Amsler, 1855. This is one of the oldest polar planimeters, since Amsler invented
them in 1854.
F. Weber and Co. No date, but probably about 1900.
About polar planimeters
Pictures of a Keuffel & Esser 620015
Amsler, 1855. This is one of the oldest polar planimeters, since Amsler invented
them in 1854.
F. Weber and Co. No date, but probably about 1900.