their juice. In the old mills the speed was invariably too
great. The quantity of juice expressed will not be increased by increasing
the speed of the rollers, but more of the juice will pass away in the
begass or woody refuse of the cane.

698. _Q._--What is the amount of power necessary to drive cotton mills?

_A._--An indicator or actual horse power will drive 305 hand mule spindles,
with proportion of preparing machinery for the same; or 230 self-acting
mule spindles with preparation; or 104 throstle spindles with preparation;
or 10-1/2 power looms with common sizing. The throstles referred to are the
common throstles spinning 34's twist for power loom weaving, and the
spindles make 4000 turns per minute. The self-acting mules are Robert's,
about one half spinning 36's weft, and spindles revolving 4800 turns per
minute; and the other half spinning 36's twist, with the spindles revolving
5200 times per minute. Half the hand mules were spinning 36's weft, at 4700
revolutions, and the other half 36's twist at 5000 revolutions per minute.
The average breadth of the looms was 37 inches, weaving 37 inch cloth,
making 123 picks per minute,--all common calicoes about 60 reed, Stockport
count, and 68 picks to the inch. To take another example in the case of a
mill for twisting cotton yarn into thread:--In this mill there are 27
frames with 96 common throstle spindles in each, making in all 2592
spindles. The spindles turn 2200 times in a minute; the bobbins are 1-7/8
inches diameter, and the part which holds the thread is 2-3/16 inches long.
In addition to the twisting frames the steam engine works 4 turning lathes,
3 polishing lathes, 2 American machines for turning small bobbins, two
circular saws, one of 22 and the other of 14 inches diameter, and 24 bobbin
heads or machines for filling the bobbins with finished thread. The power
required to drive the whole of this machinery is 28-1/2 horses. When all
the machinery except the spindles is thrown off, the power required is 21
horses, so that 2592, the total number of spindles, divided by 21, the
total power, is the number of twisting spindles worked by each actual horse
power. The number is 122.84.

699. _Q._--What work will be done by a given engine in sawing timber,
pressing cotton, blowing furnaces, driving piles, and dredging earth out of
rivers?

_A._--A high pressure cylinder 10 inches diameter, 4 feet stroke, making 35
revolutions with steam of 90 to 100 lbs. on th