Library Collections: Document: Full Text

When the given cards have thus been punched they are passed to another division of the office, in which they are sorted and counted in the mechanism shown in our illustration. As the cards come from the punching clerks they are, of course. arranged by enumeration districts and minor civil divisions. The cards corresponding to a given minor civil division are placed, one by one, in a press, counted, and deposited in the open sorting-box. This operation is repeated until all the cards corresponding to the given district have been thus treated. The counters to the left will now show, for the given minor civil division. such information as may be desired. At the same time the cards will be distributed into the various divisions of the sorting-box, the cards for each of the corresponding divisions of the various districts being put together until the total cards for each characteristic or combination of characteristics, for the county are brought together. Each division of cards for the county is then treated in similar manner, being further subdivided according to statistical characteristics, while any desired data for the county are obtained on the counters. The cards are then thrown together by States, thus securing a finer statistical distribution, which will facilitate the compilation of further detailed data required by State totals.

When it is remembered, for example, that at the first handling of the cards they are divided into, say, twenty statistical divisions, and at the second handling each of these twenty divisions is further subdivided into twenty subdivisions, or 400 divisions in all, and at the third handling each one of these 400 divisions is counted or tallied according to, say, forty characteristics, on forty counters, it will be seen that the third handling of the cards will give a result equivalent to a table having 16,000 columns. Very little consideration of this question will show that with the comparatively few handlings of the cards a most complete and detailed tabulation is obtained.

Punched record cards, as compared with written cards, possess, for purposes of statistical tabulation, many manifest advantages. In the first place a misplaced card can readily be detected among a thousand or more in a few seconds, by the simple fact that the punched holes of the misplaced card will not correspond with the balance. This is readily detected by means of a long needle. With written cards, on the contrary, a misplaced card can only be detected by an actual inspection of each card.

Again, in the counting and sorting mechanism errors of tabulation are practically impossible, as the machine is so provided with mechanical checks that if a wrong card is placed in the machine, or if it is carelessly or improperly placed in position, the entire mechanism will fail to operate, and only when a proper card is correctly placed in position will there be any effect on the counters or sorting mechanism. In other words, this mechanism is so constructed that the counting and sorting must either be done correctly or not at all. If the mechanism fails to operate it is evidence to the clerk that such card does not properly belong among those being handled.