A period of rapid growth began in about 1931. The first letter corresponds to the year starting with B for 1951 and ending with Z in 1975. Section of scale reading 2 to 5 From graduation figure 5 to graduation figure 7. The logarithms enable the types of calculation to be reduced by one stage; multiplication and division thus become addition and subtraction, while the raising of numbers to powers or the extraction of roots becomes multiplication or division respectively. Two out of three of mine are really easy to read.
Scales on the front of the slide rule: 1st tangent scale T 1 tan 0. Complete with two part hardboard case. Intermediate result: 51·2, on D. I'm not sure how much these rules retailed for back then, but I can assure that you they typically cost considerably more than the more common full size versions now-a-days! A pity they didn't keep making slide rules for a little bit longer. Has pythagorean scale P , expanded square scales, folded scales and scale over-ranges.
While their first rules until 1946 were of 'swiss pearwood', there was a brief period 1946-48 where beech and 1948-1950 maple were used, after that period they were made of 'special wood' a wood composite with laminated scale surfaces. Example: To set to 318, first find 3. On the e x and e -x scales, reading can then be taken of the e powers. With the slide in the zero position C 1 above D 1 and C 10 above D 10 the cursor line is brought into position above D 1-1-8-4, and the result - 3. Proceed as with division, i.
The odd numbers are obtained by halving the distance between two graduation marks. Complete with plastic display case and instructions. It's still very nice, with a smooth spring and nice grip, and slight magnification due to the curvature of the face. A very powerful and beautifully made log log rule, equal to the K+E 4181-3 and Post versalog 1460, if not better. I've included a copy of the standard Post 1447 instruction booklet up above, but more interesting is the French version of the Hughes Owens 341 3526 instruction manual prepared for the Quebec market.
A magnifying glass may help you see it. This way, the curvatures of the slide and the frame are opposite, and counteract each other. It is up to you, the reader, to determine the suitability of, and assume responsibility for, the use of this information. To my surprise I found a webpage from Prof. The outside of the box was torn, but everything inside is fine. I find that my rule collects dust like crazy. Total time from ordering to delivery was 19 days.
Solution: With the aid of the cursor line, place W 2-42·3 and W 2'-71·7 opposite each other, and find the result 0-589 above the black index-10, on W 2. We set on K and read off on D. The back cover is blank apart from a date and version code at the bottom right. Cursor line on C-4·56 or D 4-56 ; the result 2. Many cursor lines are not visible, they are located on the sides of the cursor body. A beautiful tool, really fun to work with.
If I find out any more, I'll let you know. Then place C 1 above D 256 and move the cursor. For centuries it had made calculations easier for countless mathematicians, physicists, engineers, and other occupations. . Both models are only partly depicted, the left-hand half of No.
This rule has a wood core, with white celluloid faces, black and red filled and engraved scales, plus 2 side cursors and scale sets. Superficially, the patina on this specimen is clearly much whiter, although it has some red ink discolourations along the inch ruler edge. It applies to the range 5°-6°. Section of scale reading 5 to 10 Each interval is equivalent to 2 sub sections. As for the age, I now know that this body design was used in the 1930's and 40's, and was definitely gone by the 50's I used to think it was more recent.