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On the upper corner of the cut will be seen the picture of a perforated card. A skilled operator can read off one of these cards as if it were a book. It tells him if the person referred to is white or black; it tells the age, where born, if literate or illiterate, etc. But as this degree of skill is not to be expected from every one, templates are provided in which the perforated card can be laid, and the results read through the apertures. In their regular use such reading is unnecessary. The cards are used for tabulating results automatically. The apparatus used for that purpose we also illustrate.

A frame holding a number of depending points corresponding with a certain number only of the 240 possible apertures of a single card is arranged so as to be raised or lowered by a handle. When depressed, the points come in contact with mercury cups, one below each point, making electric contact, and each thereby causes the movement of the index of a specific dial. Thus, when depressed, each of the indexes corresponding to the contact points in use would move forward one division. If, before pressing the handle, an unperforated card were introduced, none of the contacts could be made, and none of the indexes would move. If, however, a perforated card is introduced, wires will descend through such of the perforations as correspond with the contact points in use, and contacts will be made corresponding to the perforations in the card, and the indexes corresponding thereto will move forward one division. Thus a single depression of the handle, the card being placed, causes its story to be transmitted in whole or in part to the case of dials seen facing the operator. It would be manifestly impracticable to make a single machine of sufficient capacity to include all the tabulations possible. It is here that the specializing system comes into play. A tabulating machine may be, and in practice is always, restricted by the omission of a portion of the contact points to a narrow range of subjects.

As in use at the census bureau, the machine has forty dials, and at most only forty data can be provided for on each. A box divided into compartments may be noticed at the side of the operator. This has lids to its many compartments, which are opened by electricity. As the operator presses the handle, one of the electrical connections, it may be that referring to race or any other desired particular, causes a special compartment of the box to open for the reception of the card just tabulated. Thus the cards are classified for transmission to succeeding machines.

The machines, it will be seen, go no further than to record upon dials. The results, it is obvious, may, at the close of each day, be entered in books from the dials. It will be noticed that the power of introducing or omitting contact points gives the tabulating machines a very large range. This is still further increased by the assorting case, with its twenty-six lids automatically opened or shut by certain contacts. This enables a single machine to sort out cards for as many succeeding machines as there are lids to the case. The same elasticity of function applies to the tabulating of the special schedules. A great number of these are to be treated, and the greatest variety of requirements is embodied in the execution of the operations.

The work of this census is the first ever executed by electricity. In the mere enumeration in gross 15,000,000 schedules were twice gone over. The count proper began on July 1, and in six weeks the names were counted twice. The figure of 50,000 names per day was reached on one day by forty-three operators. One operator, a lady, reached the total of about 80,000 names. The female clerks averaged about 47,000 names, against 32,000 for the male clerks. The magnitude of the work may be inferred from the fact that some four thousand employes are engaged in tabulating results and executing the other operations of the census. It is estimated that the population of the world, if scheduled, could be counted by the United States census office in 200 days.

The early completion of the count was due to the improved appliances by which it was executed. The tabulation of results from the general and special schedules will be still more facilitated by the electric machinery. It lends itself to all modifications of data, and owing to it, it is hoped that the results will be reached and printed in half the time required for the last census. The apparatus was invented by Mr. Herman Hollerith, of Washington, D. C. To a mechanical and electrical inventor the accuracy and early completion of the census work is in great part due, illustrating an interesting alliance of the abstract and concrete.