The punched card tabulator | IBM

The punched card tabulator

An electrical counting machine automated data handling, transformed industries and became the basis for a highly profitable new company called IBM

During a short stint compiling manufacturing statistics for the US Census Office, Herman Hollerith grew frustrated with the organization’s manual process of counting questionnaires. The tedious, error-prone labor was creating an operational nightmare for an overtaxed agency. Certain that automation was the answer, he invented an electric-powered counting machine. It introduced the world to mechanized data processing and laid a foundation for the development of computers and the binary system of zeros and ones still used in information processing today.

Hollerith’s punched card tabulator, developed in the 1880s, eased the administrative burden of hand-counting the population in a country whose numbers were exploding. Its success in the 1890 census led countries around the world, including Austria, Canada, Cuba, France, Norway, the Philippines and Russia, to procure Hollerith’s tabulator for their own national counts.

Hollerith also licensed the machine to private businesses for statistical and accounting purposes, including for railroads, department stores and public utilities. Over the next 60-plus years, variations of the tabulator and its punched-card methods would itemize, categorize and compile data on all kinds of products and people across society. While spitting out numbers, these machines generated exorbitant profits over decades for the company that would become known as IBM.

Hollerith Tabulator/Sorter, 1890

A patent schematic of the “Machine for tabulating statistics”

A contest to handle the US census

A mining engineer from Buffalo, New York, Hollerith didn’t set out to be an inventor. But the challenge of stripping banal labor from the census process appealed to him. After a colleague at the Census Office proposed the idea of automating calculations in 1879, he got to work designing the new apparatus.

Hollerith applied for his first patent in 1884, outlining a proposed method to store data using holes punched into strips of paper, similar to how player pianos read thick rolls of paper full of notched notes. By 1886, he switched to punched cards, and a year later he applied for a second patent. The patents were granted in 1889.

Punched cards weren’t Hollerith’s idea. About 80 years prior, Joseph Marie Jacquard of France devised a way to use punched cards to automate steam-powered weaving looms. In the mid-1830s, English mathematician Charles Babbage developed plans for a computing engine — later dubbed the Analytical Engine — that could do math using instructions from punched cards. But Hollerith was the first to apply the principle to data processing.

In 1886, Hollerith began testing his machine by compiling mortality statistics for Baltimore, Jersey City and New York City. In 1888, the Census Office held a competition to find the fastest tabulating solution. The winner would earn a contract to process the 1890 census. His two competitors clocked in at 144.5 and 100.5 hours to capture the data used for the challenge. Hollerith came in at 72.5 hours. Hollerith’s machine also excelled at the task of preparing the data for tabulation, logging a time of 5.5 hours, which dramatically outperformed his competitors’ times of 44.5 and 55.5 hours.

Hollerith’s Machine

Up to 2x

faster in data capture compared to his two competitors

Up to 10x

faster than competitors in preparing the data for tabulation

Herman Hollerith, circa 1888

The dawn of the binary principle

The census contract in hand, Hollerith readied his mechanical system for the audacious task. The multistage tabulating process required various machines and gadgets to record, sort and compile the information. First, clerks would manually transfer census data from paper schedules to punched cards using a hole puncher (or pantograph). Each hole corresponded to a different piece of demographic data collected from surveyed households. Census clerks performed this phase at a rate of about 500 per day.

These punched cards then were fed manually into a card reader, which resembled a modern sandwich press. Closing the top flap lowered spring-loaded metal pins onto the punched card. When a pin passed through an open hole in the punched card it would connect with a mercury reservoir and close an electrical circuit. This sent a pulse to one of 40 dials that corresponded to the demographic data on the card and registered a “1” on the dial. No connection was the same as registering a “0.” This binary principle of ones and zeros is still used today in detecting the presence or absence of an electrical charge in semiconductors.

He later added a separate machine that sorted the cards into as many as 24 categories. Based on the location of the holes on the card, the lid on the sorter bin would open and the clerk would drop them in....