SOLD Rare American Induction machine by Töpler ca.1890

This model of an electrostatic induction generator, very much in vogue for electromedical purposes towards the end of the nineteenth century, is based on the principles of electrophorus and duplicator function. It is derived from the mechanical improvements made between 1865 and 1880 by the physicist August Töpler, the German physicist Wilhelm Holtz (1836-1913) and by J. Robert Voss, a mechanician from Berlin. Voss devised this self-excitation model in 1880, perfecting a machine presented by Töpler the previous year. The quantity of charge captured through induction by the combs is collected by the two mobile, brass collection rings, the terminal spherules of the spark-gap are each charged by the opposite sign with respect to the sign of the comb with which they are in contact. In this manner the machine is able to produce sparks, at times very long ones, especially if the poles of the spark-gap are in contact with the internal shields of the two Leiden jars. 40cm high 34cm deep 50cm wide.