First, apologies for the lengthy gap since my last post; I’ve been unwell but the skill of the ship’s chirurgeon has got me back on deck and scampering up the rigging with the best of ’em.
That’s me, but what about Halley? Well, he’s been sailing steadily southwards (well, SSE) since leaving St Iago (Santiago) in the Cape Verde Islands and reached Rio de Janeiro on December 14, where he’ll stay for two weeks. This section of his voyage, down to his most southerly latitude (which he’ll reach about the end of January), isn’t very eventful and so I thought this was a suitable time to take a look at his second logbook, which begins with this heading:
A Journal of a Voyage in his Ma:tis Pink ye Paramore intended for the Discovery of ye Variation of the Compass kept by Edmund Halley Commander anno 1699 & 1700
Like the first logbook, the second is not written by Halley but presumably by his clerk, William Curtiss, and so again the spelling and abbreviations are the clerk’s and not Halley’s. The log is written on the same size (roughly 41cm high by 27cm wide) and type of paper as the first logbook and covers 53 sides (the first was 17 sides).
Unlike the first journal, the second is not signed at the end by Halley and it also differs slightly in structure. The first log included several tables of data, ranging from two days to forty-three, but the second has only two tables of eight and eleven days, and instead largely gives the data in prose, as in these two examples for 2 and 11 November 1699:
[2 Nov] By a very good observation I am in 7°.40′ North Latt: Since yesterday noon we have had the Winds from EbN to NEbE a fine gentle Gale; in the night we had much Lightning, but no Thunder. We have made our way S24°E Distance 73 Miles, Diffrence of Longitude 30′ East, My Long from Lon: 18°:57′ West
[11 Nov] By a good observation I am in Latt 2°.42′ We have had the wind mostly at SSE and have made our way good W38S. 62 Miles diffr of Long 48 Minutes Long West from Lon. 20°:37′ a Fine Gale and fair weather Saturday Morning and Evening I had a good observation of the Variation Morn Ampl[itude] 18°:50′ Even 21°:30′.
So at noon each day he records his latitude, the weather, his course, miles covered, difference of longitude from the previous day’s measurement, and his total longitude west from London. Most entries at sea include this basic information in this style, and a number of days include additional data (variation and amplitude) and anything out of the ordinary (such as birds flying around the ship). I’m rarely tweeting a full entry, usually the latitude, weather and any general information. I’ve also occasionally silently added some punctuation and have always rendered values as DD°MM’ regardless of how they appear in the log.
There is no overall ‘story’ to the second voyage, unlike the first with the hostility and court martial of Lieutenant Harrison. Halley is now focused on collecting his data and we’ll see what use he puts it to at the end of his voyage.
One thing I find surprising (and frustrating) is that he makes very few remarks about the places he visits and appears to show little interest in the lands or native inhabitants – and this leads me to wonder whether Halley might perhaps have kept a private journal?
His second logbook is very much a ship’s log rather than a natural philosopher’s journal, but as an active member of the Royal Society I would expect him to take an interest in a far wider range of topics with which he might entertain the Fellows on his return.  When Halley was at the Chester Mint, in the two years before his first voyage, he sent several reports back to the Society (a number of which were published in the Philosophical Transactions), so it seems strange that he would sail around the Atlantic and not make notes of events that would be likely to interest the Fellows. 
I haven’t encountered any suggestion of a private journal but we saw from the Society’s minutes that he collected botanical specimens on his first voyage, which was not indicated in his logbook, and there are similarly some unreported items that will appear at the end of this voyage, so a private journal or notes might perhaps have existed – and how much more interesting that would surely be for the general reader!
But there are some entertaining entries still to come in his official logbook, which will resume on 29 December when he leaves Rio for the southern latitudes and he and his crew encounter something none of them have ever seen before…
 Halley was elected Fellow of the Royal Society on 30 November 1678 but had to resign his fellowship when he became clerk in January 1686. He was re-elected FRS on 30 November 1700.
 These accounts from Chester published in the Phil Trans give some idea of the range of subjects Halley might report on: a dog born “per anum” and a Roman altar; two reports of a hailstorm here and here; a trip to Wales to try the Torricellian experiment; observations of a lunar eclipse.