Imagine snapping a photograph of a song?
The phonodiek is an instrument of amazing delicacy and high tolerance. The specimen now in the CWRU Department of Physics’ possession is made of brass. The detail of the mirror shown in figure 11 gives some indication of the scale. The pivots and cap jewels, made of sapphire “in the manner of the balance-wheel staff of a fine watch,” are shown in the diagram with a mottled pattern in the cross section. The block and cap, shown by fine diagonal lines, were bronze. The staff, on which the mirror (facing to the right) was cleverly mounted so that the whole assembly has one axis of inertia, was only 0.1 millimeter in diameter at the pivots. The whole mirror and staff assembly, pulley included, was 3.3 mm high and 1.6 mm wide overall, and had a mass of 2.72 mg. The scale and precision of craftsmanship displayed here are nothing if not amazing.