Hollerith Electric Tabulating System The 60 million cards punched in the 1890 United States census were fed manually into machines like this for processing. The dials counted the number of cards with holes in a particular position. The sorter on the right would be activated by certain hole combinations, allowing detailed statistics to be generated. An average operator could process about 7,000 cards a day.
Nordsieck Differential Analyzer Arnold Nordsieck started building his differential analyzer when most other computing researchers were experimenting with vacuum-tube digital electronic computers. Nordsieck needed a simple, cheap, and practical machine. A small differential analyzer fit the bill.