Jaap's Mechanical Calculators Page

The Add-A-Mite Pocket Calculator

The Add-A-Mite Pocket Calculator


The Add-A-Mite
Video
Advertisements and articles
Patents
Links


The Add-A-Mite Pocket Calculator

The Add-A-Mite is a simple circular shopping adder. It is comparable to the Itemizer, or even the Webb Adder.
The back of the machine a rotatable disc marked with the numbers 00 to 99, and its current state is visible through a window in the front face. The face is also marked around its rim with the numbers 0 to 99. There is a pointer that can be disengaged from the read disc by pushing it down, and it can then be freely rotated to any of the numbered markings. If you then rotate it back to the zero position without pushing it down, it will rotate the rear disc by the the same amount, adding that amount to the displayed value.
It has a second smaller window that displays part of a smaller disc that keeps track of the hundreds. When the large disc rolls over from 99 to 00, it rotates the hundreds disc one step too. This hundreds disc can also be rotated manually using a knob on the left hand side.

The Add-A-Mite Pocket Calculator
The Add-A-Mite Pocket Calculator
The Add-A-Mite Pocket Calculator
The Add-A-Mite Pocket Calculator
The Add-A-Mite Pocket Calculator
The Add-A-Mite Pocket Calculator
The Add-A-Mite Pocket Calculator
The Add-A-Mite Pocket Calculator
The Add-A-Mite Pocket Calculator
The Add-A-Mite Pocket Calculator
The Add-A-Mite Pocket Calculator


The front bears the Add-A-Mite name and the name of the maker, Monogram of California, based in San Francisco. This company started in 1940 and made personalised gifts, especially paper products such as napkins. Its president was Percy M. Barker. In the 1950s it made napkins with funny cartoons printed on them, and these sold very well. This company should not be confused with Monogram Pictures, which made movies and in particular Westerns.

The patent for the Add-A-Mite was filed in 1950 by Sahn K. Lowe, and it was granted in 1953. The Add-A-Mite was on the market in 1951, but it seems that it was sold only for a short time since they always have "Patent Pending" on them rather than the patent number.


Add-A-Mite Pocket Calculator video

Here is a video where I demonstrate my Add-A-Mite.




Advertisements and articles

Here are a few ads for the Add-A-Mite.

1951-11 Christian Herald
1951-12 Better Homes and Gardens


Here are a few ads and articles related to the inventor Sahn K. Lowe.

1933-08-18 Honolulu Star Bulletin (Hawaii)
1939-03-21 Honolulu Star Bulletin (Hawaii)
1939-09-03 The Honolulu Advertiser (Hawaii)
1940-08-07 Honolulu Star Bulletin (Hawaii)


Lastly here are some ads and articles related to Monogram of California.

1946-08-04 The San Francisco Examiner (California)
1946-10-30 Green Bay Press Gazette (Wisconsin)
1948-01-26 The Robesonian (Lumberton North Carolina)
1948-12-02 Imperial Republican (Nebraska)
1951-02-14 The Marion Star (Ohio)
1952-08-25 Daily News (Los Angeles California)
1953-11-29 The San Francisco Examiner (California)
1954-10-21 The Times (San Mateo California)
1955-05-16 St Louis Globe Democrat (Missouri)
1969-03-25 US867185 Trademark



Patents

The Add-A-Mite was invented by Sahn K. Lowe. He was an inventor of Chinese origin who worked for the Mutual Telephone Co. in Hawaii. His other inventions include a machine for grinding herbs (US 1,517,564), and the "Lo-Light" which illuminates the arm of a car driver when making a turn signal (US 1,898,842).

PatentFiling datePublish dateNameDescription
US 2,637,49724-03-195005-05-1953Sahn K. LoweVest-Pocket Type Calculator

Links

RetroCalculators has an Add-A-Mite including packaging and instructions.
Detlev Bölter has an Add-A-Mite and shows its internal mechanism.
Rechner Lexicon has a page about the Add-A-Mite.
Rechnen Ohne Strom has a page about disc adders which includes the Add-A-Mite.
Chris Staecker's YouTube Channel has a page about Add-A-Mite.
USPTO's Trademark site has a record of a logo trademark for Monogram Of California (72267054).


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