These were used by pilots to do simple arithmetic, conversions and other calculations in an era before gps and calculators. The slide rule is based on the mathematical principle of logarithms developed by scotsman john napier in 1614. Just line up the two numbers to get quickly tabs on all their multiples. Many pilots watches made make use of a circular slide rule on the bezel of the watch. The e6b flight computer, nicknamed the whiz wheel or prayer wheel, is a form of circular slide rule used in aviation and one of the very few analog calculating devices in widespread citation needed use in the 21st century. Using a slide rule is a bit of a lost art but with a bit of practice, it can be a useful everyday tool. This new form of a slide rule was patented by gilson on october 19, 1915 and was considered far more accurate than the traditional straight slide rule. Slide rules were key to engineers in the 1950s and 1960s even though. The concise company of japan still manufactures circular slide rules which can be purchased. On this page are links to a number of software simulations of slide rules, mechanical. How to use a circular slide rule caliper timepieces inc. The lower picure shows the answer on the leftmost cursor. This specialpurpose 1950s circular slide rule from remington rand was used by programmers to optimize how the roomsize mainframe executed instructions. Datalizer wheel chart calculators are designed for quick calculating.
The appeal of slide rules for use and as collectables. Slide rule was invented by english minister william oughtred in 1622. Conray radiological tables and circular slide rule. All other scales on a slide rule are referenced to the c and d scales. Slide rule software sphere researchs slide rule universe. The radiological tables and circular slide rule were compiled and designed to provide a compact calculator and reference source to aid the radiologist or radiation therapist in his or her daily duties. Old pilots watches feature these slide rules, and any newer pilotstyle watches also have this. Circular slide rule based on my guess concerning nystroms calculator design. A large number of templates for circular slide rules are given, along with many other templates. To someone who doesnt know how to use it, a slide rule looks like a ruler designed by picasso. Interestingly the first computer programmer turned out. Today planes rely on very different technologies but the rule is still useful whenever you want to do operations without having to type.
Once all the pilots had a rule of this kind on the clock, knowing how to do multiplication and division quickly could save your life. Insurance wheel replaces the old circular slide rules. Sophisticated models have more scales than my simple circular slide rule, making for greater flexibility. With the introduction of this device every engineer sold their souls to the. As the programmer, i have to agree with your complaints. Unfortunately because of the screen resolution, numbers are displayed digitally. It was around this time that engineering became a recognized profession, resulting in widespread slide rule use in europebut not in the united states.
This program replicates the most common types of slide rules. Circular slide rule article about circular slide rule by. The last slide rule manufactured in the united states was produced on july 11, 1976. An historical introduction to slide rules from the museum of hp calculators. Tim has provided a free downloadable software emulation of the sliderule. There are also a couple of slider calculaters from brian and myself. Extra marks and windows facilitate calculations specifically needed in aviation. As graphical analog calculators, slide rules are closely related to nomograms, but the former are used for general calculations, whereas the latter are used for applicationspecific computations. I f youve ever seen a watch with a slide rule bezel and havent known how to use it, we have a little guide for you.
Many calculating histories write off the slide rule around the 1970s. Professionally engineered and custom manufactured by datalizer. One slide rule remaining in daily use around the world is the e6b. I did a lot of research on them, and when i did, i discovered that there are circular variations.
This is a circular slide rule first created in the 1930s for aircraft pilots to help with dead reckoning. The construction is bamboo, a wonderfully stable, mildly lubricious material. This set is unused and immaculate the box is a little worn. Sep 16, 2014 before there were computers, insurance companies used a round slide rule device called an insurance wheel to calculate how much premium was to be refunded for a policy cancelled before its expiration date. This circular slide rule was included in samuel glasstone and philip j. This site hosts a portable package of derek ross, stefan vorkoetters, and brian bartholomews virtual slide rules browserhosted slide rule simulators. This slide rule is a genuine classic and deservedly so, with one of the best scale layouts ever devised for professional technical work. Slide rule and art like many other neat things slide rules always inspired writers, poets, dancers, singers i guess and artists.
Electronic versions are also produced, resem bling calcu lators, rather than m anual slid e rules. Also because of all the detail, the 30loop spiral slide rule converts to a. My collection of circular and combination slide rule devices. Oct 28, 2017 also because of all the detail, the 30loop spiral slide rule converts to a lowrez bitmap data image while you move it, then back to a vector based image as soon as you release. Contribute to dustincswagnersliderule development by creating an account on github. It is designed for people who have never used a slide rule before or who have used one in the past but largely forgotten what to do. Henry suttons slide rule top was an early circular rule circa 1663. Contribute to dustincswagner sliderule development by creating an account on github. Esperanto programming languages are java, php hypertext pre. It replaces the cardboard circular slide rule that just about every natural gas engineer has received from a compressor vendor at some point.
Circular and combination slide rule devices erics slide. Includes a brief side show slide show of famous and interesting slide rules, most of which are in the authors collection. There are at least three different scales, and on most of them the numbers arent even spaced evenly apart. Circular slide rules here is different emulator for circular slide rule 1and other. The slide rule, also known colloquially in the united states as a slipstick, is a mechanical analog computer. Get the best deals on circular slide rule when you shop the largest online selection at.
This is peculiar, but it is intended that this rule will be used in conjunction with the one with two fourdecade loglog scales, normal and reciprocal, as part of a set. If both the outside and inside circular rules have identical scales with a full range from 10 to 90, then you have what are known as c and d log scales. Circular slide rule calculators wheel chart volvelles by. Feb 17, 2014 here i cover the most basic operations of a slide rule. Relax, you dont have to load any to actually run your slide rule, these are training and experimentation aids. A brief tutorial on finding the log of a number, useful for db scales. One of the nice things about circular slide rules is that youll. The top picture shows the setting for the multiplier 8 in the sum 8 x 6. Fowlers longscale calculator vest pocket modelrx for engineers, draughtsman and science students supplied complete in leather case fowlers calculators, like all slide rules, are based on the properties of logarithms, which enable multiplication to be performed by addition and division by subtraction. Its usage is identical to that of a real slide rule, but tim has introduced two major enhancements.
You can enter and read a number typically to two or three decimal digits only. The slide rule also does not tell you the sign of your result. I worked at eastman kodak for 30 years as a software engineer specializing in realtime. Slide rule for windows is a revolutionary new software it is a single sided slide ruler for windows 3. I have used this software to build demonstration sliderules for papers that i have prepared for the international meetings and can highly recommend it. Instruction booklet that came with the conray radiological tables and circular slide rule. Customers tell us that they know circular slide rule style calculators as. Our next project will include a circular slide rule in the design of the watch. Addition slide rule wolfram demonstrations project. Takeda concise 300 circular slide rule diameter 412, c scale length 10 made in japan this concise circular slide rule has the standard 10 scales arranged on a doublesided plastic disc of about 5 diameter. A gift from a retired engineer, this marks my first cylindrical rule, also known as a tubular or helical slide rule.
Updated november 3, 2001 types of slide rules and their scales. Scientific american may 2006 university of vermont. May 24, 2016 also because of all the detail, the 30loop spiral slide rule converts to a lowrez bitmap data image while you move it, then back to a vector based image as soon as you release. This one is for a generalpurpose rule, except that hyperbolic functions are present, and loglog scales omitted. The reverend william oughtred and others developed the slide rule in the 17th century based on the emerging work on logarithms by john napier. After seeing phil bs making your own slide rule, i went on a huge slide rule kick. The first of three templates to build a circular slide rule background. Compared to a calculator, a slide rule is severely limited in its accuracy. Tapping three times in the same place will return the program to the home position. Aviation remains one of the few places that the slide rule is still in widespread use. Circular slide rules also eliminate offscale calculations, because the scales.
Dozens of scales are included and numerous features that could never exist on a physical slide rule are also included, such as color options, numeric displays of the values under the hairlines, and so on. Dolans popular childrens book, the effects of nuclear weapons, which along with classics like hersheys hiroshima and lapps the voyage of the lucky dragon, made growing up in the 1960s the delightful, carefree experience it was. The design site for hardware software, and firmware engineers. The first thing youll need to do is design the rule. Slide rule circular logarithmic ruler kl1 ussr calculator.
See the page devoted to the watch style of slide rule at the international slide rule museum. There are places on the internet that have templates for circular rules. The single slide rule is designed for beginner, consisting of k, a, b, ci, c and d scales only. The first circular slide rule on this link uses a cd case as the basis for the slide rule.
Keeping it up with my math helping tools and after i finished my straight cardboard slide rule, i decided to make. As many of you know, watches with slide rule functions have 2 logarithmic scales the outer of which turns. The slide rule, also known colloquially in the united states as a slipstick, is a mechanical. Slide rules usually look like a narrow ruler, but for todays demonstration we will be building a circular slide rule. This circular slide rule was used to calculate the most efficient code for. A slide rule in a circular form whose advantages over a straight slide rule are its precision, because it is equivalent to a straight slide rule many times longer than the circular slide rule s diameter, and ease of multiplication, because the scale is continuous. Slide rule scales build your own sr slide rule museum.
This page gives my own templates see below for constructing a circular. Overview of the major categories of slide rules, and descriptions of common scale labels and meanings. Circular slide rule calculators wheel chart calculators. Insurance wheel is a useful tool for insurance brokers as well as insurance carriers.
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