Such changes as have been made since were largely aimed at refinements, but there are some very noteworthy features added to the performance of both types of machines, which are explained and described in following chapters, where the subject will be treated under the class of machines they affect.
The High-Speed Calculator
The High-Speed Calculator
As previously stated, the calculating machine was old when Felt improved the Art by combining the key-drive with a plurality of co-operative orders of adding mechanism. The advantage in the machine he produced existed in the great increase in rapid manipulation which it offered over the older Art, especially in addition. To improve upon Felt’s contribution to the Art of calculating machines from a commercial standpoint demanded a combination that would give still greater possibilities in rapid manipulation.
Felt improvements on Comptometer
The patent records show that Felt again came to the front and gave to the public a new machine containing many new combinations of highly-organized mechanism that produced the above-named result. The patents showing these features are Nos. 762,520 and 762,521, the two patents being divisional patents of the same machine.
Although there were several patents on key-driven calculators issued to others and a key-driven calculator placed on the market, which was sold to some extent, none of these calculators offered anything that would increase the possibility of more rapid manipulation than was to be had from Felt’s old Comptometer.
Scientific distribution of functions