"That is before sorting?"
"Or after. Cards may be tabulated along a lot of different lines. And the sorting device depends again upon another machine, operated by the same principle."
The chief led the boy to another portion of the floor.
"This sorter," he said, "can be set for thirteen different compartments. In determining the country of birth, for example, at any given point on the card, an electrically charged brush finds the hole punched and directs the card in between two of those finely divided wire levels, where a traveling carrier picks it up and runs it along to the point where the wires stop, the top wire extending to the furthest compartment. As the card falls, it is tilted into place against the pile of preceding cards, an automatic receiver holding them together, the operator clearing away the pile from each division as it becomes full. As you can see, that feed knife moves so rapidly and the endless band fingers carry the cards out of the way in such a hurry that they move along in a steady stream. We have only twenty of these machines and they handle all the cards."
"It's hard to believe," said Hamilton wonderingly, "that these machines don't think."
"We're just building one in here," the supervisor replied, leading the way into a little partitioned-off section of the room, "that has an uncanny ingenuity. This machine feeds itself with cards, verifies and tabulates at an incredible speed. It took some time to perfect all the adjustments, but it is running finely now, and it will simplify the work of the next census amazingly, just as the machines you saw have made the old hand punching machines of former times seem very cumbersome. But this one," he added, "is a gem."
PIN-BOX AND MERCURY CUPS. Details of mechanism which almost magically detects mistakes in any census card. (Courtesy of the Bureau of the Census.)
"It's a little like magic, it seems to me," said Hamilton, "to think of every person in this whole country being registered on a card with a lot of little holes in it, and practically the whole history on it. It certainly is queer."
"There is something mysterious in it," the chief answered with a laugh. "One feels as though all the secrets of the United States were boxed up and in the storage vaults of the building. But the magician is the Director. He is the man whose spells have woven this web of organization, whose skill and knowledge have unlocked commercial secrets, and whose perception has always seen the essential fact."