Cylindrical (Drum) & Spiral Calculators

KEEP ISRM FREE!
Donations are
tax deductable
This page contains cylindrical slide rules constructed in the shape of a drum and can incorporate linear or spiral (helical) scales in their design. Some images provided by major museums and private collections. Some specimens are duplicated in other galleries.


Manufacturers represented in this gallery:
Billeter, National,
Bygrave AML (UK),
Bygrave (German),
Bygrave (Japan),
C.O. Browne,
Keuffel & Esser (Thacher),
Loga, Daemon-Schmid,
McFarlane,
Nestler,
Otis King,
W.F. Stanley (Barnard, Fuller, etc.),
Elizur Wright (Arithmeter).

Reference reading:
Calculating cylinders, the slide rules with the long scales by by Heinz Joss, Dällikon/Switzerland, September 2000
Long Scale Slide Rules Revisitedby Edwin J. Chamberelain JOS Vol. 13, No. 1, Spring 2004

In some cases there are historical or photographic records of logarithmic slide rules but the actual artifact has not been found. In the example on the right a photo from 1908 shows a Cylindrical Slide Rule comprising two wheels with scales on the outside edge. Each can rotate separately from the other, with a foot operated brake to lock the wheels while transfering calculations. The diameter looks to be about 4 feet which gives a scale length of 150 inches, or 15 times the length of a standard slide rule. The wheels and base appear to be made of cast iron. This unique design which is wildly different than any of the designs that made it into broad production, was quickly made obsolete by other designs that were cheaper to make and had a higher resolution in the scales like the Billeter, Loga, Thacher, Fowler and many others. One cannot be found, simply because the iron was too valuable, and was probably melted down to supply metal for the first world war.



Billeter, National Rechenwalze, A.G. "System Billeter"

Originally: Julius Billeter Rechenwalze. Gallery includes specimen by son Ernest Billeter
Julius Billeter (1828 - 1914) made 'Rechenwalze' (Computing Rollers) cylindrical slide rules for the financial industry based on Billeter's 1894 patent. US Patent No. 513,172 January 23, 1894. French Patent No. 217,367 Nov. 10, 1891. Most of the designs were marked as "System Billeter".



National Rechenweize "System Billeter"
Modell No 20 - 1918 Cylindrical Slide Rule

ISRM 13.03.15.01.X



Carolina Radu, John And Walter

John William Radu
(1879-1944)

John William Radu with Crow
National Rechenweize System Billeter Modell No20 1918
Cylindrical Slide Rule (Computing Roller)

Made in Switzerland by National Rechenwalzen. Zurich, Switzerland. c1940,
Construction: Varnished paper scales on 20.5cm (8.12in) dia. x 57.3cm (22.5in) long metal cylinder and on sliding cylindrical cage. Metal support stand.
Scale: 80 sections of C & D scales equivalent to 20 meters (65.6 ft) in length.
As part of the artifact, the wooden box is present that it was shipped in when it was sent from Zurich to New York City in 1940.

Robert A. Ecker
This specimen was acquired from Robert Ecker of Long Valley, New Jersey, who owned and preserved this excellent math instrument for 60 years. Robert graduated from Brown '55 (mechanical engineer, tau beta pi); commissioned USAF, active duty Germany '57-'58 (missile guidance), reserve Capt. until '62 . Employed by ExxonMobil '56-'85, (refinery ops, supply planning, tanker design). Robert is a current ham radio operator (W2EKZ Amateur Extra), Robert A. Ecker expanded Biography
Robert writes: "It belonged to my grandfather, John William Radu (born 6/3/1879 in Poland or Romania, and died in Manhattan 6/4/1944.. He lived in Rochester, NY where he graduated from the University of Rochester and later moved to New York, NY. He was a many talented person designing and building medical instruments for his own company and teaching at well known technical Stuyvesant High School in New York. He built telescopes, collected minerals, conceived magic tricks for Howard Thurston, collected clocks and music boxes, and must have been a very interesting person. I was only 11 when he died but remember him showing me his collection of fluorescent minerals under a black light."
A record search shows that he attended U of R between 1903-1908 and that he had his own company, as General Manager of Radu Surgical Instrument Co. during the same time from 1907-1911. Then he was superintendant of the German Insurance Building, in Rochester, starting in 1911. In 1920 he was approved to be an assistance teacher (Instrument making) for high schools and appointed to Stuyvesant (NY Times Jan 30,1920).One can see why he liked this slide rule. More info on his career was in a donation to UofR in 1947 in his name that shows a more detailed work history (see attached). There is a reference that he married Clara Louise Coit who was an Alumnae class of 1897 Elmira College. She was Robert Ecker's Mother's Mother.


REF Billeter Rechenwalze 4M Cylindrical Slide Rule
Billeter Rechenwalze 4M Cylindrical Slide Rule
Made in Switzerland by Julius Billeter. Zurich, Switzerland c1900,
Construction: Varnished paper scales on 5-cm dia. metal cylinder and on metal vanes on a sliding cylindrical sleeve. Wood support stand
Scale: 20 rows of C & D scales equivalent to 4 meters in length
Note: This is an early example matching Billeter's 1894 patent. Later examples carry "National Rechenwalze - System Billeter"
Archive - Ed Chamberlain Collection


REF National Rechenwalzen System Billeter Modell No8 Cylindrical Slide Rule
National Rechenwalzen System Billeter Modell No8 Cylindrical Slide Rule
Made in Switzerland by National Rechenwalzen. Zurich, Switzerland c1900,
Construction: Varnished paper scales on metal cylinder (8 cm dia. x 16 cm long) and on metal vanes on a sliding cylindrical sleeve. Metal support stand.
Scale: 40 rows of C & D scales equivalent to 8 meters in length.
Note: Formerly Julius Billeter Rechenwalze. Frequently used by European banks and accounting offices.
Archive - Ed Chamberlain Collection


REF National Rechenwalzen System Billeter Modell No16 Cylindrical Slide Rule
National Rechenwalzen System Billeter Modell No16 Cylindrical Slide Rule
Made in Switzerland by National Rechenwalzen. Zurich, Switzerlan c1910,
Construction: Varnished paper scales on 16cm dia. x 36.5cm long metal cylinder and on metal vanes on a sliding cylindrical sleeve. Metal support stand.
Scale: 80 rows of C & D scales equivalent to 16 meters in length.
Note: Formerly Julius Billeter Rechenwalze. This cylindrical slide rule has a metal support stand that could be wall mounted. Frequently used by European banks and accounting offices.
Archive - Ed Chamberlain Collection


REF National Rechenwalze System Billeter Modell No20 1918 Cylindrical Slide Rule
National Rechenwalze System Billeter Modell No20 1918 Cylindrical Slide Rule
Made in Switzerland by National Rechenwalzen. Zurich, Switzerlan. Alleinige Fabrikanten, Switzerland c1920,
Construction: Varnished paper scales on 20.5cm dia. x 57cm long metal cylinder and on sliding cylindrical cage. Metal support stand.
Scale: 80 sections of C & D scales equivalent to 20 meters in length.
Note: Formerly Julius Billeter Rechenwalze. This cylindrical slide rule has a metal support stand that could be wall mounted. Commonly used by European banks for currency trading. This is a previously unknown size. The largest previously known National cylindrical slide rule had a 16-m scale length.
Archive - Ed Chamberlain Collection

C.O. Browne, Melbourne, Australia



C.O. Browne Cylindrical "Long Scale Rule"

REF
C.O. Browne Cylindrical "Long Scale Rule"
Made in Australia by C.O. Browne. , No. F.C.46
Diameter 3", length 13" closed, 18" maximum
Similar construction to Fuller Cylindrical Slide Rules.
The single helical scale is marked on a cylinder about 2-3/4" in diameter and 4-1/2" long. The scale makes 50 turns around the cylinder, for a total length of 413" (34 feet, or 10.5 metres). It is marked to 4 significant figures at the top end, and can be read to 1 part in 20000. The inner core of the rule is covered with tables of constants, formulae, and conversion factor
Scan provided by John Wolff. Australia

Air Ministries Laboratory (AML) Bygrave


GB162895A
In 1920 Capt. Leonard Charles Bygrave of the Royal Air Force patented (GB162,865A) a slide rule design in which the scales formed helices wrapped around concentric telescoping tubes. This allowed the scales to be made sufficiently long (nearly 8 meters) to obtain the required calculational accuracy. Bygrave's method for solving the navigational triangle involves splitting it into two right triangles and applying Napier's rules. The required operations can then be reduced to a series of multiplications and divisions of the trigonometric functions of the relevant angles. By suitable rearrangement these can all be written in terms of cosines and cotangents, or equivalently secants and tangents, The Bygrave slide rule scales are the logarithms of these functions. Versions of the Bygrave slide rule were produced in Germany and Japan both for marine and aerial use. In German versions, a mechanism that allowed the sliding scale tubes to be locked to together during calculations was introduced.

See "Bygrave Scales" by Robin G. Stuart, 2014 for making your own Bygrave scales.



AML Bygrave Position Line Slide Rule Mark II

REF
AML Bygrave Position Line Slide Rule Mark II
Invented by Leanord Charles Bygrave in 1921. Made in England by the Air Ministries Laboratory
Bygrave scales. See Reference: "PositionLineSlideRules" By Ronald W.M. Riet ©2008"
Archive - Smithsonian Air And Space Museum, Science Museum of London.




AML Bygrave Position Line Slide Rule Mark IIA

REF
AML Bygrave Position Line Slide Rule Mark IIA
Invented by Leanord Charles Bygrave in 1921. Made in England by the Air Ministries Laboratory
Bygrave scales. See Reference: "PositionLineSlideRules" By Ronald W.M. Riet ©2008"
Archive - Anderson and Garland auction


Höhenrechenschieber (Dennert & Pape) Bygrave (German version)


German MHR1 Bygrave Position Line Slide Rule For Navigation

REF
German MHR1 Bygrave Position Line Slide Rule For Navigation
Made in Germany by Dennert & Pape.

Also See: Reference: "PositionLineSlideRules" By Ronald W.M. Riet.2008"
Archive - Ebay Photos

See A reproduction of the German MHR1 Position Line Slide Rule


Bygrave (Japanese version)


Japanese WWII Navy Bygrave Position Line Slide Rule For Navigation

REF
Japanese WWII Navy Bygrave Position Line Slide Rule For Navigation
Made in Japan - cWWII - Japanese copy of Bygrave slide rule

Also See: Reference: "PositionLineSlideRules" By Ronald W.M. Riet.2008"
Archive - Ebay Photos


Keuffel & Esser

The 4012 and 4013 are cylindrical slide rules designed by Edwin Thacher in the late 1800s. It was patented in 1881. In 1891 K&E purchased the rights to the patent and began producing it. The rule is a series of segmented B, C, & D scales arranged on a rotating cylinder. The 4012 is the basic rule. The 4013 is a 4012 with a magnifying glass mounted on it.
The rule was produced by K&E from 1891 to 1952. There were 3 variations in the construction methods over the life of the product:
Note: Thacher's spiral slide rules were rebranded by K& E Models Type I: 1740N, 1740, 1741 (1887-1900); Type II: 4012, N4012, 4013, N4013 (1900-1952) .
Type I ---- Model numbers 1740 and 1741 produced from 1891 to 1899.
Type II --- Model numbers 4012 and 4013 produced from 1900 to 1927.
Type III -- Model numbers N4012 and N4013 produced from 1927 to 1942. The N4012 continued on till 1952. Scale numbering was added to the end of the scales.


K&E 4012 Thacher's Calculating Instrument

REF
K&E 4012 Thacher's Calculating Instrument
Made in USA - Designed by Edwin Thacher
Archive - Michael O'Leary Collection (USA)


LOGA
Daemon-Schmid, Uster near Zurich, Switzerland.

Heinrich Daemen-Schmid(18?? - 19??) emigrated from Germany to Zurich, Switzerland, and produced cylindrical slide rule calculators with the Loga Calculator company from 1900. Circular (Disks) and cylindrical (roller drum) slide rules were made by the company Billeter, Daemen-Schmid (Zurich, Switzerland), later renamed Loga (short for logarithm). Most of the cylindrical type were made in the 1930's and occupied a niche in the banking industry, while other manufacturers were making linear slide rules. The company stopped production soon after WWII.
The indication of the meter length refers to the total length of the individual stripes on the cylinder. The longer, the more exact the calculations. There were models of 1.2 m, 2.4 m, 7.5 m, 10 m, 15 m and 24 m. The 24 m type was the most accurate slide rule in the world with an accuracy of 5 to 6 decimal places, and cost 1921 Fr. 1000. A simple 1.2 m hand model was available for Fr. 110.

Note: A patent of Julius Billeter is indicated on several Loga models. However, the connection between the two remains unclear. The Billeter family believ ting machine, which is not true. It has been mentioned before in 1888 and has been developed and improved. ref: Loga Calculator (History) by Kecko. Production: From 1889 to 1903 in Zurich, from 1903 to 1915 in Zurich-Oerlikon and from 1915 to 1979 in Uster.

Daemon-Schmid
patents for
cylindrical
calculators:

CH45516 (1908),
CH59697 (1912),
CH70303 (1914),
CH75358 (1917),
CH84469 (1920),
CH86695 (1920),
CH93322 (1922),
CH100740 (1923),
CH106811 (1924),
CH115150 (1926),
CH129926 (1929),
DE221251 (1908),
US1036575 (1912),
US1219261 (1917)


Loga (Daemen-Schmid) 1.2 meter cylindrical (Hand Model)
ISRM 24.07.04.10
Loga (Daemen-Schmid) 1.2 meter cylindrical (Hand Model)
Made in Switzerland by Daemon-Schmid c1900
20 individual 12.5cm long scales. 64mm diameter x 175mm long drum.
Gift of Debra Dilatush. Ted Dilatush collection


Loga (Daemen-Schmid) 2.5 meter cylindrical

REF
Daemen-Schmid (Loga) 2.5 meter cylindrical
Made in Switzerland by Daemon-Schmid c1930
Archive - Herman's Slide Rule Catalogue


Loga (Daemen-Schmid) 7.5 meter cylindrical

ISRM (deaccessioned 11.15.2023)
Loga (Daemen-Schmid) 7.5 meter cylindrical
Made in Switzerland by Daemon-Schmid c1930


Loga (Daemen-Schmid) 7.5 meter cylindrical

REF
Daemen-Schmid (Loga) 7.5 meter cylindrical
Made in Switzerland by Daemon-Schmid c1930
Archive - Ed Chamberlain Collection


Loga Calculator (Daemen-Schmid) 15 meter cylindrical

REF
Loga Calculator (Daemen-Schmid) 15 meter cylindrical
Made in Switzerland by Daemon-Schmid


Daemen-Schmid (Loga) 24 meter cylindrical

REF
Daemen-Schmid (Loga) 24 meter cylindrical
Made in Switzerland by Daemon-Schmid 1915-1920
Paper faced aluminum drum
CD (100-1000) scales divided into 60 segments for a total length of 24 meter
Archive - Ed Chamberlain Collection
Galai Photo.


Loga Slide Rule

REF
Loga Slide Rule
Made in Switzerland - Paper and metal backing
Front Scale:
Zz(K1), A [ B, R, C ] D, Zz(K2)
Back Scale:
A [ B, R ] C, Currency Conversions
Archive Herman van Herwijnen's Slide Rule Catalogue


Loga Pocket Slide Rule

REF
Loga Pocket Slide Rule
Made in Switzerland - Paper and metal backing
Front Scale:
K, A [ B, R, C ] D, Log
Back Scale:
A [ B, R ] C, Currency Conversions
Archive Herman van Herwijnen's Slide Rule Catalogue

McFarlane, Glasgow, Scotland


McFarlane's 6 inch Calulating Cylinder (1835)
REF
McFarlane's 6 inch Calulating Cylinder (1835)
Made by McFarlane, Glasgow, Scotland. Mid 19th century
McFarlane's Calculating Cylinder" (c. 1833), consisting of a cylinder with three separate revolving parts, on which are inserted several series of numbers, calculated to propose and answer questions to an almost indefinite extent in the first four rules of arithmetic. Note that this device does not utilize logarithmic scales. Made of paper covered turned mahogany, 6 3/8" long overall x 2 1/4" diameter, in 3 sections plus 2 threaded end pieces. There are two columns on the top section, one column on the center section, and three columns on the bottom section. The apparatus is designed facilitate calculations in interest on English money. It is one of the earliest examples of a handheld cylindrical calculating device.
Archive - Images from 2009 Phillip Wiess Auction, London Science Museum Collection, Gemmary,com
1833 at NMSI.UK




Nestler 1.6m Cylindrical Rule (Rechenwalze)

REF
Albert Nestler 1.6m Cylindrical Rule (Rechenwalze)
Made in Germany - circa1930
Scale: C ( D ) = 1.6 meters long
Archive - Ed Chamberlain Collection


Albert Nestler 12.5m Cylindrical Rule (Rechenwalze)

REF
Nestler 12.5m Cylindrical Rule (Rechenwalze)
Made in Germany - circa1930
Scale: C ( D ) = 12.5 meters long
Archive - Ed Chamberlain Collection

Carbic Ltd., London

Cylindrical Pocket Slide Rule with Helical Scales
Scale effective length 66 in (168 cm) with 4 significant figures.

Otis Carter Formby King biography by Susan Richards

Known addresses of Carbic Ltd. (1921-1972):
0: 44 & 66 Bray's Lane, Coventry (1921)
A: "Ashdene," Emscote Road, Stoke, Coventry (1922)
1: 51 Holborn Viaduct, London, EC1 (c1940)
2: 137 Conway Road, London, N14
3: 171 Seymour Place, London, W1
4: 54 Dundonald Rd, London, SW19
(Addresses 0, 1, 3, and 4 are found
on instruction sheets or rules)
Patents
UK patent GB 183,723 (1921)
UK patent GB 207,762 (1922)
UK patent GB 207,856 (1922)
US patent US 1,645,009 (1923)
Canadian patent CA 241986
Canadian patent CA 241076
French patent FR569985
French patent FR576616
German patent DE 418814


Otis King Classification Types

There are 4 principle types, defined by Richard Lyon
A, B, C and D and a B/C Hybrid. See Richard Lyon's Website

Sketch from Colin Barnes article in JOS Vol 4 No 2

Patent UK183723 Issued Aug 3, 1922

Manual 8 Pages
(524Kb PDF)

Known Scale Sets: 409/410, 414/423, 416/417, 422/424, 429/430
Known Models: K, L, N.



REF Otis King Model K Cylindrical (Type A 1921-1923)
Otis King Model K Cylindrical (Type A)
Made in England - 66 inch scales for multiplication and division
Patents: UK 183723
Serial number:
Scales: 424 and 422
Archive - Ebay Photo
Leather Case


Otis King Model K Cylindrical (Type A 1940)

ISRM 14.01.03.03
Otis King Model K Cylindrical
Made in England - 24mm Dia. x 260mm Long, 66 inch scales
Patents: UK 183723
Serial number: 5673
Scales: 423 and 414
Snap Case


Otis King Model K Cylindrical (Type C 1960)

ISRM 11.12.29.01
Otis King Model K Cylindrical
Made in England - 24mm Dia. x 260mm Long, 66 inch scales
Patents: UK 183723
Serial number: V7554
Scales: 423 and 414
Manual PDF 21MB Leather Case


Otis King Model L Cylindrical (Type B 1960)

ISRM 11.12.29.02.X
Otis King Model L Cylindrical
Made in England - 24mm Dia. x 260mm Long, 66 inch scales
Patents: UK 183723
Serial number: Z2275
Scales: 429 and 430
Note: Came in Green cardboard box (missing top)

Otis King Type C Model K and L Instructions


R.H. Smith



R.H. Smith Cylindrical Slide Rule

REF
R.H. Smith Cylindrical Slide Rule
Helical scales
Made by J.H. Steward
Archive - Conrad Schure Collection

W.F. Stanley, Great Turnstile, Holborn, London

The company was founded in 1854 by William Ford Robinson Stanley (1829-1909). it became a limited company (corporation) in 1900. In 1861 Stanley invented a prize-winning straight-line dividing machine that was used to make accurate scales for slide rules and other mathematical instruments. Among the slide rules manufactured and distributed by the Stanley company were the C.T. Cooper slide rule and the Fuller spiral slide rule, designed by George Fuller in 1878. The H.O. Barnard's slide rule is from 1919. Included in Stanley's 1912 catalogue and continuing there until 1958 was Barnard's Coordinate calculator. It is very similar in construction to the Fuller instruments but its pointers have multiple indices so additional trigonometrical functions can be used. It cost slightly less than the Fuller-Bakewell and a 1919 example is held by the Science Museum, London. In 1962 the Whythe-Fuller complex number calculator was introduced. As well as being able to multiply and divide complex numbers it can convert between Cartesian and polar coordinates.

Note: Professor Fuller's spiral slide rules were rebranded by K& E Models 1742 (1887-1900) and 4015 (1900-1961).




Barnard's Co-ordinate Spiral Slide Rule

ISRM 24.06.10.01


Note: the LAT COS (Latitude) and DEP SIN (Departure) scale labels.
Barnard's Co-ordinate Spiral Slide Rule 1909 sn23
Made in United Kingdom Designed Henry (Henri) Osmand Barnard - (1869-1934). Geodesic engineer. M.S., A.C.H. and Fellow of the Royal Astronomical Society. He was a Superintendent Trigonometrical Surveys, Ceylon (now Sri Lanka) Survey Department. Made by W.F. Stanley & Company See more of his biography in the SR Who's Who page
Description from 1914 catalogue: The Co- ordinate Spiral Slide Rule has been designed to meet these requirements by Mr. H. O. Barnard, Like Professor Fuller's rule, upon which it is an improvement, it enables the user to perform Barnard's co-ordinate spiral slide rule.with speed and accuracy arithmetical computations involving multiplication, division, proportion, continuous fractions, powers, roots, and logarithms ; but in addition, the natural and logarithmic values of trigonometrical functions of any angle can be determined by inspection with the same accuracy as in numerical computation, while the products, quotients, etc. , of these functions, by lengths or numbers, integral or fractional, are obtained with equal ease, rapidity and precision . The scope of its operations will be gathered from the examples which are given to illustrate its use in the instructions supplied with the rule. Although the co-ordinate spiral rule, as all varieties of slide rules, is based primarily upon the theory of logarithms, a knowledge of that theory is by no means essential to its practical use.


Original owner: Dr Garry J. Tee, (1933-18Feb2024), Professor Emeritus (1968) Department of Mathematics, University of Auckland, New Zealand.
Gift facilitated by the Powerhouse Museum, Sydney, Australia with permission from Dr. Tee.
Prof. Dr Garry J. Tee, (1933-18Feb2024)(B.Sc. 1952, M.Sc. 1954). grew up during the 1930s Great Depression and in the South Island railway camps of that era. After Garry Tee graduated from Auckland University College as M.Sc. (N.Z.), his first job was as a computer, with an oil prospecting team in northwest Australia. In 1958, human computers began to be supplemented by electronic computers in geophysics, and it was obvious to him that electronic computers were going to become extremely important. Accordingly, he went to England, where he became a mathematician in English Electric Company, which manufactured DEUCE computers (based on Alan Turing's design for ACE). From 1964 to 1968 he was a foundation member of the Department of Mathematics at the University of Lancaster, and then he returned to the Department of Mathematics at the University of Auckland. He has published on numerical analysis and on the history of science, and he has translated books and papers on numeric analysis from Russian to English. Full Obituary



Professor Fuller's Calculating Slide Rule

ISRM 12.01.03.01.X

Professor Fuller's Calculating Slide Rule
Made in United Kingdom by W.F. Stanley & Company - Designed by Prof. George Fuller in 1878.
Original owner in UK
Description from 1912 catalogue: "Professor Fuller's Calculating Slide Scale, the most accurate od all calculating scales, is equal to a straight slide rule 83 feet long, and gives logarithm, multiplication, division, proportion, etc., results in four or five figures. Its range is greater than that of most arithetical machines, as besides the operationsof multiplication and division which many instruments can only perform, results requiring the reciprocals, powers, roots or logarithms of numbers can be quickly and easily obtained by its use. Largely used by civil, electrical, and mechanical engineers, actuaries, quantity surveyors, etc. In mahagonay case with instructions for use."

Elizur Wright Arithmeter
Made by Joseph W. Fowle, USA, 1869

Elizur Wright III (1804-1885), born in South Canaan, Connecticut, was an American mathematician and abolitionist. He was a graduate of Yale College. He is sometimes described in the United States as "the father of life insurance", or "the father of insurance regulation", as he campaigned that life insurance companies must keep reserves and provide surrender values. Wright served as an insurance commissioner for the Commonwealth of Massachusetts. He devised a new formula and created actuarial tables to help insurance companies set premiums. finding the values of policies of various terms, known as the “accumulation formula,” and, in order to facilitate his work, invented and afterward patented (1869) the “arithmeter,” a mechanical contrivance for multiplication and division, based on the logarithmic principle, a form of cylindrical slide rule. U.S. Patent 93,849 issued August 17, 1869. wikipedia.


Wright's Arithmeter No. 8 Cylindrical Slide Rule

REF
Wright's Arithmeter No. 8 Cylindrical Slide Rule
Made by Joseph W. Fowle, USA, 1869
Materials" Brass and wood. Paper scales on a brass drum.
Dimensions of Instrument: 36 cm x 48.2 cm x 48.2 cm; 14 3/16 in x 18 31/32 in x 18 31/32 in
Note: Wright sold the Arithmeter to insurance companies for $500.00, though only about 20 were made.

Archive - National Museum of American History

Wright's Arithmeter No.11 Cylindrical Slide Rule

REF
Wright's Arithmeter No.11 Cylindrical Slide Rule
Made by Joseph W. Fowle, USA, 1869

Archive - Computer History Museum in Mountain View, California

Copyright © 2003-
International Slide Rule Museum