CHAPTER XVII.

IMPROVED CORLISS ENGINES. BY THE WATTSCAMPBELL COMPANY, NEWARK, N. J.

Strength and Design.

EACH size of these engines is made from its own special patterns, which makes it possible to maintain correct proportions. In the design of the several sizes, if they have erred at all it has been in the direction of unnecessary strength rather than in the opposite direction. This, at the most, can only result in a little additional cost of material and labor, and can be counted but once; but an error in the opposite direction is a constant cost to the purchaser, in decreased efficiency, expensive break-downs and delays, and inferior durability.

For a given cylinder capacity these engines are heavy, but we are satisfied that any reduction in this respect would be a direct loss to the purchaser, even if the price were regulated by the weight. They sell an engine to work at a given power; they are aware that circumstances are likely at any time to require this rated power, either temporarily or permanently, to be materially exceeded - perhaps doubled. An engine should always be so constructed that this may be done without danger of breakage or heating. An engine is not cheap at any price

unless it possesses sufficient strength and ample rigidity to permit this.

Materials and Construction.

In the construction of these engines they use none but the material best suited to each particular detail. The cylinders are made from special brands of iron, mixed and remelted in their own foundry, for the purpose of making a perfectly homogeneous casting of the desired quality as to hardness, and without blow-holes or other disfiguring and damaging features. They invite special attention to all the castings used in their engine-work, both as to smoothness and soundness as well as to strength.

For forgings they use either steel or iron, as experience has shown us to be best for the particular part for which the piece is used.

Their business is to build steam-engines, for doing which they are supplied with tools especially adapted to that purpose. The use of jigs and gauges enables them to preserve sizes and to manufacture the various parts in duplicate.

They will not, under any circumstances, vary from their fixed plan of using only the best material, and maintaining standard excellence of workmanship. They will not build so-called cheap engines. In this respect they study the best interests of their customers, as well as their own. Every engine sold by them is made for hard work, twenty-four hours a day if required.

RELEASING-GEAR.

This is shown somewhat in detail in Fig. 64. In the gear ordinarily employed with the Corliss engine, the construction is such as to lead to some inconvenience and annoyance from the parts wearing loose and shaky. The effect of the action of the releasing-gear is also to slightly disturb the governor; the latter is the more serious fault, because its tendency is to impair the regulation, preventing its being brought to that degree of perfection which is desirable.

The improved releasing-gear effectually overcomes these objections. The shock upon the governor incident to the use of the crab-claw is avoided, the effect at the time of release being unnoticeable. It is noiseless in operation. The arrangement of parts is such that the leverage to the detaching-gear is absolutely uniform under all conditions, and the work of unhooking reduced to a minimum; at the same time, a long and ample bearing-surface is provided to the moving parts, with the power applied substantially in line with the resistance. By the use of this releasing-gear they improve the regulation, avoid the necessity for any resisting attachment to the governor, and increase the durability very materially.

DASH-POT.

They have also recently added a new dashpot. This is shown in Fig. 65. They consider