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Lawrence Engineering Service

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1935 - Wabash, Indiana, 1938-1947 - Peru, Indiana A 10 person shop owned by George Lee Lawrence and Vivian C. Lawrence After a divorce became Engineering Instruments, Inc. 1947-1967 Peru, Indiana Owned by Vivian C. (was Lawrence) Bozarth and Frank H. Bozarth For an in-depth historical account, read David Rance's The Unique Lawrence (v9) originally published in the Proceedings of the IM2011 hosted by the Oughtred Society. and currently updated.

George Lee Lawrence with third Wife Nellie Mowbray 1960

Lawrence Pocket (5-B) P001	Lawrence Pocket (5-B) - 1964 Made in USA Front Scale: A [ B, CI, C ] D, K Back: Blank Scans and Photos Contributed by Vern Estes. This model was sold for $.40 each in the 1964 Estes Industries Model Rocketry Catalog. Vernon Estes founded the company on encouragement from G. Harry Stine, who founded the National Association of Rocketry (NAR) in 1958. Many rocketeers (including the ISRM Curator) were introduced as teenagers to slide rules through the Estes Technical Reports to calculate model rocket performance.
Lawrence 6-0p Flashrule GE & Westinghouse Lamps P173	Lawrence 6-0p Flashrule GE & Westinghouse Lamps Made in USA - (c)1946 Front Scale: ASA [ Shutter speed (5 scales), Feet ] F stop Back: Instructions
Lawrence 6-Ow Flashrule Wabash Lamps REF	Lawrence 6-Ow Flashrule Wabash Lamps Made in USA - Wabash, Ind. - 1935-1937 Front Scale: A [ B, C ] D Back: Conversion Chart Archive - Scan donated David Rance Collection Sassenheim, The Netherlands
Lawrence 8-A Basic Mannheim ISRM 24.07.04.53.X	Lawrence 8-A Basic Mannheim Made in USA - Wabash, Ind. - 1935-1937 Note: the difference between the 8-A and 8-B is the CI scale added to the 8-B, which is the most common. The 8-A is actually rare. Front Scale: A [ B, C ] D Back: Conversion Chart Tom Dilatush Collection, Paradise, UT
Lawrence 8-B Mannheim (1947) ISRM 12.04.03.01	Lawrence 8-B Mannheim Made in USA - Wabash, Ind. - 1938-1947 Front Scale: A [ B, CI, C ] D, K Back: Conversion Chart Original Owner (written in well): Mary Elizabeth Exley, A-7, a relative of the donor. Gifted to ISRM by Henry Eck, of Catonsville, Maryland. 1939 Instructions (12.5MB PDF) - Manual gifted to ISRM by Mark Hornung, Minneapolis, Minnesota, who found this in his parent's home
Lawrence 8-B Mannheim (1947) ISRM 13.00.00.82	Lawrence 8-B Mannheim Made in USA - Wabash, Ind. - 1938-1947 Front Scale: A [ B, CI, C ] D, K Back: Conversion Chart Belonged to Mike Konshak in 1961 when he was 14 years old Mike, who happens to be the ISRM Curator, used this slide rule to calculate model rocket altiudes in Colorado with the National Association of Rocketry. His membership is NAR 896. and attended NARAM 2 and NARAM 3 held in Colorado Springs, Colorado. 50 years later, he was the Contest Director for NARAM 52, also held in Colorado. Read Mike's article Slide Rules For Rocketeers (1.14MB PDF) written by Mike that was published in the Journal of the Oughtred Society. 2008 Vol 17.1.
Lawrence 8-B Mannheim Dumont S499	Lawrence 8-B Mannheim Dumont Made in USA by Lawrence for Dumont, Zanesville, Ohio Front Scale: A [ B, CI, C ] D, K Back: Conversion Chart
Lawrence 8-L Copper Wire Selector ISRM 18.04.06.61	Lawrence 8-L Copper Wire Selector Made in Peru, Indiana, USA - Copyright 1946, Uses 1946 National Electrical Code (NEC) Note: Same scales as Voltage Drop Motor Wiring slide rule Front Scale: Length of Wire, Distance to Load [ Load (Amperes), Voltage Drop % 440V,220V, 32V, 110V ] Cu Wire Size (AWG) Back: Motor and Wire Data Gift of Leroy Hausler Collection
Lawrence 8-L Simple Voltage Drop Calculator ISRM 20.09.11.01	Lawrence 8-L Simple Voltage Drop Calculator Made in USA - (c)1946 Front Scale: Distance to Load [ Load (Amperes), Voltage Drop % ] Cu Wire Size Back: Motor and Wire Data Gift Of Joseph L. Krause
Lawrence 8-L Simple Voltage Drop Calculator ISRM 22.03.01.110	Lawrence 8-L Simple Voltage Drop Calculator Made in USA by Lawrence Engineering Services, Peru, Indiana. (c)1946 Made for: The George Worthington Co. Electrical Division. Front Scale: Total Length of Wire, Distance to Load [ Load (Amperes), Voltage Drop % (32V, 440V, 220V, 110V) ] Copper Wire Size, A.W.G. Back: General Data, Motor, current and Wire Data Original owner (name on stock): K.C. Miller Gift Of Philip E. Stanley
Lawrence 9-K Music Transposer REF	Lawrence 9-K Music Transposer Made in USA - by Lawrence, Peru, Ind.- Copyright 1946 Front Scale: Semitone Count, Chromatic Notation [ Chords: Major, Minor, Augmented, Diminished ] Chromatic Notation/Subscript, Piano Key Back of Slide: Not shown Back: Not shown Well: Not shown Archive - Scan donated David Rance Collection Sassenheim, The Netherlands
Lawrence Music Note Transposing REF	Lawrence Music Transposing Made in USA - by Lawrence, Peru, Ind.- Copyright 1948 by Thomas Front Scale: Position for Harmony, Position for Transposing [ Interval, Music Notes] Music Notes (Diminished), Music Notes Back of Slide: Not shown Archive - Scan donated David Rance Collection Sassenheim, The Netherlands
L.E. Waddington Musicians Rule S322	L.E. Waddington Musicians Rule Made in USA - by Lawrence, Peru, Ind.- 1947 Front Scale: Semitone Count, Chromatic Notation [ Chords: Major, Minor, Augmented, Diminished ] Chromatic Notation/Subscript, Piano Key Back of Slide: Interval Ratios, Harmonic Series, Octaves Back: Subscript Notation, Instrument tables Well: Reference Frequency
Lawrence 10-B ISRM 12.03.21.04	Lawrence 10-B - c1942 Made in USA - Peru, Ind. Front Scale: A [ B, CI, C ] D, K Back: Conversion Chart Note: Front side painted, Back screened on bare wood. Donated by Henry (Hank) Benoit, Kingston, Ontario, Canada See Hank's picture and bio with his personal slide rules in the Aristo 0970 Multilog and 870 (pocket) Multilog in the Aristo Gallery and the Faber-Castell 989 Complex Slide Rule in the Faber-Castell Gallery.
Lawrence 10-B (white back) ISRM 14.07.02.56	Lawrence 10-B - c1942 Made in USA by Lawrence Engineering Service,Peru, Indiana. Note: 8-B graphics on back which shows Wabash, IND. Both sides painted before screening text. Front Scale: A [ B, CI, C ] D, K Back: Conversion Chart Gift Of Ed Millis, Dallas, Texas
Lawrence 10-B (unpainted back) ISRM 14.07.02.56	Lawrence 10-B - c1942 Made in USA by Lawrence Engineering Service,Peru, Indiana. Note: Front side painted. Full length conversion table Front Scale: A [ B, CI, C ] D, K Back: Conversion Chart Gift Of Ed Millis, Dallas, Texas
Lawrence 10-B S029	Lawrence 10-B - Glass Magnifying Cursor c1940 Made in USA - Peru, Ind. Front Scale: A [ B, CI, C ] D, K Back: Conversion Chart Note: This glass magnifying cursor is very rare and was later replaced by an injection molded plastic magnifier. The molding machines were not transferred to Engineering Services after the 1947 Divorce settlement.
Lawrence 10-B Magnifying Cursor ISRM 11.11.05.02	Lawrence 10-B - Plastic Magnifying Cursor c1942 Made in USA - Peru, Ind. Front Scale: A [ B, CI, C ] D, K Back: Conversion Chart (Black Ink on Wood)
Lawrence 10-B Flat Cursor Lens ISRM 18.12.30.16	Lawrence 10-B - Flat Cursor Lens c1944 Made in USA - Peru, Ind. Scales are silkscreened with Blue Ink on White Lacquer Front Scale: A [ B, CI, C ] D, K Back: Conversion Chart (Blue Ink on White Lacquer) Note: Back is painted white before equivalents silkscreen was applied Gift Of Peter Eickenberry
Lawrence 10-B Magnifying Cursor ISRM 11.03.23.01	Lawrence 10-B - Plastic Magnifying Cursor c1944 Made in USA - Peru, Ind. Scales are silkscreened with Blue Ink on White Lacquer Front Scale: A [ B, CI, C ] D, K Back: Conversion Chart (Blue Ink on White Lacquer) Note: Back is painted white before equivalents silkscreen was applied Donated by David Sweetman
Lawrence 10-B Magnifying Cursor 8-B Artwork (rare) ISRM 14.07.02.55	Lawrence 10-B - Plastic Magnifying Cursor c1944 (rare production run) Made in USA - Peru, Ind. Front Scale: A [ B, CI, C ] D, K Back: Conversion Chart (Blue Ink on White Lacquer) Note: Back is painted white before 8-B equivalents silkscreen was applied. Artwork shows Wabash, IND. rather than Peru, Indiana. Donated by Ed Millis, Dallas, Texas
Lawrence 10-C Engraver's and Photographer's Proportional Calculator ISRM 13.06.10.01	Lawrence 10-C Engraver's and Photographer's Proportional Calculator Made in USA by Lawrence Engineering Service, Wabash, Ind. - circa 1946 Note: Typo in brand name Lawrence "Enginering" Service Front Scale: Original Size) [ Copy Size, % Size ] % Area Gifted by Judy Gorin of St. Louis, Missouri, daughter of Charles Meyerson Charles B. Meyerson worked for Einson & Freeman Advertising Agency in Long Island City, NY from 1950-1953. He used the proportion calculator/slide rule for print ads/photos in newspapers, magazines and pamphlets they developed. Mr. Meyerson was a docent at the St. Louis Zoo for over 15 years and a member of the 1904 St. Louis World's Fair Society. He died in St. Louis in 2009.
Lawrence 10-C Engraver's and Photographer's Proportional Calculator REF	Lawrence 10-C Engraver's and Photographer's Proportional Calculator Made in USA by Lawrence Engineering Service, Wabash, Ind. - circa 1946 Note: Typo in brand name Lawrence "Enginering" Service Front Scale: Original Size) [ Copy Size, % Size ] % Area Back Adv: Philips & Jacobs Chemicals Archive - Scan provided by Barry Mcallister
Lawrence 10-D American Lumberman (1935) ISRM 21.11.03.02 Note: This slide rule is assumed to be part of a promotional give-a-way to subscribers of the magazine, c1935-1940	Lawrence 10-D American Lumberman (established 1873) Made in USA by Lawrence for the American Lumberman (trade Journal), Chicago, Illinois. Front Scale: Thickness in inches [ Width in inches, Length in feet ] Board Feet Back Table: Average weight in pounds per cubic foot of commonly used lumber (12% moisture). Gift Of Karen Eccks of La Mesa, California. The American Lumberman was a weekly trade journal created on January 1, 1899, from the merger of Northwestern Lumberman, established in 1873, and The Timberman, established in 1886. It was published in Chicago. During its time, American Lumberman was the leading periodical read by lumber industry management and workers in the United States. The magazine consisted of articles and photographs documenting the history, management, business activities, operations, individuals, and social life of lumber companies and lumber towns throughout the United States. The trade journal was published as American Lumberman until 1961 when the name changed to Building Materials Merchandiser, a name that would again change to Home Center in 1972.
Lawrence 10-D Lumber Calculator (1935) REF	Lawrence 10-D Lumber Calculator Made in USA - Wabash, Indiana - 1935 Thickness [ Width, Length ] Board Feet Back: Not Shown Archive - Scan donated David Rance Collection Sassenheim, The Netherlands
Lawrence 10-D Lumber Calculator (1946) REF	Lawrence 10-D Lumber Calculator Made in USA - Peru, Indiana - Copyright 1946 Thickness [ Width, Length ] Board Feet Back: Not Shown Archive - Scan donated David Rance Collection Sassenheim, The Netherlands
Lawrence 10-F Pricing And Inventory Rule REF	Lawrence 10-F Pricing And Inventory Rule Made in USA - Wabash, Indiana - Copyright 1946 Discount, Mark Up [ Cost: Gross, Dozen, Each ] Selling Price, Inventory (Number in Stock) Back: Not Shown Archive - Scan donated David Rance Collection Sassenheim, The Netherlands
Lawrence 10-G Cutting Speed Calculator REF	Lawrence 10-G Cutting Speed Calculator Copyright 1946 Made in USA - Peru, Ind. Front Scale: Cutting Speed (fpm) [ Diameter: Inch, Millimeters, Drill Size ] Spindle Speed (rpm) Back Adv: Gargoyle Lubricants Archive - not in collection.
Lawrence 10-G Cutting Speed Calculator REF	Lawrence 10-G Cutting Speed Calculator Copyright 1946 Made in USA - Peru, Ind. Front Scale: Cutting Speed (fpm) [ Diameter: Inch, Millimeters, Drill Size ] Spindle Speed (rpm) Back Adv: Donald Robertson & Company, Chicago, Illinois Archive - Jim Cerney Collection.
Lawrence 10-N Printers Proportional Ruler REF	Lawrence 10-N Printers Proportional Ruler Made in USA - Peru, Ind - Copyright 1946 Front Scale: Inches [ Inches, Picas ] Picas Back: Not Shown Archive - Scan donated David Rance Collection Sassenheim, The Netherlands
Lawrence 10-1 Model Builders Slide Rule REF	Lawrence 10-1 Model Builders Slide Rule Made in USA - Peru, Ind - Copyright 1947 Prototype (Scale/Foot) [ Model: English, Rairoad Gauge, Metric , Prototype (Scale/Foot) ] Model: English, Metric , Back: Not Shown Archive - Scan donated David Rance Collection Sassenheim, The Netherlands
Lawrence - Dupont 011 REF	Lawrence - Dupont 011 Made in USA for Dupont Chemicals Note: Same as Dietzgen 1767P National Front Scale: A [ B, CI, C ] D, K Back Scale [ S, L, T ] Back: Conversion Chart Archive - Scan donated by David Rance collection, Sassenheim, The Netherlands
Lawrence - Copyfitter 12-H REF	Lawrence - Copyfitter 12-H Made in USA by Lawrence - Copyright 1946 by Owen T. Taylor, Dayton 7, Ohio Front Scale: Measure Length of Picas [ Number of Lines, Length in Points, C.P.P. ] Characters, type size Archive - Scan donated by David Rance collection. Sassenheim, The Netherlands
Lawrence - Copyfitter 12-H (Taylor Publishing) REF	Lawrence - Copyfitter 12-H Made in USA for Taylor Publishing Co., Centerville, Ohio. Copyright 1946 Front Scale: Measure Length of Picas [ Number of Lines, Length in Points, C.P.P. ] Characters, type size Archive - Scan donated by David Rance collection. Sassenheim, The Netherlands
Lawrence 12-J Pro-Rater REF	Lawrence 12-J Pro-Rater Made in USA by Lawrence - Copyright 1946 by Owen T. Taylor, Dayton 7, Ohio Front Scale: Dates (Months/Days)[ Days, Days. ] Premium Back: Table of day factors for a year Archive - Scan donated by David Rance collection. Sassenheim, The Netherlands
Lawrence 250-BT [Slide #402] S030	Lawrence 250-BT [Slide #402] Made in USA - Peru, Ind. c1942. Metal framed cursor. Front Scale: A [ B, CI, C ] D, K Back Scale: [ S, L, T ] Back: Conversion Chart
Lawrence 250-BT [Slide #503] ISRM 18.09.17.37.X	Lawrence 250-BT [Slide #503] Made in USA - Peru, Ind. c1946. Black and Red ink. Plastic cursor Front Scale: A [ B, CI, C ] D, K Back Scale: [ S, L, T ] Back: Conversion Chart Gift of Donald S. Bachelor Collection
Lawrence 250-BT [Slide #611] ISRM 20.08.15.30	Lawrence 250-BT [Slide #611] Made in USA - Peru, Ind. c1946. Black and Red ink. Plastic cursor Front Scale: A [ B, CI, C ] D, K Back Scale: [ S, L, T ] Back: Conversion Chart
Lawrence 250-BT [Slide #705] REF	Lawrence 250-BT [Slide #705] Made in USA - Peru, Ind. c1946. Black and Red ink. Plastic cursor Front Scale: A [ B, CI, C ] D, K Back Scale: [ S, L, T ] Back: Conversion Chart Archive David Rance Collection, Netherlands
Lawrence Code Maker Slide Rules Comparison REF	Lawrence Code Maker Slide Rules Comparison Made in USA by Lawrence Engineering Services - Peru, Ind. c1939 Front Scale: Alphabet [ Alphabet, Alphabet Inverted, Numbers ] Numbers Scans Donated by Kenneth Lewis Collection Cover of Box ----- Open Box ----- Instruction Manual Lawrence Secret Code Outfit came with two slide rules, for you and your friend, and set of instructions (copyright 1939) written by W. St John Maloney which includes Vigenere table. The box is 8 15/16" Long, 3" Wide, 1/2" Thick
Lawrence RCA F.M. Transmitter Coverage ISRM 14.07.02.36	Lawrence RCA F.M. Transmitter Coverage Made in USA by Lawrence Engineering Services - Peru, Indiana, for RCA Radio Corporation of America Front Scale: Miles Radius of Urban Coverage Are (1000 Microvolts per Meter), (50 Microvolts per Meter) [ Transmitter: 50KW, 10KW, 3KW, 1KW, 250W ] Feet Height of Transmitting Antenna, Square Miles Urban Coverage. Back: Instructions Gift Of Ed Millis, Dallas, Texas.
Lawrence - Miller Motor Company Air And Hydraulic - Boosters And Accumulators REF	Lawrence - Miller Motor Company Air And Hydraulic - Boosters And Accumulators Made in USA by Lawrence - A Model 10-B with two added scales Front Scale: DIA, A [ B, CI, C ] D, K, GAL Back: Not Shown Archive - Scan donated by David Rance collection. Sassenheim, The Netherlands
Lawrence - Low Pressure Gas Line Flow Capacity Slide Rule, B.F. Grizzle REF	Lawrence - Low Pressure Gas Line Flow Capacity Slide Rule, B.F. Grizzle Made in USA by Lawrence for B.F. Grizzle, Copyright 1941 Front Scale: Length of Line, Specific Gravity [ Pressure drop (Inches), Pressure drop (ounces), Cubic Feet/Hr (B, A,)] Nominal Pipe Diameter (A, B) Back: Not Shown Archive - Scan donated by David Rance collection. Sassenheim, The Netherlands
Lawrence - Gas Pipe Line Slide Rule, B.F. Grizzle ISRM 18.03.20.05	Lawrence - Gas Pipe Line Slide Rule, B.F. Grizzle Made in USA by Lawrence for B.F. Grizzle, P.O. Box 126, Terre Haute, Indiana, Copyright 1944. Note: has K&E cursor Front Scale: B (Inlet Gauge Pressure), A (Outlet Gauge Pressure)[ A1 (Outlet Gauge Pressure), C (Pressure Ext.), Q (Cu. Ft per Day), L (Length in Miles)] D (Inside Diameter -inches), Spec. Gravity, Pressure Base, E, F (Pressure Extension), H (% line Looped) Back Slide: BI(Outlet Gauge Pressure), CI(Pressure Ext.), K (Equivalent Length per Mile of Loop), R, M, G (% Increase Capacity), DL (Diameter of Loop Line) Belonged to Robert N. Curry. Gifted by his friend Alice Bowling of Louisville, Kentucky. Robert N. Curry He was a 1949 graduate of Western Kentucky University. Bob was the head of Measurement for Texas Gas Transmission Corp and authored a book on Natural Gas processing Fundementals of Natural Gas Conditioning. He was former chairman of the AGA Transmission Measurement Committee. Several of his slide rules are currently in the ISRM galleries.
Lawrence - Water Line Capacity Slide Rule, B.F. Grizzle ISRM 14.07.02.88	Lawrence - Water Line Capacity Slide Rule, B.F. Grizzle Made in USA by Lawrence for B.F. Grizzle, Copyright 1944 Front Scale: Inside Pipe Diameter [ Length of Line, Flow Rate CuFt/Hr, Gallons/24Hr] Coefficient of Roughness, Loss of Head, Pressure drop] Back: Not Shown Gift of Ed Millis, Dallas, Texas
Lawrence - Concrete Quantity Calculator (Prototype) REF	Lawrence - Concrete Quantity Calculator (Prototype) Made in USA by Lawrence - Paper Scales, possibly a prototype/low volume rule Front Scale: Thickness (A) [ Width or Height (B), Length (C) ] Volume (D)(cubic feet/cubic yards) Back: Not Shown Archive - Scan donated by David Rance collection. Sassenheim, The Netherlands
Lawrence - Antenna Slide Rule (RSC - Confidential) REF	Lawrence - Antenna Slide Rule (RSC - Confidential) Made in USA by Lawrence for Radiation Laboratory, M.I.T., Cambridge, Massachusettes Front Scale: Full Widths, Side Lobes [ Angle, Gain, Wavelenth ] Diameter Back: Not Shown Note: RSC = The Radiation Safety Committee Archive - Scan donated by David Rance collection. Sassenheim, The Netherlands
Lawrence - Gamma-Ray Slide Rule REF	Lawrence - Gamma-Ray Slide Rule Made in USA by Lawrence for ? Front Scale: Exposure Time [ Thickness of Steel, Alloy Section, Film to Source Distance ]Milligrams of Radium, Equivalent Steel Thickness Back: Not Shown Archive - Scan donated by David Rance collection. Sassenheim, The Netherlands
Lawrence - Cutter Speed Calculator REF	Lawrence - Cutter Speed Calculator Made in USA by Lawrence for Madison Manufacturing Co. Muskegon, Michigan Copyright 1947 Front Scale: Cutting Speed FPM [ Cutter Diameter, Madison Bar Diameter ] R.P.M. Back: Not Shown Archive - Scan donated by David Rance collection. Sassenheim, The Netherlands
Lawrence - "K" Factor Calculator REF	Lawrence - "K" Factor Calculator Made in USA by Lawrence for Tokheim Corp. Fort Wayne, Indiana Copyright 1948 Front Scale: Degree Days [ Gallons ] "K" Factor Back: Not Shown Archive - Scan donated by David Rance collection. Sassenheim, The Netherlands
Lawrence - Liquid Propane Gas Calculator REF	Lawrence - Liquid Propane Gas Calculator Made in USA by Lawrence for Tenbrook Enterprises. Kokomo, Indiana Copyright 1948 Front Scale: Gallons Corrected [ Gallons Delivered ] Propane Temperature Back: Not Shown Archive - Scan donated by David Rance collection. Sassenheim, The Netherlands
Lawrence - Traffic Managers Slide Rule REF	Lawrence - Traffic Managers Slide Rule Made in USA by Lawrence - Copyright 1939 by M.T. Brockman Front Scale: Class Rate [ Percent Class, Weight ] Rate and Charge Back: Not Shown Archive - Scan donated by David Rance collection. Sassenheim, The Netherlands
Lawrence - Poker Meter REF	Lawrence - Poker Meter Made in USA by Lawrence - Copyright 1939 by M.T. Brockman Front Scale: % Card Stud [ Recommended Plays ] 5 Card Draw Back: Not Shown Archive - Scan donated by David Rance collection. Sassenheim, The Netherlands
Lawrence - DeYOE Slide Rule, U.S. Army for Artillery Ranging REF	Lawrence - DeYOE Slide Rule, U.S. Army for Artillery Ranging Made in USA by Lawrence Front Scale: E-Mils [ R or H, R or dH ] UOE Back: Not Shown Archive - Scan donated by David Rance collection. Sassenheim, The Netherlands

Lawrence 8-B Anco Products REF	Lawrence 8-B_Anco Products Made in USA by Lawrence for Anco Products Co., Painted wood body - Black text on top Front Scale: A [ B, CI, C ] D, K Back: Not Shown Scan Donated by David Rance, The Netherlands
Climatemaker Slide Rule Service 10-B 21.02.10.01	Climatemaker Slide Rule Service 10-B Made in USA - for Climatemaker, Bloomington, Illinois (Lawrence 10-B OEM) White painted wood body with Blue text. Magnifying Cursor. Front Scale: A [ B, CI, C ] D, K Back Scale: [ S, L, T ] Back: Conversion Chart
Lawrence 505 U.S. Navy S495	Lawrence 505 U.S. Navy c1942 Made in USA - Peru, Ind. (Lawrence 10-B) Painted wood body - Black text on top Front Scale: A [ B, CI, C ] D, K Back Scale: [ S, L, T ] Back: Conversion Chart
Lawrence 505 U.S. Navy REF	Lawrence 505 U.S. Navy c1942 Made in USA - Peru, Ind. (Lawrence 10-B) Painted wood body - Red text on top Front Scale: A [ B, CI, C ] D, K Back Scale: [ S, L, T ] Back: Conversion Chart Scan Donated by David Rance, The Netherlands
Charvoz-Roos SR-31 REF	Charvoz-Roos SR-31 c1942 Made by Lawrence - c1942 (Same as 10-B) for Charvos Roos Material: Painted Scales on Wood Stock Front Scale: A [ B, CI, C ] D, K Back: Not Shown Scan Donated by David Rance, The Netherlands
Lietz No.2974N REF	Lietz No.2974N c1942 Made by Lawrence - c1942 (Same as 10-B) for the A. Lietz Co. San Francisco, California. Material: Painted Scales on Wood Stock Front Scale: A [ B, CI, C ] D, K Back: Not Shown Scan Donated by David Rance, The Netherlands
Lietz 2976 Mannhiem (Lawrence 10-B) ISRM 15.04.06.02	Lietz 2976 Mannhiem (Lawrence 10-B) Made in USA by Lawrence Engineering. Shows Pat. Pend. Front Scale: A [ B, CI, C ] D, K Back Slide: Blank Back:white painted background. Blue color text. Decimal Equivalents of Fractions
National Foreman's Institute Productivity Rule ISRM 21.02.05.01 Online publications can be downloaded from the University of Pennsylvania Online Books by National Foremen's Institute. However, noe of these publications mention the above slide rule as a foreman's tool.	National Foreman's Institute Productivity Rule 1946 Made in USA by Lawrence Engineering for National Foreman's Institute, Deep River, Connecticut. Front Scale: A' - Standard Hours per 100 units, A - Standard Minutes per Unit [ B - Number of Units Produced, C - Productivity Percentage, D - Job Rate-Dollars per Hours ($0.40-$3.00)] E - Daily Incentive Earnings, Standard Hours Produced, Actual Hours Spent. Back and Slide: Blank The National Foreman's Institute existed between 1937 through 1962 (or longer) and published books and paper's on Factory Cleaning, Factory sanitation, Grievance procedures, Industrial relations, Labor contract, Leadership, Personnel management, Sabotage, and Technical education. Contributing authors: Edward Silver Maclin, John A. Lapp, Roy Dalton Bundy, Harry Desmond Farren, Albert N. Gillett, and R. F. Vincent, etc.
NOBEMA 10-B REF	NOBEMA 10-B c1942 Made by Lawrence - c1942 (Same as 10-B) for NOBEMA Products Co., USA Material: Painted Scales on Wood Stock Front Scale: A [ B, CI, C ] D, K Back: Not Shown Scan Donated by David Rance, The Netherlands

1958 Sales brochure

Lakeside Draft-A-Plan Pocket Slide Rule (1962) ISRM 15.03.19.01	Lakeside Draft-A-Plan with Pocket Slide Rule (as part of kit) Kit was made by Lakeside Toys, a subsidiary of Lakeside Industries, Inc Made in USA by Engineering Instruments, 1962 Front Scale: A [ B, CI, C ] D, K Draft-A-Plan was a beginning drafting kit which had a small electric back lighted table, T-square, 30-60 and 45 degree triangles (made by C-Thru Industries) and this re-branded slide rule made by Lawrence Engineering. It included drafting vellum, lettering guides, tracing and blueprint paper and a small book on drafting practice and math using the slide rule. This kit is missing two small objects, a pencil sharpener and a rubber eraser. A 1974 catalog still shows it being produced. The book for the kit Drafting is Fun can be downloaded on the left (14MB Pdf).
Engineering Instruments Book Version ISRM 09.10.30.02	Engineering Instruments Book Version Made in USA - Peru, Indiana Front Scale: A [ B, CI, C ] D, K Back: Conversion Chart This model was included with the book Mathematics Made Simple
Engineering Instruments - No Model number (10-B) ISRM 12.03.21.05	Engineering Instruments - No Model number (10-B) - c1947 Made in USA - Peru, Ind. Front Scale: A [ B, CI, C ] D, K Back: Conversion Chart Note: Front side painted, Back screened on bare wood. Donated by Henry (Hank) Benoit, Kingston, Ontario, Canada See Hank's picture and bio with his personal slide rules in the Aristo 0970 Multilog and 870 (pocket) Multilog in the Aristo Gallery and the Faber-Castell 989 Complex Slide Rule in the Faber-Castell Gallery.
Engineering Instruments - No Model number (10-B) ISRM 17.05.02.35	Engineering Instruments - No Model number (10-B) - c1947 Made in USA - Peru, Ind. Front Scale: A [ B, CI, C ] D, K Back: Conversion Chart Note: Front side painted, Back screened on bare wood.Alternate silkscreen Gift Of Mike Weaver UK
Lawrence 10-B Unbranded OEM Version ISRM 22.03.20.01	Lawrence 10-B Unbranded OEM Version - c1947 Made in USA by Engineering Instruments,Peru, Indiana. Note: Front side painted white with Black text. Full length conversion table Front Scale: A [ B, CI, C ] D, K Back Scale: Blank Back: Conversion Chart Gift Of Debra Sscheidt, of Fento, Missouri.
Lawrence 10-B (unpainted back) ISRM 18.09.17.37	Lawrence 10-B - c1947 Made in USA by Engineering Instruments,Peru, Indiana. Note: Front side painted white with Black text. Full length conversion table Front Scale: A [ B, CI, C ] D, K Back: Conversion Chart Gift Of DonaldBachelorCollection
Engineering Instruments 10-N, Printers Proportional Rule ISRM 08.11.17.01	Engineering Instruments 10-N, Printers Proportional Rule Made in USA by Engineering Instruments, Peru, Ind. - 1947 Front Scale: Inches [ Inches, Pica ] Pica (Note: Inches here are logarithmic, not linear) Back: Blank, (a cursor was not required for this slide rule) Owned by Alfred Wilcox who operated a two-person advertising agency in Breinigsville, PA until 1976. Donated by Ruth Moyer of Reston, VA, who's mother, Gladys Moyer, was employed by Alfred, as the other person in the shop.
Engineering Instruments Codemaker P185	Engineering Instruments Codemaker Made in USA by Engineering Instruments, Peru, Ind. Front Scale: Alphabet [ Alphabet, Alphabet Inverted, Numbers ] Numbers Back: Blank
C.V. Ore S-M Slide Rule REF C.V. Ore S-M Slide Rule Ad, Popular Science, May, 1956 pg261, was found by George Keane, (1933-2020) Festus, Missouri. PDF Manual is from the later Acu-Rule S-M Slide Rule version.	C.V. Ore S-M Slide Rule - Copyright 1955 Made in USA by Eng. Inst.  for C.V. Ore, Harvey, Illinois Front Scale (10 inch long stock) DS [ CI, C ] D, DM Back: Blank Archive - David McFarland collection See the Acu-Rule/Acu-Math gallery for a later plastic version. Mr. C. V. Ore of Harvey, Illinois describes his slide rule, which sold for $1.50 in 1956, as follows: "The S-M Slide Rule is a simplified, multi-purpose calculating instrument designed especially for the beginner. It contains the basic scales of professional slide rules ( C, D, CI ) as used by engineers for 80 to 90 percent of their work. And in addition to the basic scales the S-M Slide Rule has two special purpose scales for teaching the beginner the mechanics of the slide rule and to aid him in reading conventional C, D, and CI scales."
Dick Tracy Secret Code Maker P190	Dick Tracy Secret Code Maker Made in USA by Engineering Instruments, Peru, Ind. Front Scale: Alphabet [ Alphabet, Alphabet Inverted, Numbers ] Numbers Back: Blank Came with Magnifying Glass Instructions 2.18MB PDF
Gene Loewy 10-B S265	Gene Loewy 10-B (Circa 1954) Made in USA by Eng. Inst.  for Gene Loewy, New York, NY Front Scale: A [ B, CI, C ] D, K Back: Conversion Chart
Engineering Instruments - American Log Log 77A REF	Engineering Instruments - American Log Log 77A Type Duplex Log Log Decimal Trig - pre 1968 Made in USA by Acumath for Engineering Instruments, Peru, Indiana Front Scale: LL01, K, A [ B, T, ST, S ] D, L, LL1 Back Scale LL02, LL03, DF [ CF, CIF, CI, C ] D, LL3, LL2 Scan found by David Rance, The Netherlands
Engineering Instr. 250-BT S031	Engineering Instruments 250-BT  Made in USA - Peru, IN.  Front Scale: A [ B, CI, C ] D, K Back Scale: [ S, L, T ] Back: Conversion Chart
Engineering Instruments 250-BT ISRM 14.01.10.17	Engineering Instruments 250-BT- New all plastic cursor Made in USA by Engineering Instruments, Inc., Peru, Ind. Front Scale: A [ B, CI, C ] D, K Back Scale: [ S, L, T ] Back: Conversion Chart Gift of the Bill Wehrend Collection, Palo Alto, California.
Engineering Instruments No Model# (250-BT) ISRM 15.08.29.14	Engineering Instruments No Model# (250-BT) Made in USA by Engineering Instruments, Inc., Peru, Ind. Note: Plastic Cursor, Painted scales Front Scale: A [ B, CI, C ] D, K Back Scale: [ S, L, T ] Back: Conversion Chart Original owner: Marilyn Stobbs (name written on sleeve and in well) Gift of the Marilyn D. (Stobbs) Ulrich of 0'Fallon, Missouri Marilyn used this slide rule at Marquette Catholic High School, class of 1960. At the time she lived in Alton, Illinos. She married George W. Ulrich in 1964 and moved to Florissant. George's slide rules are also shown in the ISRM galleries. George W Ulrich (1938-2015) was one of the first to attend Marquette High School and Alton High School simultaneously. He took his skills in design and construction to McDonnell Aircraft's spacecraft and defense programs while attending Washington University night school. He retired from Boeing in 2003. During those years he served in the Army.
Engineering Instruments 250-V S195	Engineering Instruments 250-V Made in USA - Peru, Ind.  K&E 4058 cursor and sleeve (was Eng. Inst. an OEM to K&E?) Plastic laminate over wood body Front Scale: A [ B, CI, C ] D, K Back Scale: [ S, L, T ] Back: Conversion Chart
Engineering Instr. 250-V ISRM 11.03.23.03	Engineering Instruments 250-V Made in USA - Peru, Ind. - Plastic Cursor Plastic laminate over wood body Front Scale: A [ B, CI, C ] D, K Back Scale: [ S, L, T ] Back: Conversion Chart Donated by David Sweetman
Miller Motor - Air and Hydraulic Calculator S528	Miller Motor - Air and Hydraulic Calculator - Copyright 1950 Made in USA by Eng. Inst. for Miller Motor Co. Melrose Park, IL Front Scale: DIA, A [ B, CI, C ] D, GAL Back: Conversion Chart

Brief history 1901 - George Lee lawrence born in Chicago, IL. Pre 1935 - Lawrence Slide Rule Company - George Lee Lawrence makes Photographic Slide rules in Chicago. 1935 - Lawrence Engineering Services was set up in Wabash, Indiana 1938 - Moved to nearby Peru, Indiana (10 man shop run by Ed Snyder) c1940 - A glass magnifier was developed c1942 - OEM supplier to Post (model 1446D) during WWII, when Japanese importation was halted. c1943 - Injection molded plastic cursor replaces fragile glass magnifier 1947 - A divorce settlement gives company to wife Vivian, briefly called Lawrence Engineering Company c1948 - Vivian marries Frank C. Bozarth, forms Engineering Instruments, Inc. in Peru, Indiana c1960 - Engineering Services OEM's the 77A plastic American Log Log (Acu-math 1500) 1967 - Company building burns down, Engineering Instruments ceases to exist. 1976 - George Lee Lawrence dies