Field Testing

In 1884, Hollerith won a contract to test his machine at the Office of Registration in Baltimore. Despite some problems, Hollerith's counting machine was successful enough that New Jersey and later New York City made use of it. In 1888, the Surgeon General's Office of the War Department rented a machine. Data to be counted included number of sick days. For the first time Hollerith encountered data that occurred over a large range. The number of sick days in a single month could range from 1 to 31. To overcome this problem Hollerith designed a machine that performed integration. This allowed one hole to stand for more than one unit of a particular element.

By 1885, additional Hollerith's machines were being used by the Navy. Sale of the idea to the Navy was not only important in terms of increasing the number of units in use, but establishing the military as a customer was crucial to Hollerith while he awaited the next census. Interests of national security drive government spending. Thus, the military generally sustains cutting-edge technology as the general market does not have funds to invest in it. With the military's financial support Hollerith had the resources to optimize the machines for their real test, the twelfth census.