To make a blueprint, place the tracing in a blueprint frame with the inked side next to the glass and lay a sheet of blueprint paper with the sensitized side next to the tracing. Put the back of the frame in place and lock it in position so as to hold the tracing paper. Expose to sunlight for 30 seconds.

Frame Blueprint

To make a blueprint, place the tracing in a blueprint frame with the inked side next to the glass and…

An illustration of a young boy tracing his shadow on a wall while three young girls watch.

Shadow Drawing

An illustration of a young boy tracing his shadow on a wall while three young girls watch.

"An instrument which, when applied over an artery, traces on a piece of paper moved by clockwork a curve which indicates the changes of tension of the blood within... a, band by which the instrument is fastened on; b, spring which rests upon the artery; c, adjusting-screw (with graduated head) which regulates the pressure of the spring b according as the pulse is strong or weak; d, d, supports for paper upon which the tracing is made; e, e to engage the paper positively; g, small spring clockwork (incased) by which motion is imparted to the feed-roller e1; h, milled-headed winding key; i, stop-motion; j, tracer attached to the oscillating arm k, which is moved by the rod l that connects this arm with the spring b." —Whitney, 1889

Sphygmograph with All Parts Labeled

"An instrument which, when applied over an artery, traces on a piece of paper moved by clockwork a curve…