%center% (Text reads "The Adder" "Registered Trade Mark")

The UK Patent for The Adder was granted to Arthur J. Postans as inventor on 1 December 1904 - see [[ http://meta-studies.net/pmwiki/uploads/AdderPatent.pdf|UK Patent Application GBD190224868]].

The US Patent  for The Adder was granted to Arthur J. Postans as inventor on 11 April 1905 - see [[ http://meta-studies.net/pmwiki/uploads/AdderPatentUSA786839W.pdf|US Patent 786839]].

The US Patent  for The Adder was granted to Arthur J. Postans as inventor on 11 April 1905 - see [[ http://meta-studies.net/pmwiki/uploads/AdderPatentUSA786839W.pdf|US Patent 786839]].  (NB this is a 1 MB file).

The Adder was a 3 digit adding machine which added one digit at a time via a ten key keyboard. It was designed by Arthur James Postans (1867-1940), a British engineer from South Kensington, London, England.  He applied for a British Patent (along with patents in a number of other countries) in 1904 and later received patents for similar machines in Sweden, Switzerland and Canada as well as improved designs in the UK.[^The Adder, http://history-computer.com/CalculatingTools/Gadgets/Adder.html, viewed 26 May 2014^] According to Martin, the production of The Adder began in 1908 and ended in the 1920s.[^Ernest Martin, '/The Calculating Machines/' (a translated reprint of Die Rechenmaschinen, 1925), The MIT Press Cambridge, Massachusetts London, England, and Tomash Publishers Los Angeles and San Francisco, 199, p. 200.^]

!!!Patents

As with the other adders in this collection, the adding was done primarily to the right hand column, but in this case with the elaborated possibility also of adding 10.  (To add 30 the 10 key would be depressed three times).  On the left is a clearing lever which resets the machine to zero in all three windows.

The Adder was a 3 digit adding machine which added one digit at a time via a ten key keyboard. It was designed by Arthur James Postans (1867-1940), a British engineer from South Kensington, London, England.  he first applied for a British Patent (along with patents in a number of other countries) in 1902 and later received patents for similar machines in Sweden, Switzerland and Canada as well as improved designs in the UK.[^The Adder, http://history-computer.com/CalculatingTools/Gadgets/Adder.html, viewed 26 May 2014^] According to Martin, the production of The Adder began in 1908 and ended in the 1920s.[^Ernest Martin, '/The Calculating Machines/' (a translated reprint of Die Rechenmaschinen, 1925), The MIT Press Cambridge, Massachusetts London, England, and Tomash Publishers Los Angeles and San Francisco, 199, p. 200.^]

As with the other adders in this collection, the adding was done one digit at a time, but in this case with the elaborated possibility also of adding 10.  (To add 30 the 10 key would be depressed three times).  On the left is a clearing lever which resets the machine to zero in all three windows.

!!!Patent


!!!Instruction brochure.

The instruction brochure for The Adder is shown below:

(:title The Adder ~1908 single column adding machine, serial no. 1306:)