Thickness of valve, one inch; seat, one and three-eighths inches deep, brass.

Receiving valve is a single clapper valve of brass, working on a brass seat three and one-fourth inches bore; seat one and three- eighths inches deep.

Caps for valve chambers, lugs for bolts, one and one-fourth inches thick.

Flanges at bottom of pump, seven-eighths inch thick.

Fourteen holding bolts, three-fourths inch diameter.

Eight cap bolts, seven-eighths inch diameter.

Cold water pump rods.- Length, center to center, four feet one- half inch; diameter at upper neck, one inch; at lower neck, seven-eighths inch, straight taper; journals, one and one-fourth inches diameter, one and one-half inches long. End of rod is tapered and inserted into the piston and fastened with a nut; the follower is screwed down by a nut threaded on the rod.

All the valves to be nicely ground into their seats perfectly tight, and all the connecting rods, links, journals, boxes, shafts, cranks, and bolts to be made a fitted up in a good, substantial, and workmanlike manner.

All the pipes to be copper except the one that supplies the ash pit, which will be gas pipe.

Cylinder heads and all bonnets for valve chambers to be nicely scraped together.

The drawings and specifications exhibit the plungers in the forcepumps as being four and one-half inches in diameter when they should be five inches in diameter.

The areas of the pipes will be changed accordingly. It will be necessary to carry the heaters out to the sides of the hull of the vessel, and lower down than they are exhibited in the drawings. In doing that it will require about forty feet more pipe than it would to put them on the top of the columns.

Each force-pump will supply the water to the boilers through a distinct check-valve attached to the second boiler from each side. The exact length of the pipes cannot now be definitely ascertained. The thicknesses will be one-eighth and three- sixteenths inch thick; and the diameters as are mentioned in specification, except as are altered as above.

Shaft to be fagoted iron, ten inches diameter, about twenty-two feet and eighth inches long, outer ends to have cranks fit on, to be turned ten inches diameter by ten inches long; collars, twelve inches diameter, one inch wide; bearings ten inches diameter, twelve inches long; then eleven inches diameter for eight inches in length, and these parts are bored and shrunk turned collars, two inches thick be three inches deep, to which are bolted the four cams by eighth 7/8-inch bolts and nuts four and one-half inches long. At suitable distances on the body of the shaft are to be four bosses, twelve inches diameter by twelve inches long, which are to be turned to carry the flanges. Those flanges are to be of cast-iron, with sockets for nineteen wrought-iron arms, outside diameter of flanges to be four feet ten inches, diameter of bosses one foot six inches by ten inches through, with bored hole twelve inches diameter, round each side of bosses to be shrunk a wrought-iron band or hoop one and one-fourth inches is shrunk on a projection cast on the back of flange, near the outer diameter; thickness of metal in flange seven-eighths inch.