throughout its history. Our history of the silde rule will begin with John Napier. John Napier is credited

Transcription

1 History of Mathematics Summer 2016 Essay 3: Slide Rule Breanna Emmert The invention of the slide rule involved many people and has been adapted to many fields throughout its history. Our history of the silde rule will begin with John Napier. John Napier is credited with the publication of the logarithm. Shortly after its release to the public an Oxford intellect named Edmund Gunter developed a calculating tool utilizing the logarithm. The device also included tools so it could be used for multiplication and division. In 1630 a Cambridge inventor named William Oughtred created a circular slide rule. A few short years later, Oughtred combined his invention with Gunter s to create the slide rule that is thought of today. The basic slide rule has different scales used for different calculations. For example the C and D scales were intended for multiplication and division. The C and S scales were used for sine and cosine angles. The T and C scales were used for tangent calculations. Squares and square roots used the C and B scales. Cube and cube roots used the D and K scales. There were also scales for logarithm calculations. These would be some of the calculations the most basic slide rule could be used for. Many alterations have been made to the slip stick to make it usable in different fields. For example, the Coggeshall slide rule in 1677 was two feet long and used for timber measure. Nathaniel

2 Bowditch created a slide rule used for navigation problems. Paul Cameron created a version that utilized the sun and stars to navigate. There has even been a rule specifically used for the estimation of a cattle s weight as seen in a John Rabone & Sons 1892 catalog. In the year 1859, when engineering was on the verge of becoming a recognized profession, a French Lieutenant named Amedee Mannheim created the modern slide rule. The slide rule became a symbol of an engineer and was widely used throughout Europe. Its use eventually spread throughout America and was commonly seen hooked to the belts of college students. Depending on the profession, the slide rule could be comparable to students and their cell phones at a campus today. As time progressed into the 1900 s, there were many other slides that had applications such as loan calculations, aircraft altitude, fuel, and range calculations, and specialized engineering formula calculations.

3 There were an estimated forty different types of slide rule through the 1600s and 1700s. These included circular and spiral designs. Then in the 1800s were approximately 250 different slide rules. With such an incredible number of designs, its impact can be seen by the industrial revolution. It is estimated that nearly 40 million slide rules were made in just the 20 th century. Soon thereafter we begin to see another change in technology that will put many of the manufacturers of the slide rule out of business.

4 Electronic computers became a new technology in the 1950s. Towards the 1960s they became accessible to more people and the use of the slide rule began to decrease. The use of calculators by the younger students at universities to some seemed cliché at first. Just like the opposition to cell phones or advanced calculators in the classroom today, some older generations were the first to oppose this change. The use of calculators was part of the transition in the way people approached calculations. When using the slide rule an emphasis was put on algebraic calculations prior to using the slide. The problem would need to be simplified as much as possible first. Now with the calculator it became easier to avoid the effort needed for the algebraic calculations and simply use the calculator. By the 1970s handheld calculators were available to the masses and by the late 1970s were inexpensive enough for the masses to afford. The use of electronic calculators, just like any other technology, has its sceptics at first. As they became more widespread, they proved to have their benefits. Many of the sceptics began to understand its benefits. The slide rule was an incredible invention and without it we would not have progressed to where we are today, but it did have its downfalls. It was difficult for many to learn to use and was primarily used only for specialized fields that it applied to. It was slower to use when compared to the calculator and with the slide rule engineers would take short cuts to make their calculations easier. This caused inaccuracies that became unacceptable as new technologies arose. As engineered structures became more immense and required more dynamic models, the demands surpassed the use of the slide rule and the slide rule became obsolete, in exchange for the calculator. The history of this tool, the people that made it possible, and the revolution it led us to is incredible and for this we are grateful. The slide rule has proven to be an integral part of our history and many teachers still believe students should have a basic understanding of its uses. Providing students with a learning opportunity as such gives students a chance to appreciate where mathematics has come from and where it has led us.

5 Just as teachers prefer students to learn how to do calculations by hand and learn why something is happening rather than simply typing it into a calculator, learning to use a slide rule is another step that can still be used in a classroom. There are even numerous online interactive slide rules and sites that teach the reader how to use such an instrument.

6 Sites used: