Investigation with rock drills

The object of this thesis is to investigate the different shapes of bits in rock drilling. My intention at first was to run more extensive tests on bits, but due to the large amount of work necessary in rigging up the apparatus, and the maintainence sic of same, I found it necessary to reduce my work to two bits, which I name Flat and Regular, the Flat Bit being an invention of Professor C. R. Forbes, and the Regular Bit being the common one used by the Leyner Company --page 2