------------+-----+-------+-------+-------+-------+-------
Diameter | | | | | |
of |2-1/4| 3 | 4 | 5 | 6 | 7
Cylinder. | | | | | |
------------+-----+-------+-------+-------+-------+-------
Stroke. | 6 | 6 | 6 | 6 | 6 | 6
------------+-----+-------+-------+-------+-------+-------
Revolutions | | | | | |
Per | 150 | 150 | 140 | 140 | 130 | 130
Minute. | | | | | |
------------+-----+-------+-------+-------+-------+-------
Piston Speed| | | | | |
in Feet | 150 | 150 | 140 | 140 | 130 | 130
Per Minute. | | | | | |
------------+-----+-------+-------+-------+-------+-------
Cubic Feet | | | | | |
of Free Air | 2 | 3 | 6 | 9 | 12 | 17
Per Minute. | | | | | |
------------+-----+-------+-------+-------+-------+-------
Working | 150 | 150 | 100 | 100 | 100 | 100
Pressure. | | | | | |
------------+-----+-------+-------+-------+-------+-------
Horse | | | | | |
Power | 5/8 | 3/4 | 1-1/2 | 2 | 2-1/2 | 4
Required. | | | | | |
------------+-----+-------+-------+-------+-------+-------
Pipes.
------------+-----+-------+-------+-------+-------+-------
Suction. | 3/4 | 1 | 1-1/2 | 2 | 2 | 2-1/2
------------+-----+-------+-------+-------+-------+-------
Discharge. | 3/4 | 1 | 1-1/2 | 1-1/2 | 1-1/2 | 1-1/2
------------+-----+-------+-------+-------+-------+-------
Dimensions.
------------+-----+-------+-------+-------+-------+-------
Length. | 22″ | 22″ | 24″ | 30″ | 36″ | 36″
------------+-----+-------+-------+-------+-------+-------
Width. | 13″ | 14″ | 15″ | 16″ | 18″ |19-1/2″
------------+-----+-------+-------+-------+-------+-------
Height. | 32″ |33-1/2″| 38″ |40-1/2″| 43″ | 44″
------------+-----+-------+-------+-------+-------+-------
------------+-----+-------+-------+-------+-------+-------
Diameter | | | | | |
of |2-1/4| 3 | 4 | 5 | 6 | 7
Cylinder. | | | | | |
------------+-----+-------+-------+-------+-------+-------
Stroke. | 6 | 6 | 6 | 6 | 6 | 6
------------+-----+-------+-------+-------+-------+-------
Revolutions | | | | | |
Per | 150 | 150 | 140 | 140 | 130 | 130
Minute. | | | | | |
------------+-----+-------+-------+-------+-------+-------
Piston Speed| | | | | |
in Feet | 150 | 150 | 140 | 140 | 130 | 130
Per Minute. | | | | | |
------------+-----+-------+-------+-------+-------+-------
Cubic Feet | | | | | |
of Free Air | 2 | 3 | 6 | 9 | 12 | 17
Per Minute. | | | | | |
------------+-----+-------+-------+-------+-------+-------
Working | 100 | 100 | 90 | 85 | 60 | 60
Pressure. | | | | | |
------------+-----+-------+-------+-------+-------+-------
Horse | | | | | |
Power | 1/2 | 5/8 | 1-1/4 | 1-3/4 | 2 | 2-1/2
Required. | | | | | |
------------+-----+-------+-------+-------+-------+-------
Pipes.
------------+-----+-------+-------+-------+-------+-------
Suction. | 3/4 | 1 | 1-1/2 | 2 | 2 | 2-1/2
------------+-----+-------+-------+-------+-------+-------
Discharge. | 3/4 | 1 | 1-1/2 | 1-1/2 | 1-1/2 | 1-1/2
------------+-----+-------+-------+-------+-------+-------
Dimensions.
------------+-----+-------+-------+-------+-------+-------
Length. | 16″ | 16″ | 16″ | 24″ | 24″ | 30″
------------+-----+-------+-------+-------+-------+-------
Width. | 13″ | 14″ | 14″ | 14″ | 14″ | 18″
------------+-----+-------+-------+-------+-------+-------
Height. | 28″ |29-1/2″|33-1/2″|37-1/2″|37-1/2″| 42″
------------+-----+-------+-------+-------+-------+-------
_With increase in altitude_ the barometric or atmospheric pressure
falls from 14.7 pounds per square inch at sea level to about 10 pounds
at 10,000 feet above sea level. Since the density of the air decreases
with its pressure it is obvious that at such an altitude the total
weight of air handled by a given displacement is considerably less
than at sea level; and that to fill any volume—a rock drill cylinder,
for instance—with air compressed to 90 pounds, a greater free-air
displacement will be necessary than would be required at sea level. The
relative capacities of a given displacement to do work—as through rock
drills or pumps—at varying altitudes are figured in the following table: