NavList:

I have a rare and historically important book for sale on ebay, ending Saturday. It's the Tables Requisite or T.Reqs (not to be confused with T.Rex):
https://www.ebay.com/itm/142844101337

From my description for the auction:

Exceptionally rare. The "Tables Requisite", 2nd edition, 1781.

The long title is "Tables Requisite to be Used with the Nautical Ephemeris for Finding the Latitude and Longitude at Sea". This was one of the key prototypes for all later books on navigation. Moore's Practical Navigator, Norie's Navigator, and Bowditch's "New American Practical Navigator" were all fundamentally based on and derived from the "Tables Requisite".

The small-ish (almost "pocket-sized") standard "Nautical Almanac" in the late 18th century contained only the "ephemeral" data, the daily positions of the Sun and Moon and planets, the carefully calculated "lunar distances" for finding longitude, but a modern celestial navigator would be surprised to find no correction tables, no tables of refraction, no dip of the horizon, no mathematical tables, and very little explanation. All of this relatively unchanging information was provided in this separate work, the Tables Requisite, the creation of Nevil Maskelyne, British Astronomer Royal, and the Royal Observatory at Greenwich. It included extensive explanations on all of the calculations of nautical astronomy (as celestial navigation was known then) including the process for working "lunars" for longitude by various methods. 

This volume is in very fine condition, especially considering it is 237 years old. The leather binding is strong, though scratched and a bit tattered at the edges, and the pages are generally clean, showing only minimal spotting and foxing. This is an exceptionally rare work in the history of celestial navigation, nautical astronomy, and maritime science, and I have not seen another copy offered for sale in over ten years. 

An early owner's name and inscription is written in manuscript on the first page: "Johannes Emerson Thompson, Mathematician, Newcastle, 1802".

Frank Reed