sigh -- so many good books!

I was using my copy of Barlow's Tables (1952) to find square roots in graphing circles, and happened to notice an advertisement on the back cover for Engineers' Illustrated Thesaurus 1952, which looks like an awesome book! It has 'over 8,000 illustrations of mechanical movements, machine parts and details...' just the few graphics in the advertisement are intriguing -- but since we went to an auction (for household things) today, books will have to wait a bit longer.

I have a new chapter for the math problem -- but I have to take the time to work out a new diagram and decide if I am going to work on this part separate from the original, or as a continuation of the original problem. I think separately, at the moment.