If you are familiar with the red dot style rifle sight, I think George N. Martin was thinking along that line in April, 1943.  The attached pic shows him buying the book, 'Aircraft Radio and Electrical Equipment', by H.K.Morgan on April 30, 1943, from the Georgia Division of the Bell Aircraft Corp.  Perhaps he was an employee, note the sales ticket where it says, "I hereby authorize Bell Corp. to deduct above amount from my pay in _____weekly installments."

He was doodling on a piece of paper which he stuck in the pages in the chapter on 'Oscillographs'.  It is hard to read his writing, it is very tiny and light, but it appears he was drawing a circuit that was taking inputs from the airspeed 'computer' (his words) a logarithmic taper pot attached to a gun mount, a  a magnetic input from a compass all to deflect the spot on a CRT.  His notes refer to aim, angle, leading, and show a small plane with single and dual tail guns.  Perhaps he was sketching a simple drawing of the existing system in a plane, or he was trying to create a better way to shoot down the enemy.

I am always on the look out for books on how things were wired in WW II aircraft, especially the B17 that I am involved with the rebuild of.  I have two of these books, one I got from Brian, KN4R, the other I bought from ABE Books several months earlier, but I do not know which one the paperwork was in.  The book also contains info and schematics on several pieces of gear, a lot of RCA stuff , a Collins 17D transmitter,  various Lear transmitters including the UT-6 that I spent a couple years trying to find info on, and a bunch of Western Electric aviation gear.  Fold out schematics on very thin paper, inter aircraft wiring diagrams and a ton of info on how things interconnected and functioned are included in the almost 400 page book with very small print.  I did  a comparison on books several years ago, basic novels that seem to always be in hardback and thick.  Turns out, books used to have small print and 700-900 words on a page, but now, they use thicker paper, larger print, with about 300 words on a page.  Again, with books and more words per page using less paper,  those of us who bought Coke and milk in a glass bottle to be turned in, cleaned and refilled, fixed out toaster and vacuum instead of throwing them away, were still more environmentally aligned than the latest GenZ person.

I have a 1930's 3" Triumph 'Oscillograph' that still works quite well, but I had to put in one of those little power supplies I found on Amazon that makes 2000 volts out of 6 which I got by rectifying and filtering the filament volts, needed  to use for the trace as the HV tapped secondary quite making CRT HV.   Makes a nice 160 and 75 meter AM mod indicator.

If you see books on epay or used book sites about vintage aircraft, especially any on electrical or radio, power plants are also  interesting,  they are great reads on how things were done in the day, like how many planes they wrecked trying to figure out a supercharger for all altitudes .  While today we have a computer that feeds drivers and takes in signals from sensors,  those are childs play when you see how it was all done in the days of analog, both mechanical and electrical.  Check out the aiming computer for the 16" rifles on any WW II battleship.

Charlie in NC