Given enough time and enough vacuum tubes, a tool might be invented to sum a column of numbers, and another one to keep track of inventories and another one to alphabetize lists of words. A well-equipped business would have one of each: gleaming cast-iron monsters with heat waves rising out of their grilles, emblazoned with logos like ETC and Siemens and Hollerith, each carrying out its own specialized task. Just as a carpenter had a miter box and a dovetail jig and clawhammer in his box.