Another interesting feature was the proposed introduction of a water charge at the beginning of the compression stroke for the • purpose of keeping the compression pressure under control.
A second claim embodied in the same patent covered the use of liquid fuels with the employment of a spraying valve but without the air injection feature. The engine was to be started by some explosive agent in the cylinder for the initial stroke. The expansion was to be carried to such a point that the exhaust gases were to be cold enough to be used as the cooling medium in the cylinder jacket.
— \ An engine was constructed along these lines but never turned over beyond the initial stroke, during which it was completely wrecked. At this late date no information seems available as to the cause of this wreck, but it is to be presumed that the starting charge of explosives was the destructive agent.
This disappointment caused the builders of this engine to partially abandon Dr. Diesel's ideas, and a water-cooled engine was built in which the admission of heat was at constant pres sure instead of at constant temperature as originally contem plated by Dr. Diesel. The first of these later engines actually ran but never was able to carry any load. The development of the Diesel proceeded slowly for a few years, and it was not until 1897-1898 that a commercial engine was produced, this being a single-cylinder 25 h.p. engine of vertical design and using a crosshead.
From this modest-powered engine it was but a question of a relatively few years before engines of a thousand horsepower per cylinder were in commercial use. The engine was patented in practically every country, and for a few years all European manufacturers operated under a license; this, however, was discontinued around 1904, and but few manufacturers paid royalties. The popularity of the Diesel engine in Europe has ' been due, to a large extent, , to the type of manufacturer building these engines. In Germany a number of the strongest steam engine builders, having the facilities to do the extensive experimenting necessary, early took up this engine. In Switzer land and the Scandinavian countries the engine found early favor. The British Diesel Engine Co., even when the engine
temporarily fell into disrepute in Germany, continued their labors, and much credit for the successful outcome of the Diesel, usually attributed to German firms, actually is due to the ac tivities of the British manufacturers.
The Diesel was introduced into the United States by Adolphus •Busch of St. Louis. The first American Diesel engine was com pleted in 1898, being of the two-cylinder vertical A-frame design, and developed 60 h.p.. The early history of the Diesel engine in America was one of disappointment; part of the adverse criticism of the engine that is encountered even now is the result of the policies of the early firms. During the past five years a number of American engine builders have taken up the manufac ture of the engine; the designs, in the main, follow European practice, though in the tendency toward horizontal frames can be detected the objection which the American engineer has toward the vertical type engine.
Die§el Marine Engine.—It is for marine work that the Diesel possesses many favorable characteristics, and the past two years have found the majority of builders engaging their shop facilities in the manufacture of this type of Diesel. The first marine Diesel was constructed in 1903 by French engineers for use on a canal boat. This particular engine was single cylindered with opposed pistons and worked on the four-stroke-cycle. While French firms produced a considerable horsepower of the marine engines, the greatest development occurred in Russia where the demand for river boat engines stimulated the activities of the Diesel builders. Credit must also be given to Nobel Bros. of Petrograd for the production of the first Diesel for submarine service in 1908. This phase of Diesel manufacture has received great attention since 1914, and undoubtedly the greatest improve ments in design have occurred on the submarine engine.
While of late years engines have been built having a capacity of 2000 h.p. per cylinder, the American operator is actually concerned in engines ranging below 1200 h.p. per unit.