Instruments and methods used in radiometry - II
A 1913 technical paper from the National Bureau of Standards describing radiometric instruments — thermopiles, radiometers, galvanometer circuits — written for physicists and instrument makers. The line drawings are spare black diagrams on tan stock: sawtooth thermocouple arrays, coiled lead wires, dashed hidden edges, dimension arrows in millimetres, and sectioned housings with screws and mirrors.
