Scientific American Supplement, No. 611, September 17, 1887(txt+pdf+epub+mobi电子书下载)

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Scientific American Supplement, No. 611, September 17, 1887试读：

NEW YORK, SEPTEMBER 17, 1887

IMPROVED OSCILLATING HYDRAULIC MOTOR.

The motor of MM. Schaltenbrand & Moller is adapted for use for household purposes, where small power is required, as in driving sewing machines.

Fig. 1 shows the motor with all its parts in side elevation, the flywheel and head rest being in section. Fig. 2 is a side view, with the air reservoir and distribution valve in section through the line 1-2. Figs. 3 and 4 represent the same apparatus, but without support, as where it is to be used on the table of a sewing machine, with the crank of the motor directly fastened to the flywheel of the sewing machine. Fig. 5 is a plan or horizontal section at the level of the line 3-4, and Fig. 6 is a section passing through the same line, but only including the cylinder and axis of the distributing valve. Fig. 7 is a horizontal section of the button of the cock through the line 5-6 of Fig. 3. Finally, Fig. 8 shows in detail, plan, and elevation the arrangement of the starting valve.Figs. 1 through 8IMPROVED OSCILLATING HYDRAULIC MOTOR.

This little motor does not show any new principle. It uses the old oscillating cylinder, but it embraces in its construction ingenious details which render its application very simple and very easy, especially, as we have already said, to sewing machines.

In the first place, the oscillating bronze cylinder, A, is cast in one piece with the distribution cock, a, Fig. 3, and its seat, b, also of bronze, is adjusted and fastened by means of the screw, b, to the air reservoir, C', cast with its cistern, C, acting as foundation or bed plate for the motor. This cistern is held either on the base of the cast iron bearing frame, D, of the main shaft, d, d, Figs. 1 and 2, or directly on the sewing machine table, Figs. 3 and 4, by means of two pins, e and e', so that it can oscillate about an axis which is perpendicular to the shaft, d, to which is attached the disk, F, carrying the crank.

This arrangement of parts, in combination with the horizontal axis of the distribution valve and with the piston rod, g, considered as a vertical axis of rotation, forms a species of universal joint between the crank pin and the table, so that it can be put in place without adjustment by any workman, who only has to screw up the two screws, h, to fasten to the table the standard, E, and the piece, E', in which are screwed the pivots, e and e', which support the tank, and this all the rest of the motor.

As is seen more clearly in Fig. 2, the water under pressure enters by the pipe, c, to which is attached a small tube of India rubber, and leaves by the pipe, c', and is carried away by another India rubber tube.

The openings of the distribution cock are symmetrically pierced in the seat and plug, which latter is divided internally by a horizontal diaphragm so arranged that at each oscillation communication is established alternately above and below the piston. So that it can be started or stopped quickly, the opening and closing of the throttle valve, i (Fig. 2), is effected by a single pulling movement upon the handle, I, and this draws out the valve horizontally. For this end the lever is pivoted upon the extremity of the valve stem, and ends in a bar engaging with a fork which acts as its fulcrum. This fork is cast in one piece with the plug, J, which closes the opening through which the valve is put in place, as shown in detail in Fig. 8. To prevent the lever from spinning out of the fork when it is pulled or pushed, this lever is prevented from turning by the valve stem, provided for this purpose with a double rib, i' (Figs. 2 and 8), which engages in slots in one piece, j, secured in the interior of the plug, J.

Lest the friction of the conical distribution valve oscillating with the cylinder should occasion a loss of power, care is taken to leave the key free in its seat, b, by not forcing the pivot, k (Figs. 1, 3, and 5), whose position in its seat is regulated by the screw, k'. It follows that a very slight escape of water may be produced, but that does no harm, as it is caught in the reservoir, C, provided with a little pipe, K (Figs. 1 and 3), to carry it away.

To maintain proper relations between the pressure of the water, or the work it is called upon to do, and the motor, the quantity of water introduced into the cylinder at each stroke of the piston is regulated by adjusting the length of stroke by the crank pin. For this end the course of the latter is made variable by means of the piece, f, adjusted by set-screw in the interior of the disk, F (Figs. 3 and 7), and tapped for the reception of a screw terminated by a milled button, f. If this button is turned, it moves the piece, f, and therefore regulates the distance of the crank pin, g', to which the piston rod, g, is attached (Fig. 3) from the center of rotation.

When the motor is arranged as shown in Figs. 1 and 2, or for the transmission of motion by means of a band wheel, p, cast in one with the flywheel, P, the disk which receives the crank pin of variable position is fixed directly upon the axle, d, of the same flywheel carried by the support, D; but when the motor can be applied directly, as is the case for example in the Singer sewing machine, upon the axle of the machine, no support is used, and the arrangement shown in Figs. 3 and 4 is adopted. In this case the disk, F', is cast with three arms which serve, by means of a screw, to fasten it to the flywheel carried by the axle of the sewing machine.

When the motor is used on the upper stories of buildings, the changes of speed incidental to drawing the water from the lower stories from the same pipe can be compensated by the use of an accumulator. This accessory apparatus is composed of a reservoir of a capacity of 10 liters or more, intercalated in the pipe which supplies the motor, so that the water coming from the principal pipe enters the bottom of this reservoir, passing through an India rubber valve opening inward, the supply for the motor coming through a tube always open and placed above this valve. The air trapped in the accumulator is compressed by the water, and when the pressure in the pipe decreases, the valve closes and the compressed air drives the water through the motor with decreasing pressure until normal pressure is re-established in the pipes.—Publication Industrielle.

TRIAL TRIP OF THE OHIO.

Some important trials of the new machinery of the screw steamer Ohio, belonging to the International Navigation Company, have recently taken place on the Clyde. The Ohio is an American built steamer measuring 343 ft. by 43 ft. by 34 ft. 6 in., and of 3,325 tons gross. She has been entirely refitted with new engines and boilers by Messrs. James Howden & Co., Glasgow, who also rearranged the bunker, machinery, and hold spaces, so as to give the important advantage of increased cargo accommodation obtainable from the use of their improved machinery, which occupies considerably less space than the engines and boilers of the same power which have been replaced. The new engines are of the triple expansion type, and the boilers, which are designed for supplying steam of 150 lb. pressure, are worked on Howden's system of forced draught, which combines increased power with high economy in fuel. The object of the owners in refitting the Ohio was to test the capability and economy of this system of forced draught on a sufficient scale to guide them in dealing with steamships of the largest class and great power.

In the refit of the Ohio the boilers were designed to work with a very moderate air pressure, this being sufficient for the power required by the contract. The combined power and economy, however, guaranteed by Messrs. Howden & Co. for the use of their system of forced draught was higher than has hitherto been attempted in any steamship, and sufficient, if attained, to prove the large reduction that could safely be made in the number and size of boilers for the use of the system, and the quantity of coal required to produce a given power. The contract for the refit of the steamer required that 2,100 indicated horse power (which was the maximum power of the engines removed) should be maintained during the trial on a consumption of 1.25 lb. of coal per indicated horse power per hour. Originally the boilers of the Ohio, from which this power was produced, were three in number, double ended, 12 ft. 6 in. in diameter by 17 ft. 6 in. in length, having each six furnaces 3 ft. in diameter, or eighteen furnaces in all, with an aggregate fire grate area of 300 square feet. The new boilers, fitted with the forced draught, are likewise three in number, but single ended, 13 ft. in diameter by 11 ft. 2 in. in length, having each three furnaces 3 ft. 3 in. in diameter, or nine furnaces in all, with an aggregate fire grate area of 112 square feet. Air for combustion is supplied to the boilers by one of Messrs. W.H. Allen & Co.'s fans, 5 ft. 6 in. in diameter, driven direct by an engine having a cylinder 7 in. in diameter with stroke of 4 in. The boilers removed had two stoke holds across the ship, one fore and one aft of the boilers, while the new boilers have only one stoke hold on the after side. The engines removed have cylinders 57 in. and 90 in. in diameter by 48 in. stroke, while the new engines have three cylinders 31 in., 46 in., and 72 in. in diameter respectively, with piston stroke of 51 in.

During the trials the coals were weighed out under the supervision of the officers of the company, who also took the record of speed and other data. After running down Channel for a considerable time, the trial on the coals weighed out began, and lasted 4 hours 10 minutes, during which time 10,885 lb. of Welsh coal were burned, the trial ending with the same revolutions of engines and the same pressure in boilers with which it began. The mean indicated horse power, calculated from the mean of seven sets of indicator cards, taken during the trial, and the mean revolutions per minute, found by dividing the total revolutions recorded on the engine counter by the minutes in the period of the trial, amounted to 2,124, thus making the consumption 1.23 lb. per indicated horse power per hour, and the power per square foot of fire grate almost exactly 19 indicated horse power. While testing the indicated horse power and consumption of coal, the steamer ran to and fro between the Cloch and Cumbrae lights, and also made several runs on the measured mile at Skelmorlie, from which the mean speed of the vessel was found to be 14.12 knots per hour. The remarkably high results obtained were most satisfactory to the representatives of the owners, and a large party of experts on board congratulated Mr. Howden on the successful fulfillment of the onerous guarantees undertaken.—Engineering.

THE CEARA HARBOR WORKS.

The works illustrated by the engravings are now being constructed under a concession from the imperial government of Brazil. The province of Ceara has an area of about 50,000 square miles, and is one of the richest in Brazil. Its produce comprises sugar, coffee, cocoa, cotton, tobacco, spices, fruit, cabinet and dye woods, India rubber, etc. Its population at the last census, taken in 1877, amounted to 952,624 inhabitants, that of the capital, the city and port of Ceara, being about 40,000. Although Ceara is the principal seaport at which lines of English, French, American, Brazilian, and other steamers regularly call, prior to the commencement of the harbor improvements it was almost an open roadstead, passengers and goods having to be conveyed by lighters and boats between vessels and the shore. The official statistics of the trade and shipping of the port show that an income of £35,750 per annum will be collected by the Ceara harbor corporation from the dues which they are authorized by their concession to charge on all imports and exports and on the vessels using the port and from the rent of the bonded warehouses.NEW HARBOR WORKS, CEARA, BRAZIL.

The drawings given here show the nature of the works, which are of a simple character. The depth of water along the principal quay, which is being constructed of solid concrete, and is connected with the shore by an iron and steel viaduct over 750 ft. in length—which is already completed—will be 19 ft. at low water and 25 ft. at high. This quay and breakwater is shown in perspective, in plan, and in section, and is of a very heavy section, as will be gathered by the scale given immediately below it. Meanwhile the landing of cargo is temporarily carried on at the end of the viaduct, which at high tide has a depth of about 20 ft. of water. The custom house and bonded warehouses are being built of the fine granite obtained at the Monguba quarries, which adjoin the Baturite railway, about sixteen miles from the port. A new incline has also been constructed from the rail way down to the port. The line has been laid along the viaduct, and will be extended over the quays as soon as they are completed. The concrete, of which a large quantity is being used, is mixed by Carey & Latham's patent mixers, and the contractors have supplied the very large and complete plant for carrying out the operations.

The engineer to the corporation is Mr. R.E. Wilson, M. Inst. C.E., Westminster, and his resident at Ceara is Mr. R.T.H. Saunders, M. Inst. C.E. The contractors for the work are Messrs. Punchard, McTaggart & Co., their representative at Ceara being Mr. George Wilson, M. Inst. C.E.—The Engineer.

ELECTRIC STREET RAILROADS.

Why should we prefer electricity as the propelling agent of our street cars over all other known methods? I answer, without hesitation, because it is the best, and being the best is the cheapest. Briefly I will present the grounds upon which I take my stand.

To-day the only methods for tramway service are three in number: Horses, with a history of fifty years and over; cables, with a history of fifteen years; and electricity, with a history of two years. I give the latter two years on the basis of the oldest electric street railroad in existence to-day, and that is the Baltimore railroad, equipped with the Daft system.

The main points for consideration common to each are six in number:● 1st. Obtaining of franchise.● 2d. Construction of buildings, viz., engine house or stable.● 3d. Equipment—rolling stock, horses, engines and dynamos.● 4th. Construction of tramway.● 5th. Cost of operation.● 6th. Individual characteristics and advantages.

Each of these requires a paper by itself, but in as concise a way as possible, presenting only the salient reasons and figures, I shall endeavor to embody it in one.

1st. Obtaining of franchise.

I assume the municipal officers and the promoters honest men.

It is the universal settled conviction that a street car propelled with certainty and promptness by mechanical means is infinitely to be preferred to horses. Hence, if this guarantee can be given, there need be no fear from the other side of the house. Years of experience prove that this guarantee can be given.

The mechanical methods are electricity and the cable. To suit local conditions the former has three general applications—overhead, underground, and accumulator systems; while the latter has but one, the underground. Hence, the former, electricity, has three chances to the latter's one to meet the whims, opinions, or decisions of municipal authorities. Other advantages accruing from mechanical methods are cleaner streets, absence of noise, quick time, no blockades, no stables accumulating filth and breeding pestilence, and lastly the great moral sympathetic feeling for man's most faithful and valuable servant, the horse. These all are directly in favor of obtaining the right franchise.

The three general ways of obtaining the same are a definite payment of cash to the authorities, a guarantee of an annual payment of a certain per cent. of the earnings, and lastly a combination of the two. For the city or town the latter way is the safest, and the best, all things considered. As electricity is mechanical, and as it can be shown that it is the cheapest to construct and most economical, and has three chances to operate, it stands by far the most likely to obtain the franchise.

2d. Construction of buildings.

The governing factors under this head are the local land valuation and tax. The system necessitating a spread eagle policy on the land question will cost. What could be a more perfect illustration than the horse railroad system? The motive power of the New York Central Railroad between New York and Albany could be comfortably stowed in the barns of some of the New York City street railways. What a contrast! The real estate, buildings, and fixtures of the Third Ave. line are valued at $1,524,000, and what buildings! Cattle sheds in the metropolis of America. Surely they did not cost a tithe of this great sum. What did? The land, a whole block and more. Henry George

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