The comptometer was the first commercially successful mechanical calculator, patented in 1887

Besides being an incredibly fun word to say, the comptometer was the first commercially successful mechanical calculator, patented in 1887. Beginning with ‘Model A’ each design introduced new and improved features to make the comptometer faster and more reliable. The early comptometers were often called “woodies” as they were made with wooden boxes for a lighter weight frame, but as a consequence these comptometers were also quite fragile. The wooden box style was popular in 1887, producing 6500 machines until 1903.

Model J was released in 1926, and remained in production until 1939. This “shoebox design” included metal casing, which was used on the comptometers until 1942. The stronger design made the machine more reliable as it required fewer repairs. It also featured green keys in replacement of the traditional black keys for a new look.

There was an electronic addition added to the comptometer in 1961, creating a link between the mechanical and electronic calculator industries. The 1970s marked the end of the comptometers relevance as electric calculators and computers began to take over the market.

The Model J comptometer in the Maple Ridge Museum collection (pictured here) was owned by Margarete (Marg) and Lawrence (Lawrie) Speer of Maple Ridge. Lawrie worked for Grand and Toy, and Marg was a secretary. Grand & Toy incorporated in 1883 with the partnership of Samuel Toy and James Grand, opening their first retail store in Toronto. The company still offers office supplies, furniture and paper in Burnaby, BC.

How to work a Comptometer
Comptometers were primarily for addition, but they could also do subtraction, multiplication and division. Occasionally, special models were produced to calculate currency exchanges, times and imperial weights, which created a learning curve for the user as they were required to adapt to the new keys and calculations.

Comptometer Operator: The Profession
When purchased, a comptometer would be accompanied by a 600 page illustrated manual on “applied mechanical arithmetic” addressing every possible type of business and commercial calculation for troubleshooting. Comptometer schools were even set up to teach new methods, making a comptometer operator an established profession.

Comptometer training schools were established in 1905 to formalize operator training, and to teach new methods of calculation. Comptometer schools typically recruited young women, and occasionally men of age 16. Training began with the basics, and continued with procedures for subtraction, multiplication and division, along with the calculations for percentages, proportions and square roots. Students were expected to memorize common conversion factors and be able to perform partial calculations mentally.

By the 1920s, comptomertry was well established and recognized. Businesses began to seek out trained operators, due to the high learning curve. The profession declined during the 1960s as computers began to take over manual systems in accounting and business fields.

The museum also has a very large collection of items from Eileen Perry, who was a professional comptometer operator here in Maple Ridge. Operators had to be well trained to improve efficiency of calculations, which ultimately drove the success of the comptometer.