When did calculators replace slide rules?

The use of slide rules continued to grow through the 1950s and 1960s even as digital computing devices were gradually introduced; but around 1974 the pocket calculator made the slide rule largely obsolete and most suppliers left the business.

Did NASA use slide rules?

The slide rule. NASA engineers used slide rules to build the rockets and plan the mission that landed Apollo 11 on the moon. It’s said that Buzz Aldrin needed his pocket slide rule for last-minute calculations before landing.

What slide rule did Apollo astronauts use?

NASA chose a 5-inch, metal rule, model “N600-ES,” manufactured by the Pickett Company for their use. It was a model that was popular among engineers, scientists and students at the time. No modifications were needed for use in space. This rule was used by the crew of Apollo 13, in April 1970.

When was slide rule invented?

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.

Are slide rules still being made?

Though they’re no longer produced, the company still stocks around 1,200 or so and occasionally gets an order for some. Why would anyone still want to buy a slide rule, when inexpensive calculators are so readily available? According to Haase, slide rules are better suited to some functions than are calculators.

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.

Are slide rules still made?

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.

Why was slide rule invented?

William Oughtred made the first slide rule by inscribing logarithms on wood or ivory. Before the invention of the pocket or handheld calculator, the slide rule was a popular tool for calculations. The use of slide rules continued until about 1974, after which electronic calculators became more popular.

Are old slide rules worth anything?

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 accurate are slide rules?

A slide rule is only as accurate as its manufacture and calibration and your ability to set it and read values. In practice, you get between two and three significant figures from slide rule calculations, and these errors compound as you use intermediate values in subsequent calculations.

Who is the inventor of slide rule?

William Oughtred
Slide rule/Inventors
About 1622, William Oughtred (Figure 1, right), an Anglican Minister, today recognized as the inventor of the slide rule in its actual form, by placing two such scales side by side and sliding them to read the distance relationships, thus multiplying and dividing directly. He also developed a circular slide rule.