This American Mechanical Powers Demonstrations Apparatus, dates from the last quarter of the 19th century and carries a label of Alfred Robbins Chicago.
The apparatus stands 26~1/2 tall and consists of a base plate with capstan, a tall pillar with two pulleys and a drum on a cast iron arbor, and a two-part weight that may be supplemented with additional weight.
The capstan has brass spokes that may be used by the student to wind the string, noting differences in the variables of the pulleys, drum and/or the weights. A very nice American physics demonstration apparatus in good condition.
Offered by Esoterica Curiosa: Dale Beeks, specialist collector, purveyor & curatorial consultant of historical surveying & scientific instruments. Item #426