Fascinating book, all about the very early applications of oscilloscopes. The tubes were very simple back then, just a directly heated cathode, the focussing sleeve, the anode and the 4 deflection plates. The face of the tube was also a segment of a sphere, not flat. Engineers did very strange things with them back then, like modulating the anode voltage to produce radial displacement of the beam (which Watt consistently calls an "electron jet", or achieving very long trace lengths with a spiral scan. Also lots of tricks that exploit the eye's ability to pick signals out of noise.
My copy is a very plain paper edition published in 1941 in England by HMSO. They must have thought the information therein was valuable enough to be worth promoting, back then in England's "darkest hour" as Churchill later called it.