SRTC: Hemmi Catalogue Raisonne: Without Model Numbers

Hemmi Slide Rule Catalogue Raisonne

Part II: Rules Without Known Model Numbers

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.g., the 1938 "Astronavigation" rule. I will be greatly indebted to anyone who can supply any more information about any Hemmi slide rule. Special thanks to D. Boone, Bill Lise, Atsushi Tomozawa and Hitoshi Nori for the help they have given.

Paul Ross

Click here to return to Part I of the Hemmi Catalogue Raisonne.

SKF Bearing Rule, 1930s

Designed and distributed by SKF. Implements various calculations related to bearings. Table on back explains scales and formulas. ( Picture is modified from Herman van Herwijnen's Catalog.)

Matsuda Tube Waterways Rule, 1930s

Implements "Hazen & Williams formula" for pressure loss due to friction in pipes. No date code. The picture is of a rule belonging to D. Boone.

Astronavigation Rule, 1938
Jihei Miyazaki [Development History of the Slide Rule, May 1956] and Katsunori Kadokura [Chronology of Japanese Slide Rules, Journal of the Oughtred Society, vol. 1, no 2, August 1992.] both list an "Astronavigation" rule as being introduced in in 1938.

Ratio/Percentage Rule, 1939
Jihei Miyazaki [Development History of the Slide Rule, May 1956] lists a "Ratio" rule as having been introduced in 1939. Katsunori Kadokura [Chronology of Japanese Slide Rules, Journal of the Oughtred Society, vol. 1, no 2, August 1992.] translates the same item as "Percentage" rule.

IJN 98 (Imperial Japanese Navy Maneuvering Rule, Type 98), 1938-43

Handheld device for naval gunnery calculations. Type 98 means "type approved in imperial year 2598" (1938). Photo is from a June 2005 auction on Yahoo! Japan; information is from Bill Lise who examined a museum specimen dated 1943 on its back.

Air Navigation Rule, 1939
Jihei Miyazaki [Development History of the Slide Rule, May 1956] and Katsunori Kadokura [Chronology of Japanese Slide Rules, Journal of the Oughtred Society, vol. 1, no. 2, August 1992.] list an "Air navigation" or "Navigation" rule as being introduced in in 1939. Both list it in addition to the 1938 Astronavigation rule, above.

Conversion Slide Rule, Pre WWII

250 x 34 mm. The pictures are from a Japanese auction which ended February 5, 2008. Here is Atsushi Tomozawa's explanation of the scales: "The scales are captioned (from top to bottom) Year(G), Month(E), Month (F), Reverse(CI), Day(C), Day(D). The gauge marks on M scale are various units of length and area, some Japanese and some European. It appears that this rule is designed especially for unit conversion." I can find no Hemmi documentation of this rule.

Merchant's Slide Rule
400 mm x _. The only information I have on this rule is the name from Bill Lise.

Artillery Rule, 1942

Jihei Miyazaki [Development History of the Slide Rule, May 1956] and Katsunori Kadokura [Chronology of Japanese Slide Rules, Journal of the Oughtred Society, vol. 1, no. 2, August 1992.] both list an "Artillery" rule as being introduced in 1942. The rule pictured here belongs to D. Boone. It came in a box marked "Artillery" and "Science School #215;" its identification as the Artillery Rule of 1942 is tentative but the style of writing on the box definitely dates it before 1945. Scales on the pictured rule are: Upper slanted edge: Two linear scales 0-10 and 600-0. Face: L1, DF [CF, L2-L1, CI, C] D, A. Bottom edge: 0-20 cm. Body rear: 0-200 linear and 5 - infinity reciprocal. Slide rear: T1, T2, S2, S1. Trig functions seem to use a system wherein 1600 units equal 90 degrees.

Nishiki, 1942

Top, slanted edge carries a 0-50 cm scale. All four scales on face of rule are identically divided linear scales (0.4 mm per unit) which means the rule is for addition and subtraction--not multiplication and division. Scale on upper stator is 200 - 0 -200, 160 mm long in center of rule. Upper scale on slide is 0 - 500, 200 mm long at left end of slide. Lower scale on slide is linear 100 - 1350 offset by 50 units from upper scale on slide. (Total length 500 mm) Scale on lower stator is same as scale on upper stator except placed at right end of rule. Hairline on left cursor extends over upper two scales only; hairline on right cursor extends over lower two scales only. Face width 34 mm.

Specimen rule belongs to D. Boone who also supplied the name "Nishiki"--which means 2nd year of the 26th century since the founding of Japan--i.e. 1942.

Transmission Rule, 1943
Jihei Miyazaki [Development History of the Slide Rule, May 1956] and Katsunori Kadokura [Chronology of Japanese Slide Rules, Journal of the Oughtred Society, vol. 1, no. 2, August 1992.] both list a "Transmission" rule as being introduced in in 1943.

Communications Engineering Rule, 1943
Jihei Miyazaki [Development History of the Slide Rule, May 1956] and Katsunori Kadokura [Chronology of Japanese Slide Rules, Journal of the Oughtred Society, vol. 1, no. 2, August 1992.] both list a "Communications Engineering" rule as being introduced in in 1943.

Altitude Correction/Height Adjustment Rule, 1943
Jihei Miyazaki [Development History of the Slide Rule, May 1956] lists an "Altitude Correction" rule as having been introduced in 1943. Katsunori Kadokura [Chronology of Japanese Slide Rules, Journal of the Oughtred Society, vol. 1, no. 2, August 1992.] translates the same item as "Height Adjustment."

Triangulation Rule, ca 1940

This 50-cm rule has only one magnifying cursor; the picture shows two cursors because it is stitched together from two scans. Function of rule is unknown; "triangulation" is just a guess. I suspect it may be the Altitude Correction/Height Adjustment Rule above but my friend Atsushi Tomozawa suspects it was used by airplane navigators or for aerial surveying.

Front scales are e [L, N^1/3, N^1/2, T, N] X and a partial-length unlabeled scale below the X scale. The e, N, and X scales are three-cycle logarithmic: e runs from 10cm to 100m, N and X run from 1 to 1000. The N^1/3 and N^1/2 scales are the cube and square roots of the N (and X) scale. The N (X) scale gives the tangent of angles which are engraved on the right end of the N^1/2 scale and the full length of the T scale. The range of angles is 6^o to 89^o57'. (Compare to usual range of 6^o to 45^o.) The unlabeled scale on the bottom of the rule is marked 1' to 17'; each graduation is 1/60 of the graduation on the X scale.

There are three scales on the back of the slide: S ranges from 500m to 20km; log S ranges from 2.7 to 4.3; a ranges from 3' to 90^o.

There are several tables of formulas on the back. The following is a paraphrase of Tomozawa'a explanation of those tables: One is definitely related to distance (height) estimation using triangulation. The second table consists of triangle formulas. The third table contains three items: (1) Indirect method of level estimation; (2) Level measurement by barometer; (3) Earth parameters. The fourth and fifth tables are related to map reading. The sixth set of formulas is titled "Westward inclination of earth magnetic field." Seventh: (1) Formulas for photographic surveying; (2) Angle conversion factors. Eighth table contains various constants such as 1 mile = 1,609 meter.

Picture provided by D. Boone.

"Byoutou," 1944

//Closed body||. 250 x 34 x 11 mm. (Same body as Hemmi 50W.) Calculating scales on four surfaces (front, back of slide, top slanted edge, and bottom vertical edge). Top, slanted edge carries a non-linear scale labeled "V" near left end and a 0 - 10 cm scale at right end. Face of rule carries eight full-length non-linear scales labeled simply (1) - (8). Bottom edge of rule carries non-linear scales (9) and (10). Labels (11), (12) and (13) appear at the right ends of scales (2), (3) and (6). Labels (14) and (15) appear at the right ends of scales (6) and (5) but upside down--as if the user were to reverse the rule when using them. Non-linear scales (16), (17) and (18) are on the back of the slide. Special cursor with flexible tab extending from top edge; cursor must be reversed when using scales on bottom edge of rule. It is possible that some operations were to be performed with the rule upside down, with the slanted edge toward the bottom. There is a plastic table on the back with settings for the C and D scales and trigonometry formulas; none of which seems to relate to this slide rule.

The following information is from Atsushi Tomozawa: The name "Byou-tou" comes from two Chinese characters "byou" and "tou" on a box containing a specimen of this rule in the Hemmi Offices in Tokyo. The first character translates to sprout, bud or shoot of a young plant; the second means "head." "Shooting Heading" is not an impossible translation. "Development History of the Slide Rule" by Jihei Miyazaki states that the Byoutou rule was introduced in 1944 but does not mention what function the rule served. Another book, "History of the Slide Rule," written for the Royal Navy Military Schools in 1944 explains how to use the rule to calculate a correction angle for firing at moving ships; the corrected angle is called "corrected byoutou."

It is possible that this rule is an improved version of the Artillery Rule of 1942, above.

These rules are relatively common but cursor is usually missing.

Slide Projector Slide Rule, 1940s

Labeled "SUN HEMMI 'Projection Slide Rule (4)' (for simplex)". Manufactured by "NIHON KOGEI CO., LTD" for use with lantern slide projectors which were popular for technical presentation in the 1940s and 50s. Scales are identical to Hemmi model 2662. Three sheets are superimposed: (1) Scales on face of rule, (2) Scales on rear of slide, (3) cursor. More modern projection slide rules for overhead projectors use the same three sheets.

Picture and all information courtesy Hitoshi Nori.

Power Load Rule, 1955
Jihei Miyazaki [Development History of the Slide Rule, May 1956] says a "Power Load Rule" was developed in 1955 for Kyushu Electric Co.

Postrig, 1947 - 52

The first slide rule Hemmi developed to the specifications of the Frederick Post Co, Chicago. Post sold Hemmi rules exclusively starting about 1930--except during and immediately after WWII when they sold rules manufactured by Grafton Plastics Co. and by the Roos Co. One of those Roos slide rules, Post Catalog Number 1462, had a scale set (T, DF [CF, CIF, CI, C] D, S, ST and LL0, LL00, A [B, K, L, C] LL3, LL2, LL1) which was particularly well adapted for general engineering use. When Post returned to importing Hemmi rules about 1947 they asked Hemmi to make a rule with the same scale set. The resulting rule was named the "Postrig" and sold as Post model 1462H. Many Postrig rules are marked "Made in Occupied Japan;" the rule pictured here has a date code of "CG" (July 1952) which indicates it was one of the last Postrig rules made. The Postrig was replaced by the Versalog--Post model 1460/Hemmi 258--whose scale set is based upon it.

Pocket Versalog, 1960 - 68

Manufactured by Hemmi for the Frederick Post Co. of Chicago (Post model number 1461) and for the Hughes Owens Co. of Canada (Geotec 341 3050). Same scales as full-size Versalog (See Hemmi 258): LL0, LL/0, K, DF [CF, CIF, CI, C] D, R1, R2, L and LL/1, LL/2, LL/3 [T T, SecT ST, Cos S, C] D, LL3, LL2, LL1. 125 x 34 x 3.5 mm.

Replaced by Pocket Versalog II (same model numbers) in November 1968.

Versatrig 1960 -

Manufactured by Hemmi as a cheaper version of the Versalog Slide Rule. Post Catalog Number 1450 until ca 1972 after which it became Teledyne-Post 44CA-500. Sold in Canada as Geotec 341 3120. Available from about 1960 (Instructions copyright 1961) but did not appear in Post Catalogs until 1969. Scales K, DF [CF, CIF, CI, C] D, R1, R2 and L, A [T T, SecT ST, Cos S, C] D, DI. 250 mm x 1-5/8 x 1/4 inch.

YS-11M-A Aircraft Load Adjusting Rule 1964-74

||Closed body|| All-plastic. English language. Load adjuster for NAMC (Nihon Aircraft Manufacturing Co.) YS-11 twin-engine turbo prop. Plane was manufactured from 1964 to 1974; rule presumably dates from that period. Picture copyright by Bill Lise.

Real Estate, 1964

All-plastic ||closed body|| in two sizes: 200 x 28 x 5 mm and 120 x 25 x 3 mm. Front scales: To, m² [Ken, m] m, Ken. Rear scales: Blank. Japanese language. Known date codes OJ, OK. Instructions printed 1965.

Carrier Ductuler, 1965

All-plastic ||closed body|| 200 x 28 x 5 mm. For design of air conditioning ducts. Probably predecessor to Hemmi model P141. Date code of rule shown is "PC" = March 1965.

Electrician's Rule, ca 1965

12.5-cm all-plastic closed body. Scales seem to be oriented toward selection of wire gauge and calculation of voltage drop and power loss. Rear of slide carries three scales. Possibly same as Power Load Rule (1955) described above.
Picture courtesy D. Boone; the rule carries no date code.

Accumulator Slide Rule

An accumulator seems to be a device for "storing" hydraulic pressure. Manual is in English and Japanese. Pictures and information courtesy D. Boone.

Pocket Electronics Rule

125 x 38 x 3 mm all-plastic closed body. The pictured rule carries no date code.

SMC Pneumatics Slide Rule, ca 1965-67

Plastic duplex. 250 x 46 x 5 mm, same blank as Hemmi P261, P262 which were made ca 1965-67. The pictured specimen belongs to D. Boone.

Foxboro Flow and Valve Rule, 1967

Plastic duplex. 250 x 46 x 5 mm. No date code but instructions are copyright 1967. No mention of Hemmi except "Hemmi Japan" embossed into cursor. There are two versions of this rule: "English Units" (upper picture) and "Metric Units" (lower picture.

CJ-805-3B Engine Performance, 1967

GE jet engine CJ-805 powered the Convair 880 and Convair 990 airliners. The pictured rule belongs to D. Boone; date code is "RD."

Metal-Chemistry Rule I, 1967

Duplex, 500 mm x 1-3/4 x 1/4 in. Front scales: L, K, A, DF [CF, CIF, CI, C] D^oK, LL3, LL2, LL1 Folded at p. Rear scales: Ch A~M, Ch N~Z, M1, Xw [X, M2, T^oF, T^oC, T^oK] Patm, PmmHg, T^ow, G.

This rule belongs to D. Boone; it is the only specimen of this variant known to me. It carries a date code of "RA." See discussion of Metal-Chemistry Rule II below for additional information.

Metal-Chemistry Rule II, 1968-

Duplex, 500 mm x 1-3/4 x 1/4 in. Front scales: L, K, A, DF [CF, CIF, CI, C] D^oK, LL3, LL2, LL1 Folded at p. Rear scales: Ch A~M, Ch N~Z, M1, Xw [X, M2, TI, SI, G] Patm, PmmHg, T^oF, T^oC.

Two specimens of this rule are known; neither has a date code. Atsushi Tomozawa purchased the rule pictured here along with a Japanese language instruction manual directly from Hemmi about 2004. The Hemmi employees he dealt with identified it as a "Metal-Chemistry" rule. (D. Boone owns the other specimen.) Based upon its similarity to the Hemmi Chemistry rule (model 257L) it is possible that this rule was intended to be marketed as model 277 but no such model number appears in any known Hemmi documentation.

Versalog II, 1968 -

The original Versalog was the same as Hemmi model 258 and is described under that model number on the main page of this Catalogue Raisonne. The Versalog II, introduced in November 1968, re-arranged the original Versalog scales and added an "A" scale. Scales: LL/0, K, A, DF [CF, CIF, CI, C] D, R1, R2, LL0 and L, LL/1, LL/2, LL/3 [T T, SecT SRT, Cos S, C] D, LL3, LL2, LL1. 250 mm x 1-3/4 x 1/4 inch. Sold in the United States by the Frederick Post Co. as model 1460 (Same number as original Versalog) until ca 1972 when it became Teledyne-Post model 44CA-600. Sold in Canada by the Hughes Owens Co as Geotec model 341-3012. Versalog IIs can be easily distinguished from original Versalogs by the presence of the "A" scale.

Pocket Versalog II, 1968 -

Same scales as full-size Versalog II. 125 x 34 x 3.5 mm. Sold in the United States as Post model number 1461 until ca. 1972 when it became Teledyne-Post 44DA-610. Sold in Canada as Geotec model 341-3050.

Baseball, ca 1969

125 x 28 mm. Similar construction to Hemmi P37 which was made ca 1969. Possibly a promotional item from the Yomiuri Giants professional baseball team. All four scales are 1-cycle logarithmic but the upper scale on the slide is folded at 0.9. Came with a full sheet of instructions plus abbreviated instructions on back of rule. The pictured rule belongs to D. Boone.

Pocket Versatrig, 1969 -71

Manufactured by Hemmi for the Frederick Post Co. of Chicago (Post catalog number 1451) and the Hughes Owens Co of Canada (Geotec Model 341 3125). Scales K, DF [CF, CIF, CI, C] D, R1, R2 and L, A [T T, SecT ST, Cos S, C] D, DI (same as Versatrig). 125 x 34 x 3.5 mm.

Appeared in only one Post Catalog (1971). All known Post specimens carry date code "SF" (June 1968) but the only Geotec specimen I'm aware of has date code "TE" (May 1969).

Mechanical Testing Laboratory, ca 1970

12.5-cm duplex--same body as Hemmi 149A except solid plastic. Calculation of useful lifetime of bits used in metal turning lathes. The name "Mechanical Testing Laboratory" is printed in Japanese characters on the back. (The "Mechanical Testing Laboratory" is now known as "National Institute of Advanced Industrial Science and Technology.")
Picture courtesy D. Boone; the rule carries no date code. Information courtesy Atsushi Tomozawa.

Body Weight Balance, 1972

200 x 28 mm (same blank as Hemmi P45D, P45K, P45S). Listed in a 1972 Japanese language flyer. Calculates "obesity" (similar to body mass index, BMI?), "Raurel Index," and "Carp Index" based on student's weight and height. Brochure specifically uses the word "student."

Calorie, 1972

Plastic duplex. 250 x 46 x 5 mm. Described in same 1972 Japanese-language Hemmi brochure as the Body Weight Balance rule, above. This picture is from Kim's Japanese website, http://www.tok2.com/home/kim/sliderule/Calorie.html (which, unfortunately, seems no longer available). Calculates basal metabolism and required calorie intake from height and weight. "Calorie" is printed in English on face but the rule may not have been available with English instructions.

Denkishoin Electrical Slide Rule, ca 1976

Plastic duplex. 250 x 46 x 5 mm, same blank as Hemmi P261, P262. Rear scales are Tq₂, Tq₁, Sq, R₁ [R₂, B, CI, C] D, SR, TR₁, TR₂. This rule was advertised for sale in at least two 1976 issues of "Denki-Keisan," a magazine published by Denkishoin--a publisher of electrical books and manuals. (Information from Hitoshi Nori.) This specimen, which carries no date code, belongs to Atsushi Tomozawa who provided the picture.

Versor Electronic Calculators, 1976

In 1976 Hemmi teamed with Brother Industries to produce a a line of electronic calculators. There were four models: Versor 804, 814, 824 and 834. (The pictured calculator is marked "Hemmi Versor 824.") This information is from Hitoshi Nori who is not aware of any specimens in existence in 2009.

PressMate, Late 1980s?

Calculates bending and shearing forces in machine presses. Back is covered with tables and formulas. Scales are 120 mm long; body is 46 mm wide and uses same CP-280 cursor as P280, P281 and P283 slide rules. 16-page instruction manual. All Japanese language except name "Pressmate" on box and some labels like "(shear strength)" on rule. No date code but a date in the late 1980s can be inferred since the scales are silk screen printed with thin transparent overlay like P135k (which was made in 2004) and the device was distributed by "MISUMI Shoji Co., Ltd." which used that name only from 1963 to 1989. All information from Hitoshi Nori who also supplied the photograph.

Diver's Decompression Slide Rule, 2004

||Closed body|| 200 x 32 x 4.3 mm. All-plastic. (Same blank as Hemmi P135k.) Custom manufactured by Hemmi ca 2004. The pictured specimen was given to a group of Japanese slide rule collectors as an example of Hemmi's recent production; it is presently in the possession of Mr. Nori. Two of the phrases in red translate to "Body gas pressure" and "Dive depth;" I think it calculates decompression times for divers.

Meteorological Slide Rule?

eBay auction 6248834536, Feb-05-06 . Won by "Waynesworld." Here is the seller's description:
"A 10 inch bamboo base Sun Hemmi rule, no model number, and not listed in the catalogs available. The face scales are: Pressure in mmHg, B, CI, Height(same as C scale) ABS Temp (-50 to +200 C). The reverse side scales are: Height in Km, Pot. Temp. Coef. (mmHg.mb), and Temp. Fact. (-60 to +40 C). The rule has a 10 inch scale on the lower edge and a 0-27cm scale on the upper edge. Possibly used for barometric calculations and other meteorological purposes."