Storage Battery—Batteries of Planté, Faure and Brush—Electric Welding—Direct Generation of Electricity by Combustion—Electric Boats—Electro-Plating—Edison’s Electric Pen—Electricity in Medicine—Electric Cautery—Electrical Musical Instruments—Electric Blasting.
A prominent factor in the electrical art is the Storage Battery, Secondary Battery, or Accumulator, as it is variously called. A storage battery acts upon the same general principle as the ordinary galvanic or voltaic battery in giving forth electrical current as the correlated equivalent of the chemical force, but differs from it in this respect, that when the elements of a primary battery are used up, the battery is exhausted beyond repair. With the storage battery, it may be regenerated at will by simply subjecting it to an electric current from a dynamo. The dynamo stores up in this battery its electric force by converting it into chemical force, which is imprisoned in chemical compounds that are formed while the power of the dynamo is being applied. These chemical compounds are, however, in a condition of unstable chemical equilibrium, which is undisturbed so long as the poles of the storage battery are not connected, but when connected through a circuit, the instability of the chemical compounds asserts itself, and in passing back to a condition of normal equilibrium the disruption gives off the correlative equivalent of electric current stored up in it by the dynamo.
Probably the earliest suggestion of a storage battery is by Ritter in 1812, in his “secondary pile.” This device consisted of alternate discs of copper and moistened card, and was capable of receiving a charge from a voltaic pile and of then producing the physical, chemical, and physiological effects obtained from the ordinary pile. The first storage battery of importance, however, was made by Gaston Planté in 1860, which consisted of leaden plates immersed in a 10 per cent. solution of sulphuric acid in water. In Fig. 64 is shown a modification of the Planté type of storage battery, composed of a series of plates shown on the left. Each of these plates is built up, as shown in detail in Fig. 65, of lead strips corrugated and arranged in layers alternately with flat strips, within perforated leaden cases. The corrugation of the leaden laminæ gives greater superficial area, and the alternation of flat and corrugated strips keeps them properly spaced, so the sulphuric acid solution may penetrate and act upon the same. Each plate section has a rod to connect it with its proper terminal. When the charging current is applied, the positive lead plate becomes covered with lead peroxide (PbO2) and finely divided metallic lead is deposited on the negative plate. When the battery is being discharged the peroxide of lead gives up one of its atoms of oxygen to the spongy metallic lead deposited on the other plate, and both plates remain coated with lead monoxide (PbO).
The most important development of the storage battery was made by Camille A. Faure, in 1880 (U. S. Pat. No. 252,002, Jan 3, 1882). In the early part of 1881 there was sent from Paris to Glasgow a so-called “box of electric energy” for inspection and test by Sir William Thomson, the eminent electrician. It was one of the first storage batteries of M. Faure. The illustration, Fig. 66, shows a battery of this type in which the lead plates covered with red lead (Pb3O4) replace the plain lead plates in the Planté cell. The action of the battery is that when a current of electricity is passed into the same, the red lead on one plate (the negative) is reduced to metallic lead, and that on the other is oxidized to a state of peroxide (PbO2). These actions are reversed when the charged cell is discharging itself. The elements of this battery consist of alternate layers of sheet lead, and a paste of red oxide of lead. These are immersed in a 10 per cent. solution of sulphuric acid in water. Many minor improvements have been made in the storage battery, covered by 716 United States patents, most of which relate to cellular construction for holding the mass of red lead in place. The most notable are those of Brush, to whom many patents were granted in 1882 and 1883.
The storage battery finds many important applications. For furnishing current for the propulsion of electric street cars it has proved a disappointment, on account of the vibrations to which it is subjected, and the great weight of the lead, which in batteries of suitable capacity runs up into many thousands of pounds. The storage battery finds a useful place, however, for equalizing the load in lighting and power stations, and is there brought into action to supplement the engine and dynamo during those hours of the day when the tax or load is greatest. It is also used to keep up electrical pressure at the ends of long transmission lines; for telegraphing purposes; for isolated electric lighting; for boat propulsion; the propulsion of automobile carriages; and in all cases where a portable source of electric current would find application. The great growth of automobile carriages in the past year has greatly stimulated the output of storage batteries. One large company (The Electric Storage Battery Company), manufactured and sold storage batteries for the year ending June 1, 1899, to the amount of $2,387,049.91, and there are many other manufacturers.
Electric Welding was invented by Prof. Elihu Thomson, of Lynn, Mass., and patented by him August 10, 1886, No. 347,140-42, and July 18, 1893, No. 501,546. It is useful for the making of chains, tools, carriage axles, joining shafting, wires, and pipes, mending bands, tires, hoops, and lengthening and shortening bolts, bars, etc. For electric welding a current of great volume or quantity, and very low electro-motive force, is required. Thus a current of from one to two volts, and one to several thousand amperes, is best suited. Referring to Fig. 67, the current from the dynamo is conducted to one binding post of the commutator 3, which is arranged to send the current through one-sixth, one-third or one-half of the primary wire P of a transformer or induction coil. The other binding post of the commutator 3 extends to one terminal of an isolated primary coil 4, and the other terminal of this coil connects with the dynamo. The coil 4 is provided with a switch to regulate the amount of current. The rods to be welded are placed in clamps C C′, C being connected with one terminal of the secondary conductor S, and the movable clamp C′ with the other. When the current is turned on C′ is moved so as to project one of the surfaces to be welded against the other, and as they come in contact they heat and fuse together, as shown at W. Larger apparatus has been devised to weld railroad joints on the roadbed, and for other applications.
The generation of electricity for commercial purposes is almost entirely dependent upon the dynamo, as this is cheaper than the voltaic battery. The dynamo, however, must be energized by a steam engine. The direct production of electric energy by the combustion of coal would be the ideal method. A process invented by Edison (Pat. No. 490,953, Jan. 31, 1893), is interesting as an effort in this direction, and is presented in Fig. 68. A carbon cylinder D is suspended in an air-tight vessel B, and is surrounded by oxide of iron F, the whole being placed above a furnace. The temperature being raised to a point where the carbon will be attacked by the oxygen, carbonic oxide and carbonic acid will be formed, which are exhausted by the suction fan E. A constant current of electricity is given off from the two electrodes through the wires, the metallic oxide being reduced and the carbon consumed.
Electrical Navigation began with Jacobi, who made the first attempt on the Neva in 1839. He used voltaic apparatus consisting of two Grove batteries, each containing sixty-four pairs of cells, but little progress was made in this field until the secondary battery was perfected. In 1881 Mr. G. Trouvé made an application of the storage battery and electric motor to a small boat on the Seine. The electric motor, which was located on top of the rudder, as seen in Fig. 69, was furnished with a Siemens armature connected by an endless belt with a screw propeller having three paddles arranged in the middle of an iron rudder. In the middle of the boat were two storage batteries connected with the motor by two cords that both served to cover the conducting wires and work the rudder. Electric launches have in later years rapidly gained in popularity. Visitors to the Chicago fair will remember the fleet of electric launches, which afforded both pleasure and transportation on the water, at that great exposition, and to-day every safe harbor has its quota of these silently gliding and fascinating pleasure crafts. Fig. 70 is a longitudinal section and a general view of one of these launches.
Electro-plating is one of the great industrial applications of electricity which had its origin in, and has grown into extensive use in, the Nineteenth Century. It originated with Volta, Cruikshank, and Wollaston in the very first year of the century. In 1805 Brugnatelli, a pupil of Volta, gilded two large silver medals by bringing them into communication by means of a steel wire with the negative pole of a voltaic pile and keeping them one after the other immersed in a solution of gold. In 1834 Henry Bessemer electro-plated lead castings with copper in the production of antique relief heads. In 1838 Prof. Jacobi announced his galvano-plastic process for the production of electrotype plates for printing. In the same year he superintended the gilding, by electro-plate, of the iron dome of the Cathedral of St. Isaac at St. Petersburgh, using 274 pounds of ducat gold. In 1839 Spencer described an electrotype process and carried the date of his operations back to September, 1837. In 1839 Jordan also describes an electro-plating process. In 1840 Murray used plumbago to make non-conducting surfaces conductive for electro-plating. In 1840 De Le Rive made known his process of electro-gilding, employed by him in 1828, and in the same year (1840) De Ruolz took out a French patent for electro-gilding, and in the following year formed electro deposits of brass from cyanides of zinc and copper. In 1841 Smee employed his battery for electro-plating with various metals. In 1844 there were published the electro-plating experiments of Dancer, made in 1838. In 1847 Prof. Silliman imitated mother-of-pearl by electro-plating process.
In the last half of the century the production of electrotype plates for printing in books, and for the production of rollers for printing fabrics, and the extensive art of electro-plating with gold, silver, nickel and copper, has grown to enormous proportions, but the fundamental principles have not materially changed. The dynamo, however, has generally supplanted the voltaic battery in this art. The deposition of silver and gold on baser metals not only increases the ornamental effect, but prevents oxidation. Silver plated goods for the table and articles of vertu are to be found everywhere. Nickel is employed for cheaper ornamental effect, and copper finds a large application for electrotypes for printing and for coating iron castings as a protection against rust. In Fig. 71, which shows the interior of an electro-plating establishment, the dynamo is shown on the right connected by wires with two horizontal rods running along the wall and across the various tanks containing the plating solution. On the tanks are rods supporting the articles to be plated, which are suspended in the solution. Similar rods support the opposite electrodes of the tank. Wires connect these rods to the rods on the side of the wall, and to the opposite poles of the dynamo.
The electric pen of Edison, brought out in 1876 (U. S. Pat. No. 196,747, Nov. 6, 1877), is one of the simple applications of electricity, which for a number of years was in quite general use for making manifold copies of manuscript. In the illustration, Fig. 72, this is shown. It comprises a stylus b reciprocated in a tube a by the vibratory action of an armature k over the poles of an electro-magnet, supplied with a suitable current and vibrating contacts l h. The stylus was rapidly reciprocated, and as the operator traced the letters on the paper, the stylus produced a continuous trail of punctures which permitted the paper to be used as a stencil to make any number of copies. It has, however, been rotated out of existence by manifolding carbon paper, and the almost universal use of the typewriter.
Electricity in Medicine.—The superstitious mind is prone to resort to mysterious agencies for the cure of diseases, and for many years men of no scientific knowledge whatever have been employing this seductive instrumentality for all the ills that flesh is heir to. That it has valuable therapeutic qualities when rightly applied no intelligent person will doubt, and it is unfortunate that for the most part it has been in the hands of charlatans who sell their wares, and rely upon a faith-cure principle for the result. Still there have been intelligent experimenters in this field, and it is one of much promise for further research.
In the first century of the Christian Era (A. D. 50) Scribonius Largus relates that Athero, a freedman of Tiberius, was cured of the gout by the shocks of the torpedo or electric eel. In 1803 M. Carpue published experiments on the therapeutic action of electricity. The discovery of induction currents by Faraday in 1831 brought a new era in the medical application of electricity, in the use of what is known as the Faradaic current. The first apparatus for medical use, which operated on this principle, was made by M. Pixii in France, and the first physician who employed such currents was Dr. Neef, of Frankfort. The medical battery is a well-known and useful adjunct to the physician’s outfit. Electric baths are also common and effective modes of applying the electric current. An early example of such a device is shown in the U. S. patent to Young, No. 32,332, May 14, 1861. The electric cautery and probe are also scientific and useful instruments. The cautery consists of a loop of platinum wire carried by a suitable non-conducting handle, with means for constricting the white hot loop of wire about the tumor or object to be excised. It was invented in 1846 by Crusell, of St. Petersburgh. A form of the electric cautery is shown in Fig. 73, in which a is the platinum wire loop whose branches slide through guide tubes, the ends being attached to a sliding ring B. The current enters through the wire at the binding posts at the end of non-conducting handle A, and heats the platinum loop, a, red hot. The loop, a, being around the object to be excised, is constricted by drawing down the handle ring B.
Of the various applications of electricity in body wear and appliances there is scarcely any end. There are patents for belts without number, for electric gloves, rings, bracelets, necklaces, trusses, corsets, shoes, hats, combs, brushes, chairs, couches, and blankets. Patents have also been granted for electric smelling bottles, an adhesive plaster, for electric spectacles, scissors, a foot warmer, hair singer, syringes, a drinking cup, a hair cutter, a torch, a catheter, a pessary, gas lighters, exercising devices, a door mat, and even for an electric hair pin and a pair of electric garters.
Electrical Musical Instruments include pianos, banjos, and violins, all of which are to be played automatically by the aid of electrical appliances. In the illustration, Fig. 74, is shown a modern electrical piano. A small electrical motor 1, run by a storage battery or electric light wires, turns a belt 3, and rotates pulley 4 and a long horizontal cylinder 5 running beneath the keyboard. Above this cylinder is the mechanism that acts upon the keys. It consists of a series of brake shoes which, when brought into frictional contact with the cylinder 5, are made to act on small vertical rods which bring down the keys just as the fingers do in playing. The selection of the proper keys is made by a traveling strip of paper perforated with dots and dashes representing the notes, which strip of paper passes between two metal contact faces, which are terminals of an electric battery. When the contacts are separated by the non-conducting paper the current does not flow, but when the contacts come together through the perforations the current is completed through an electro-magnet, and this is made to bring the proper brake shoe into position to be lifted by the cylinder 5, which rotates constantly.
Electro-blasting.—In 1812 Schilling proposed to blow up mines by the galvanic current. In 1839 Colonel Pasley blew up the wreck of the “Royal George” by electro-blasting. On Jan. 26, 1843, Mr. Cubitt used electro-blasting to destroy Round Down Cliff, and in our own time the extensive excavations in deepening the channel and removing the rocks at Hell Gate, from the mouth of New York harbor, was a notable operation in electro-blasting, and doubtless owes its success largely to the electric current employed.
Only the briefest mention can be made of the induction coil and the electrical transformer, of electric bells and hotel annunciators, of electric railway signalling, and electric brakes, of electric clocks and instruments of precision, of heating by electricity, of electrical horticulture, and of the beautiful electric fountains. These, however, all belong to the Nineteenth Century, and include interesting developments.
Electro-chemistry and the electrolytic refining of metals represent also, in the applications of electricity, a large and important field, more fully treated under the chapters devoted to chemistry and metal working.
Hero’s Engine, and Other Early Steam Engines—Watt’s Steam Engine—The Cut-Off—Giffard Injector—Bourdon’s Steam Gauge—Feed-Water Heaters, Smoke Consumers, Etc.—Rotary Engines—Steam Hammer—Steam Fire Engine—Compound Engines—Schlick and Taylor Systems of Balancing Momentum of Moving Parts—Statistics.
When the primeval man first turned upon himself the critical light of introspection, and observed his own deficiencies, there were born within him both the desire and the determination to supplement his weakness, and become the ruling factor in the world’s destiny. The strength of his arm unaided could not cope with that of the wild beast, he could not travel so fast as the animal, nor soar so high as the bird, nor traverse the waters of the sea like the fish. The magnificent power of the elements first inspired him with awe, then was worshiped as a god, and he trembled in his weakness. Then he began to invent, and seeing in physical laws an escape from his fears, and a solution for his ambitions, he trained these forces and made them subservient to his will, and established his right to rule. Out of the maze of the centuries a steam engine is born—not all at once, for that would be inconsistent with the law of evolution—but gradually growing first into practicability, then into efficiency, and finally into perfection, it stands to-day a beautiful monument of man’s ingenuity, throbbing with life and energy, and moving the world. What has not the steam engine done for the Nineteenth Century? It speeds the locomotive across the continent faster and farther than the birds can fly; no fish can equal the mighty steamship on the sea; it grinds our grain; it weaves our cloth; it prints our books; it forges our steel, and in every department of life it is the ubiquitous, tireless, potent agency of civilization. Does the ambitious young philosopher predict that electricity will supersede steam? It is not yet a rational prophecy, for the direct production of electricity from the combustion of coal is still an unsolved problem, and behind the electric generator can always be found the steam engine, modestly and quietly giving its full life’s work to the dynamo, which it actuates, and caring nothing for the credit, unmindful of the beautiful and striking manifestations of electricity which astonish the world, but humbly doing its duty with a silent faith that the law of correlation of force will always lead the way back to the steam engine, and place it where it belongs, at the head of all useful agencies of man.
The Nineteenth Century did not include in its discoveries the invention of the steam engine. The great gift of James Watt was one of the legacies which it received from the past, but the economical, efficient, graceful, and mathematically perfect engine of to-day is the product of this age.
The genesis of the steam engine belongs to ancient history, for in the year 150 B. C. Hero made and exhibited in the Serapeum of Alexandria the first steam engine. It was of the rotary type and was known as the “aeolipile.” During the middle ages the spirit of invention seems to have slept, for nearly eighteen centuries passed from the time of Hero’s engine before any active revival of interest was manifested in this field of invention. Giovanni Branca in 1629, the Marquis of Worcester in 1633, Dr. Papin in 1695, Savary in 1698, and Newcomen in 1705, were the pioneers of Watt, and gave to him a good working basis. Strange as it may appear, there was in 1894 and probably still is in existence in England an old Newcomen steam engine (see Fig. 76), which for at least a hundred years has stood exposed to the weather, slowly rusting and crumbling away. It is to be found in Fairbottom Valley, half way between Ashton-under-Lyne and Oldham, and is the property of the trustees of the late Earl of Stamford and Warrington. It is erected on a solid masonry pillar 14 by 7 feet at the base, which carries on its top, on trunnions, an oak beam 20 feet long and 12 by 14 inches thick. This beam is braced with iron, and has segmental ends with a piston at one end, and a balance weight at the other. The piston and pump rods are attached by chains. The cylinder is of cast iron, 27 inches in diameter, and about six foot stroke, the steam entering at the bottom only. It was formerly used for pumping a mine.
The distinct and valuable legacy, however, which the Nineteenth Century received from the past, was the double acting steam engine of James Watt, disclosed in his British Pat. No. 1,321, of 1782. Prior to this date steam engines had been almost exclusively confined to raising water, but with the invention of Watt it extended into all fields of industrial use. Watt’s double acting engine is shown in Fig. 77. It comprised a cylinder A, with double acting piston and valve gear E F G H; the parallel motion R for translating the reciprocating motion of the piston into the curved oscillatory path of the walking beam; a condenser chamber K, with spray I, for condensing the exhaust steam; a pump L J to remove the water from the condenser, and also the air, which is drawn out of the water by the vacuum; a water supply pump N; the automatic ball governor D, and throttle valve B. Two pins on the pump rod L strike the lever H and work the valve gear, and a collecting rod P and crank Q convert the oscillations of the walking beam into the continuous rotation of the fly wheel.
Watt’s automatic ball governor is shown in Fig. 78 and its function is as follows: When the working strain on an engine is relieved by the throwing out of action of a part of the work being performed, the engine would run too fast, or if more than a normal tax were placed on the engine, it would “slow up.” To secure a regular and uniform motion in the performance of his engine Watt invented the automatic or self-regulating ball governor and throttle valve. A vertical shaft D is rotated constantly by a band on pulley d. Any tendency in the engine to run too fast throws the balls up by centrifugal action, and this through toggle links f h, pulls down on a lever F G H, and partially closes the throttle valve Z, reducing the flow of steam to the engine. When the engine has a tendency to run too slow the balls drop down, and, deflecting the lever in the opposite direction, open the throttle valve, and increase the flow of steam to the engine. This double acting engine of Watt marks the beginning of the great epoch of steam engineering, and his patent expired just in time to give to the Nineteenth Century the greatest of all natal gifts.
Steam engines are divided into two principal classes, the low pressure engine, using steam usually under 40 pounds to the square inch, and the high pressure engine, using steam from 50 to 200 pounds. In the low pressure engine there is the expansive pressure of the steam on one side of the piston, aided by the suction of a vacuum on the opposite side of the piston, which vacuum is created by the condensation of the discharging, or exhaust steam, by cold water. As there are two factors at work impelling the piston, only a relatively low pressure in the boiler is required. In the high pressure engines there is no condensation of the exhaust steam, but it is discharged directly into the air, and this type was originally called “puffers.” Familiar examples of the low pressure type are to be found in our side wheel passenger steamers, and of the high pressure type in the steam locomotive.
One of the most important steps in the development of the steam engine was the addition of the cut-off. Prior to its adoption steam was admitted to the cylinder during the whole time the piston was making its stroke from one end of the cylinder to the other. In the cut-off (see Fig. 79), when steam is being admitted through the port p, and the piston is being driven in the direction of the arrow, it was found that if the steam were cut off when the piston arrived at the position 1, the expansive action of the steam behind it in chamber a would continue to carry the piston with an effective force to the end of its stroke, or to position 2. This of course effected a great saving in steam. Various cut-offs have been devised. Perhaps that most easily recognized by most persons is the one seen in the engine room of our side wheel steamers, of which illustration is given in Fig. 80. This was invented in 1841 by F. E. Sickels, and was the first successful drop cut-off. It was covered by his patents, May 20, 1842, July 20, 1843, October 19, 1844, No. 3,802, and September 19, 1845, No. 4,201. A rock shaft s is worked by an eccentric rod e from the paddle wheel shaft. The rock shaft has lifting arms a that act upon and alternately raise the feet c on rods b b. One of these rods b works the valves that admit steam, and the other the valves that discharge steam. The valve rod that admits steam has a quick drop, or fall, to cut off the live steam before the piston reaches the end of its stroke. In Fig. 81 is shown the celebrated Corliss cut-off and valve gear, in which a central wrist plate and four radiating rods work the valves. This valve gear was covered in Corliss patents, No. 6,162, March 10, 1849, and No. 8.253, July 29, 1851.
Among other important improvements in the steam engine are those for replenishing the water in the boiler, and the Giffard Injector is the simplest and most ingenious of all boiler feeds. It was invented in 1858 and covered by French patent No. 21,457, May 8, 1858, and U. S. patent No. 27,979, April 24, 1860. Prior to the Giffard Injector, steam boilers were supplied with water usually by steam pumps, which forced the water into the boiler against the pressure of the steam. The Giffard Injector takes a jet of steam from the boiler, and causes it to lift the water in an external pipe, and blow it directly into the boiler against its own pressure. So paradoxical and inoperative did this seem at first that it was met with incredulity, and not until repeated demonstrations established the fact was it accepted as an operative device. Its construction is shown in Fig. 82. A is a steam pipe communicating with the boiler, B another pipe receiving steam from A through small holes and terminating in a cone. C is a screw rod, cone-shaped at its extremity, turned by the crank M, and serving to regulate and even intercept the passage of steam. D is a water suction pipe. The water that is drawn up introduces itself around the steam pipe and tends to make its exit through the annular space at the conical extremity of the latter steam pipe. This annular space is increased at will by means of the lever L, which acts upon a screw whose office is to cause the pipe B and its attached parts to move backward or forward. E is a diverging tube which receives the water injected by the jet of steam that condenses at I, and imparts to the water a portion of its speed in proportion to the pressure of the boiler. F is a box carrying a check valve to keep the water from issuing from the boiler when the apparatus is not at work. G is a pipe that leads the injected water to the boiler. H is a purge or overflow pipe, K a sight hole which permits the operation of the apparatus to be watched, the stream of water being distinctly seen in the free interval. Fig. 83 shows the application of the injector to locomotives, which are now almost universally supplied with this device.
To keep the pressure in the boiler within the limit of safety, and adjusted to the work being performed, is an important part of the engineer’s duty, and this he could not do without the steam gauge. One of the best known is the Bourdon gauge, shown in Fig. 84, constructed on the principle of the barometer invented by Bourdon of Paris in 1849 and patented in France June, 1849, and in the United States August 3, 1852, No. 9,163. A screw threaded thimble B, with stop cock A, is screwed in the shell of the boiler, and a coiled pipe C communicates at one end with the thimble and is closed at the other end E and connected by a link F, with an arm on an axle, carrying an index hand that moves over a graduated scale. The coiled pipe C is in the nature of a flattened tube, as shown in the enlarged cross section, and is enclosed in a case. When the steam pressure varies in this flat tube its coil expands or contracts, and in moving the index hand over the scale indicates the degree of pressure.
In line with the development of the steam engine must be considered the efforts to economize fuel. These may be divided into the following classes: Increased steam generating surface in boiler construction; surface condensers for exhaust steam; devices for promoting the combustion of fuel and burning the smoke, and feed water heaters. Even before the Nineteenth Century Smeaton devised the cylindrical boiler traversed by a flue, but the multitubular steam boiler of to-day represents a very important Nineteenth Century adjunct to the steam engine. Our locomotives, fire engines, and torpedo boat engines would be of no value without it. Sectional steam boilers made in detachable portions fastened together by packed or screw joints also represent an important development. These permit of the removal and replacement of any one section that may become defective, and are also capable of being built up section by section to any size needed. For promoting the combustion of fuel the draft is energized by blasts of air or steam, or both, either through hollow grate bars, jet pipes in the fire box, or by discharging the exhaust steam in the smoke pipe. Surface condensers pass the exhaust steam over the great surface area of a multitubular construction having cold water flowing through it. Feed water heaters utilize the waste heat escaping in the smoke flue to heat the water that is being fed to the boiler, so that it is warm when it is injected into the boiler, and the furnace is relieved of that much work.
In the reciprocating type of steam engine the inertia of the piston must be overcome at the beginning of each stroke and its momentum must be arrested at the end of each stroke, and this involves a great loss of power. If the power of the steam could be applied so as to continuously move the piston in the same direction this loss would be avoided. The effort to do this has engaged the attention of many inventors, and the devices are called rotary engines. The most successful engines of this kind are those of the impact type, in which jets of steam impinge upon buckets after the manner of water on a water wheel, and which are known to-day as steam turbines. The earliest of these is Branca’s steam turbine of 1629 (see Fig. 85) and the most important of this class in use to-day are those of Mr. Parsons, of England, and De Laval, of Sweden. The internal construction of the Parsons turbine is seen in Fig. 86 and is covered by British patent No. 10,940, of 1891, and United States patent No. 553,658, January 28th, 1896. A series of turbines are set one after the other on the same axis, so that each takes steam from the preceding one, and passes it on to the next. Each consists of a ring of fixed steam guides on the casing, and a ring of moving blades on the shaft. The steam passes through the first set of guides, then through the first set of moving blades, then through the second set of guides, and then through the second set of moving blades, and so on.
In the application of his turbine to marine propulsion Mr. Parsons employs a plurality of propeller shafts and steam turbines, as seen in Fig. 87, and covered under United States patent No. 608,969, August 9, 1898.
The De Laval turbine, as shown in Fig. 88, is of very simple construction, consisting only of a steel wheel with a series of buckets at its periphery enclosed by a circular rim, and a series of steam nozzles on the side with diverging jet orifices directing steam jets against the buckets. A speed of 30,000 revolutions a minute may be attained by this construction. In Fig. 89 is shown a 300 horse-power steam turbine of the De Laval type applied to a dynamo; to which this type of engine is peculiarly adapted. The dynamo is seen on the extreme right, the steam turbine on the extreme left, and the drum-shaped casing between contains cog-gearing by which the high revolution of the turbine wheel is reduced to a proper working speed for the dynamo. Within the last few years application of the Parsons steam turbine has been made to marine propulsion with very remarkable results as to speed. The small steam craft, “The Turbinia,” built in 1897, and supplied with three of Parsons’ compound steam turbines, developed a speed of 323⁄4 knots, and more recently the torpedo boat “Viper” has with steam turbines attained the remarkable speed of 37.1 knots, or over 40 statute miles an hour. About 2,000 United States patents have been granted on various forms of rotary engines.
In the transportation building of the World’s Fair at Chicago in 1893 one of the most conspicuous objects of attention was the model of the great Bethlehem Iron Co.’s steam hammer, standing with its feet apart like some great “Colossus of Rhodes” and towering 91 feet high among the models of the great ocean steamers and battleships which are so largely dependent upon the work of this Titanic machine. Its hammer head, in the working-machine, weighs 125 tons, and many of the seventeen inch thick armor plates for our battleships have been forged by its tremendous blows.
In 1838, during the construction of the “Great Britain,” the largest steamship up to that time ever built, it was found that there was not a forge hammer in England or Scotland powerful enough to forge a paddle shaft for that vessel. The emergency was met by Mr. Nasmyth, of England, who invented the steam hammer and covered it in British patent No. 9,382, of 1842 (U. S. Pat. No. 3,042, April 10, 1843). A modern example of it is seen in Fig. 90. It consists of a steam cylinder at the top whose piston is attached to a block of iron, forming the hammer head and sliding vertically in guides between the two legs of the frame. Valve gear is arranged to control the flow of steam to and from the opposite sides of the piston, and so nicely adjusted is the valve gear of such a modern steam hammer that it is said that an expert workman can manipulate the great mass of metal with such accuracy and delicacy as to crack an egg in a wineglass without touching the glass. To the steam hammer we owe the first heavy armor plate for our battle ships and the propeller shafts of our earlier steamships. In fact it was the steam hammer which first rendered the large steamship possible. Mr. Nasmyth not only invented the steam hammer, but the steam pile driver as well.
For quick action, nicely adjusted machinery, and showy finish the steam fire engine is a familiar and conspicuous application of steam power. A dude among engines when on dress parade, and a sprinter when on the run, it gets to work with the vim and efficiency of a thoroughbred, and is a most business-like and valuable custodian of life and property. The first portable steam fire engine was built about 1830 by Mr. Brathwaite and Capt. Ericsson in London. In 1841 Mr. Hodges produced a similar engine in New York City. Cincinnati was the first city to adopt the steamer as a part of its fire department apparatus. To-day all the important cities and towns of the civilized world rely upon the steam fire engines for their longevity and existence. Time economy in getting into action is the great objective point of most improvements of the fire-engine, and one of the most important is the keeping of the water in the boiler hot when the engine is out of action at the engine house, so that when the fire is built and the run is made to the scene of action, the water will be hot to start with. This attachment was the invention of William A. Brickill, and was patented by him August 18, 1868, No. 81,132. In the illustration, Fig. 91, the two pipes passing from the engine through the trap door in the floor connect with a water heater in the basement below, which heater maintains a constant circulation of hot water in the steam boiler. Couplings in these pipes serve to quickly disconnect the engine when the run to the fire is to be made.
FIG. 91.—STEAM FIRE ENGINE WITH WATER HEATING ATTACHMENT.
Among other useful applications of the steam engine are the steam plow, steam drill, steam dredge, steam press, and steam pump, of which latter the Blake, Knowles, and Worthington are representative types.
FIG. 92.—THE SIX-CYLINDER QUADRUPLE EXPANSION ENGINES OF THE “DEUTSCHLAND,” 35,640 HORSE POWER.
The highest type of modern steam engines is to be found in the compound multiple-expansion engine, in which three or more cylinders of different diameters with corresponding pistons are so arranged that steam is made to act first upon the piston in the smallest cylinder at high pressure, and then discharging into the next larger cylinder, called the intermediate, acts expansively upon its piston, and thence, passing into the still larger low pressure cylinder, imparts its further expansive effect upon its piston. The fundamental principle of the compound engine dates back to the time of Watt, its first embodiment appearing in the Hornblower compound engine, as described in British patent No. 1,298, of 1781, but modern improvements have differentiated it into almost a new invention. A fine example is shown in Fig. 92, which represents the quadruple expansion engines of the “Deutschland,” the new steamer of the Hamburg-American Line. The two high pressure cylinders, however, do not appear in the illustration, being too high for the shops. They stand vertically, however, upon the two bed plates which appear at the top of the two low pressure cylinders. In each set of six cylinders the two low pressure cylinders are in the middle, the two high pressure cylinders immediately above them or arranged tandem, while at the forward end is the first intermediate cylinder, and at the after end is the second intermediate. The low pressure cylinders are 106 inches in diameter, the intermediate cylinders are 73.6 inches and 103.9 inches respectively, and the two high pressure cylinders are 30.6 inches, and the steam pressure is 225 pounds. Its improvements comprehend the systems of Schlick, patented in the United States November 23, 1897, No. 594,288 and 594,289, and Taylor, patented November 22, 1898, No. 614,674, which embody fine mathematical principles for balancing the momentum of the great masses of moving parts, so that the engine may run up to high speed without vibrations and damaging strains upon the hull.
Mulhall gives the steam horse power of the world in 1895, not including war vessels, as follows:
| Stationary. | Railway. | Steamboat. | Total. | |
|---|---|---|---|---|
| The World | 11,340,000 | 32,235,000 | 12,005,000 | 55,580,000 |
| United States | 3,940,000 | 10,800,000 | 2,200,000 | 16,940,000 |
The increase in steam power in the United States has been from 3,500,000 horse power in 1860, to 16,940,000 horse power in 1895, or about five fold within thirty-five years.
Prof. Thurston says that in 1890 the combined power of all the steam engines of the world was not far from 100,000,000[2] horse power, of which the United States had 15,000,000, Great Britain the same, and the other countries smaller amounts. Taking the horse power as the equivalent of the work of five men, the work of steam is equivalent to that of a population of 500,000,000 working men. It is also said that one man to-day, with the aid of a steam engine, performs the work of 120 men in the last century.
[2] Prof. Thurston’s estimate doubtless includes war vessels, which Mulhall’s later estimate does not (see Mulhall’s “Industries and Wealth of Nations,” 1896, pages 4 and 379).
The influence of the steam engine upon the history and destiny of the world is an impressive subject, far beyond any intelligent computation or estimate. It has been the greatest moving force of the Nineteenth Century. The labor of 100,000 men for twenty years might build a great pyramid in Egypt, and it remains as a monument of patience only, but the genius of the modern inventor has organized a machine with muscles of steel, far more patient and tireless than those of the Egyptian slave. He gave it but a drink of water and making coal its black slave, and himself the master of both, he has in the Nineteenth Century hitched his chariot to a star and driven to unparalleled achievement.