# Comptometer Tables

Felt & Tarrant printed many small tables to help the operator with common calculations. Such tables were usually printed on thick cardboard for durability. In the 1920 edition of "Easy Instructions for operating the Controlled-Key Comptometer" a list is given of various tables that were available at that time. I reproduce that list here. The ones on this list that I own are marked by an asterisk.

Form NumberTitleDescription
1Tonnage TableGives the decimal part of a ton of any number of pounds.
3Lumber TableGives result of dividing 12 into any dimension up to 11 7/8.
4*Discount TableGives the net of chain discounts.
5Lumber TableGives number of board feet in pieces of various sizes.
6Gross TableGives the decimal for each fractional part of a gross and for each unit.
7*Grain TableGives the decimal part of a bushel of any number of pounds of different grains.
8Ten and 100 and 1000 X Inches and Fractions to Eighths TableUsed only in connection with the Engineering Model Comptometer for figuring beams, pipe, etc.
9Reciprocal TableUsed for making division quickly and easily by multiplication.
10British Currency TableGives the decimal part of a £ of any number of shillings and pence.
12British Currency TableGives the decimal part of a £ for pence and 32nd fractions.
21Quarters and Pounds of a Ton TableGives the decimal part of a ton of any number of Quarters and Pounds.
22Quarters and Pounds of a Cwt. TableGives the decimal equivalents of a Cwt. from 1/2 lb. to 3 qrs. 27 lbs.
24Interest TableGives the interest on \$1.00 for different numbers of days at different rates.
25Net Discount TableShows the net left from \$1.00 after discounting for the required number of days.
26Decimal TableUsed for figuring elapsed time. It gives the decimal part of a 360-day year up to any date.
29*Decimal Equivalents of Fractions TableGives decimal equivalents of fractions from 1/4 to 63/64.
32Cooperage TableUsed to determine how many staves of one size are equivalent to another size.
33*Interest TableGives the interest on \$1.00 for one day for rates from 1/8 % to 12 7/8 %.
35*Payroll TableGives the decimal part of a month for any number of days and eighths of days.
36Insurance Cancellation TableShows decimal part of the year for months and days.
37Figuring Elapsed Time TableShows decimal part of a year for each day.
38Pounds, Ounces, and Drams TableGives the decimals of a 16-oz. pound for any number of drams and ounces.
184Interest TableGives the interest on \$100. at 7% for from 1 to 364 days.
191Grain TableGives the Dockage and the net bushels per 1000 lbs. for different rates of dockage.
205Weights per Foot and Inch for Rounds, Squares, etc. of Different Thicknesses TableEnables one to get the weight of a piece.
234Iron and Steel TableGives the price per 100 lbs. at .01 to \$100. per gross ton.
237Interest TableUsed for figuring interest on a 365-day basis, where interest rates run from 1 to 12%.

Decimal Equivalents of Common Fractions To be used in Connection with the Comptometer.
Felt & Tarrant Mfg. Co., Chicago, U.S.A.
Series No. 2
108mm × 164mm

This card was included when I bought the 1911 edition of "Methods of Operating the Comptometer", so is likely from around that time, especially since the picture on it is of a model B or C Comptometer. The card is signed on the back by Adelina Artesani who according to the 1900 and 1910 census was born in 1894 and resident in Boston, MA.

Decimal Equivalents of Common Fractions To be used in Connection with the Comptometer.
Comptometer Division, Felt & Tarrant Mfg. Co., Chicago, Illinois
Form 29
102mm × 235mm

This card was included when I bought the "Table of Reciprocals" book, and it supplements that book by supplying some fractions that have numerators other than 1. Unlike most of the other cards, this one is printed partly in colour. It has no copyright year, but was probably printed in the 1940s as it has a picture of the model M.

Discount Table Showing net of \$1.00 after discounts, shown at top and side, are taken off.
Comptometer Co., Chicago, U.S.A.
Form No. 4
165mm × 279mm

This card has no copyright year, but was probably printed in the 1940s as it has a picture of the model M. It is likely that earlier prints of this card exist.

Grain Table Pounds Expressed in Decimal Parts of a Bushel.
Felt & Tarrant Mfg. Co., Chicago, U.S.A.
Form 7
117mm × 267mm

This card has no copyright year, but was probably printed in the early 1920s as it has a picture of the model H.

Interest Table (360-day basis) To be used in Connection with the Comptometer
Felt & Tarrant Mfg. Co., Chicago, U.S.A.
Form No. 33
225mm × 159mm

This card has no copyright year, but was probably printed in the early 1920s as it has a picture of the model H.

Pay Roll Table Decimal Equivalents of Days and Eighth Fractions of Days, for 24-31 Day Months also Minutes expressed in Decimal Equivalents of an Hour.
Comptometer Co., Chicago, U.S.A.
Form No. 35
195mm × 322mm

This card carries a copyright year of 1925, but it must have been a reprint from the 1940s as it has a picture of the model M.

Decimal Equivalents of Fractions from 3rds to 26ths inclusive To be used in Connection with the Comptometer.
Comptometer Co., Chicago, U.S.A.
Form No. 368
185mm × 235mm

This card has no copyright year, but was probably printed in the 1940s as it has a picture of the model M.

Decimals of a Foot for each 1/8 of an Inch To be used in Connection with the Comptometer in Figuring Lumber, Steel Beams, Angles, Etc.
Comptometer Co., Chicago
Form No. 386
152mm × 253mm

This card carries a copyright year of 1925, but it must have been a reprint from the 1940s as it has a picture of the model M.

Ounces and Drams Reduced to Decimal of a Pound Table of Decimal Equivalents to be used in connection with the COMPTOMETER
FELT & TARRANT LTD., Aldwych House, Aldwych, London, W.C. 2.
Dec. Card No. 3
253mm × 192mm

This piece of paper has no copyright year, but it has a picture of the Model H or J, and I suspect it is from about 1928. It is printed by the UK company, and lists the various Felt & Tarrant branch offices around the country.

WAGES TABLE FOR 48-HOUR WEEK To be used in connection with the Comptometer
FELT & TARRANT LTD., Aldwych House, Aldwych, London, W.C. 2.
Dec. Card No. 5
304mm × 178mm

This piece of paper has no copyright year, but it has a picture of the Model H or J, and I suspect it is from about 1928. It is printed by the UK company, and lists the various Felt & Tarrant branch offices around the country.

For Calculating TIMBER SPECIFICATIONS Table to be used in connection with the COMPTOMETER
FELT & TARRANT LTD., Aldwych House, Aldwych, London, W.C. 2.
Dec. Card No. 6
354mm × 240mm

This piece of paper has no copyright year, but it has a picture of the Model H or J, and I suspect it is from about 1928. It is printed by the UK company, and lists the various Felt & Tarrant branch offices around the country.
It is stamped with the name of the company that used it, W.H. Wheeler & Sons, Portsmouth.

For Calculating the Weight of Deals, Battens, and Boards at 66 cubic feet to the Ton Table of Decimal Equivalents to be used in connection with the COMPTOMETER
FELT & TARRANT LTD., Aldwych House, Aldwych, London, W.C. 2.
Dec. Card No. 7
228mm × 240mm

This piece of paper has no copyright year, but it has a picture of the Model H or J, and I suspect it is from about 1928. It is printed by the UK company, and lists the various Felt & Tarrant branch offices around the country.

GROSS, Each Fractional Part & each 144th To be used in connection with the COMPTOMETER. For Figuring Gross Invoices, Inventories, Plate Glass, etc.
FELT & TARRANT LTD., Aldwych House, Aldwych, London, W.C. 2.
Dec. Card No. 8
209mm × 260mm (1925), 203mm × 256mm (1934)

This piece of paper has no copyright year, but it has a picture of the Model H or J, and I suspect it is from about 1928. It is printed by the UK company, and lists the various Felt & Tarrant branch offices around the country.

This is a later print of the same table. It has a picture of the Model K so probably dates from about 1934.

Decimal Part of a Year for Each Day on a 365-Day Basis To be used in connection with the COMPTOMETER
FELT & TARRANT LTD., Aldwych House, Aldwych, London, W.C. 2.
Dec. Card No. 9
184mm × 360mm

This piece of paper has a copyright year of 1914, though it was printed at a later date. From the dates used in the examples printed on the back I suspect it is from 1928. It is printed by the UK company, and lists the various Felt & Tarrant branch offices around the country.

Annas & Pies as Decimal of One Rupee Table of Decimal Equivalents to be used in connection with the COMPTOMETER
FELT & TARRANT LTD., Aldwych House, Aldwych, London, W.C. 2.
Dec. Card No. 10
328mm × 211mm

This piece of paper has no copyright year, but it has a picture of the Model H or J, and I suspect it is from about 1928. It is printed by the UK company, and lists the various Felt & Tarrant branch offices around the country.

QRS. & LBS. into CWT. and QRS. & LBS. into TON To be used in connection with the COMPTOMETER
FELT & TARRANT LTD., Aldwych House, Aldwych, London, W.C. 2.
Dec. Card No. 21, Dec. Card No. 22
151mm × 239mm (1925), 164mm × 264mm (1934)

This piece of paper has no copyright year, but it has a picture of the Model H or J, and I suspect it is from about 1928. It is printed by the UK company, and lists the various Felt & Tarrant branch offices around the country.

This is a later print of the above tables. It has a picture of the Model K so it is probably from about 1934.

Decimal Equivalents of Common Fractions To be used in Connection with the Comptometer.
FELT & TARRANT LTD., Aldwych House, Aldwych, London, W.C. 2.
Dec. Card No. 29
127mm × 203mm

This card has no copyright year, but I suspect it is from about 1928. It is printed by the UK company. It has a list of useful conversion factors on the back.

Pence & Sixteenths of One Shilling and Pence & Thirty-Seconds of One Shilling To be used in connection with the COMPTOMETER
Felt & Tarrant, Ltd., London.
267mm × 209mm

This piece of paper has no copyright year but probably dates from 1934. It is printed by the UK company, and lists the various Felt & Tarrant branch offices around the country.