REGULATION OF STEAM.

121

diameter of the circle of the eccentric pulley centre, round thecentre of the crank shaft (C X 2) = 50 parts. Eccentric rod, 300parts in length (R); opening of port, 20 parts; lap, 5 parts.

3qo 2 = 90000; C = 25; C 2 = 625-

Then taking 90000—625 = 89375, and ^89375 = 299—ThenV-or the versed sine would but equal 300—299—; or 1 X : equalto but of the entire travel of the valve.

DOUBLE ECCENTRICS AND LINK MOTION.

The mode of setting out the link motion for the marine enginediffers but little from that pursued for the locomotive type. Withthe former the double eccentrics and link are simply introduced, soas to get a convenient arrangement for handling the engines, thelink being rarely used to work with varying expansion, it beingeither full up or full down. The reversing lever in general makes

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VALVEOtSäLf Stroh»

XeveLHinö

Fig. 66 .—Double Eccentrics and Link Motion for the. Marine Engine.

a half revolution around its axis, the point of Suspension on thelever being either up or down, the link being in full gear for the for-