Otis King’s Patent Calculator

I was a research assistant working on this project about April , I think. At that time I was working for Lockheed on a Defense Department project designed to provide some improvements in computational power for tank crews. Our initial goal was to provide an electronic calculating device for use by tank gunners and crew, generally for calculating ammunition trajectories. This task generally had to be performed in poor lighting conditions, perhaps under battle conditions with emergency lighting only. The task was approached from several angles We looked at the available devices which could achieve our aims, including off-the-shelf calculators.

Post Versalog II slide rule

This part of the Hemmi Catalogue Raisonne lists Hemmi-made slide rules for which I know no model number. These rules were given names “Calorie,” Real Estate” instead of model numbers, or were made for other companies SKF, Carrier, Foxboro or made for the military. There are also some rules which probably were assigned Hemmi model numbers but I don’t know what that model number was–e.

I will be greatly indebted to anyone who can supply any more information about any Hemmi slide rule. Ltd was still in business in Tokyo. They are engaged in development and manufacturing of printed circuit boards, fluid control devices, semiconductor manufacturing equipment and several minor businesses–one of which is the design and manufacture of custom slide rules of the style I would call a “slide chart.

At the time, this became the lowest known rule with a serial number, but no date code. Later, I found ANOTHER of these “rare orphans” as Ted called them, the.

All purchases and fees on this page go toward maintaining the museum website and supporting the Slide Rule Loaner Program for Schools. The specimens they replace, however, may be items in the fund raiser. The recommended fee is based on the average total cost of ebay sales for similar specimens over the past two years. All returns accepted, just pay return postage.

If you wish to contact me directly and offer a different amount, we will work with you to serve both our needs. Call the Curator, Mike Konshak, at days and evenings A list of specimens to be offered is being compiled and will be shown here, very soon. Then each slide rule, manual or other related items will be scanned or photographed and added to the listing. The descriptions will be brief as one may look at other specimens in the respective galleries. Thank you for your patience. Email or call Mike, if you run into problems please.

Sliding Through Science History, Part 2

Skip navigation! Story from Living. In , the DM slide is a classic move.

Post A very nice slide rule equivalent to a K&E Made of bamboo by Hemmi in Japan. This example dates to Oct (date code OJ stamped into.

Other Slide Rule dates are currently in development. Assistance in this effort will be appreciated. Please refer to the museum library and individual galleries as this page is being built. Example: St. Louis 12, Missouri. The following time-line, researched by Denise M. He becomes their Midwest sales rep. Charles Bruning is Fred Post goes to work at Eugene Dietzgen’s company. The Bruning boys work for another blueprint company. They all learn the blueprint business. Jacob Bruning and W. Huey form American Blueprint Co.

Frederick Post starts Frederick Post.

My Slide Rule Collection

Post sold a wide variety of slide rules, both under its own name and under the names of various manufacturers. Post itself actually made no slide rules; even those rules that bore the Post brand name were manufactured by others. Until about , Post slide rules were made by a variety of German manufacturers.

The author had founded the Unique Slide Rule Company in the up-to-​date instrument has, as might be expected, advanced greatly beyond the After reading the instructions we have given for extracting cube roots by the A, B, C and.

In most cases dating of a particular slide rule requires consideration of several parameters. The following characteristics are used in combination with each other to fully identify a given rule:. Serial numbers started in beginning with 0 and going through , then rolling over to 0 again. There were three rollovers occurring in , , and The following graph approximates the four production cycles.

Dates Marked With Stars: The stars in the above chart represent benchmark dates for particular rules where their purchase dates are known. Rules are only accepted as benchmarks if they were main sellers and usually did not sit on distributors shelves very long. Benchmark Rules: Follow links for details. It should be noted that the production rate changes at some of these benchmarks.

At this time we do not have enough benchmark rules to allow approximating a smooth curve.


Post Versalog II slide rule. Date: Inventory Number:

Charles Bruning leaves Post & Jacobi, and after a honeymoon in Europe, returns to the US and settles in NYC. Frederick Post.

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John & Della Ireton

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My Slide Rules. Post image. Concise CTCS, Roos Company No. SR, Pickett T Simplex Trig. Here is my humble collection of slide.

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Next Continue. Over the 19th and much of the 20th centuries the slide rule was the primary instrument for calculation used by many people engaged in the trades and in engineering. Although originally invented in the 17th century, and widely used for gauging or estimating the quantities of certain products such as alcoholic spirits it took until around for the slide rule to become generally popular with those for whom mathematics was a daily task.

His scales were the “C” and “D” scales, ranging from 1 the index to 10 and used for multiplication and division, and the “A” and “B” scales, ranging from 1 the index to and used for squares and square roots. New arrangements of scales appeared in the 20th century with the Rietz arrangement in and the Darmstadt arrangement in The Rietz scales added a log “L” scale, a “CI” or C inverted scale which was useful for calculations involving the reciprocal of a number, and the trigonometric scales: sine “S”, tangent “T” and “ST” for the small angles were the sine and tangent are the same, to the front face of the stock.

The Darmstadt arrangement added a series of Log-Log scales. The Hemmi Company was considered one of the best slide rules manufacturers in the world and they exported millions of versions of their many types of slide rules to numerous countries especially the US between about and

Slide Rules!

Sokoloff’s work opened up the field of neuroscience by providing a way to image how brain function affects mental health. The power came from the number of scales and the use of lettering, which enabled the log-log scales to be doubled. Pickett dropped the Eckel name in , and the logo dates from , but scientists would care mainly about its usability, not its date of manufacture. This powerful tool belonged to Dr. Joseph E.

Find many great new & used options and get the best deals for August “​Post” Versalog Hemmi Slide Rule + Leather Case-EH Date Stamp at the best.

Guide – Hemmi Date Codes. Greg’s Slide Rules. After Hemmi dropped the ‘Made in Occupied Japan” logo in about they began placing date codes on certain rules. This code took the form of a two letter code marked somewhere on either the top or bottom of the rule. This code gives the year and month of manufacture and allows the rule to be dated fairly accurately.

Depending upon the age of the rule the code may be in a different location. Older Post Versalog rules will have the date code on the top of the rule following the “Hemmi Bamboo – Japan” and they will be coloured. Here is a sample: Late in Hemmi moved the date code from the top of the rule to the bottom near one end of the rule and stopped colouring it. To find the date code you need a good strong light and sometimes a magnifying glass as the imprint is very small and quite faint.

I was unable to get an example to show up using a scanner as the markings do not stand out at all. Code Details. There are two code segments, The first letter indicates the year of manufacture, the second letter then indicates the month of manufacture. Year Code: A. Samples Explained.

Talk:Slide rule

With this quote, President John F. In fact, some even doubt whether it ever occurred. One giant leap for mankind. Imagine traveling , miles, unfolding a landing vehicle and separating it from the command module in order to land on the moon, picking up samples, re-entering the landing vehicle, launching it off the surface of the Moon, reconnecting with the command module, and returning home with a computer onboard that only had 36K of memory and 1 Megahertz processor.

The key to this achievement was an iterative process of taking the next step toward the ultimate goal.

Teledyne Post ceased selling slide rules in the mid s. POST Dating Post Brand Slide Rules. * Before , Post brand slide rules were made by various.

Over the past twenty years I have given much thought to analog clocks, sorobans, and slide rules. The case of the analog clock is the simplest: for a time, it looked as though analog clocks and watches might be replaced completely by digital clocks and watches. That did not happen. Because I have surmised, and undoubtedly there is considerable research that backs me up people cannot organize their time using a digital clock the way that they can with an analog.

Twenty minutes on an analog clock is one-third of a pie. I’ve thought less, but some, about sorobans. The word is that these analog calculators are still in use in Japan, where most people can add and subtract numbers more quickly with sorobans than they can with digital calculators. Apparently, a calculator is faster for multiplication and division. So, for a while and it may still be the case , it was common to purchase a soroban with a calculator built on the side.

A soroban looks and functions much like an abacus, but has a single row of beads in the second column rather than two rows. As for the poor forgotten slide rule: engineers tell me that calculators are superior in every way, and have been since Texas Instruments started producing them. I am skeptical, and will remain skeptical. I believe that a slide rule requires its user to function at a higher level in order to do a calculation, and that the higher functioning has positive effects: checking, mental exercise.

Engineers tell me: rubbish.

Calculators available for adoption

I bought my first scientific calculator in a Decimo E, ‘Electronic Slide Rule’ and my ‘analogue calculator’ rapidly gathered dust. It was only about two years ago that I renewed a latent interest in them and started to explore the many superb resources available, which prompted me to purchase a selection. I wouldn’t describe myself as a collector, I bought one example each of styles and of makers that particularly interested me and my ‘collection’ has stopped at eleven.

Making examples from published templates is also fun.

FS: Anonimo Ivan Basso Slide Rule Chronograph Date Watch Brand: Anonimo Brand Style: Ivan Basso Model #: Ivan Basso 1 – 1 of 1 Posts.

Frederick Post Co. Richardson was a supplier to Post in and Post began importing Sun Hemmi slide rules with the Post brand around After April, slide rules were just stamped “Made In Japan” as before the war. Post was acquired by Teledyne in December, Some Versalogs began to be labeled with the Teledyne brand in late The Versalog made specifically for Post by Hemmi is their most well known and collected slide rule.

Andrew Andy David Keller had a long career as an ergonomist, industrial psychologist and human factors engineer, working 17 years for IBM.