJECT TO IMMEDIATE RECALL O JUN 1 1990 C RECEIVED JUN 1 2 199C LIBRARY, UNIVERSITY OF CALIFORNIA, DAVIS Book Slip-Series 456 DEPARTMENT BOOK CARD I69iili7 Leffel. J.J dami TC51iO & co» Construct ion of mi3] Ui PHYSICAL SCiENCES LIBRARY TC5^0 LIBRARY UNIVERSITY OF CALIFORNIA DAVIS 169447 3 1175 00660 2836 THIS BOOK IS DUE ON THE LAST DATE STAMPED BELOW BOOKS REQUESTED BY ANOTHER BORROWER ARE SUBJECT TO RECALL AFTER ONE WEEK. RENEWED BOOKS ARE SUBJECT TO IMMEDIATE RECALL O JUN 1 1990 C RECEIVED LIBRARY, UNIVERSITY OF CALIFORNIA, DAVIS Book Slip-Series 458 DEPARTMENT BOOK CARD I69hli7 Leffel. J>^ Hajn.q^ & C0» Construction of mill TCgliO Ih PHYSICAL SCIENCES LIBRARY LIBRARY UNIVERSITY OF CALIFORNIA * DAVIS 169447 3 1175 00660 2836