FIG. 89.—DE LAVAL TURBINE GEARED TO DYNAMO.
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.
FIG. 90.—STEAM HAMMER.
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.