Results Pagination - Page 1 1 2 3 4 5 6 7 8 9 Collectible Slide Rules Nostalgic original Keuffel and Esser slide rules with their advanced trigonometric and logarithmic scales invoke fond memories in accountants, engineers, scientists, and business consultants. What is the significance of the Keuffel and Esser linear slide rule? What is the significance of the Breitling circular slide rule? How are mechanical calculators, slide rules, used in ?
How do I choose a slide rule from the many types on sale? Simplex Linear: Simplex models use two scales of base ten logarithms on its front and slide to perform multiplication and division in scientific notation. A sliding line over the scales on each of the three rules displays your answer. Duplex linear: Duplex models have scales of logarithms on their front, back, and slide, which can be removed, turned, and reinserted for additional calculations.
Circular Models: Circular models with spiral scales of logarithms are the most accurate. The base of the circular rule is suspended above a central pivot.
A circular rule has one or two cursors. The E6B circular rule scales are used internationally for safe manual calculation of air time, distance, speed, temperature, compass errors, and fuel consumption. More To Explore. The symbol indicates whether to use the plus or the minus procedure. The first three rows of Table 4 show the most common operations on a slide rule: product, quotient, and power.
The last three rows show less common formulas that can be evaluated. The first number in that row, , indicates the entry in the pdf table , 26 means it is the 26th distinct formula in the table, and 2 means it's the second way to evaluate this particular formula. These numbers are not important for the example, but they illustrate the organization of the pdf table. Caveats apply even more so than to the one variable Table 2 and 3 above. The variables have to be in certain ranges, and you may have to be judicious about which variant of the relevant scale you use to read your result.
Of course, slide rule manuals do not list thousands of formulas. They describe basic principles and then people can figure out how to use slide rules to best advantage for their particular applications. There are more pedestrian ways to compute but if you have to evaluate such expressions many times you'll find the shortcut eventually.
Once you have it you can impress your friends and coworkers! The last example in Table 4 requires an LL scale on the slide. When I went to high school our work horse slide rule was the Aristo Scholar One version of it has a body and cursor with one side, but a slide with two sides.
The back of the slide shows several LL scales. So prior to doing this calculation you need to turn the slide around. This gives you a very strange slide rule without a C scale. For years I have wondered for what kind of application one would want to turn the slide on the Aristo Scholar, and after writing this web page I know! Three Variables Suppose we consider a variant of the PLUS procedure where instead of the index we use a number on a fourth scale. Thus we start again by putting the hairline above the number u on scale 1.
Then we move the number v on scale 2 underneath the hairline. Next we move the hairline above the number w on scale 3. Finally we read the result on scale 4 underneath the hairline. Scales 1 and 4 are on the body, scales 2 and 3 on the slide. With the 13 scales assumed here, there are 24, distinct such expressions, filling 2, printed pages that you can view or download here. The four columns following the mathematical expression give the scales 1, 2, 3, and 4 being used. Sophisticated Multiplication and Division Sophisticated Multiplication sounds like an oxymoron, but it isn't in slide rule lore.
We can multiply and divide using the C and D scales, and so in particular we can multiply with and compute reciprocals. The purpose of these additional scales is to make multiplication and division fast and easy by minimizing the number of times and the distances that the slide and cursor have to be moved, particularly when doing repeated division and multiplication.
Try it, and you'll see that it is especially convenient if multiplications and divisions alternate. If you have a sequence of multiplications only you can replace some of them with a division by the reciprocal of the relevant factor, using the CI and DI scales. It so happens that is close to that square root and works almost as well. In addition however, it makes it possible to multiply or divide by without any slide movement at all.
At some stage in the past someone had the quite brilliant idea to approximate the square root of 10 by. Quadratic Equations As discussed above, one thing slide rules can do that calculators can't is create tables. That readable little book describes very many applications of slide rules. Suppose we want to find the roots of the equation.
Cursor Marks Many slide rules have special purpose marks on the cursors, in addition to the hairline. As an illustration, here is a list of calculations that can be accomplished with the cursor marks on the Faber Castell Slide Rule pictured above. Put the hairline over the diameter of a circle on scale D or C and read the area of the circle under a special mark on scale A or B. The same marks can be used with the CI scale to compute the volumes of cylinders.
To multiply a number with 3. Of course, reversing that procedure let's you divide by 3. Specific Slide Rules Table 5 lists scales on some specific slide rules. Numbers indicate the number of scales present. For example, 8 LL scales usually means 8 distinct scales, 2 C scales usually means there is a C scale on each side of the slide rule.
A green entry means the scale is on the slide, a black it is on the body. Name is the name of the slide rule. Sides lists how many sides are used one or both, or one and a half in the case where the slide is reversible but there are no scales on the back of the body.
Scales lists the total number of scales. The table is sorted by decreasing total number of scales. Marks lists how many marks are on the cursor, including the hairline, and the remaining columns indicate the specific scales as listed above. Answers to all those questions. Visit our amazing document server. Welcome to the Slide Rule Universe! You can order any slide rule here just by picking up the phone, and calling during normal office hours, PST.
Sphere Research Corporation Sunnyside Rd. NIB Rules. NIB Pickett Rules. Pocket Rules. Circular Rules. The Slide Rule Universe All kinds of reference information.
Buying and Selling Slide Rules To make your life easier, and help you find exactly what you want, we have broken the on-line slide rule catalogs into smaller sections. You can also send your order data by email if you think it's safe , or by FAX at: You can also place your order, and send in the payment by mail. Slide Rules for Sale! Sorted by Type. Just a few. These are disappearing quickly.
We have so many different kinds just now, we have split them into Pickett and Non-Pickett pages, for quicker viewing. Don't miss your chance to get a brand new rule! When these last few lots disappear, we do not expect to ever see any more at these very low prices. We have pooled resources from collectors all over the world to bring you this rich and varied assortment, but for many types, the quantities are low, and they will soon be gone forever.
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