Herman Hollerith: Electric Tabulating Device, 1890
Punch CardsFor 1890 census data, an operator, using a pantograph, transcribed information items dictated from report sheets to punch holes in specified row locations on a card—one card for each person. The card contained 40 columns. An operator then slipped each card into the tabulating machine, pressed down the detector pins which then "read" the card and registered an increment on a corresponding dial for each hole detected. Thus, forty characteristics were measured in a single pass of the card. |
