Les instruments du calcul savant > Instruments d'intégration conservés au musée des arts et métiers

Orthogonal Planimeter/Integrimeter

Orthogonal planimeter/integrimeter with wheel-and-cylinder mechanism, according to Abdank-Abakanowicz (type III)
Maker: Branville & Cie., Paris; instrument no.: none (presumably one-of-a-kind); pre-1885
Inventory: CNAM, inventory no. 13300-0003-
Details: On the socket: »S^me B. ABDANK ABAKANOWICZ« and »INTEGROMETRE DE BRANVILLE & Cie Paris« (according to file). Entry CNAM: 1900
References: Abdank-Abakanowicz 1886, 32-33 and Abdank-Abakanowicz 1889, 28-29 (with illustrations)

Orthogonal planimeter/integrimeter according to Abdank-Abakanowicz, type III

This instrument, too, makes use of the continuous screw (vis à pas variable); the screw is realised like in the previous instrument by a wheel, pressed on the mantle of a cylinder.

Fig. 24, Abdank-Abakanowicz 1886, 31 = Fig. 27, Abdank-Abakanowicz 1889, 28

The point of contact between wheel and cylinder and at the same time the direction of the wheel are now changed directly by leading the tracer pin along the boundary of the figure to be measured, which enormously simplifies the utilisation of the instrument. Changing the position of the tracer pin controls the movement of two carriages along their respective tracks just like the simultaneous turning of the two screws with their milled heads did it in the type I planimeter/integrimeter, and like the simultaneous turning of one screw and the movement of the tracer arm did in the type II planimeter/integrimeter (see CNAM 13300-0002-). Thus the functioning of the instrument is identical to the one of previously described types I and II - but its utilisation is much more convenient.