German K.R.S.40 Serial Number 1022

This three disk circular slide rule measures 18" in diameter and weighs in at 41 pounds, including its integral steel carrying case. The maker's code is "gwr." It also carries the German stamp 763 underneath the 3rd Reich eagle on the inside of the case. If you have information on this, please contact me...




A unique Japanese combination slide-rule/nomograph, dated 1936, for calculating ballistics corrections for temperature, barometric pressure, vertical and horizontal wind and muzzle velocities. Probably used in land-based Army operations in China. Weighing a hefty 16 pounds it measures 30x38x2.5 cm. It has a thick wooden base, thick bronze or copper dovetail slides (with matching serial numbers 26) , and white brass faceplates. Three sliding scales are side-by-side, with a fourth sliding scale inserted in the center slide. Their positions are shown in the photographs (left) and are also illustrated in the instructions printed on the faceplates. A boilerplate located on the right edge is illustrated below:


The boilerplate reads: No. 31 Nippon Keiki Seizo KK (Japan Instrument Manufacturing KK) Tokyo, Manufactured March, 1932.


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Click here for a larger translated image.

Translations were generously provided by William Lise.

Compare this with:

  • Graphic Sight Tables (GST) used by the US Army.
  • A gun rule (slide rule) for the BL 5.5 inch gun.
  • Type 98 Imperial Japanese Navy slide rule.
  • Vickers Maching Gun slide rule.

Please email me at nick/dot/gessler/at/duke/dot/edu f you have any more information...

x Slides partially open.

x Slides edge on.

Dated 1962, this pair of 16" circular slide rules, each one weighing 6 pounds, is double-sided, providing the functionality of four calculating devices. They are constructed of heavy aluminum, stainless steel and brass and are adjustable for field calibration. Enclosed in the heavy steel carrying case, the ensemble weighs 26 pounds. The case and flip-sides of the rules are pictured below. A standard CD-ROM is placed in the center foreground for scale.
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