Figure 2607 -- Duddell Moving Coil Oscilliograph General view of electromagnet form of Duddell moving-coil oscillograph, showing the oil bath, and electromagnet...
with Duddell moving-coil oscillograph, consisting of a large rotating light-shutter wheel and a mirror moved by a cam, to draw marker lines on moving film...
2622, 2623 -- Interior of cinematograph camera as used on Duddell moving coil oscillograph for obtaining long records. The loose ends of the case are...
