A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: David C
Date: 2020 Oct 16, 21:29 -0700
I have in hand, a copy of Inman’s Nautical Tables, 1947 version, first published in 1821. My copy contains a reviser’s preface which describes a revision made by Rev Hall, in 1910.
A copy of Chambers's seven figure mathematical tables arrived in the post today. I was puzzled until I remembered that I had purched the volume after reading Lars' comment about the quarter squares method of multiplication. The first thing I noted was that the book is published by W & R Chambers Ltd and is called Chambers's, not Chambers' tables as I would write it. Also Hughes Tables aare called Hughes' Tables not Hughes's Tables. Why this matters to me is that I was educated in the 1950s when we were taught punctuation. I get very grumpy at today's common misuse of the apostrophe. Chambers's is probably not wrong but it annoys me.
The contents page is interesting as it indicates that with the exception of haversines the volume could probably replace Norie.
I can see an immediate use for these tables. I was learning the Doniol-Rudzinski-Ix method but came to a stop when I discovered that long multiplication was needed. With the quarter squares table that is no longer an obstacle. I multiplied 456 by 791 as follows:
Sum 1247 Quarter square 38 8752
Difference 335 Quarter square 2 8056
Difference quarter squares 360696
By fx-82AU the answer is 360696. As a final check I should probably try long multiplication:
360696 --------the first long multiplication I have done for decades!!!