When I was a kid, I read several novels by the Australian author Neville Shute about his experience as a bomber navigator in WWII. It seemed like a miracle to me that they could fly above the cloud cover in the dead of night and determine a reasonably accurate position with a 3 lb. hand-held device and a book of tables. Then in 1976 I found a functional air sextant and a Rude star finder at a camera store – the owners didn’t know what they were, and let me have it all for $15.00. I still use them, today. The hook was set!