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The Calculator / Lightning Adding Machine

The Calculator The Lightning Adding Machine The Lightning Adding Machine

The Calculator
The Lightning Adding Machine
Newspaper and Magazine Advertisements
Articles and Documents

The Calculator

The Calculator is an early dial calculator made from 1915 to 1922 in Grand Rapids, Michigan. It has a wedge-shaped wooden desk stand in which there is a hole for storing the metal stylus.

There are 7 dials. Through a hole in a dial its current digit is displayed. To add a number, set your stylus next to the digit you want to add and use it to turn the dial clockwise as far as possible. As the display holes move around, the current digits are somewhat tricky to read. There is a carry mechanism but it only works for addition, for clockwise turns of the dials. If you try to subtract by turning the dials anti-clockwise, then no carries are not performed.

The Calculator
The Calculator
The Calculator
The Calculator
The Calculator
The Calculator
The Calculator
The Calculator
The Calculator


A video demonstrating The Calculator:

The Lightning Adding Machine

The Lightning Adding Machine is a very common 7-digit adder manufactured in the USA. The one shown here was made in February 1946 according to the date stamp printed on the back.

The Lightning Adding Machine
The Lightning Adding Machine
The Lightning Adding Machine, close-up
The Lightning Adding Machine, stylus
The Lightning Adding Machine, reverse
The Lightning Adding Machine, date
The Lightning Adding Machine, reverse of stand
The Lightning Adding Machine, logo on bakelite stand

It sits on a felt pad inside a Bakelite stand that tilts the machine up at a 30 degree angle. It comes with an aluminium stylus that can be stored on the ridge at the front of the stand.

There are seven dials which the user can adjust using the stylus provided with the machine. Each dial drives a hidden number wheel to its top right, of which only a single digit is visible through a hole. The numbers 1 to 9 are printed around the outside of each dial. To add a number, enter the digits one at a time simply by putting the stylus in the hole next to the digit you want to add and turning the wheel clockwise until the stylus hits the tab at the bottom right between the 0 and 9. At the point where a dial's number wheel turns from 9 to 0, the dial also drives the next number wheel for one step so that a carry is performed.

The last two digits represent cents and are subtly separated from the other digits with a decimal point. The other five digits represent dollar amounts, and there is a similarly subtle comma separating the thousands digits. The dials are distinguished by their colours, where the middle three dials are silver coloured and the rest are copper coloured.

This version has no clearing mechanism. Each dial has two red lines marking one of the holes. A digit can be reset to zero by putting the stylus in the marked hole, and turning anti-clockwise until the stop. This action will not cause a carry, so the digits can be reset in any order. This also means that subtraction has to be done using clockwise turns by adding complementary numbers.

In about 1948 the mechanism was redesigned. The carry mechanism was changed to work in both directions so that subtraction could be done with anti-clockwise turns. A clearing mechanism was added, in the form of a tab on the left hand side that you have to pull out. The machine kept the same length and width, but became twice as thick to accomodate the clearing mechanism. The bakelite stand was changed accordingly, and has a cut-out on the left for the clearing tab. These changes raised the price of the adding machine from $12.95 to $14.95.

The Lightning Adding Machine
The Lightning Adding Machine
The Lightning Adding Machine
The Lightning Adding Machine
The Lightning Adding Machine
The Lightning Adding Machine
The Lightning Adding Machine
The Lightning Adding Machine

Here is another redesigned adder, grey like the one above, but this one is in its original box. It no longer has its original stylus.

The Lightning Adding Machine
The Lightning Adding Machine
The Lightning Adding Machine


Suggestions and Illustrations for Operating The Lightning Portable Adding Machine
4-page leaflet

The original version of the Lightning Adding Machine would be supplied with a 4-page instruction leaflet, and an inspection card.

The Lightning Adding Machine Instruction leaflet
The Lightning Adding Machine Instruction leaflet
The Lightning Adding Machine Instruction leaflet
The Lightning Adding Machine Instruction leaflet
The Lightning Adding Machine Instruction leaflet
The Lightning Adding Machine Instruction leaflet
The Lightning Adding Machine Instruction leaflet
The Lightning Adding Machine Instruction leaflet

The Lightning Adding Machine Inspection card
The Lightning Adding Machine Inspection card
The Lightning Adding Machine Inspection card

How to get the most from your new Lightning Adding Machine    (PDF, 1.55 MB or archive.org)
8-page stapled leaflet
81mm × 152mm

The redesigned Lightning Adder came with a small instruction booklet, though it seems hardly necessary given that subtraction is now so easy and the basic instructions are written on the front of the machine.

Instructions for the Lightning Adding Machine
Instructions for the Lightning Adding Machine
Instructions for the Lightning Adding Machine

The text is as follows:



A course of instruction is not necessary for operating the Lightning Portable Adding Machine. It is remarkably simple. Anyone who can dial a telephone can put it to practical use immediately. It will be worth your while, however, to read the following carefully.


The first two dials, on the right end of the machine, are used for cents — the first one for units, the second for tens. The three middle dials, right to left, are for dollars, tens of dollars, and hundreds of dollars — in that order. The last two dials (the sixth and seventh, on the left end of the machine) are for thousands and tens of thousands. In short, the number is placed on the machine in the same order as when writing it on paper.

Above each dial is an answer window, through which one figure shows. These figures denote your total, or answer, when adding or subtracting.


The machine is clear and ready for business when each of the answer window figures is zero. To clear the machine, simply use your left thumb to give the automatic clearance lever (on the left end of the machine) a firm pull to the left. Immediately, every dial automatically clears so that zero shows in the answer windows.


You Use Only The Large White Figure to Add.

Clear the machine to zero — as instructed above. Now let's say the first number in our column to be added is 67 cents. Place the stylus in the hole opposite large white figure 6 in the second dial from the right. Turn the dial firmly clockwise until it comes to a stop, holding the stylus in an upright, vertical position. The 6 will be instantly registered in the answer window. Then register the 7 in the same manner in the first right-hand dial. You will now see the 67 cents registered in the machine through the answer windows. The next item is 40 cents. Register this the same as you did the 67 cents by placing the stylus opposite large white figure 4 in the second dial from the right, and then turn the dial clockwise. This completes the operation for the 40 cents as it is never necessary to register a zero when adding. You will now see the total of the amounts is $1.07. Thisishows through the answer windows without pushing any keys or pulling any levers. The machine has carried the total automatically into the dollars column (third answer window from the right).

Now register $2.55 in the same manner being sure to start this figure in the dollars column (the third dial from the right). Your total will be $3.62. Register $62.10 starting in the fourth dial or tens-of-dollars column. Your total, $65.72, will show through the answer windows.

Now, pull the automatic clearance lever, and you are ready for the next column of figures.

Caution— You use only the large white figures to add. Always use the stylus when operating the machine. Do not use a pencil. Also, do not oil. The Lightning is properly and permanently lubricated before leaving the factory.


Here is another feature which users of the Lightning Adding Machine praise. One of the problems a person faces when mentally adding up a long column of figures is that he may be interrupted before finishing the column. This usually means starting over. The Lightning, however, is specially designed so that it can be lifted from its base and placed directly on the column of figures. It keeps your place and guards against interruptions. Taking the addition problem again to illustrate this point — while registering the 67 cents, the machine should be resting directly under this number. To add the 40 cents move the machine down the sheet until just under the 40 and register the number. Now move it down until just under the 255 and register this number. Now, suppose you are interrupted — the phone rings. The machine rests under the last figure you have added. You can answer the phone and then resume your work where you left off. Furthermore, you have in front of you the total as far as you have gone.


Use Only The Small Yellow Figures to Subtract.

The Lightning Adding Machine is one of the few machines, regardless of price, upon which you can subtract without learning what is called the "complementary" system. The Lightning subtracts as easily as it adds, thus making it possible for you to reverse-check long columns of addition, eliminating all doubt.

Subtraction on the Lightning is just like adding, with but two exceptions:
   First: You use the small yellow figures instead of the large white ones.
   Second: You turn the dial backward (counter-clockwise) which is just the opposite direction used in adding.

For example, suppose you have $15.79 showing in the answer windows and you want to subtract $1.42. Place the stylus in the hole opposite the small yellow number 1 in the third dial from the right. Turn the dial counter-clockwise until it stops. Then do the same with the small yellow figure 4 in the second dial from the right, and the same with the small yellow 2 in the first right-hand dial. You will now see $14.37 registered in the answer windows. You may continue subtractions in this manner, remembering to use only the small yellow numbers and to move the dial counter-clockwise.

In this way you can easily subtract such items as Social Security tax, unemployment tax and any other salary deduction so as to arrive at the exact amount of each paycheck.

It is equally simple to verify a long column of addition merely by keeping the total in the answer windows and then subtracting each individual figure in the column. After this subtraction the answer windows should register all zeros, proving the accuracy of your addition.


This Lightning method of subtraction is a very valuable feature for accountants and bookkeepers. To balance an account mentally, you must add up the debits, then add up the credits, then subtract the total credits from the total debits — three operations. Likewise, on many other makes of adding machines, regardless of price, one must add up the debits, make a notation of the total, then clear the machine and add up the credits, making a notation of this total, then clear the machine again and subtract the total credits from the total debits, giving the balance — three distinct operations. The Lightning Adding Machine accomplishes this easier by simply subtracting the credit items from the debit total which remains in the answer windows.


This method is handy for balancing a bank account. Simply register the previous balance and add any subsequent deposits. Then, you just subtract the various checks drawn on the account.


Although the dials of this machine are connected so as to carry automatically from one column to another, the various dials can be used separately for tabulating two or more items at the same time.

For example, suppose you want to tabulate baled hay which is being loaded. You wish to tabulate not only the total weight of the hay, but also the number of bales.

For tabulating the number of bales you will use the first two left-hand dials. As one bale is loaded, weighing 110 lbs., you register the 1 in the second dial from the left end of the machine and register the 110 in the first three dials on the right end of the machine. As two bales are loaded, register 2 in the "bales" dial, and 225 in the "pounds" dials, and so on. When the load is complete, you not only have the total number of bales, but also the total number of pounds.
The remarkable handiness, utility, accuracy, and durability of Lightning Portable Adding Machines have been proved by over 300,000 satisfied Lightning users throughout the United States and all over the world . . . customers who have relied on Lightnings for the last thirty two years. You will find as they found that the more you use the Lightning the more you will like it — and the more time, money, and work it will save you.

Lightning Addng Machines Sales Company
2306 West Slauson Avenue
Los Angeles 43, California


Guarantee Certificate
One-sided paper slip
216mm × 86mm

The redesigned Lightning Adder also came with a guarantee certificate.

The Lightning Adding Machine Guarantee
The Lightning Adding Machine Guarantee

Guarantee Certificate and Order Form
One-sided paper slip
302mm × 64mm

This paper slip offers a guarantee and also has two forms for ordering further Lightning calculators as gifts.

The Lightning Adding Machine
The Lightning Adding Machine


Video about the 1946 Lightning Adding Machine:

Video comparing the 1946 and 1950 versions:


The history of earlier versions of this adding machine is complicated. Several calculators were produced around the same time that are identical except for the name and lettering. The following is a short overview of the time line, based on research by Bob Otnes.

Newspaper and Magazine Advertisements

Here are some of the advertisements I found in online archives for the Bonham & Schram calculator (1905), the Calculator (1915-1922), the Pangborn Adding Machine (1921), the Lightning Calculator (1921-1942), and the Lightning Adding Machine (1945-1959). Some of these ads ran for many years unchanged, so I have only included a representative sample. Most of them are actually ads looking for salesmen to sell the calculator, rather than ads for the calculators themselves.

Bonham & Schram (1905)

1906-05 Office Appliances

The Calculator (1915-1922)

1915-02-13 Duluth Herald
1916-02 Popular Mechanics
1917-01 Photoplay
1917-03-24 Indianapolis News
1917-05-12 Indianapolis News
1917-05-13 Sunday Times (Perth)
1918-12 Popular Science
1919 World Almanac and Encyclopedia
1919-01-24 Evening Post (NZ)
1919-01-26 The Daily Colonist (Victoria B.C.)
1919-12-13 El Paso herald (Texas)
1920-07 Popular Science
1921-03-26 Saturday Evening Post
1921-04-23 Saturday Evening Post
1921-06 Popular Science
1922-04-09 The Washington times
1922-04-21 The American Legion Weekly

The Pangborn Adding Machine (1921)

I found only one ad by Pangborn Adding Machine Company.

1921-11-19 Duluth Herald

The Lightning Calculator (1921-1941)

In the adverts the change to the new company name is complete by May 1922 (about two months after Pangborn's suit was filed), even though the Lightning Calculator Company first appeared in advertising in October of the previous year. Note also that the adverts don't change - even the price stays the same - so it may well be that some of the previous ads were actually already selling the new machine.
I am not sure what to make of the large ad in The American Philatelist magazine which explicitly mentions the "Lightning Calculator" but still shows a picture of the older calculator.

1921-10-31 The Washington herald
1921-12-04 Richmond times-dispatch (Virginia)
1921-12-04 The Washington herald
1922-05-19 The American Legion Weekly
1922-06-04 Richmond times-dispatch (Virginia)
1922-08-08 Freiburger Nachrichten
1922-08-18 Freiburger Nachrichten
1922-08-29 Freiburger Nachrichten
1922-09-10 Richmond times-dispatch (Virginia)
1922-12 The American Philatelist
1922-12-03 The Washington times
1922-12-23 The Literary Digest
1925-09 Popular Science
1925-09-23 New Zealand Herald
1925-09-23 The Argus (Melbourne)
1927-04 Popular Mechanics
1928-03-22 The West Australian (Perth)
1928-11-03 Salzburger Volksblatt
1929-11-17 Pilsner Tagblatt
1937-09 Popular Mechanics
1940-10-07 Life
1941-05-04 The Arizona Republic (Phoenix Arizona)

The Lightning Adding Machine (1944-1959)

1946-03-02 The Saturday Evening Post
1946-04 Office Appliances
1946-05-31 Eagle Valley Enterprise (Colorado)
1946-06 Construction Methods & Equipment
1946-06 Office Appliances
1946-06 The New York Certified Public Accountant
1946-06-06 Hardware Age
1947-01 Office Appliances
1947-06 Office Appliances
1947-07 Office Appliances 2
1947-07 Office Appliances 3
1947-07 Office Appliances
1947-09 Office Appliances
1947-12 Office Appliances
1947-12-06 Collier's
1948-02 Office Appliances
1948-03 Office Appliances
1948-04 The American Legion Magazine
1948-06 Office Appliances 2
1948-06 Office Appliances
1948-08 Office Appliances
1948-11-27 The Saturday Evening Post
1949-01 Popular Mechanics
1949-05 Popular Mechanics
1949-12 10 Story Western Magazine
1949-12-06 Look
1950-01 Office Appliances
1951-11 Office Appliances
1952-01 Popular Mechanics
1952-10 Office Appliances
1952-12 Popular Science
1953-08 Desert Magazine
1953-12-14 Newsweek (US Edition)
1954-02 Sir!
1954-04 Office Appliances
1959-02 The Office

Articles and Documents

Apart from the ads I have found very few other mentions of these calculator companies in newspaper and magazine archives.

1905-03-16 The Lake Geneva News (Wisconsin)

A Promising Invention (Bonham & Schram).
(1905-03-16 The Lake Geneva News, Wisconsin)
1905 Tools of Business - Bonham

Entry for Bonham & Schram.
(1905 Tools of Business - E. H. Beach)
1906-03 Office Appliances 1
1906-03 Office Appliances 2
1906-04 Office Appliances

Bonham & Schram at the 1906 National Business Show in Chicago.
(1906-03/4 Office Appliances)
1919 Modern Engineers and Surveyors Instruments

Description of The Calculator from a catalogue.
(1919 Modern Engineers and Surveyors Instruments - The A. Lietz Company)
1922-05-02 Official Gazette of the USPTO

Notice in the patent office gazette of the law suit between Pangborn and Hook.
(1922-05-02 Official Gazette of the USPTO)
1923-09-18 De grondwet

Discovery of a dead body in the freight elevator shaft of the Lightning Calculator building. (In Dutch)
(1923-09-18 De grondwet)
1925 Ernst Martin Lightning Calculator

Description of the Pangborn Calculator.
(1925 Die Rechenmaschinen, Ernst Martin)
1925 Ernst Martin Pangborn

Description of the Lightning Calculator.
(1925 Die Rechenmaschinen, Ernst Martin)
1945-06 Office Appliances

Improved Lightning Calculator
(1945-06 Office Appliances)
1945-06 Office Appliances 2

Caliornia Typewriter Exchange moves to new store
(1945-06 Office Appliances)
1945-07 Office Appliances

Thornton visited Grand Rapids
(1945-07 Office Appliances)
1947-05 Official gazette of the USPTO

Registration of the trademark of the lightning logo, which mentions its use started October 1945. It was used on packaging and instruction manuals, but it seems not on the machines themselves.
(1947-05 Official Gazette of the USPTO)
1947-07 Administrative Management

Improved Lightning Adding Machine
(1947-07 Administrative Management)
1948-11 Office Appliances

Business grows
(1948-11 Office Appliances)
1950-10 Office Appliances

Change of address
(1950-10 Office Appliances)
1953-12 Office Appliances

Sale of the company, new owners
(1953-12 Office Appliances)


PatentFiling datePublish dateNameDescription
US 845,74720-11-190505-03-1907Walter Richard BonhamCalculator
US 908,73106-04-190505-01-1909Walter Richard BonhamCalculator
US 1,574,24917-02-192123-02-1926Russell Wallace HookCalculator


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