What is the slide rule on a watch?
A slide rule is a circular scale that either surrounds the watch face as a bezel or is located on the inner flange. It can be rotated in either direction, allowing you to perform various calculations related to time, speed, distance, and conversions. They are a valuable aid for performing quick calculations on the fly. Today, the slide rule comprises two logarithmic scales to aid in multiplications and divisions. The inner scale is fixed, while the second scale, an outer scale, is rotational and affixed to a bidirectional bezel.
Does anyone use a slide rule anymore?
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. The accuracy of slide rules varies depending on their design and quality of construction, they are generally capable of providing results with at least two to three significant figures. This level of accuracy is often sufficient for many scientific, engineering, and mathematical calculations.
What is the modern slide rule?
As mentioned before, the slide rule is a calculator. By using various scales, a sliding central piece, and a cursor (the outermost sliding piece with a vertical red line), the user can multiply, divide, find cubes, cube roots, squares, square roots, sines, cosines, tangents, reciprocals, logarithms and exponents! Slide Rules were the pre-eminent calculating tool from their invention in around 1620, right through to their demise in the late 1980s, some 350 years later, but their decline really started in the 1960s with the advent of electronic calculators and computers, .
What has replaced the slide rule?
The slide rule was universally used for nearly 400 years and was the most commonly used calculation tool in science and engineering until it was replaced by the pocket calculator. 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.Last slide rule manufactured, July 11, 1976. William Oughtred, as well as others, developed the slide rule in the 17th century based on the emerging work on logarithms by John Napier.