Uploaded February 2023 | Updated September 2026, 4 hours ago
This model 6 Barrett Adding Machine was made in 1913. Designed by Glenn J. Barrett, it was in production from 1910 till 1924, and was considered one of the most portable adding machines of its time.
Minor correction: This machine was actually made in Grand Rapids, because although the company moved to Philadelphia in 1912, the factory did not follow until 1919.
For more information about this and other machines in my collection, please visit my website:
jaapsch.net/mechcalc
0:00 Introduction, History
1:58 Addition
2:33 Repeated addition
3:01 Clearing the keyboard
3:20 Clearing the register
3:36 Item counter
4:46 Subtraction
5:10 Lever
5:43 Outro
This model 6 Barrett Adding Machine was made in 1913. Designed by Glenn J. Barrett, it was in production from 1910 till 1924, and was considered one of the most portable adding machines of its time.
Minor correction: This machine was actually made in Grand Rapids, because although the company moved to Philadelphia in 1912, the factory did not follow until 1919.
For more information about this and other machines in my collection, please visit my website:
jaapsch.net/mechcalc
0:00 Introduction, History
1:58 Addition
2:33 Repeated addition
3:01 Clearing the keyboard
3:20 Clearing the register
3:36 Item counter
4:46 Subtraction
5:10 Lever
5:43 Outro
