It may sound like the beginning of a joke, but it's just me getting pedantic.
If you look at the title page of the first
Nautical Almanac and Astronomical Ephemeris, you'll see that it's dated MDCCLXVI, i.e. 1766. Nothing unusual there and one would normally assume that this was indeed the year of publication of the astronomical tables for the following year (and published only just in time to be of any use, it seems).
Among our manuscripts at the NMM, however, we have a letter from
Nevil Maskelyne to John Nourse, one of the London booksellers licensed to sell the new work. The letter is dated 3 January 1767 and this is what Maskelyne has to say:
I send you by the bearer your licence from the Board of Longitude to publish the Nautical Almanack & annexed tables. Mess. Richardson & Clarke in Salisbury Court Fleet Street will send you 100 copies in a day or two for present sale; be pleased to have them stitched up in blue paper; or if you think of any properer covering not expensive let me know, that I may acquaint Mess. Mount & Page to make theirs the same. Advertise the ephemeris for the day you shall be ready to publish, & let Mess. Mount & Page know the day that they may be ready at the same time.
Of course, this only matters because the process of getting the book printed and on public sale took things into the next year, but it does mean that we should really take the publication date of the first
Nautical Almanac as 1767. Some people have noticed this in the past, I think, but more often than not 1766 is the given date (as most library catalogues will agree).
Now, of course, I'm wondering how many other books weren't published when they say they were.