_a._ Four brass drain cocks, each with lever handle and of one-half inch bore, are to be provided, and located one on each end of each steam cylinder. Care should be taken to select a pattern of cock whose passageway is the full equivalent of a 1/2-inch hole. Some patterns of 1/2-inch commercial cocks although threaded for 1/2-inch pipe thread have but a 1/4-inch hole through them. Such are not acceptable. 25. OILING DEVICES. _a._ A one-pint hand oil pump, to be connected below the throttle, and a one-pint sight feed lubricator, to be connected above the throttle, must be furnished with each pump. _b._ Oiling holes must be provided for all valve motion pins, and for each end of both rock shafts. 26. STROKE GAUGE. _a._ A length-of-stroke-index must be provided for each side of pump. These must be of simple form for at all times rendering obvious the exact length of stroke which each piston is making, and thus calling attention to improper adjustments of cushion valves or stuffing boxes. _b._ The gauge piece over which the index slides must have deep, conspicuous marks at ends of nominal stroke, and also light marks at extreme positions; it need contain no other graduations. _c._ This stroke index must be rigidly secured to cross-head in such a way that it cannot get loose or out of adjustment. THE WATER END. 27. WATER CYLINDERS. _a._ These must be of hard close iron with metal so distributed as to ensure sound castings, and freedom from shrink cracks. _b._ The design should be along lines best calculated to resist internal pressure so as to avoid as much as possible the need of ribs for stiffening. _c._ They must be capable of withstanding, without showing signs of weakness, the pressures and shocks due to running under the conditions mentioned in Chapter “Tests for Acceptance,” Art. 48-54. The suction chamber should be able to withstand a water pressure of 100 lbs. Although suction chambers are not regularly subject to a pressure, it is sometimes desired to connect them to public water supplies, and where foot valves are used there is a chance of getting pressure on the suction, so that ample strength is necessary. Foundry finish may be permitted on the joints at water cylinder heads and at hand-hole plates, provided surfaces are so true that a rubber packing not over 1/16 of an inch in thickness is sufficient to secure perfect tightness. _d._ Conveniently placed hand-holes of liberal size must be provided for the ready examination and renewal of valve parts at the yoke end of water cylinders and in the delivery chamber. This will necessitate holes not less than 6 × 8 inches, or its equivalent, for the two largest-size pumps, and holes proportionately as large for the 500 and 750-gallon pumps. The easy access to the valve parts is of vital importance, and must receive careful attention.