Thomas Jefferson Papers

Description of the Physiognotrace

Description of the Physiognotrace

[Enclosure]

Explanation of Mr. Jno. I. Hawkins Physiognotrace

A is a board that mooves up and down in the frame B, B. which is fastened to the wall with brackets C, C,— This moovement is convenient to suit the heigth of different persons, and it is secured to its place by means of a screw on the back part,—D, is a hollowed board projecting 2½ Inches, to allow the Pentagraph to moove behind it. The person to be traced, setting in a Chair, rests their head on the concave part, & the hollow of the board below imbraces the shoulder—The Physiognotrace is fixed to the board A at a, and in the center of the joint b, is a conic Steel point with a spring to press it against the paper, represented by the doted lines, the Steel point is taken off the paper by means of a lever; having the upper end turned at a right angle under the spring in a wedged form, and the other end extended to the joint on the right to be in reach.

c, is an Index made of brass, the joint of which has plates on each side connected by a Center pin—to the out plate, is screwed a piece of brass 5 Inches long, with a thin edge, which edge is exactly perpendicular to the center of the joint.

This Index mooving round to trace any subject that the edge is keept too, as it mooves, the steel point in the center of the upper joint, gives a diminished size a perfectly correct representation. The paper to be traced is fixed on a square board by means of an Iron rim, and it is then placed on a door hinged to the back part of the Machine, & shut into a rabet made to receive & keep it at a proper distance from the Steel point.

MS (DLC: TJ Papers, 128:22193); in Peale’s hand.

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