The rarest slide rules are 19th Century hand-engraved instruments such as Palmers Computing Scale (a circular model), first published in 1843, or the cylindrical ‘Thacher’s Patent Calculating Instrument’ slide rules produced by Keuffel and Esser Co in the 1880s. These can run close to $1,000 in good condition.

How old is the slide ruler?

The slide rule was invented by William Oughtred in the 1600’s, but only began to be widely used in the mid 1800’s after a French artillery officer named Amedee Mannheim developed a version that became popular among engineers. By the early 1900’s engineering students in the US were commonly taught to use slide rules.

When was the last slide rule made?

July 11, 1976
Slide rules became increasingly popular in the 1950s and 1960s, before beginning to fall out of favor to pocket calculators, which, by the mid 1970s, had become affordable and were considered significantly easier to use by the masses. The last slide rule manufactured in the United States was produced on July 11, 1976.

Can you still buy a slide rule?

There are many pages about slide rules on the web, and you can still buy brand new slide rules (40 years old but never used, and still in their factory supplied box) in various places.

Is there a market for slide rules?

Where to buy slide rules? eBay is by far the largest slide rule marketplace and is the leading source of slide rules. Search eBay USA for ‘slide rule’ and more then 3,000 listings will appear, both auctions and fixed price sales called ‘Buy It Now’.

Who invented slide rule in 1620?

William Oughtred
In 1620 Edmund Gunter of Oxford developed a calculating device with a single logarithmic scale; with additional measuring tools it could be used to multiply and divide. In c. 1622, William Oughtred of Cambridge combined two handheld Gunter rules to make a device that is recognizably the modern slide rule.

Are Sliderules still used?

Slide rules are still commonly used in aviation, particularly for smaller planes. They are being replaced only by integrated, special purpose and expensive flight computers, and not general-purpose calculators.

What was the best slide rule?

Faber-Castell 2/83N Novo-Duplex: Size 38 x 7 cm, 30 scales, plastic. This model is regarded by some as one of the finest slide rules ever made. Its combination of size, build, sophistication of scales offered and attractive use of colour gives a slide rule that impresses!

Do slide rules still exist?

Does any company still make slide rules?

The only maker that still produces “classic” slide rules is the Japanese maker Concise. You’ll find more information about their current circular slide rule offerings at their website.

Where did the Hemmi slide rule come from?

Tamaya, an already a well-established and well-known firm in Japan, began selling Hemmi Slide Rules in 1913. The Hughes-Owen Company of Canada (another old firm), began selling the Hemmi Slide Rules in Canada in 1914 and in 1931, the Fredrick Post Company, of Chicago, Illinois, began selling them in the United States.

Who makes slide rules in Japan?

Hemmi Bamboo Slide Rule Company Ltd. in Japan is the oldest and most well known Japanese manufacturing company making slide rules. Jirou Hemmi and Company was founded in 1895 and, in 1912, was granted by the Japanese Patent Office Patent No. 22129 for their laminated bamboo construction method for slide rules.

What is the size of the byoutou slide rule?

Notes on the “Byoutou,” 1944 slide rule (courtesy of Paul Ross ): 250 x 34 x 11 mm. (Same body as Hemmi 50W.) Calculating scales on four surfaces (front, back of slide, top slanted edge, and bottom vertical edge).

How can you tell when a slide rule was made?

Even then, some manufacturers recycled their serial numbers over time, and the stock could have been left on a shelf for a period of time before the slide rule was assembled and shipped. Catalogs are an excellent indication of when a model was produced or discontinued.