This section is from the book "The English And American Mechanic", by B. Frank Van Cleve. Also available from Amazon: The English And American Mechanic.
In small blasts, 1 pound of powder will loosen about 4½ tons.
In large blasts, 1 pound of powder will loosen about 2¾ tons.
60 or 60 pounds of powder, enclosed in a resisting bag, hung or propped up against a gate or barrier, will demolish any ordinary construction.
One man can bore, with a bit 1 inch in diameter, from 60 to 100 inches per day of 10 hours in granite, or 300 to 400 inches per day in limestone.
Two strikers and a bolder can bore, with a bit 2 inches in diameter, 10 feet in a day in rock of medium hardness.
 
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