e square inch, supplied by
three cylindrical boilers 30 inches diameter and 20 feet long, works two
vertical saws of 34 inches stroke, which are capable of cutting 30 feet of
yellow pine, 18 inches deep, in the minute. A high pressure cylinder 14
inches diameter and 4 feet stroke, making 60 strokes per minute with steam
of 40 lbs. on the square inch, supplied by three cylindrical boilers
without flues, 30 inches diameter and 26 feet long, with 32 square feet of
grate surface, works four cotton presses geared 6 to 1, with two screws in
each, of 7-1/2 inches diameter and 1-5/8 pitch, which presses will screw
1000 bales of cotton in the twelve hours. Also one high pressure cylinder
of 10 inches diameter and 3 feet stroke, making 45 to 60 revolutions per
minute, with steam of 45 to 50 lbs. per square inch, with two hydraulic
presses having 13 inch rams of 41 feet stroke, and force pumps 2 inches
diameter and 6 inches stroke, presses 30 bales of cotton per hour. One
condensing engine with cylinder 56 inches diameter, 10 feet stroke, and
making 15 strokes per minute with steam of 60 lbs. pressure per square
inch, cut off at 1/4th of the stroke, supplied by six boilers, each 5 feet
diameter, and 24 feet long, with a 22-inch double-return flue in each, and
198 square feet of fire grate, works a blast cylinder of 126 inches
diameter, and 10 feet stroke, at 15 strokes per minute. The pressure of the
blast is 4 to 5 lbs. per square inch; the area of pipes 2300 square inches,
and the engine blows four furnaces of 14 feet diameter, each making 100
tons of pig iron per week. Two high pressure cylinders, each of 6 inches
diameter and 18 inches stroke, making 60 to 80 strokes per minute, with
steam of 60 Lbs. per square inch, lift two rams, each weighing 1000 lbs.,
five times in a minute, the leaders for the lift being 24 feet long. One
high pressure cylinder of 12 inches diameter and 5 feet stroke, making 20
strokes per minute, with steam of 60 to 70 lbs. pressure per square inch,
lifts 6 buckets full of dredging per minute from a depth of 30 feet below
the water, or lifts 10 buckets full of mud per minute from a depth of 18
feet below the water.

CHAPTER XII.

MANUFACTURE AND MANAGEMENT OF STEAM ENGINES.

CONSTRUCTION OF ENGINES.

700. _Q._--What are the qualities which should be possessed by the iron of
which the cylinder of steam engines are made?

_A._--The general ambition in making cylinders is to make them sound a