G. B. Grant—New Calculating Machine. 279 
driver will depend on the number of teeth exposed. Colmar 
varied his number by placing nine rows of teeth side by side, 
Recording wheel. 
recording wheel over them. 
Calculating machines by the score may be found in the pat- 
ent records of the United States, England and France. ol- 
mar’s idea has been twisted into every conceivable position, but 
no improvement has been made on the disposition originally 
adopted by him. And his machine is the only one now in use, 
to any mentionable extent. 
Colmar’s machine, as the first solution of an old and well 
e New Mahia = the diagram fig. 3 all framing 
unessential parts are omitted, and the positions so 
to show the principle of action most clearly. 
