Halley arrived back at Deptford on 10 October 1701 and immediately began to prepare his data for publication. He had undertaken the voyage with the aim of identifying a general rule for the complex tides of the Channel, and before he returned he had written to Josiah Burchett, Secretary to the Admiralty, to tell him that he had “discovered, beyond my expectation, the generall rule of the Tides in the Channell; and in many things corrected the Charts therof”.
Halley had observed the tides and depths in the Channel, and surveyed the coastline and hazards, such as sandbanks and shoals. He again chose to publish his data in the form of a chart, and by mid-November he had a draught ready to show to a meeting of the Royal Society. Some time later, the chart was published by Mount & Page under the title, ‘A NEW and CORRECT CHART of the CHANNEL between ENGLAND & FRANCE: with considerable Improvements not extant in any Draughts hitherto Publish’d; shewing the Sands, shoals, depths of Water and Anchorage, with ye flowing of the Tydes, and the setting of the Current’, which left the prospective buyer in little doubt as to what he was purchasing.
Halley’s chart resembles a portolan chart with its radiating lines, but it was an improvement on existing maps because Halley surveyed by taking angles from the rising or setting sun, rather than the more usual (but less accurate) magnetic compass. The chart has inset maps of the Isle of Wight and Plymouth Sound, and it records depths in fathoms around the Channel and ‘ye Hour of High-Water, or rather ye End of the Stream that setts to ye Eastward, on ye Day of ye New & Full Moon’ was indicated by roman numerals. Halley gave instructions to seamen on how they could use these figures to estimate the height of tides around the Channel, and he included his customary call to mariners to send him new data that could be added to future editions of the chart. The Admiralty were evidently pleased with Halley’s work as they again paid a bonus of £200 “as a reward to him for his Extraordinary pains and care he lately tooke, in observing and setting down the Ebbing, and Flowing, and setting of the Tydes in the Channell”.
The chart was incorporated into pilot books and reprinted many times throughout the eighteenth century, both in England and on the continent (you can view several examples on the BNF’s Gallica website here), although Halley isn’t always credited as the source in later editions. Halley’s performance probably secured him the mission to the Adriatic, where he was sent by Queen Anne to survey the Imperial coast for the purpose of identifying a harbour where English ships could overwinter during the War of the Spanish Succession. Halley made two trips to the area in 1702 and 1703, and not only identified a suitable harbour, but also directed its fortification. Ultimately the Royal Navy did not need to overwinter in the area, but Halley’s work was rewarded by the support of the Secretary of State in the election for the Savilian Professor of Geometry at Oxford, where success brought Halley’s seafaring days to a close.
This final post has been horribly delayed by what Halley would call “Domestick Occasions”.
 TNA, ADM 1/1872, 13 Sept 1701.
 In fact, this may not have been the title when it was first published: I’ve looked at several versions of the chart and they all seem to have a slightly different title and it isn’t clear which one was Halley’s original.
 Thrower, Three Voyages of Edmond Halley, p. 345.
But while Edmond had quickly resumed his old habits of attending Royal Society meetings and discoursing endlessly in coffeehouses, the sea was never far from his mind, and on 23 April 1701 he sent this proposal to the Lords of the Admiralty (remember “Lopps” is Halley’s abbreviation for “Lordshipps”):
It is humbly proposed
That if their Lopps shall think fitting to have an exact account of the Course of the Tides on and about the Coast of England, so taken as at one View to represent the whole; (which will be a work of generall Use to all Shipping, especially such as have occasion to turn to Windward, and wch is wanting towards the compleating the Art of Navigation) there be provided a small Vessell such as their Lopps shall think proper, with all convenient speed, on board of which such an account of the Tides may be taken, as their Lopps shall direct; for which service their Lopps most obedient servant humbly offers himself.
Edm. Halley 
Their Lopps did think it fitting to have the course of the tides around the southern coast of England observed and gave the order for a vessel – yes, the Paramore Pink – to be prepared for Halley’s third expedition.
So Captain Halley expects to put back to sea very very soon – there’s just the one small matter of a crew to recruit…
 Halley to the Lords Commissioners of the Admiralty, 23 April 1701, TNA, ADM 1/1872
Halley arrived back in Deptford from his second voyage on 10 September 1700 and he’ll return to sea for his third voyage in June 1701 (June 2015 by the life of this blog), so I thought I’d close this phase of my project by looking at some of the things that Edmond will be doing in the intervening months.
As we’ve seen (here and here), he began preparing his chart of magnetic variation as soon as he returned to London and there are periodic entries in the Royal Society minutes of his showing (what are assumed to be) manuscript drafts of his chart at their meetings. He presented a copy formally to the Society on 4 June 1701, when the minutes record:
Mr Halley presented the Society with a Map of his late Voiage to the South. He was thanked for it, & it was order’d to be hung in the Meeting room. 
The exact publication date of the chart isn’t known but is assumed to have been during the second quarter of 1701 (given its presentation date to the RS), and it occurs to me that a letter dated 6 May 1701 from the Admiralty to the Navy Board, awarding a bonus of £200 to Halley on the order of the king, may have been prompted by the publication of his chart:
In obedience to his Mats. [Majesty’s] Commands signified to this Board, Wee do hereby desire and direct you to cause to be paid unto Captn. Edward [sic] Halley, out of the Money in the hands of the Trea[sure]r of the Navy upon Acct. of the Tenths of Prizes the sum of two Hundred Pounds, in consideration of his great Paines and care in a late Voyage he made for the discovering the Variation of the Needle. 
Halley resumed his attendance at Royal Society meetings when they reconvened after their summer recess, and, having resigned his Fellowship in 1686 to become the Society’s clerk, he was re-elected FRS at the General Meeting of 30 November 1700 and voted one of the auditors of their accounts on December 17. 
Halley was often referred to as “Capt Halley” in the Society’s minutes of this period, but it’s somewhat surprising how few references there are to his voyage; I assume Edmond mostly talked about his expedition in the coffeehouses.
It was perhaps during this period that Halley had his portrait painted by Godfrey Kneller. The date of the portrait isn’t known, but has been estimated at around 20 years after his voyages because of a mezzotint version published after Halley became Astronomer Royal in 1720. However, Alan Cook says that Halley is wearing naval uniform and so suggests it may have been painted in 1702 after his third voyage, and this – or even 1701 – seems more likely to me, when Halley was famed for his voyages, and also because Halley appears younger in this portrait than in the one known to date before 1713. 
In between preparing his chart, attending Royal Society meetings, frequenting the coffeehouses, and perhaps having his portrait painted, Halley surely entertained his wife, Mary, and their three children with tales of adventures and of the people and animals he’d seen on his cruise. Perhaps he brought back curiosities as gifts for them?
I know he did bring back some items, and they’re partly what prompted me to speculate whether Halley had kept a private journal or notes during his voyage. Another reason is that one or both of his logs may initially have been written on loose pieces of paper and then written up later (and there is some doubt in my mind whether the fair copies were actually written up by his clerk(s)). I hope to do more research on the history of his logbooks and will perhaps write more about this at the end of his third voyage.
A further reason for my speculation is that there are extant papers besides his logbook surviving from the second voyage – namely, a series of sketches of fish! He presented these drawings (made by himself) to the Royal Society on 6 November 1700, along with some sketches of the Batavian Islands; the sketches of the Islands are seemingly lost but five sketches* of fish are safely stored in the Society’s archives and here’s perhaps the best of the set, with text written by Halley:
It was a great pleasure to see the originals in the Society’s library; they are more impressive ‘in the flesh’, and I particularly liked that they gave me a palpable sense of Edmond sitting down in his cabin and carefully sketching the fish on the table before him (you can really sense him at work on the fish’s scales towards the tail). The drawings may not display the talent of Hooke or Waller, but their ordinariness somehow serves to evoke the physical presence of Halley the man.
And so, having conjured his presence, we’ll leave him be for a while. His third voyage will start in June next year (2015 for us), and I’ll be back then to conclude this project to bring astronomer Edmond Halley’s seafaring adventures to wider attention.
Over the next two posts we’ll look at the results of Halley’s voyage, which he published in the form of a sea chart. But before we consider his chart in full, I want to pick out one detail which may help to settle the identity of those mysterious creatures that Halley saw in the South Atlantic.
In a previous post we looked at Halley’s descriptions of three animals – two birds and something akin to a whale – that he’d seen in the seas to the north-west of South Georgia, and I summarised his descriptions as follows:
a bird he takes to be a penguin with a black head and back, white breast, and a bill like that of a crow; it swims deep, dives on the ship’s approach, doesn’t appear to fly, and has a neck like a swan
a second bird he also takes to be a penguin, larger than the first, and the colour and size of a “young Cygnett”, it has a bill that hooks downwards, cries like a bittern, and also swims deep, dives on the ship’s approach, doesn’t seem to fly, and has a neck like a swan
an animal thought by the crew to be a seal but which Halley asserts is not. It bends its tail into a bow, has large fins like a shark and a head like a turtle
Giant petrel with chicks. (Brocken Inaglory/Wikimedia)
While researching that post, I wondered if the second bird might have been a petrel (because of the beak) and some readers suggested that too, but the main objection is that almost every image of petrels shows them flying, which Halley says they don’t do (“either not having wings, or else not commonly useing them”).
Another reader suggested they might have been shags and I think these seem more likely as they resemble penguins and have long necks (I’m looking at the Imperial and South Georgia varieties). They do fly, but the proportion of images of them flying is far lower than it is for petrels.
Imperial Shag, South Georgia. (Liam Quinn/Wikimedia)
In that earlier post I mentioned there was another piece of information about these birds that appears at the end of the voyage, and it appears in Halley’s chart. There, Halley gives a description of the birds and provides a little more detail:
The Sea in these parts abounds with two sorts of Animalls of a Middle Species between a Bird and a Fish, having necks like Swans and Swimming with their whole Bodyes always under water only putting up their long Necks for Air.
Now it seems to me that “a Middle Species between a Bird and a Fish” is a good way to describe penguins – but happily Halley doesn’t just describe his birds, he depicts them too! Here they are:
Er… oh, well, perhaps they’re not quite my idea of penguins after all. But before I scoff too much at Halley’s illustration, it’s worth remembering that he was trying to describe something he’d never seen before and to people who likewise had never seen such animals before, and so he has to use vocabulary and comparative imagery that were familiar to him and his readers. Additionally, he wasn’t near land when he saw the birds and he hadn’t mentioned seeing any floating ice, so he may only have seen them swimming in the sea, which would have made it very difficult for him to see them properly (have a look at this 36 second film of penguins at sea and you’ll appreciate his difficulty).
If you look closely at the birds, you can see that their beaks are slightly different, and the one on the right has a few tufts on the back of its head, so I wondered if that might have been a type of crested penguin, such as a southern rockhopper?
As to the animal the crew thought was a seal and Halley says is not, what’s curious about that is that he doesn’t call it a whale or whale-like, an animal he would have known – perhaps he was even among the crowd that went to gawp at this poor cetacean stranded in the Thames around 1690. 
I don’t have any more information about this animal, which Halley’s biographers have suggested might have been a bottlenose whale, a killer whale or a dolphin, although there are problems with each of these identifications – but I have been wondering whether it might have been a Risso’s dolphin? They have a more turtle-like head, a large dorsal fin, and unlike the bottlenose and killer whale are not remarkable in size, something which Halley fails to comment on. An unfamiliar type of dolphin might also explain why Halley doesn’t use the word whale and why the crew think it’s a seal.
But there are three objections to this suggestion: there don’t seem to be many images of them “twisting [their] tayl into a bow” as Halley describes them doing, he may have been outside their range when he saw them, and the sea temperature may have been too cold.
So we haven’t resolved for certain what these creatures were but we have added some new ideas to the list of possibilities. One thing is certain, though, and that’s that no further clues are likely to come from Halley: five months after his return to England, his recollection of these animals was even more confused as we find it minuted that at the Royal Society meeting of 5 February 1701:
Mr Halley said that he saw a kind of Tortoises in the S. of Brazile, having Necks like Swans, and all their bodies under Water. 
And for that creature, I think we may need to search among the monsters of medieval cartography, not the seas of the South Atlantic!
UPDATE MARCH 2017: HALLEY VINDICATED!
I rather scoffed at Halley’s depiction of penguins when I wrote this post in 2014, so you’ll imagine my astonishment when I came across a photograph on Twitter that entirely vindicated Halley’s drawing. The photograph was taken by Neil Spencer (@HalleyVIDoc), a doctor based at the Halley Research Station in Antarctica, who was himself surprised to see how penguins swam, tweeting “Didn’t realise penguins swim like ducks when on the surface!” and appending the photographed that demonstrated the point. Neil kindly gave me permission to use his photo – but let’s first remind ourselves of Halley’s own depiction:
Penguins swimming in Antarctic seas, by Neil Spencer. (Used with permission)
Separated at birth, no? And a lesson learned by me not to dismiss historical descriptions that seem rather naive and amusing (sorry, Edmond!).
If you’re not familiar with the Halley Research Station, it was set up by the Royal Society in 1956 as the British contribution to the International Geophysical Year of 1957/58, and named after Halley in recognition of his voyage to the South Atlantic, and to mark the tercentenary of his birth. Halley came within about 200 nautical miles of South Georgia on his second voyage, and South Georgia is roughly 1,300 nautical miles north of the Halley station (you can find them both on the map below). There have actually been six Halley stations on the Brunt Ice Shelf, and you can read about the history of these bases at the British Antarctic Survey (BAS) website here. The website has lots of information about the scientific work carried out at the station, along with photos of the six Halley bases, and details of the recent relocation of the current base, Halley VI. You might also enjoy (as I did) this look at the evolution of Antarctic bases from wooden huts to sci-fi chic, by the BBC (spot the tube roundel on the Halley III photo!).
Lastly, I wonder what Halley would think if he saw this map of the research stations now scattered all over Antarctica, having voyaged in search of the southern Terra Incognita just 300 years ago.
Map of Antarctic stations – Halley VI is near the coast of the Weddell Sea. (Source: Teetaweepo/Wikipedia)
 The text is well worth a read. You can probably make out the title, A Trew Draught of the Whale as he was seen at Blackwell Dock, and underneath it says:
This Monsterous Fish is 57 foot in Lenght & near 40 foot About, he is more in hight, then in breath, and is taken to be a matter of 50 Tunn in Wight, He was first discover’d near the Bouy of the Nore, Where he was fier’d at by a Kings Yoath so received sum Wound, & made toward the Shoure so came along by ye Hoop & beat himselfe upon ye Sand after that he was Harpoon’d & Taken, then Bought by a Quacor, etc.
The Paramore anchored in St George’s Harbour, Bermuda, on Friday 21 June 1700 and Halley and his crew remained there for nearly three weeks. They were busy during that time, the crew careening the ship in order to clean her, and Halley taking the latitude and longitude of the island, observing the tides and coastal dangers, and buying a new stream anchor to replace the one they had lost at Barbados.
Before leaving the island on 11 July, Halley wrote an informative letter to the Admiralty in London, describing his progress during the last few months:
(Halley to ?Burchett, dated 8 July 1700 from “Bermudas”, National Archives ADM 1/1871 (not autograph))
My last from St: Hellena, gave your Honour an Account of my Southern cruise, wherin I endeavoured to see the bounds of this Ocean on that side, but in Lattd. of 52°½ was intercepted with Ice cold and foggs Scarce credible at that time of the Year. haveing spent a Month to the Southwards of 40 degrees, and Winter comeing on, I stood to the Norwards Again and fell with the three Islands of Tristan da Cunha which yeilding us noe hope of refreshment, I went to St: Helena, where the continued rains, made the water soe thick with a brackish mudd, that when it settled it was scarce fitt to be drunke; all other necesarys that Island furnishes a Bundantley. at Trinidad we found excellent good water, but nothing else. Soe here I changed as much of my St Hellena water as I could, and proceeded to Fernambouc in Brassile, being desirous to hear if all were at peace in Europe, haveing had noe sort of Advice for near eight months, here one Mr. Hardwyck that calls himselfe English consull, shewed himselfe very desirous to make prize of me, as a pyrate and kept me under a guard in his house, whilst he went A Board to examine, notwithstanding I shewed him both my commisions and the smallness of my force for such a purpose, from hence in sixteen days I arrived at Barbados on the 21st of May, where I found the Island afflicted with a Severe pestilentiall dissease, which scarce spares any one and had it been as mortall as common would in a great measure have Depeopled the Island, I staied theire but three days, yet my selfe and many of my men were seazed with it, and tho it used me gently and I was soon up again yet it cost me my skin, my ships company by the extraordenary care of my Doctor all did well of it, and at present we are a very healthy ship: to morrow I goe from hence to coast alongst the North America and hope to waite on their Lordsps: my selfe within a month after the arrivall of this, being in great hopes, that the account I bring them of the variations and other matters may appear soe much for the publick benefitt as to give their Lordsps. intire satisfaction:
During his stay at Pernambuco Halley recorded In his logbook that:
Mr. Hardwick…desired me to call on him at his house this afternoon, where instead of Business he caused me to be Arrested, and a Portuguese Guard Sett over me … and I was given to understand that Mr. Hardwick had Acted in my Affair wth.out Authority being only impower’d to Act for the Affrican Company, and the Owners of the Shipp Hanniball wch. had been seized there as a Pirate and had no Commission of Consul
This “Mr. Hardwick” was one Joseph Hardwick who held the title of vice-consul in the city of Lisbon, from where the British envoy extraordinary, Paul Methuen, had given him authority to sail to Pernambuco “in Order to the takeing posession and remitting hither whatsoever remains there belonging to the ships Hanniball and Eagle which were Seized there last year  by the Governours Order”. 
I haven’t had time to uncover the full story of the seizure of these ships but I noticed that Hardwick was specifically warned not to exceed his written authority, and so unless that authority had been extended in the two intervening years, I think that Halley was right to object that “Mr. Hardwick had Acted in my Affair wth.out Authority”.
The pestilential disease contracted by Halley and some of his crew at Barbados has not been identified, but a gastro-intestinal illness, yellow fever, and typhoid fever have all been proposed, the latter suggested by Halley’s remark in this letter that it “cost me my skin”. It’s interesting that he says that “it used me gently and I was soon up again”, because his log entries show that he was ill for quite some time, falling ill on 24 May and remarking that his strength was returning “but Slowly” on 5 June, which sounds like a lengthy illness to me. 
His doctor on both voyages was George Alfrey, whom Halley seems to have known before the first voyage as he specifically requested that the Admiralty warrant Alfrey to be his “Chirurgeon”, observing that Alfrey had “served in severall of his Ma:ties shipps for some years last past.”  And though not a fellow of the Royal Society himself, Alfrey apparently knew some of the fellows as he was in communication (as we shall see) with Hans Sloane and James Petiver. It’s possible that Alfrey died less than three years after this voyage ended, as there’s a George Alfrey, “Chirurgeon of Woolwich”, who died in 1703. I’m not sure it’s the same man, but two surgeons named George Alfrey in a maritime location seems fairly unlikely. 
In any event, Halley’s belief in Alfrey’s abilities seems to have been well-judged and it’s pleasing to read that “we are a very healthy ship” as Halley and his crew prepare for the homeward passage to England.
 Instructions to Joseph Hardwick, dated Lisbon 7 Feb 1698, National Archives, SP 89/17 Part 2, ff273r-27v.
 Norman Thrower mistranscribes this as “tho it used me greatly”, but the word is definitely “gently”. See Thrower, The Three Voyages of Edmond Halley in the Paramore 1698-1701, (Hakluyt Society: London, 1980) p 308.
 Halley to the Lords of the Admiralty, 21 Sept 1698, TNA, ADM 106/519/365.
 The contents of the will of the George Alfrey who died in 1703 (TNA PROB 11/471/222) don’t settle whether he was/was not Halley’s doctor and I have some slight doubt that it’s the same man as this one may only have been 22 at the start of Halley’s first voyage, which seems rather young for a surgeon who had served for “some years last past”.
In my last post we looked at the maritime experience that Halley had accumulated as a passenger, surveyor, and diver before receiving his commission as Paramore’s master andcommander, and in this post we’ll examine his diving career more closely and take a look at my favourite thing about Halley – his diving suit!
Halley first wrote about a method for working underwater in 1689, proposing a mobile bell built upon four wheels. He discussed the effect that the weight and pressure of water had on a diver, and how water would compress air inside a bell, and rise higher as the bell descended. He suggested that if a way could be found to send air down to the bell, this would drive out the water and allow the diver – if wearing fishermen’s boots – to remain safe and dry inside. 
Robert Hooke was unimpressed, declaring Halley’s paper “the Same wth what I Shewed ye Society 25 years Since”, but diving and diving equipment have had a long and interesting history and probably neither Halley nor Hooke was quite as original as each believed himself to be, though Halley does deserve credit for being one of the few designers who went on to build a bell – and even to go down in it. 
His opportunity came during his involvement in the salvage operation on the “Guynie Friggott”, a Royal African Company ship which foundered on the south coast near Pagham around 1 April 1691, and from May of that year Halley was delivering regular reports of his activities to the Royal Society with escalating enthusiasm.
At the meeting on 26 August, he read a paper describing the bell he had built:
The Diving tub [a truncate cone] was made 5 foot at Bottom where it was open, 3 foot at top and 5 foot deep… and under the bell by three ropes I fastned a stage about 2½ foot below to stand on… Within the bell I placed a bench about a foot from the bottom for the men below to sitt on when they should be cold and where a man might sett with all his clouths at any depth drie. I made likewise in the top of the bell a window to let in the light which was very thick and strong but as clear glass as could be gotten, and I placed a small Cock in the same crown of the bell to let out the hot & effete air unfitt for further respiration. 
Halley reported that the deeper the bell sank, the higher the water rose within it, which he countered by his “principall invention” of adapting cask to be sent down filled with air, having a bunghole underneath through which water would enter, and a cock at the top (later a flexible tube) to release the compressed air when the cask was drawn into the bell and raised above water, thereby replenishing the bell’s air and lowering the level of the water.
By this means I have kept 3 men 1¾ [hours] under water and in ten fathoms deep without any the least inconvenience and in as perfect freedom to act as if they had been above.
That’s certainly impressive, but four weeks later Halley read another paper to the Society and this time he was so excited by his creation that he “desire[d] to conserve to my self the right of priority of Invention”: this was Halley’s diving suit.  But before we read his description, let’s take a look at a nineteenth-century illustration of his apparatus, which appeared in Rees’s Cyclopædia and is shown with the permission of the Science Museum:
There are several depictions of Halley’s diving bell on the internet but this is the closest to Halley’s description. You can see it’s a truncate cone built of wood with a weighted stage beneath, attached by three strong ropes to the bell. Inside is a bench with a man sat “drie” in his “clouths”, and in the roof on the right is a cock to release the “effete air unfitt for further respiration”. To the right is a cask, delivering fresh air to the bell, and to the left is the diver, wearing a not entirely convincing version of Halley’s diving attire, topped off with… but let’s hear the description of that contrivance from Halley:
A Man having a suite of Leather fitted to his body, with a cap of Maintenance… cappable to hold 5 or 6 gallons [of air]… must have a pipe coming from the Diving bell to his Capp, to bring him Air, which will be returned by another pipe, which must go from the cap of Maintenance, to a small [receptacle] of Air ?placed above the Diver into which it is to return the air, that has been breathed; whilest the other brings it to the man… 
Well that’s splendid, but what precisely did this cap of maintenance look like? Halley describes it as a “small vessell on the head of the diver which from its shape and use I call a capp of maintenance”, which is a little puzzling as caps of maintenance sit on top of the head but this presumably fitted over the head and was akin to a small bell, as imagined in the illustration above.  In which case, the device seems unlikely to pass any health and safety assessment, as when the diver bent down to retrieve something or if he tripped, the cap would presumably have tilted and flooded with water!
But that’s a trifling objection and Halley was rightly undaunted, describing his own triumphant descent in the same paper:
Having fortified my self against cold by a double or triple flannel or knit woolen westcoat and excluded the water by a well liquored leather suit made fitt and close to the body, I make my self considerably heavier than water by adding a girdle of ledon shott… with this the diver can descend easily to the Diving tubb… 
I love that detail about the waistcoat, it’s a rare evocation of Edmond’s physical presence and it brings his wife Mary to mind. Did she knit the waistcoat? Did she help with the design and fit of his suit? Alas, we know nothing of Mary’s role or her view of his projects, but we do know more about the liquored suit as Halley later described the recipe for his waterproofing oil to the Royal Society. Here’s the relevant minute:
Halley’s Liquor for his Leather Suites was said by him to consist of equall parts Bees wax, Tallow, Turpentine, and as much Train oyle [whale oil] as all the rest, dipping therein, when all is scalding hott. 
Notice it’s now “Leather Suites”, plural, and I’m assuming that’s because he’s producing them for other divers engaged in the operation, rather than enlarging his personal collection of niche-interest leatherwear. The suits seem to have been effective at keeping the divers dry and toasty as Halley – at least – was happy “to continu[e] there as long as I pleased”, while the glass window at the top admitted so much light into the bell that “I could see perfectly well to Write or Read” and “by the return of the Air-Barrels, I often sent up Orders, written with an Iron Pen on small Plates of Lead, directing how to move us from Place to Place as occasion required.” 
That was typical of Halley: when a subject caught his attention he explored it obsessively, and at Royal Society meetings throughout this period we find him reporting not just on improvements to his bell and attendant devices, but on the appearance of light below water, the strength of currents in streams, his experience of aural barotrauma (alleviated by “Oyle of Sweet Almonds”), and his idea for an instrument to measure the depth to which a diver had descended.
But it’s his diving suit that captured my own imagination: is it too fanciful to picture him donning his three waistcoats, his oiled leather suit, his fishermen’s boots, and his cap of maintenance, then lumbering downstairs to display himself to Mary, his servants and two young daughters? He must have been an impressive sight. Well, a sight, anyway.
UPDATE JUNE 2018
Wonder no more what Halley’s diving suit looked like, because since writing this post I’ve seen Halley’s own drawing of it, sketched on the back of the Royal Society minutes he was taking. You can see the suit for yourselves in this short ‘Objectivity’ video (which, alas, refers to him as ‘Sir Edmond’ – sigh).
 Royal Society, Halley Papers, Cl.P/21/28.
 Hooke, Diary, 6 March 1689, British Library, Sloane MS 4024. You can read a short history of diving here – or if you simply want to see a picture of Alexander the Great in a diving tub, enlarge the second image shown here.
In fact Halley had minimal maritime experience – although perhaps rather more than your average seventeenth-century natural philosopher – but the experience he did have was of three types: as a passenger, as a surveyor, and as a diver.
Halley was a passenger on three voyages as a young man, the first when he abandoned his degree in 1676 to sail to St Helena to map the southern stars. The two-way voyage on an East Indiaman would have taken about 5 months, and as Halley seems to have had a life-long interest in maritime matters, it seems reasonable to assume he took the opportunity to observe how the ship was sailed, how the crew operated, and to pick up a smattering of nautical terminology.
One year after his return from St Helena, he was at sea again en route to visit the great astronomer, Johannes Hevelius, at Dantzick (Gdańsk) on the Baltic coast, and at the end of the following year, 1680, he crossed from Dover to Calais (and was apparently seasick) to begin his Grand Tour, returning to England from Holland in January 1682.  Again, it seems fair to expect that he paid at least some attention to the handling of the ships.
At the end of the decade, Halley progressed from maritime passenger to coastal surveyor, although his work as a surveyor is rather obscure, being largely inferred from his presentation of two charts to the Royal Society, the first of which appeared in the minutes for 3 July 1689:
Halley produced his Sea-draught of the Mouth of the River of Thames, wherein he saith, that He hath corrected severall very great, and considerable faults in all our Sea-Carts [sic] hitherto published. 
It isn’t known for sure when he undertook his survey of the Thames approaches but Robert Hooke recorded two entries in his diary – “Hally a Sayling” on 22 March 1689, and “Hally Returnd” on 3 April – which may relate to his surveying, although the previous summer Halley had made several references to towns near the Thames estuary which may indicate that he had been surveying in the area at that time. 
His second survey, “of the West coast of Sussex between Selsey and Arundell”, was presented to the Society on 15 November 1693,  and this time we have rather more idea about the circumstances behind its production because this chart was a by-product of his diving activities.
Halley first wrote about diving in a paper of 6 March 1689, and his interest was probably prompted by the recent success of Captain William Phips’s diving operation in the West Indies, where Phips recovered a spectacular haul of treasure from a Spanish wreck and sparked a tsunami of projects connected with diving and salvage.  Halley proposed a mobile diving bell built on four wheels, and while he didn’t build that particular bell, he did build another as part of his salvage work on the wreck of the Guynie frigate.
The Guynie was owned by the Royal African Company (RAC) and in early 1691 she returned from Africa to English waters, having collected “Bees Wax & Elephants Teeth” from Gambia and “Elephants Teeth & Redwood” from “Sereleon” (Sierra Leone).  On 23 February her commander, William Chantrell, wrote to the RAC from Falmouth requesting a convoy to accompany him back to London. The RAC instructed three of their most senior officers to “waite on the Lords of the Admiralty to gett a Man of Warr to Convoy the Guynie Friggott up from Falmouth”, which might seem a little excessive for beeswax and ivory, but the Guynie was carrying something much more valuable on board. 
Captain Chantrell had undertaken to deliver a large quantity of gold on behalf of the Portuguese in Africa, and it was on this account that a convoy ship had been requested.  The Guynie sailed from Falmouth on 26 March, but on 4 April Captain Chantrell wrote from Chichester to advise the RAC that the ship had foundered.  It isn’t clear what happened to the ship, but there’s no mention of any lost men and the gold seems to have been saved, as on 8 April the RAC ordered that “a Guard of Tenn Soldjers & an Officer be sent from hence to fetch the Gold (saved out of that Shipp) from Chichester”. 
The ivory, however, went down with the ship, and it’s in this regard that Halley now appears in the affair. The Deputy Governor of the RAC was Royal Society fellow, Abraham Hill, and it may have been he who brought Halley in to try to salvage the elephants’ tusks. Halley’s initial plan was certainly ambitious as on 13 May 1691 the Royal Society minutes record that “Halley shewed the Method he intended to use in raising the Ship”, but this plan was evidently modified as on 12 August he was relating “the Success of his Experiments of going under water in his diving bell”.
Halley believed his diving bell had limitless possibilities, and on 15 September a government warrant was issued to prepare a bill granting Halley and three partners “sole use of their invention of a new engine never yet known”, and Letters Patent were issued on 15 October. On 17 November, the four patent-holders formed a joint-stock company with two other men, John Carter and Thomas Jett, who was a friend of Halley’s. 
Thomas Jett, incidentally, is interesting because he is the “Jed” in Hooke’s Diary entry for 24 March 1693, “Hally & Jed Spys”, which offers a hint (there are one or two others) that Halley may have undertaken coastal surveys on behalf of the government. 
Halley and Jett appear periodically in the RAC minutes until about spring 1694, though their level of success in salvaging the tusks is unclear – and by that time Halley had become involved in the scheme with Benjamin Middleton to obtain a ship to sail around the world, which, when the scaled-down version of the project finally got underway in late 1698, would see Halley drawing on all his modest maritime experience to serve as the Paramore‘s commander. 
In part 2 of this post about Halley’s nautical experience, we’ll take a much closer look at his diving bell – and at my favourite thing about him!
 Hooke to Halley, 1 March 1681, Royal Society, EL/H3/62; Hooke, Diary, 24 Jan 1682, London Metropolitan Archives.
 Royal Society, Journal Book Original, JBO/8 p 268.
 Hooke, Diary, 22 March 1689 and 3 April 1689, British Library, Sloane MS 4024; references to towns in RS, JBO/8.
 RS, JBO/9 p 141.
 For a fair copy of Halley’s paper, see RS, RBO/7/24.
 RAC Instructions to Captains, The National Archives, T 70/61 ff87r-88v.
 RAC Minutes, TNA, T 70/83.
 RAC Black Book, TNA, T 70/1433 p 104.
 TNA, T 70/83 f8r.
 CSP, D, 1690-91; TNA C111/192.
 BL, Sloane MS 4024. Many thanks to Hooke’s editor Dr Felicity Henderson for confirming this entry as it has hitherto appeared mistranscribed.
 I’ve read suggestions that Halley and Jett only recovered one tusk, but that is based on a mistranscription of the phrase “the elephants teeth”, where the e’s in teeth are akin to the Greek letter theta (ϑ) and have been misread as ‘oo’. This style of ‘e’ was common in the 17th century and Halley himself used it. He later told Hans Sloane that his attempt to recover the ivory had been frustrated by the wreck quickly becoming covered with “Sand and Oase”.