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Unique Slide Rule Company (U.S.R.C.)
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The British UNIQUE brand of slide rules was founded in 1920 by Burns Snodgrass (1886-1954) M.B.E, A.R.C.Sc., a mechanical engineering lecturer at Brighton Technical College. Unique specialized in a wide range of wood slide rules with celluloid covered paper scales and were most popular within the United Kingdom, and its colonies. The manufacturing process used fairly basic woodworking tools and printing presses, unlike their high end competitors which had mechanical tooling to make machine divided scales. This made possible relatively inexpensive slide rules that could also be customized to a broad spectrum of industries. The first Log Log slide rules were made around 1928-1929 and sold for 12 Shillings in 1931. Burns made these by himself on a part time basis until 1935, where he added a couple of employes, along with his son. In 1945, the last year of WWII, they sold 100,000 slide rules. In 1951 they became the Unique Slide Rule Company, Limited. Burns Snodgrass was also the author of Teach Yourself the Slide Rule ©1955 which was published in 1955, one year after his death. The book was popular for use in many schools and with other makers, although the graphics referred only to the UNIQUE brand. In 1954, The company was subsequently managed by his son, Donald Clayton Snodgrass. After an illness in 1981, Donald retired and his wife, Elain Snodgrass, took over as Managing Director. Various relatives worked in many aspects of the company making this a classic family business, much like all the other silde rule companies. It is estimated that they sold more slide rules in the UK more than any other maker, 2.5 million or more. In spite of their cheapness, older wood versions have survived in large numbers. They invested in all plastic slide rules in the early 1970's but found themselves, like other slide rule makers, obsoleted by the electronic calculator, and stopped production in 1975. They continued manufacturing other mathematical instruments as "Unique Instruments Limited" up until 1993 when Donald Snodgrass died.

Teach Yourself the Slide Rule ©1955 (45.78MB PDF scan) is available in the ISRM Library.



Unique "Junior" Code J - Training Slide Rule
ISRM 22.03.01.94		 Unique "Junior" Code J - Training Slide Rule
Made in England by Unique Slide Rule Company (USRC)
Front Scale (unconventional): A [ B, C ] D
Back: Blank
Note: Each scale on left has explanation steps. "THIS TIMES (number on Scale A) THIS (number on Scale B), MAKES EITHER THIS (number on Scale C) OR THIS (number on Scale D)".
Gift Of Philip E. Stanley, Worcester, Mass


Unique "Craft" Cost of Lumber Slide Rule
ISRM 22.03.01.96		 Unique "Craft" Cost of Lumber Slide Rule
Made in England by Unique Slide Rule Company (USRC)
Front Scale: Cost(A) [ Price per Square Foot(B), Width(C) ] Length(D), Square Feet
Back: Blank
Gift Of Philip E. Stanley, Worcester, Mass


Unique "Florida" No.F5 Slide Rule
ISRM 22.03.01.95		 Unique "Florida" No.F5 Slide Rule
Made in England by Unique Slide Rule Company (USRC)
Front Scale: A [ B, CI, C ] D, K
Well: Decimal Equivalents
Back: Trigonometrical Ratios
Gift Of Philip E. Stanley, Worcester, Mass


English Mini-Rule
REF P020		 English Mini-Rule
Made in England
Front Scale: A [ B, CI, C ] D, K
Back: Blank


Unique Universal I
REF P013		 Unique Universal I
Made in England
Front Scale: LU, S, A [ S, R, C ] D, T, LL
Back: Blank


Unique Log-Log
REF P009		 Unique Log-Log pocket
Made in England
Front Scale: LU, A [ S, R, C ] D, LL
Back: Table of Trig Ratios


Unique Log-Log
REF P202		 Unique Log-Log pocket
Made in England by Technical Supplu Co., Brighton
Front Scale: LU, A [ S, R, C ] D, LL
Back: Table of Trig Ratios


Unique Concrete Calculator
REF P010		 Unique Concrete Calculator - pocket
Made in England
Front Scale: A(thickness) [ B(height), C(length) ] D (volume)
Back: Adv: Ready Mix Concrete


Unique Five-Ten
REF P199		 Unique Five-Ten
Made in England
Front Scale: Note scales wrapped to double the length to 10 inches
A1, D1 [ C1, L1 | L2, C2 ] D2, A2
Back: Table of Trigonometrical Ratios


Unique Five-Ten (Late model)
REF 		Unique Five-Ten (Late model)
(Note: Later model, no nails to hold laminate)
Made in England
Front Scale: Note scales wrapped to double the length to 10 inches
A1, D1 [ C1, L1 | L2, C2 ] D2, A2
Well: Decimal Equivalents of Fractions
Original Owner/Location: John Sykes/England
Archive - Scan donated by John Sykes (UK)


Unique (Mannheim) Lietz 2975
ISRM 12.03.02.19		 Unique (Mannheim) Lietz 2975
Made in England by U.S.R.C.
Front Scale:
A [ B, CI, C ] D, K
Back Scale: [ S, L, T ]
Well:Decimal Equivalents of Fractions
Donated by Richard Davis, Las Vegas, Nevada
Richard is a retired Electronics Engineer in the semiconductor industry. He is a collector and Fellow of the Oughtred Society.Collects most all slide rules, has a comprehensive collection of Reiss mill finish aluminum slide rules, but prefers the spiral scale cylindrical versions. He has donated many slide rules to support the ISRM Slide Rule Loaner program.


Unique Dualistic High Speed Slide Rule
ISRM 14.11.14.01		 Unique Dualistic High Speed Slide Rule
Made in England
Front Scale: Note scales wrapped to double the length to 20 inches
P1, D2 [ C2, Q1, Q2 ] C1, D1, P2
Back Slide: [ LL1, LL2, LL3 ] Back: Table of Trigonomertric Ratios


Unique Ten-Twenty Slide Rule (w/rivets)
ISRM 14.07.02.08		 Unique Ten-Twenty Slide Rule (w/rivets)
Made in England. Laminations riveted to stock
Front Scale: Note scales wrapped to double the length to 20 inches
A1, D1 [ C1, L1 | L2, C2 ] D2, A2
Back: Equivalents, rates of exchange and material properties
Gift of Ed Millis, Dallas, Texas


Unique Ten-Twenty Slide Rule
ISRM 17.05.02.13		 Unique Ten-Twenty Slide Rule
Made in England
Front Scale: Note scales wrapped to double the length to 20 inches
A1, D1 [ C1, L1 | L2, C2 ] D2, A2
Back: Equivalents and material properties
Gift of Mike Weaver, UK


Unique J180
REF P011		 Unique J180
Made in England - 9" long
Front Scale: K, A [ B, CI, C ] D, S, T, STR
Back: Blank


Unique Universal
ISRM 22.06.01.03		 Unique Universal
Made in England - Tacked laminate, formed plastic cursor blocks
Front Scale: LU, S, A [ B, CI, C ] D, T, LL
Back: Trig Identities
Original Owner/Location:
Gift of Ron Gribnitz of South Africa


Unique Universal
ISRM 17.05.02.09		 Unique Universal
Made in England - Tacked laminate, formed plastic cursor blocks
Front Scale: LU, S, A [ B, CI, C ] D, T, LL
Back: Trig Identities
Original Owner/Location: Lawrence Williams/Tynant,
Gift of Mike Weaver, UK


Unique Universal I (1939)
ISRM 23.10.26.01.X
 Unique Universal I (1939)
Made in England - Tacked laminate, Plastic frame cursor
Front Scale: LU, S, A [ B, R(CI), C ] D, T, LL
Back: Trig Identities
Original Owner: Robert Chester, of England. 1921 - 1987
Gift Of Simon Chester of Toronto, Canada, son of Robert Chester

Robert Chester 1921-1987 purchased this slide rule in 1939 in London,preparing to study mathematics at Oxford University. He was recruited from his course in 1941 to join the Royal Air Force. He worked on telecommunications in England, North Africa, Italy and France. He carried his slide rule in his knapsack. After WWII Robert used his slide rule during his career at Proctor and Gamble. He gave it to his teenage son, Simon in the sixties who again used it at Oxford and in graduate studies in North America.



Unique Universal I
ISRM 20.08.07.02		 Unique Universal I
Made in England - Tacked laminate, Plastic frame cursor
Front Scale: LU, S, A [ B, R(CI), C ] D, T, LL
Back: Trig Identities
Original Owner/Location: M.J. Williams
Gift Of Philip Rodley, Upperhutt, NZ


Unique Universal One - Modern Logo
ISRM 22.08.04.01

 Unique Universal One - Modern Logo
Made in England - Wood stock, plastic laminate.
Front Scale: LU, S, A [ B, CI, C ] D, T, LL
Back: English/Metric Conversion Factors
Gift Of Roy and Jackie Thurley of Liandudno, North Wales, UK
Roy obtained this slide rule when he was at Mitchum County Grammar School for Boys in Mitcham, Surrey, England. He took his General Certificate of Education (GCE) Ordinary Levelel examinations in 1962 at age 15. His 'O' levels included mathematics, physics and chemistry. In 1963 he obtained two more 'O' levels in Pure Mathematics and Applied Mathematics. In 1964 he obtained Advanced Level passes in pure Maths, Applied Maths, Physics and Chemistry. The photograph was of Roy as a student in 1965 at the University of Kent at Canterbury where his interest was in computers. However the computer never arrived at the university so he was shifted to studying statistics. He dropped out of school and found clerical work at Wandsworth Borough Council in London, and eventually found his way into the computer section.which culminated a long career in computing. He retired with his wife in Liandudno, North Wales, UK.


Unique Universal One - Modern Logo (Ver 2)
REF		 Unique Universal One - Modern Logo (Version 2 label)
Made in England - Wood stock, plastic laminate. Revised back label
Front Scale: LU, S, A [ B, CI, C ] D, T, LL
Back: Mensuration Conversion Factors, English/Metric Conversion Factors, Atomic Weights, General Data, Material Densities
Imagery of variation provided by Roy Thurley of the UK


Unique Universal II
REF S062		 Unique Universal II
Made in England - Tacked laminate
Front Scale: LU, A [ B, S, T, C ] D, LL
Back: Trig Identities


Unique Universal II
REF S063		 Unique Universal II
Made in England - new cursor, no tacks
Front Scale: LU, A [ B, S, T, C ] D, LL
Back: Trig Identities


Unique Universal Two
REF S272		 Unique Universal Two (Modern)
Made in England - new cursor, new logo
Front Scale: LU(LL2), A [ B, S, T, C ] D, LL(LL3)
Back: Trig Identities


Unique Log Log
REF S126		 Unique Log Log
Made in England - Note riveted reingorcement on scale
Front Scale: LL2, A [ B, C] D, LL3
Back: Trig Identities
Owners: J.D.Freeman/The College at Marlborough England
Owners: Sidney Sussex/Cambridge College, England


Unique Log Log
ISRM 14.10.14.01		 Unique Log Log
Made in England - Note riveted reingorcement on scale
Front Scale: LL2, A [ B, C] D, LL3
Back: Trig Identities
Owners: H.G. Millhouse of England
Instructions - All Models (24.46MB PDF)


Unique Log Log (Modern)
REF S271		 Unique Log Log (Modern)
Made in England - new cursor, new logo
Front Scale: LU(LL2), A [ B, C] D, LL(LL3)
Back: Trig Identities
Owners: New


Unique Brighton
ISRM 17.05.02.12.X		 Unique Brighton
Made in England by USRC
Front Scale: 25.4mm // K, A [ B, CI, C] D, L, P || S, T
Back Scale: LL1, LL2, LL3
Well: Decimal Equivalents
Back: Trig Identities
Owners: R.N.Miles (on stock)
Gift of Mike Weaver, UK


Unique Commercial
REF S484		 Unique Commercial
Made in England
Front Scale: H, K, M [ N (Discounts Scale), R(CI), C] D, U, V
Back: Table for converting shillings and pence into pounds


Unique Electrical
ISRM 11.10.26.04
Roman Russek was known for his wide knowledge of power cables and, in later years, for his expertise the transfer of technology within international joint ventures. At the close of WWII Roman was a member of the Polish Army under British command. With Communism descending on his homeland his left to study in Britain where he earned engineering degrees from Heriot Watt University (Edinburgh) and London University. By 1949 he was a Scientific Officer in the Wood Lane Research Laboratories of British Insulated Callenders Cables in London. Continued on right 		Unique Electrical
Made in England
Front Scale: LL2, Fahr, DF [ CF, CI, C ] D, Cent, LL3
Back: Specific Resistance & Temp Coeff. Table of Metals
Owned by Roman Marian Russek (1933-2011). Donated by his wife, Shiela Russek, Toronto, Canada.
Cont'd There he was assigned to teams studying the mechanical behavior of aluminum sheaths, electrical characteristics of oil impregnated paper as well as assisting in the development of flexible joints for submarine cables destined to be used in the HVDC link between North and South Island in New Zealand. As Design Engineer and then Department Manager Roman traveled widely within Canada and internationally representing CWC in many negotiations and discussions with customers and associated firms. He was fluent in five languages. Later as Vice-President Technical Services Roman spent another 14 years transferring technology from the domestic company to the many fledgling associate companies in Mexico, Colombia, Venezuela, Dominican Republic, Ireland, Spain, Brazil. South Africa, Nigeria, New Zealand, Australia and Iran. Roman and his wife Shiela spent much of their retirement years traveling around the world.

An Article about Roman Russek by his friend XAVIER KATAQUAPIT



Unique Electrical
REF S413		 Unique Electrical
Made in England
Front Scale: LL2, Fahr, DF [ CF, CI, C ] D, Cent, LL3
Back: Specific Resistance & Temp Coeff. Table of Metals


Unique Electrical
REF 		Unique Electrical (modern cursor)
Made in England
Front Scale: LL2, Fahr, DF [ CF, CI, C ] D, Cent, LL3
Back: Specific Resistance & Temp Coeff. Table of Metals
Archive - Atsushi Tomozawa Collection


Unique Navigational Slide (c1960)
REF		 Unique Navigational Slide Rule
Made in England
Front Scale: 1:1000000 || S, A [ B, S, T, C] D, T || 1:500000
Back: Tables and factors used in navigation and windspeed calculations.
Archive - Scan By Steve Seale Collection


Unique Tubemaking And Deep Drawing
REF S540		 Unique Tubemaking And Deep Drawing - 1952
Made in England by Unique for Tube Investments, Ltd.
Departsments of Development and Research and of Plant and Construction
Front Scale: MM, R1 [ R2, TH(1G-21G), TH(22G-44G), TH(33-314), C ] D, WT (Mild Steel)
Back: Weight Conversion Factors, Given Steel=1.000
Ad


Unique Study 500
ISRM 11.12.09.01		 Unique Study 500
Made in England by Unique Slide Rule Co.Ltd. Newhaven Sussex
Front Scale: K, A [ B, CI, C ] D, S, T
Back: Blank
Donated by Ted Hume of San Angelo,Texas.
Ted is a retired structural engineer. In the past, when actively collecting and selling, Ted specialized in Post slide rules, his favorite being the Versalog. Co-author, Post Slide rule Archive. Editor and contributing author of the The Oughtred Society Slide Rule Reference Manual. Editor of Joe Soper's book K&E Salisbury Products Division Slide Rules.He received the 2010 Oughtred Society Award 2010 and is a Fellow of the Oughtred Society and past OS director. Supporter and advisor to the ISRM curator.
Copyright © 2003-2018 International Slide Rule Museum
ting author of the The Oughtred Society Slide Rule Reference Manual. Editor of Joe Soper's book K&E Salisbury Products Division Slide Rules.He received the 2010 Oughtred Society Award 2010 and is a Fellow of the Oughtred Society and past OS director. Supporter and advisor to the ISRM curator.
Copyright © 2003-2018 International Slide Rule Museum