41 .-- Drum record of impact bending test.] One size of this machine will handle specimens for transverse tests 9 inches wide and 6-foot span; the other, 12 inches wide and 8-foot span.

For compression tests a free fall of about 6.5 feet may be obtained.

For transverse tests the fall is a little less, depending upon the size of the specimen.
The machine is calibrated by dropping the hammer upon a copper cylinder.

The axial compression of the plug is noted.

The energy used in static tests to produce this axial compression under stress in a like piece of metal is determined.