Cards are sorted for one particular characteristic at a time, so that all cards having that characteristic are obtained for tabulating purposes. After the data on one set of cards have been tabulated, the cards can then be run through the sorting machine again and sorted for other characteristics. This permits using the punched cards over and over again until all of the different data which may be of interest have been taken from the cards by the tabulating machines.

Fig. 230 shows the tabulating machine as used in the general commercial work of corporations, and for State or municipal departments. The cards are placed in the machine at the left and are fed

Courtesy of the Tabulating Machine Company

Fig. 229. Hollerith Card-Sorting Machine Suitable for Use by Corporations for Statistical Work Relating to Sales, Costs, Etc.

This machine will sort about 12,000 cards per hour, and place in the right compartment all cards having the hole punched in the same position in the particular column for which the sorting is done

through automatically, one by one, so that electric contacts are made wherever there are holes punched in the card. The electric contacts cause the counting dials to revolve by just the right amount to record properly the data for each punched hole.

GENERAL METHODS

After any group of cards has been run through the machine the totals can be read off from the counting dials and written down by the operator. Then the machine is ready for some other set of cards. Machines are built with different numbers of counting heads to suit the complexity of the data in any kind of business. By having several counting heads on the same machine, different sets of information may be taken from the cards simultaneously, thus frequently permitting one run of the cards through a tabulating machine to give all the data