Palmer’s Computing Scale is widely attributed as being one of the first American circular slide rules and was invented by Aaron Palmer in 1841. The patent was subsequently bought by John Fuller in 1845 who improved upon it by adding a Time Telegraph to the reverse side and offered it along with the accompanying book.
The scale was in production between 1845-75 (through at least 7 revisions) and appears to be the first time a device rather than an individual was given the title ‘computer’. Although predominantly retailed in America, Fuller exhibited the scale at the Great Exhibition of 1851 and did produce a UK edition.
This is a US copy with the rule dated to 1847 as standard and the accompanying book (usually missing) dated to 1852 or just after. Please see images but both parts are offered in good original condition with some age related wear as to be expected. There is a small amount of curling to the disks as is common, bumping and wear to the edges and soiling and light foxing to the book. However since it is nearly 170 years old we will allow it some imperfections.
