Halley’s third logbook

I said at the start of this Channel voyage that I wouldn’t be live-tweeting the logbook as I’d done for Halley’s two Atlantic voyages, as I felt the high proportion of technical data would be of little interest to the general reader. That was a pity as the third logbook is the only one handwritten by Halley, and so from that point of view it’s an interesting document.

In fact I did tweet a few entries at the start of the voyage and I’m doing so again now at the end as these entries contain more general information – but to give you a flavour of the main substance of the log, here’s a typical entry in which Halley records soundings and the times and lunar positions of the tides:

[Sat, June 21] about 9h in the Morn I weighd and stood off to Sea, with a gentle gale of ENE wind, and about One after noon came to an anker in 18 fath. the Ness Light baring NNW; and Calis cliff ENE. here the westward tide was done at 5h.35′, or three hours and half before the Moons Southing. whence I concluded the course of the Tides here the same as at the Ness. viz that a II½ Moon ends the Eastern Tide. at 6h I weighd and stood to the eastward with a small gale of SSW wind, and about 9h fell with the West end of the Riprapps which is a narrow rigd of soft sand. I crost it severall times in 9, 8 and 7 fath and the Eastern tide being near done, I came to an anker in that depth the Ness light baring WNW and that of the South Foreland NbE p[er] Compass. here I rode two tides and found the Eastern tide done on a SW or NE Moon nearest. that it flowed about three fath. that it runs half tide here as by the Shore and that the Sett of the Stream is nearest NE and SW.

We’ll consider the purpose of this data when we look at the results of the voyage, but in this post I want to focus on what I like to call The Mystery of Halley’s Clerks.

Now that remark may excite expectations that this post will struggle to satisfy for this is not a tale of clerks going to sea and mysteriously disappearing, but rather a puzzle about what exactly the clerks did on the voyages – why, for example, was the third logbook written up by Halley and not by his clerk?

The clerk on the third voyage was one Richard Pinfold, who was the only person besides Halley to sail on all three voyages. On the two Atlantic voyages Pinfold was listed as captain’s servant, but on the third voyage he was said to have been captain’s clerk, and so I wondered whether he might have been a servant in Halley’s own household and been promoted to clerk as a ‘reward’ for going on the first two voyages, with Halley effectively covering the job himself. However, the manuscript pay and muster books show that Pinfold was actually entered as gunner’s mate and that the post of captain’s clerk was later interposed in the pay book beneath gunner’s mate. Pinfold was paid a salary as both gunner’s mate (£5 8s 6d) and captain’s clerk (£1 12s 11d), and the small wage paid to him as clerk suggests he performed that job for only a short time, and we know he wrote neither the logbook nor Halley’s letters.

The logs of the two Atlantic voyages weren’t written up by Halley, so they must’ve been written up by his clerks… well, possibly, but possibly not. There’s no immediate reason to doubt that the log of the first voyage was written by the clerk, Caleb Harmon, but the log of the second voyage is more of a puzzle. Halley wrote all his own letters to the Admiralty on both voyages, except for two on the second, and you might expect these to have been written by the clerk, William Curtiss, but they are in a different hand from that of the logbook. My first thought was that Curtiss perhaps fell ill with the “Barbadoes desease” at the same time as Halley, and so another crew member wrote them – but the two rogue letters (which are in the same hand) were written on 30 March and 8 July, either side of the period of sickness in late May, and the July letter states specifically that “we are a very healthy ship” at present. Why then did someone else write the letters, more than three months apart, and why did that person not receive extra pay as Pinfold did on the third voyage? Or why did Curtiss write the letters but not then the logbook?

The person who wrote the first logbook isn’t straightforward either. From the start of this project I’d been surprised at how neat and uniform the logs were and wondered whether they’d actually been written during the voyage or after the ship’s return to London, but then found that other logbooks were similarly neat and so thought that clerks might make draft notes and then write them up neatly while at anchor or in calm seas.

The idea of draft notes fits with a comment made by Alexander Dalrymple in an advertisement for his 1773 publication of Halley’s two Atlantic logs that

The Journal of Dr. Halley’s first Voyage is written on sundry scraps of paper, and some parts repeated in different places, and so blended that it was a very difficult matter to make it out intelligibly…

Dalrymple, who borrowed (and seemingly failed to return) these “scraps of paper” from the Board of Longitude, doesn’t mention whether the handwriting on the scraps was Halley’s or someone else’s, which is a pity as that might tell us something about how that logbook was compiled. A further curiosity is that Dalrymple seems to have been unaware of the existence of fair copies of the two logbooks (now in the British Library), and his published version of the second log was evidently compiled from another source, as there are discrepancies between the two. So what was the source for the second log used by Dalrymple, and who wrote it? And when were the fair copies of the two journals written?

These “sundry scraps of paper” also suggest a new spin on the warning given to Halley by Josiah Burchett at the end of the second voyage. Burchett wrote to Halley in Deptford, giving him permission to leave his ship to call on their lordships in London, “only lett mee give you this Caution, To have ye Books in readinesse”. Now I’d previously assumed this warning was intended to help Halley overcome the misgivings felt by some of their lordships about his handling of the prematurely-terminated first voyage* by making sure he was properly prepared when he met them, but now I wonder if it instead implies that Halley had previously displeased their lordships by returning from that voyage with only “scraps of paper” for his journal, and only had it written up on his return.

So while I think the mysteries surrounding Halley’s clerks might not rival And Then There Were None for excitement, they certainly seem to form a Problem at Sea.

* If you didn’t follow the first voyage, click on the tag for Edward Harrison to read about Halley’s problems with Lt Harrison and other officers.

Halley’s Atlantic Chart, part 2: his results

Halley undertook his Atlantic voyages to measure the magnetic variation at sea. Magnetic variation (or declination) is the angle between magnetic and geographic north in a horizontal plane. Halley thought that if a pattern could be observed in the variation, it might offer a way to determine a ship’s longitude at sea. He measured the variation regularly throughout his two voyages and began preparing the presentation of his data as soon as he arrived back in Deptford in September 1700.

Halley is noted for his ability to draw general conclusions from complex data and for his appreciation of visual representation of those conclusions, and he demonstrated both these traits in presenting his data in the form of a sea chart.

The chart – known as his Atlantic Chart – holds an important place in the history of cartography, as it is regarded as the first published chart to represent magnetic declination using what became known as isogonic lines. It was not the first time such lines had been thought of, but the earlier examples were never published and Halley is thought unlikely to have known about them. [1]

We’ll look at the chart and its data in a moment, but first I’d like to highlight some of its decorative features.

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To the east of the mysterious birds, we find The Icey Sea with the black-streaked “Mountains of Ice” that Halley and his crew had encountered in February (notice their track passing through it). Neither Halley nor his crew had seen icebergs before and Halley was unsure whether they were floating or grounded.

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The track of Halley’s second voyage is shown on the chart and indicated by representations of the Paramore pursuing her figure-of-eight course.

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There are three cartouches on the chart: the one on South America is formed by a native family reclining beneath two fruit-laden palm trees. The adults wear feathered headdresses and skirts, the woman clutches a small child and the man holds a spear, has a bow at his feet and a quiver of arrows on his back. Behind them, hanging between the trees, is a sheet bearing the chart’s title:

A New and Correct CHART Shewing the Variations of the COMPASs in the WESTERN & SOUTHERN OCEANS as Observed in ye Year 1700 by his Ma:ties Command by Edm. Halley.

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A second cartouche appears on the landmass of Africa and carries the chart’s dedication to William III and is topped by personifications of astronomy (holding a telescope and armillary sphere), navigation (a backstaff and ship) and mathematics (dividers and triangle).

The third cartouche is found on North America and explains the information depicted in the chart:

The Curve Lines which are drawn over the Seas in this Chart, do shew at one View all the places where the Variation of the Compass is the same; The Numbers to them, shew how many degrees the Needle declines either Eastwards or Westwards from the true North; and the Double Line passing near Bermudas and the Cape de Virde Isles is that where the Needle stands true, without Variation.

And here’s the full chart, shown with the permission of the Royal Geographical Society:

Halley's Atlantic Chart (© Royal Geographical Society (with IBG), Image S)

Halley’s Atlantic Chart – click to open in a new tab. (© Royal Geographical Society (with IBG) (£), Image S0015919)

You can see that it has two compass roses, the one in the mid-Atlantic radiating lines that somewhat obscure Halley’s “Curve Lines” of equal magnetic declination. (Halley himself realised this was a problem and omitted this feature on the World Chart he published around a year later.) It is on a Mercator projection, with lines of latitude and longitude, and the meridian of London, the equator and tropics identified, but no indication of scale.

This version of the chart includes text that was written subsequently by Halley and printed in two strips that could be stuck to the sides of the original chart. It describes how to consult the chart by way of examples, and explains that it has two uses:

  • to enable the mariner to know by how much he needs to adjust his course to take account of the magnetic variation, and
  • to estimate a ship’s longitude at sea, the curve lines running nearly north-south (as off the west cost of Africa) giving “a very good Indication of the Distance of the Land” from the ship

This useful knowledge is obtained by reference to the isogonic lines. They are a little difficult to pick out but you can easily see the double curved line to the right of the central compass, which Halley has named The Line of No Variation (the agonic line) and the curved lines above and right show the degree to which the compass varies west of geographic north, and to the left, east of geographic north (the number of degrees of variation is shown on the horizontal line above The Icey Sea).

As mentioned above, the chart was (and is) regarded as the first (extant) published use of isolines (contour lines), and until the nineteenth century these lines were known as Halleyan lines.

So the chart is impressive and historically important, but how accurate was it? Alan Cook observed that it was “an improvement on anything that had gone before”, [2] but as I wrote in a previous post, the problem with longitude is knowing both where you are and where the place is that you’re heading. Halley’s recorded longitude was often inaccurate and sometimes considerably so: when he was sailing towards St Helena from the east, the longitude value he reported is actually west of the island – and so the degree of variation he thought applied to the east of the island in fact applied to the west.

Similarly the coordinates of islands and land weren’t then accurately known: Cape Horn, for example, is roughly 10° further west on Halley’s chart than we now know it to be, so his lines of variation near that coast must be likewise misplaced. [3] It seems to me that the moral of this exercise is that to devise a chart that helps estimate a ship’s longitude at sea, the deviser needs to have a fairly accurate knowledge of longitude in the first place.

But Halley was alert to the likelihood of error in his chart and in his final paragraph he wrote that:

…all knowing Mariners are desired to lend their Assistance and Informations, towards the perfecting of this useful Work. And if by undoubted Observations it be found in any Part defective, the Notes of it will be received with all grateful Acknowledgment, and the Chart corrected accordingly.

And I think that’s how Halley’s chart was most useful: it was a cartographic innovation from which better and more accurate maps might evolve.


[1] For details of prior manuscript isoline charts see Thrower, The Three Voyages of Edmond Halley in the Paramore 1698-1701 (Hakluyt Society: London, 1981) pp 57-58, and Thrower, Maps & Civilization (3rd ed, Chicago and London, 2008) pp 97-101.

[2] Cook, Edmond Halley: Charting the Heavens and the Seas (Oxford, 1998) p 281.

[3] In 1714 Halley defended his World Chart (an extended version of his Atlantic Chart, incorporating data supplied by others) in the Philosophical Transactions from charges of inaccuracy by the French Royal Academy of Sciences, including that he had placed Cape Horn too far west.

All images © Royal Geographic Society (with IBG) (£), Ref S0015919.

Halley and longitude

If you’ve been following this blog about Halley’s voyages, you’re probably aware that 2014 is the 300th anniversary of the Longitude Act, which offered financial rewards for practicable methods of finding longitude at sea to specified degrees of accuracy.

Halley was involved with the quest for longitude throughout his long life: in 1675, aged 18, he was present when Flamsteed and Hooke visited the proposed site of the new observatory in Greenwich, being built by order of Charles II to help find longitude at sea; he was made a commissioner under the 1714 Longitude Act, courtesy of his position as Savilian Professor of Geometry (later also as Astronomer Royal), and around 1730 it was Halley who sent clockmaker John Harrison to see George Graham to discuss his ideas for a marine chronometer.

By the second half of the 18th century, there were two serious contending methods for finding longitude at sea, lunar distances and timekeepers, but in the late 17th and early 18th centuries, a diverse range of schemes were proposed, including finding longitude via magnetic variation.

Magnetic variation (or declination), the angle between magnetic and true north in a horizontal plane, was well known to the scientifically-minded, as too was the fact that it varied in different locations and also over time. It was thought that if an underlying pattern to the variation could be identified, it might offer a way of finding one’s longitude – and it was this that Halley was seeking to do on his voyage.

We’ll see Halley’s results in due course but for now we’ll consider one of the key difficulties with the theory, which is best illustrated by comparing data from four ships’ logs. [1]

At the start of Halley’s first voyage, he sailed from the Isle of Wight to Madeira in company with Admiral Benbow’s squadron and four of the five ships’ logs have survived, so we can compare their recorded latitude and longitude over several days:


1698 Falmouth Gloucester Lynn Paramore
Dec 2 47°28′ 47°39′ 47°24′ 47°23′
Dec 3… 46.28 46.30 46.13 46.20
Dec 14 32.39 32.36 32.43 32.25
Dec 15 32.22 32.26 32.19 32.15

Here, I’m showing the first and last two days that all four ships recorded data (leaving the English Channel and approaching Madeira) and you can see immediately that the latitudes are very similar – but the reported longitudes present a very different picture (first/last 5 days):


1698 Falmouth Gloucester Lynn Paramore
Dec 2 149.3 8°01′ 2°10′ W 8°00′
Dec 3 60.1 6.59 3.30 9.10
Dec 4 5.53 5.12 10.03
Dec 5 29.9 5.34 6.00 10.09
Dec 6… 51′-5/10 4.27 7.07 11.07
Dec 11 8.41 W 3.00 9.35 12.15
Dec 12 8.55 W 3.00 9.39 12.15
Dec 13 10.50 1.08 11.15 14.09
Dec 14 12.03 0.14 11.42 15.03
Dec 15 13.20 13.11 16.07

This table looks like a confused jumble, demonstrating that this is a problematic coordinate. Looking first at the Paramore, Halley always noted that his longitude position was measured west from London, and on December 15 he described himself as being to the south-east of Madeira, which is 16°55′ west of London, and so 16°07′ seems a respectable figure for his position.

The Gloucester does not specify where its longitude is measured from but apparently starts from the same longitude as the Paramore but then declines in value to zero as it approaches Madeira, and so that ship’s longitude is being measured east from Madeira (or possibly El Hierro in the Canaries, a common zero meridian of the time, in which case the final value is over a degree out).

The Lynn‘s figures increase like the Paramore‘s, but the values are quite different and I think these values are measured from Lizard Point as they depart from the English Channel (it isn’t specified). The later values for the Falmouth are similar to the Lynn‘s but the earlier ones are unlike any others and I’m assuming these positions are only partially calculated and represent the minutes travelled since the previous noon.

So these logs demonstrate one of the problems with longitude: even if you could accurately measure your longitude, where did you measure it from? (The prime meridian at Greenwich wasn’t agreed upon until the 1880s.) And how did this varying data affect the accuracy of the period’s maps and charts?

In other words, Halley didn’t really know where he was (his recorded longitude is often erroneous, sometimes considerably so) or even, strictly, where he was heading as many places were wrongly laid down in maps – and so how useful could a theory be that was founded on wrongly-placed locations?

In spite of this, Halley apparently found all the islands he states he will sail for, even though some are little more than large rocks in a vast ocean. Halley followed the customary practice of parallel sailing (sailing along a coast until you attained the latitude of the place you were aiming for and then sailing east/west until you reached it) but on his “Southern cruise” he was seeking tiny islands (Tristan da Cunha, Martim Vaz) from the middle of the Atlantic ocean – I think he must have had at least one very sharp-sighted crew member on board!

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[1] References for the logs are: Falmouth NA, ADM 51/341; Gloucester NA, ADM 51/401; Lynn NA, ADM 51/3892; Paramore BL, Add MSS 30398. The figures are (mostly) degrees/minutes but the notation differs in each log (I’ve used the Paramore‘s).

Christmas at sea

Halley offers no clues in either of his logbooks as to how he spent Christmas; he’s anchored in Rio during Christmas on his second voyage and for all we know he and his crew could be having a beach barbecue and dancing the samba!

View of Sugarloaf Mountain from the Silvestre Road by Charles Landseer, c 1827. (Credit: Wikimedia Commons)

View of Sugarloaf Mountain from the Silvestre Road by Charles Landseer, c 1827. (Credit: Wikimedia Commons)

We do have some idea of how a ship’s crew celebrated Christmas Day in the late seventeenth century from the highly entertaining Diary of Henry Teonge, which provides two accounts of Christmas spent on board a ship. [1]

Henry Teonge (1621-1690) was a Warwickshire clergyman with a wife and four children, who, probably owing to poverty and debts, went to sea as a Royal Navy chaplain in his mid-50s.

On his first voyage, Henry was entered as chaplain on board the fourth-rate frigate Assistance on 27 May 1675, under the command of Captain William Houlding; on his second, he served on board the Bristol under Captain Anthony Langston, transferring mid-voyage with his captain to the Royal Oak. He kept a diary of both voyages (May 1675-Nov 1676 and May 1678-Jun 1679) and it seems fair to say that the ageing Henry proved a natural-born seaman.

He was interested in all aspects of life on ship and in the places he visited, but his main interest – sensible man – was his belly, and his diary has numerous, highly-detailed reports of meals, including those he enjoyed on Christmas Day.

His first Christmas entry was for 1675:

Chrismas day wee keepe thus. At 4 in the morning our trumpeters all doe flatt their trumpetts, and begin at our Captain’s cabin, and thence to all the officers’ and gentlemen’s cabins; playing a levite at each cabine doore, and bidding good morrow, wishing a merry Chrismas. After they goe to their station, viz. on the poope, and sound 3 levitts in honour of the morning. At 10 wee goe to prayers and sermon; text, Zacc. ix. 9. Our Captaine had all his officers and gentlemen to dinner with him, where wee had excellent good fayre: a ribb of beife, plumb-puddings, minct pyes, &c. and plenty of good wines of severall sorts; dranke healths to the King, to our wives and friends; and ended the day with much civill myrth.

Not bad, but his second Christmas dinner (1678) seems even better, though it was apparently not as good as they had actually planned:

Good Chrismas Day. Wee goe to prayers at 10; and the wind roase of such a sudden, that I was forced (by Captain’s command) to conclude abruptly at the end of the Letany; and wee had no sermon. And soone after, by the carelessnes of som[e], our barge at starne [stern] was almost sunk, but recovered. Wee had not so greate a dinner as was intended, for the whole fleete being in this harbour, beife could not be gott. yet wee had to dinner, an excellent rice pudding in a greate charger, a speciall peice of Martinmas English beife, and a neat’s tounge, and good cabbige, a charger full of excellent fresh fish fryde, a douzen of wood-cocks in a pye, which cost 15d., a couple of good henns roasted, 3 sorts of cheese; and last of all, a greate charger full of blew figgs, almonds, and raysings; and wine and punch gallore, and a douzen of English pippens.

Wine and punch galore! One can’t help thinking that a Royal Navy ship was rather a good place for a destitute gourmet to spend his Christmas. But it was also a day of contrasting emotions for Henry, as his entry continues:

The wind was so high all this night, that wee ever expected when it would have broake our cable or anchor. But the greatest losse wee yet sustayned was this: about 11 or 12 a clock our honest Leiuetenant, Mr. Will. New, dyed, and left a mornfull ship’s company behind him. Yesterday our Capt. bought 3 Spanish hoggs: the ruffnes of the weather made them so sea sick, that no man could forebeare laughing to see them goe reeling and spewing about the decks.

As I said, we have no idea how Halley spent his Christmas but it seems a safe bet that the atmosphere was a lot friendlier on the second voyage than on the first, and so I hope they were as merry then as Henry and his brother seamen evidently were on his second voyage.

Wishing all our readers a Merry Christmas – and do go easy on those “minct pyes”!


[1] The Diary of Henry Teonge, Chaplain On Board His Majesty’s Ships Assistance, Bristol, and Royal Oak, Anno 1675 to 1679 (London, 1825). There is an online version here.

Halley’s second logbook

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

(I’ve written before about the correct spelling of Halley’s first name and that of his ship.)

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. [1] 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. [2]

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…


[1] 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.

[2] 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.

The end of Halley’s first voyage



Extract from Halley’s first logbook, in another hand but with his signature (© British Library (£), Add MSS 30368, f.8v)

“The Gunns and Gunners Stores were delivered to the Tower Officers and that Same Evening we moord our Shipp at Deptford”

This was the final entry dictated by Captain Halley to his clerk on Tuesday 11 July 1699, with Halley’s own signature bringing the log of his first voyage to a close.

Halley was paid wages of £168 0s 0d, less deductions for the Royal Hospital for Seamen at Greenwich and for “bearing Supernumery’s”, leaving net pay of £140 2s 8d. Lieutenant Harrison received £71 5s 2d (£71 0s 0d net), and the clerk Caleb Harmon was paid £15 19s 3d (£15 3s 1d net), which his father apparently collected.

The pay book was signed by both Halley and Harrison:


Extract from the Pay Book (© National Archives (£), ADM 33/196)

There was one final page to Halley’s logbook: “A Table of the true Latitudes & Longitudes of the Severall Islands and Ports mentioned to have been seen in this Voyage”, and I’ve adapted that table for inclusion below.

Otherwise, Halley will spend the next few weeks persuading “their Lopps” to allow him a second voyage in Paramore – and he’ll set sail again in mid-September when this blog and his twitter feed (@HalleysLog) will resume.

I hope you’ll join us again in September, when we’ll start by looking at what Halley got up to over the summer – in the meantime, I wish all our readers a great summer!

Halley’s table of latitudes and longitudes

I’ve separated Halley’s table into two parts – one for latitude and one for longitude – so that I could add modern values for comparison with Halley’s. The modern values are taken from Wikipedia and may not represent the exact same location where Halley made his own observations, and so the figures and differences are indicative only (I haven’t noted whether the differences are plus/minus to keep things simple). 1 degree of latitude is roughly equal to 69 miles (approx 111 km), and 1 degree of longitude is also about 69 miles at the equator, but lessens as you approach the poles.

In both tables, the place names and ‘Halley’ column are taken from the table that concluded Halley’s logbook, but the values there are not always the same as those he recorded during the voyage. For example, the longitude values he recorded during the E-W Atlantic crossing were significantly in error – undoubtedly owing to his inexperience in reading the currents – but he realised this on reaching Brazil (via astronomical observations) and so recalculated his longitude values for the final table. (Harrison seems to have recorded more accurate values during this passage.)

As you’d expect, his latitude values are more accurate than his (amended) longitude values, although his longitude values around the Caribbean seem pretty good. Longitude is measured West from London.

Table 1 – LATITUDE





The Lizard




North part of Scilley








Isle of Sall




St Iago ye North Cape




Isle of May




Porto praya South side of St Iago




Fernando Loranho




Cape Dello at the Mouth of ye River of paraiba in Brasill




















Monte serrat North end








Nevis Road




Old Road of St Christophers












St Bartholomew




St Martins













The Lizard




North part of Scilley








Isle of Sall




St Iago ye North Cape




Isle of May




Porto praya South side of St Iago




Fernando Loranho




Cape Dello at the Mouth of ye River of paraiba in Brasill




















Monte serrat North end








Nevis Road




Old Road of St Christophers












St Bartholomew




St Martins








Harrison’s book

If you’ve been following this blog, you’ll know I’m an admirer of Halley and expect that I side with him in his difficulties with his lieutenant – yet when I first read about Edward Harrison and his book, I did have some sympathy and respect for the lieutenant.

Harrison described himself as “sea-bred”, indicating he’d been at sea from an early age, but he was evidently a man of some, if limited, education. These facts suggest someone of modest background and resources, and so it seemed to me rather impressive that he had written a book, got it printed, and circulated it to the Royal Society and the Admiralty – and I could feel some sympathy for his dismay when Halley then dismissed his enterprising efforts.

But then I read his book and that sympathy disappeared. The book, Idea Longitudinis, was published by Harrison in 1696; he’d submitted a paper of his ideas to the Royal Society about 2 years earlier but received no encouragement and so he decided to “appear on the Publick Stage”. [1]

The book includes a dedication to the Lords of the Admiralty, a preface, and 8 chapters including a conclusion, the whole about 97 pages long. The first 3 chapters cover: where to set a first meridian, a definition of longitude, a definition of time (solar, sidereal year), and chapters 4-7 consider the different methods of finding longitude: horological, magnetic variation, lunar, and Jovian.

The book seems not without merit as a handbook for his “Brother Tar”, and some of his remarks about the problems that would be encountered (refraction, parallax, impossibility of using a long telescope (for the Jovian method) on a rolling ship) are helpful – but this was all commonplace to the fellows of the Royal Society, and I would guess that that was the opinion Halley gave to their Lordships.

What Halley actually said about the book doesn’t seem to be extant, but a slightly later review of another paper of Harrison’s may give us some indication. While Halley was away on his second voyage, Harrison submitted another paper to the Royal Society on tides and winds, and this was reviewed by Richard Waller, who ends his 2-page review with “between you and me [he’s writing to Hans Sloane] I see nothing in the Paper but what is better explained in the places I have above quoted”. [2]

The opening lines of Harrison's Chapter V are taken from Halley's 1683 paper

The opening lines of Harrison’s Chapter V are taken from Halley’s 1683 paper

Perhaps Halley gave a similar assessment – that it contained nothing new – an opinion that would be reinforced when he found that the opening lines of Harrison’s chapter on magnetic variation (see image) were copied almost verbatim from his 1683 paper on the same subject (there’s at least one other section copied directly from Halley’s paper).

Alan Cook describes Harrison’s book as “[s]cientifically and technically… poor, second-hand, and ill-digested. It is shot through with aspersions on mathematicians, the manner is aggressive, and it shows a deep inferiority complex”, and possibly the most interesting aspect of the book is what it reveals about Harrison himself, giving us some idea of what Halley had to deal with on board his ship. [3]

Harrison comes across as having a rather inflated view of himself. He twice compares himself to Columbus as being someone who “shewed the way”, and warns us that some “ordinary Mathematicians may hate to be out-done by a Tarpolin, if they have ought to say against him, its because his Practice and Experience may prove him to be a more Competent Artist in Navigation then [sic] themselves”. [4]

Hindsight makes the opening lines of the dedication seem ironic: “It is a saying in the Navy, He that knows not how to obey Command, is not worthy to bear Command”. As, too, does this sentence, given he’d lifted passages from Halley and then gone on to despise him for dismissing his book: “If any Envious Person pretend I have borrowed most of my Book, may he be obliged to Quote the Authors, where I have not”. [5]

The passages that revealed most about his personality were also the most unexpected:

“…if I know more than others, it is by Divine Authority, by Industry and Experience, by an Inborn Idea, and Instinct in Nature; it was ordained for me by God Almighty, from my Mother’s Womb.” [6]

And when considering the location of a first meridian:

“I could Bafle and Impose on the World as our Predecessors have, false Arguments for other places, from whence they might account their first Meridian. God forbid I should be so wicked, Honour and Glory, and beginning of Good, belongs to God; a first Meridian may be represented, and if the Heads of our Church and State, think it good, let there be made a Figure, representing a first Meridian, and Erected over St. Pauls Church in London, with this Inscription, Glory be to God, good Will towards Men…” [7]

Harrison's Idea Longitudinis, preface

Harrison’s Idea Longitudinis, preface

Blimey. These passages took me by surprise, as it had never occurred to me that Harrison might be religious, and they perhaps provide another reason why Harrison was so hostile towards Halley, as Halley had something of a reputation for being irreligious. I think Halley must have had a hard time dealing with Lieutenant Harrison, and yet, as he tells us, he “endeavoured all I could to oblige him”. [8]

My feeling is that Halley gave an honest critique of Harrison’s book, but that Harrison was not the type of person who could accept criticism and so nursed a grievance towards Halley (whom perhaps he had once admired, given his imitation of his works) and seized the opportunity to wreak his revenge when chance put them together on board the same ship.

I suspect that Harrison was rather fortunate in the court’s verdict

This post was originally published on 10 July 2013 and revised in July 2017.


[1] Edward Harrison, Idea Longitudinis (London, 1696), preface

[2] Richard Waller to Hans Sloane, dated 4 Dec 1699, Royal Society, EL/W3/68

[3] Alan Cook, Edmond Halley: Charting the Heavens and the Seas (Oxford, 1998) p 264

[4] Harrison, preface

[5] Harrison, preface

[6] Harrison, preface

[7] Harrison, pp 3-4

[8] Captains’ Letter Book, National Archives, ADM 1/1871