The Bay Counties Power Company, Colgate, Yuba County, Cal., obtains its power from the Yuba River. The company has three power houses with an aggregate capacity of 15,640 horse-power and the possible development is 55,000 horsepower. There are nine high potential lines, going to Sacramento, Nevada City, Oakland, San Jose and other cities.

At the Power Development Company, San Francisco, Cal., water is taken from the Kern River and led through a tunnel 8,484 feet. The flow of water is 300 cubic feet per second. The installation consists of three wheels, one to each generator. Each wheel develops 750 horse-power. The generators are 450 K. W., of 600 horse-power each. The current is transmitted to Bakersfield.

The Mt. Whitney Power Company, Tulare County, Cal., has a power house containing three water wheels, of 700 horsepower each; three generators of 450 K. W. Water is had from the Kaweah River. The current is transmitted to Tulare, Visalia and other towns.

The plant of the Sierra Power Company, North Ontario, Cal., and that of the San Gabriel Electric Company, are run in parallel, although 25 miles apart. The Sierra Power Company have installed two 300 K. W. two-phase generators and two water wheels of the impulse type. Current is carried 25 miles to Azusa, where it joins the San Gabriel current. In the San Gabriel plant there are four water wheels, each unit of 550 horse-power being really two wheels on a single shaft. The current with that from the parallel plant of the Sierra Power Company is transmitted to Los Angeles.

The Pike's Peak Power Company, near Victor, Colo., is a typical California power plant. Here West and Middle Beaver Creeks are made use of by a dam, steel faced, granite back filled, 375 feet long on top, 220 feet long on base, 72 feet high, giving a capacity for 150 days' continuous operation at full station load. From here is a wood pipe 22,400 feet long, built of redwood staves, bound with steel. This is continued by a steel pipe 2,900 feet long. There are four 400 K. W., three-phase, generators driven by two impulse wheels each, directly connected with generators, running 450 revolutions under 505 pounds pressure. The current is sent to Victor, 81⁄2 miles, at 12,600 volts, and from there is distributed to various mining towns. A peculiar feature of this installation is, that owing to the character of the country and the impossibility of erecting poles during the first 3,400 feet from the power house, four granite ridges serve as supports and one span here is 1,120 feet.

The Utah Light and Power Company, near Salt Lake City, has a plant consisting of four double-nozzle wheels 61 inches i diameter, 600 horse-power, 300 R. P. M., which furnish the power to drive four three-phase 400 K. W. generators. Current is generated at a pressure of 500 volts and raised to 10,500 volts for transmission. Circuits transmit current to Salt Lake City, 14 miles, and also to Murray. This company has also a plant at Ogden, Utah, of five impulse wheels direct-connected to five three-phase generators developing 1,000 horse-power each. Pressure is raised to 16,100 volts and transmitted by two circuits to Salt Lake City, where it is distributed from sub-stations at 2,300 volts.

The Walla Walla Gas and Electric Company, of Walla Walla, have a pipe line of wooden staves 5,600 feet long from Mill Creek to their power house. A McCormack turbine is connected by a friction clutch to a 300 K. W. monocycle generator. Current is transmitted a distance of 5 miles.

The Quebec Railway, Light and Power Company has obtained, at Montmorency Falls, a working head of 180 feet, and a cotton mill uses the water afterwards under a head of 60 feet. The present installation comprises 5 turbines of 800 horse-power each; four two-phase generators yielding 5,500 volts at 286 revolutions; one two-phase double current generator yielding direct current from one side at 550 volts and alternating current from the other at 400 volts.

The St. Lawrence Power Company, Massena, N. Y., has an effective head of water, varying from 32 to 40 feet. Seven 5,000 horse-power units are installed, and the company expect to put in 8 more. These yield 2,200 volts, 3,000 cycles.

The Hamilton Electric Light and Cataract Power Company, in Ontario, has two 2,000 K. W. generators direct connected to Italian turbines running at 286 R. P. M.; and two 1,000 K. W.

generators direct connected to American turbines which run at 400 R. P. M. Current is transmitted to Hamilton, Ont., a distance of 35 miles.

The Shawinigan Water Power Company has constructed a canal 1,000 feet long from which water is conducted to the power house 130 feet below by six penstocks. The power house contains six units of 5,000 horse-power each. The generators are two-phase and the water wheels have a capacity of 6,000 horse-power each. Current is transmitted to Quebec, a distance of 90 miles, and to Montreal, 84 miles, at a voltage of 40,000.

The West Kootenay Power and Light Company, Ltd., obtains a head of water, varying from 34 to 42 feet, and has installed two turbines of 1,250 horse-power each, and one turbine of 1,800 horse power; also 2 three-phase generators of 1,000 horse-power each. The current is transmitted to Nelson, 10 miles, and a projected line will carry 60,000 horse-power from Bonnington to Rossland.

The Twin City Rapid Transit Company, at Minneapolis, utilizes a fall of 20 feet in the Mississippi and has an available horse-power of from 3,000 to 8,000. The installation consists of four horizontal turbines, eight 1,000 horse-power alternating generators and two 1,000 horse-power continuous current generators. Continuous current is used for the nearby portions of the railway system and the alternating current goes to Minneapolis sub stations and to St. Paul, 6.6 miles away.

The Kalamazoo Valley Electric Company, has built in the Kalamazoo River a dam 29 feet high and obtains a head of 24 feet with a flow of from 90,000 to 100,000 cubic feet per minute. Four pairs of 45-inch horizontal wheels, having a total of 2,800 horse-power and a generator of 1,500 K. W. capacity, comprise the equipment of this plant. Current is transmitted to Kalamazoo, 22 miles, and thence to Battle Creek, a total distance of 46 miles.

At Great Falls, Mont., the Great Falls Water Power and Townsite Company has an available head of 40 feet, from which is developed about 20,000 horse-power. The present installation consists of two pairs of 221⁄2-inch Victor register turbines and one pair of 18-inch Victor cylinder turbines, a number of generators and three M. D. 50-light series arc dynamos. Current is transmitted to the center of the city 21⁄2 miles.

The Hudson River Transmission Company, at Mechanicsville, N. Y., has a head of water of 18 feet and there are 14 pairs of 42-inch turbines, each consisting of two pairs of wheels. At 114 R. P. M. the total power of each set of turbines is 1,000 horse-power. There are also two sets of 18-inch wheels. Seven 1,000 horse-power generators and two 150 horse-power exciters complete the outfit. The current goes to Schenectady, 19 miles, also to Watervliet, 12 miles, and to Albany, 18 miles. At Canon Ferry, on the Missouri River, the Missouri River Power Company has installed a plant of 10 alternating current units, each consisting of a pair of 42-inch turbines, and one 750 K. W. alternator; six units, each consisting of a pair of 45-inch turbines and one 750 K. W. alternator. Current is transmitted to Helena, Mont., 18 miles; to East Helena, 11% miles, and to Butte, 65 miles.

Interesting plants have also been installed at Oregon City, on the Willamette River, Oregon, where 12,800 horse-power is developed by a fall of 40 feet and transmitted 14 miles at 5,000 volts; and at Redlands, Cal., 1,600 horse-power. Richmond, Va., has a plant of 11,000 horse-power; the Racquette River, at Hannawa Falls, N. Y., yields 1,250 horse-power. At Big Hole River, Montana, 4,000 horse power is obtained; on Jordan River, Utah, 2,800 horse-power is the yield, and at Delta, Pa., 500 horse-power is obtained from a small creek 5 miles distant. Another California plant is on the Santa Ana River, in the San Bernardino Mountains, from which 3,000 kilowatts are sent 83 miles at 33,000 volts to Los Angeles.

A company has been organized in Arizona for the unique purpose of mining ice. For some time it has been known that extensive caves existed in Arizona which contain great quantities of ice. Recent explorations have shown that the supply is practically inexhaustible, and it is for the purpose of procuring the cave ice to supply the local market that the company alluded to has been organized.

D draws the parts solidly together. This construction avoids a shoulder on the high pressure piston rod and the consequent liability to fracture. The low-pressure rod is supported at this point between the two cylinders by the slipper F. The slipper is made so as to be clamped around the low-pressure rod as indicated at E.

In large horizontal engines it is necessary to make provision for expansion and contraction of the cylinders on the bed. The ordinary method is to mount the rear end of the cylinder on a pedestal or slide so that it is free to move longitudinally. A tandem cylinder connected in this manner would be without attachment to the foundation at all since both the front and rear ends would have to be free to move. In the engine for the Cambria Steel Co. the high-pressure cylinder is mounted on a flexible connection at each end which consists of thin steel plates, perhaps 1⁄2 or -inch thick, bolted to the base and to flanges cast on the cylinder,

United States in its present important position in the iron and steel-making business. The success of at least one great steel manufacturer is largely attributed to his being a great "scrapper" of old machinery. Under his administration roll. ing mills and engines costing thousands of dollars were yearly relegated to the scrap-pile in favor of new ones of improved and heavier design. This policy is unquestionably a correct one from a business standpoint and is being religiously followed by all the principal steel mills to-day.

A mechanical engineer of Pittsburg, whose name is associated with the design of the rolling mill machinery of many of the principal steel mills at and in the vicinity of that famous center of industry, is Julian Kennedy. During a trip to the Smoky City something less than a year ago the writer had the pleasure of a personal interview with this gifted engineer and was shown some of the original schemes developed by him and incorporated in the designs of different machines. His work is undoubtedly characterized by great strength, simplicity and originality.

24"

Industrial Press, N. F

Fig 3.

CC

R. 18

as indicated in Fig. 2. This construction allows the cylinder to expand freely and at the same time holds it rigidly to the base.

The same engine has a fly-wheel 30 feet in diameter and weighing 100 tons. The rim is rectangular in section and hollow. Its depth is 36 inches and width 24 inches. The walls are 4 inches thick. The rim is built of sections, held together by steel rings shrunk in place on each side, as indicated in Fig. 3. Where these rings set into the rim, the walls are reinforced so that the thickness of metal is uniform throughout. The reinforcement is indicated by the dotted lines cd and ef in the sectional cut. In this wheel the steel ring A is 21 inches internal diameter and 29 inches external diameter, the depth of the section being 4 inches; the thick

In Fig. 1 is shown an ingenious and effective method of uniting the high and low-pressure piston rods of a tandem compound rolling mill engine. This scheme was used on a 42-inch by 72-inch by 60-inch engine built for the Cambria Steel Co. The low pressure piston rod is 14 feet long and 14 inches in diameter with a 10-inch hole through the center. The engine was designed so that the low-pressure piston is carried free of the cylinder, there being a clearance all around of 4-inch. The great weight of the piston and the length of the piston rod required it to be at least of the diameter given, otherwise there would have been considerable deflection at the center. As it is, the deflection is only about 1-100 inch in 14 feet. To connect the high-pressure piston rod to the lowpressure rod having a 10-inch hole, was something of a problem. The way it was done is shown in the cut. A is the high-pressure rod and B is the low-pressure rod. A cupshaped piece C, familiarly referred to as a "stove-pipe hat," was designed to fit the internal diameter of B and to fit over the end of piston-rod A. The piece B has a flange abutting against the end of the low-pressure rod. A key-way is cut through and both piston-rods so that the draft of the key

ness is 31 inches. This construction is used to some extent in European practice, but we believe not extensively. Its obvious advantage over the ordinary form of shrunk link i that the seat is readily machined, being circular in form A cutter set in a boring bar with the segments B and B in proper relative position is used to bore out the annular seat The shrinkage allowance can be very accurately made, which is usually not the case with the ordinary shrunk link. In this case the shrinkage allowance was about 164 inch. The

limiting feature of the ring form of link is the depth of the rim. It is obvious that the ring must be of sufficient diameter to inclose large enough sections C C' to have shearing strength about equal to the tensile strength of the ring. Therefore, it cannot be used advantageously on shallow rims. The shock of reversal of rolling mill engines having such heavy fly-wheels is something tremendous. Where wheels are keyed with the ordinary form of key and keyway, it is necessary that the bore of the hub fit the shaft closely and that the key fit closely in the keyway. To remove a 30-ton steel gear from its shaft when fitted in this manner, is, of course, a job of considerable difficulty, but the worst feature of it is that such construction does not well stand the shocks of reversing and when once loosened, the key must be renewed. Fig. 4 shows a method of keying fly-wheels and gears to their shafts, which was developed by Mr. Kennedy. The Kennedy system employs two tapered keys C C' of approximately square section set with their diagonals radially. The shaft B is fitted comparatively loosely in the hub A, so that when the keys are removed, the wheel or gear is free to be removed. The keys are fitted so the reaction due to their wedging action is in the direction of the arrows. The faces ef, cd, gh, and ij are, therefore, the ones in compression. One

key drives in one direction and the other in the opposite direction. Driving in either key tightens both. In the ordinary form of key, the metal composing it is subjected to shearing stress; in this form it is always in compression. The keys are usually made with heads D D' for convenience in removal.

Fig. 5 illustrates the method of setting a feather for a wheel or gear working on a splined shaft. The feather C has its sides radial with the shaft B instead of the time-honored square form commonly used in machine construction. A little reflection will demonstrate that the metal of the shaft is better able to resist shearing stress at right angles to the sides of the feather C than if it was of the ordinary form. Another decided advantage is that C is fitted in A in a manner that prevents its readily becoming loose, and if it does become loose, it cannot turn in the keyway without shearing off a substantial corner. It is also apparent that it is much easier to get a tight permanent fit with the dove-tail construction than with the other form. If the feather ever does work loose a shim placed in the bottom of the slot and the feather driven in on top of it makes it as good as new.

The minimum expense of keeping a battle-ship in commission is estimated by Admiral Melville to be not less than $1,000 a day. The actual cost of our completed fighting vessels, and the total estimated cost of those building, will probably teach $275,000,000. This is said to represent but half of the expenditure incurred in creating a navy, however, the numerous auxiliaries, training schools, dock yards, coaling stations, etc., swelling the grand total.

BELT DRIVE FOR SHAFTS AT RIGHT ANGLES. GRAPHICAL METHOD OF LAYING OUT A REVERSIBLE, THREE-PULLEY DRIVE.

FORREST R. JONES.

It frequently occurs in practice that power is to be transmitted by belting between two horizontal shafts at right angles to each other, one near the ceiling and the other near the floor of a room; or, what amounts to the same thing, so far as the belting is concerned, to transmit power between a horizontal and a vertical shaft at some distance apart. The general statement of the case is for a belt drive to connect any two shafts at right angles to each other, but some considerable distance apart. A method that is very commonly practised is to use two pulleys, one upon each shaft, and so set that the belt will run correctly for rotation in one direction with either pulley acting as the driver, without the addition of any idle, guide, or binder pulleys. With such an arrangement the reversal of the rotation to even a small extent will throw the belt from the pulleys on account of the manner in which it is put on, and not depending upon whether there is any power transmitted or not. This inability to run in both directions is, in itself, often a very serious fault with a belt drive, for it prevents rotating the shafting backward, which is frequently desirable in many cases. In addition to this there is another fault which becomes very great when the pulleys are large in diameter, and the belt wide, in proportion to the distance between the shafts. This fault, well known to those who have to deal with belting, is a rapid wearing out of the belt on account of the side bend that it must make at the point of leaving each pulley. This side bend stretches the edge of the belt, of course, and almost invariably makes it crooked, and consequently short-lived on account of the excessive stretching. This stretching is all at the same edge when the same side of the belt, as the hair side, runs against both pulleys. And, furthermore, when the pulleys are large in diameter and the belt is wide in comparison with the distance between the pulley centers, a new belt will not run upon the pulleys when they are located in the positions that would be correct for a narrow belt upon the same pulleys. The stiffness of the belt is accountable for this. The wider the belt and the stiffer it is, the more must the pulleys be set out of what may be called their true position when a new belt is first put in place. As the belt stretches upon the edge and becomes more flexible, the pulleys have to be gradually moved back toward their true positions, but do not reach these positions until the belt is nearly worn out, if they ever reach them at all. Of course, by using pulleys very much wider than the belt-say half again as wide, or double the width-the necessity of adjusting them along their shafts might be obviated by setting them so that the belt will run near one side of the face when new, and gradually work over toward the other side as it becomes worn. Few engineers, however, would care to exhibit such a belt drive in an establishment where they are responsible for this branch of the plant.

In order to have a drive in which the belt will give its longest life, it is necessary that the arrangements of pulleys be such that rotation can take place in either direction and have the belt still remain in its correct position. This can be done by introducing a third pulley as an idle or guide pulley, so placed as to act upon one stretch of the belt between the pulleys upon the driving and driven shafts. This may be done, as shown in Fig. 1, which is an isometric drawing representing two shafts, the one, A, near the ceiling of a room and the other, B, near the floor. The upper one, A, is perpendicular to the end wall of the building, and the lower one, B, parallel to both the end wall and the floor. Instead of the actual belt in place upon these pulleys, a string is shown corresponding to its center line. If the pulleys are placed so that this string will run properly upon them, then the belt will also keep in place. Further, if an amount of crowning is given the pulleys in proportion to the belt width, there will be no appreciable uneven stretching of the edges of the belt. The twist of the belt between any pair of pulleys should not greatly exceed a quarter turn for a length six or seven times as great as the width of the belt. This means

that the belt should not have a width greater than one-sixth of the distance between A and B, which distance is equal to the length of the stretch of the belt between them.

In Fig. 1 the pulley on A and that on B are so placed that one stretch of belt, represented by its center line or by the string, is vertical between them. In other words, the point of tangency of the string with the upper pulley is directly over its point of tangency with the lower one. In order to make clear just how the idle pulley must be located, it may be well to set forth the conditions that must be necessarily fulfilled in order that the belt shall run in either direction upon the pulleys. This condition is that each stretch of belt running off from any pulley must have its center line perpendicular to the axis of that pulley. Another way of ex. pressing this is, that the center lines of the two stretches of belt leading from a pulley must lie in a plane passed through the middle of the pulley and which is, of course, perpendicular to the pulley axis and to the axis of the shaft which supports it. This is called the median plane of the pulley.

The problem which presents itself, therefore, is to locate this idle pulley so that its median plane shall contain the center lines of the belt stretches leading from it. This can be done in practice by setting lines corresponding to the center lines of the two stretches of belt leading to the idle pulley, and then locating a third line corresponding to the axis of the idler which shall be perpendicular to the plane of the two center lines just mentioned. This assumes that the main shafting, or at least the building, has been erected. As is common to all construction work, however, it is often necessary to determine the location of shafting and pulleys before the building is erected, and to send out such drawings as will enable the millwright to get out the necessary timber, supports, etc., before any shafting is in place. The manner in which the drawings can be made, therefore, will be given first, and then the method which may be followed for locating the shafting and pulleys.

In Fig. 2 three views of the main pulleys and their shafts are shown by the method in common use for making drawings of machinery, buildings, etc. The top view in Fig. 2 corresponds to a projection upon the floor in Fig. 1; the side view corresponds to the projection upon the side wall of the building (not shown in Fig. 1), and the end view of Fig. 2 corresponds to the projection upon the end wall in Fig. 1. The co-ordinate axes XY and Y'Z are shown in Fig. 2 intersecting at 0. In the top view both pulleys are represented by heavy-line rectangles and the axes of their shafts by dash-and-dot lines; in the side view the pulley A is represented by the heavy-line rectangle As, and B by the circle whose center is at Bs; and in the end view A is represented by a circle with center at Ae, while B is represented by a heavy-line rectangle whose center Be is on the same horizontal line as Bs. It is absolutely necessary that the distance of the center of the pulley Ah from the co-ordinate axis XY, in the top view, shall be equal to the distance in the end view of the center Ae of the large pulley from the co-ordinate axis Y'Z. The same is true of the center of the pulley B, in that in the top view, the distance from the center of the pulley Bh to the co-ordinate axis XY must be the same as the distance, in the end view, of Be from the co-ordinate axis Y'Z. It is not necessary to have the rectangular projections of these pulleys appear in the drawings, as far as the actual solution of the problem is concerned, but they have been shown here in order to bring out their positions more distinctly. The problem can be solved by only the projections of the median planes of the pulleys. This is really the better way, since it obviates the confusion of an unnecessary number of lines. In Fig. 2 the light lines drawn through the middles of the rectangular projections of the pulleys represent the projec tions of the median plane of the pulleys and also, in part, the projections of the center lines of the various stretches of belt. No further reference will be made to the heavy lines of these rectangular projections of the pulleys.

The binder pulley may, of course, be placed at any height throughout a considerable range between the upper and lower pulleys. In this case it will be taken as midway be The directions which the center lines of

tween the two.

the stretches of belts leading to the idle pulley must follow may be determined by assuming, first, that the idle pulley is to have no sensible diameter, but is only an infinitely small pin or pulley on which the center line of the belt runs. Referring to the side view, the two stretches of belt running from the upper pulley As will have both center lines in the median plane of the pulley As down as far as the point where this imaginary small idle pulley is located. Under the assumption which has just been made, this point will be midway between As and Bs, which is at the point Ms. From Ms the stretches of belt run to the two sides of the pulley Bs, the one stretch continuing vertically downward, and the

other at an angle with the vertical to the point of tangency a with the pulley Bs. Draw Ms-a, extending it to intersect Y'Z at b. The projection of Ms in the end view will lie at Me where a horizontal line through Ms intersects the projection of the median plane of Be in the end view.

Draw b perpendicular to Y'Z and intersecting the median plane of Be at F. Through Me draw a line tangent to Ae at r, extending it to meet Y'Z at f; e-Me is the projection of the center line of the stretch of belt between r and the imaginary small idle pulley at Me. Through F draw FY parallel to rf. From Me draw Me- perpendicular to rf and of indefinite length, intersecting FY at P. On rf take the