Most people know something of the events in 1714 when the British government
instituted a prize for the discovery of a successful way to find longitude
at sea. The aim was to reduce the heavy toll of shipwrecks caused by the
crude navigational method of dead reckoning. Dava Sobel gave new life to
this episode in her bestselling book, Longitude: The true story of a lone
genius who solved the greatest scientific problem of his time (1995), which
inspired the widely viewed television programme Lost at Sea (aired in 1998).
After these came a feature film directed by Charles Sturridge in 1999,
starring Michael Gambon and Jeremy Irons. All these versions place at their
centre the heroic figure of John Harrison and his struggles to perfect a
clock which would finally carry off the prize of £20,000. Meanwhile, an
early rival who figures in the tale has gone down in history as another
projector from Yorkshire, named Jeremy Thacker. Unfortunately Thacker never
existed and his proposal now emerges as a hoax.
The measure to award the prize was rushed through Parliament, passing all
stages in the Lords between July 5 and 7, 1714. The haste came from the need
to get it on the statute book before Parliament was prorogued on July 9. On
that day Queen Anne gave the Royal Assent, in the last clutch of acts she
signed before her death just over three weeks later. Before they drew up the
Bill, a special committee had taken advice from Isaac Newton and Edmond
Halley, among others. What emerged was a scheme “for providing a Public
Reward for such Person or Persons as shall discover the Longitude at Sea”,
offering premiums at various levels according to the accuracy achieved by a
given method. The new law set up a board of commissioners to act as
adjudicators, though this body would hardly ever meet for years to come. The
original board included Newton as President of the Royal Society; Halley, as
Savilian professor at Oxford; and their enemy John Flamsteed, the Astronomer
Royal. In addition, there was the Lucasian Professor at Cambridge, a post
held by many distinguished mathematicians from Newton to Stephen Hawking. At
this date the holder was a blind man, the Newtonian disciple Nicholas
Saunderson. But it was only three years since he had taken over from
Newton’s successor in the chair, William Whiston, recently expelled from the
university for his Arian views.
A month before the act went through, Whiston had joined with Humphrey Ditton,
master of the mathematical school at Christ’s Hospital, to produce what many
thought a crack-brained scheme to find the longitude. This involved the use
of strategically placed ships which would fire off a number of shells
programmed to explode at a set time. Even during foggy weather the
explosions would be audible, and, just in time for the project, a reasonably
accurate estimate (very slightly on the high side) had been made for the
speed of sound, using gunshot reports. The findings came from the Revd
William Derham, himself a man well versed in clockmaking, and they were
published by the Royal Society in 1709. The committee had already looked at
the Whiston–Ditton proposal, and the pair optimistically drafted an
advertisement to launch a heavy press campaign, declaring that their method
had been “so far approved by this present Parliament, that they have passed
an Act, ordering a reward of 20000£. for such a Discovery”. In the event,
the flying bombs turned out to be unworkable and did not get into contention
for the prize. If Whiston had restrained himself on the subject of the early
Church and the need for a reformed liturgy, he might have sat in judgement
on his own idea. Nothing daunted, he arranged a display to prove his theory
in July 1715: this involved letting off rockets at intervals across an area
of thirty-six square miles centred on Hampstead. He never gave up hope of
solving the problem.
The prospect of winning the enormous jackpot naturally brought before the
public a rash of more or less futile methods to ascertain the longitude.
Even Christopher Wren sent the Royal Society a list in cipher of three
instruments he had devised for the purpose. The means that others proposed
ranged from a universal clock and barometers, to the use of tide tables (a
nod at Halley’s pioneering work in this area), improved lunar charts and
magnetic compasses. Some came from serious engineers, but others were the
product of back-garden astronomers and deranged inventors. None excited as
much popular scorn as the Whiston–Ditton project, but equally, none remotely
qualified for the prize. Later scientists could take the lunar route when
Leonhard Euler made a more exact calculation of celestial motions, enabling
Johann Tobias Meyer to provide accurate tables of longitude. But that
opportunity still lay half a century ahead.
Only one of the early proposals has escaped the condescension of posterity.
This came with a pamphlet entitled The Longitudes Examin’d, attributed to
Jeremy Thacker of Beverley, who signs his opening “epistle to the
Longitudinarians” with the additional phrase “Philomath. Well-wisher to the
Twenty Thousand Pounds”. The second half of his work sets out a method using
a clock placed inside a vacuum chamber like a bell jar, and fitted with an
auxiliary spring to supplement the mainspring during winding. The author
then describes some experiments he conducted to test his equipment.
Without a single exception historians of science have taken Thacker at his
word, and graded his work as a brave near miss among an array of doomed
projects. Experts on navigation, horology and cartography have all commended
his efforts. Even Rupert Gould (1890–1958), the distinguished naval
historian who restored Harrison’s clocks, had a good word to say. For the
film Jeremy Irons portrayed Gould as an obsessively engrossed student of
clockmaking techniques, as driven in his own way as John Harrison. When
Gould wrote his book on the marine chronometer (this last word, as we shall
see, a coinage of Thacker’s), he credited the projector with having
anticipated Harrison by twenty years in devising the auxiliary spring
mechanism.
Dava Sobel herself joined in the chorus. She remarks that “one of the most
astute, succinct dismissals of fellow hopefuls came from the pen of Jeremy
Thacker of Beverly, England”, and analyses the account he gave of his
experiments. In the light of what he says, the method “fell short of
perfection, and Thacker knew it”. The equipment could not deal properly with
changes in temperature. Moreover, “the plan falls apart”, because “Thacker
owned that his chronometer occasionally erred by as much as six seconds a
day”. Consequently, though this proposal was “the best of the lot” reviewed
by the board in its first year, it “didn’t raise anyone’s hopes very high”.
Since nobody else saw or tested the equipment, this was hardly surprising.
In fact, the reputation of Thacker as a brave pioneer stems from a misreading
of a literary joke. The proposal may or may not have come closer to the
successful methods Harrison used, but if it did that is no more than a happy
coincidence. Abundant evidence exists to show that the real aim of
Longitudes Examin’d was to parody the other hopeful projects, in the process
embedding some apparently plausible scientific discussion.
Who, to start with, was Jeremy Thacker? Anyone seeking such a person will draw
a blank on the genealogical websites. His name does not appear among the
growing number of mathematical teachers up and down the country, and though
there was an Anthony Thacker who taught at King Edward’s school, Birmingham,
this was in the period shortly before his death in 1744 – a generation too
late. Jeremy also seems to be absent from local records in Beverley. After
1714 he drops straight back into obscurity.
Earlier writers have confidently described him as an inventor and watchmaker;
a nautical instrument maker; and even as an experienced navigator. The major
scholar in the field, E. G. R. Taylor, included Thacker in her survey of
early mathematical practitioners – the bible of this subject. She dubbed him
“a Yorkshire gentleman and amateur instrument-maker”, but she was unable to
cite any external source. Outside the claims of the pamphlet itself, no
evidence survives to place him in any of these categories. Even Ruth Wallis
and the late Peter Wallis, authors of the most complete “biobibliography” of
British mathematicians, did not sniff him out.
Then we need to inspect the term “philomath”. The OED suggests that the
primary meaning was “a student, esp. of mathematics, natural philosophy, and
the like”. The entry continues, “formerly popularly applied to an astrologer
or prognosticator”. This is putting the cart before the horse. The once
respectable word underwent a precipitous decline around the early eighteenth
century, from which it never fully recovered. Commonly it was applied to
quacks, often by way of self-description. Writing on fortune-tellers in the
Spectator in 1712, Joseph Addison referred scornfully to “some prophetic
Philomath”. A year later, the Tory periodical the Examiner spoke of the
craze for French prophets in London in the previous decade, and remarked
that “not a Philomath or Orthodox Astrologer” could be heard in the din:
even the famous almanac-maker John Partridge gave up and resolved to die a
second time. (This of course refers to Jonathan Swift’s Bickerstaff
pamphlets, which had predicted the death of Partridge so convincingly that
most people were taken in. The Tatler had described Partridge himself as a
“Philomath”.) Leading almanacs like that of John Wing continued to use the
label in an unselfconscious way. One or two land-surveyors clung on to it,
and people entering puzzle competitions in magazines used it as a pseudonym.
But by 1714 mathematicians and inventors pushing a serious idea found it
risky to own up to this profession. The word was left to dodgy projectors
and snake-oil salesmen.
We could multiply examples from many sources. It was, however, Swift and his
immediate circle who had done most to bring about this linguistic swerve. In
1709 a mock-prophecy appeared under the title of A Famous Prediction of
Merlin, attributed to “T. N., Philomath”, but really from the pen of Swift.
In the following years the group of Scriblerian satirists, who also included
Alexander Pope, John Gay and John Arbuthnot, wrote a series of pamphlets
ridiculing vain and semi-literate projectors who promised the earth and
delivered nothing. In 1717 “E. Parker, Philomath” produced A Complete Key to
the new Farce, call’d Three Hours after Marriage, a solemn
pseudo-explication of the Scriblerians’ own farce. An exchange in Three
Hours runs, “Do you deal in longitudes, Sir? – I deal not in
impossibilities”. In the same year Parker was responsible for Mr. Joanidion
Fielding his true and faithful Account of the Strange and Miraculous Comet
which was seen by the Mufti at Constantinople. The main target is Whiston,
who had taken the study of comets into millenarian realms. For the satirists
he became the epitome of a learned fool, and either Gay or Thomas Parnell
joined in with a short and scabrous “Ode for Musick on the Longitude”.
Many of these riffs on deluded quasi-science are reorchestrated in the Memoirs
of Martinus Scriblerus, assembled by Pope after his collaborators had died
or, in Swift’s case, descended into senility. Among other touches, the
Memoirs have a reference to the hero’s “Method of discovering the Longitude
by Bomb-Vessels”. One of these pamphlets stands out for a particular reason:
Annus Mirabilis (1722), also probably written by Pope and Arbuthnot in
collaboration. This predicts a universal sex-change, induced by a
conjunction of the planets. The title-page names its author as “Abraham
Gunter, Philomath. A Well-wisher to the Mathematicks”. This exactly matches
the formula used by Jeremy Thacker – whose name follows the very same
cadence as that of Gunter, another ghost. Annus Mirabilis mocks both the
wild fantasies of the astrologers and the crazed certainties that Whiston
displayed of the links between celestial activity and life on earth.
Similarly, in Pope’s ridiculous “Key” to his own Rape of the Lock (1715),
the author is named as Esdras Barnivelt, Apoth. At the start of the pamphlet
he receives a set of complimentary verses from “a Well-willer to the
Coalition of Parties”.
But what of the experiments that Thacker described in careful detail? They
follow the accustomed pattern of Royal Society transactions, with
painstaking mathematical logic:
As for Example, if the Semicircle FPB be of about nine Inches Radius, and the
Pendulum describes nearly a Quadrate of it each Vibration, as it will do in
going from a to b, then the Arc describ’d, will run pretty much out of the
Cycloid; but if the Radius of FPD, or what is the same, the Rod of the
Pendulum, be four times as long as that which is made use of to swing
Seconds, and the Pendulum itself pretty heavy, it will swing in the Arc DPp,
where the Circle and the Cycloid are sensibly the same Line; and therefore
if no Force makes the Pendulum fly out farther than ordinary in its
Vibrations, they will be all perform’d in the same Time, because then the
Cycloidal Arcs are describ’d.
Along with the accompanying diagrams, this looks convincing enough to an
inexpert eye. But so does this:
To explain the manner of its progress, let A B represent a line drawn across
the dominions of Balnibarbi, let the line c d represent the loadstone, of
which let d be the repelling end, and c the attracting end, the island being
over C: let the stone be placed in position c d, with its repelling end
downwards; then the island will be driven upwards obliquely towards D. When
it is arrived at D, let the stone be turned upon its axle, till its
attracting end points towards E, and then the island will be carried
obliquely towards E; where, if the stone be again turned upon its axle till
it stands in the position E F, with its repelling point downwards, the
island will rise obliquely towards F, where, by directing the attracting end
towards G, the island may be carried to G, and from G to H, by turning the
stone, so as to make its repelling extremity to point directly downward.
That is Gulliver on his third voyage, as he describes the workings of the
flying island of Laputa – and he too has his helpful diagram in the text.
What the historians of longitude seem to have missed is that satires had to
make their pseudo-science look as though they were the real thing.
The pamphlet ends with a sneer at the Heath Robinson engines that inventors
had dreamt up to boost their proposals: “In a word, I am satisfy’d that my
reader begins to think that the Phonometers, Pyrometers, Selenometers,
Heliometers, Barometers, and all the Meters are not worthy to be compar’d
with my Chronometer”. Thacker may have come up with a term of lasting
scientific currency, but that does not mean that he really constructed or
tested such an instrument. Unlike Harrison, he had no need to produce
anything that would work. He merely had to mimic viable procedures, and use
the right descriptive language. Unlike the serious projectors, he could
afford to point out the ways in which his system went wrong – thus
transparently undercutting his boast that it easily outdid all the methods
previously published. That claim just echoes the sales talk of an immodest
proposer.
Everything about the pamphlet should have raised a warning flag. Thacker’s
absurdly grandiose style goes far beyond the wishful claims of the usual
dotty projectors. His unblushing admission that he only cares about the
£20,000, with no figleaf claims of benefit to mankind, is equally untypical,
and even less likely to have won over the commissioners.
Assuming that the intent of the pamphlet was wholly satiric, we might wonder
if the Scriblerians had anything to do with the elusive Jeremy Thacker
himself. His pamphlet was indeed reprinted, with slight cuts, in a
two-volume collection called The Miscellaneous Works of the Late Dr.
Arbuthnot (Glasgow, 1751). The Works contained some irresponsible
attributions, which have been quietly dropped by subsequent scholarship. But
they do include a few authentic items, and we ought to reserve the
possibility that The Longitudes Examin’d might also be genuine. The Scottish
John Arbuthnot (1667–1735) was a true polymath: a physician to the Queen,
mathematician, student of probability and coinage, classical scholar, a
lover of music who belonged to the Handel circle, and a witty polemicist who
had enshrined John Bull as the stereotypical Englishman in a series of
pamphlets published in 1712. The Longitudes Examin’d must have been written
by a competent scientist, a well-connected observer, and a skilled author of
caustic satire. Not many candidates present themselves, and none who had
been – like Arbuthnot as a young man – a teacher of mathematics.
We know that Arbuthnot took a close interest in the developing longitude
story, and that he had actually been waiting for the Whiston–Ditton scheme
to come out. On July 17, just days after the Bill passed into law, he wrote
to Swift:
Whetstone [sic] has at last published his project of the longitude; the most
ridiculous thing that ever was thought on, but a pox on him! he has spoiled
one of my papers of Scriblerus, which was a proposal for the longitude, not
very unlike his, to this purpose, that since there was no pole for East and
West, that all the princes of Europe should join and build two prodigious
poles, upon high mountains, with a vast light-house to serve for a
pole-star. I was thinking of a calculation of the time, charges, and
dimensions. Now you must understand, his project is by light-houses, and
explosion of bombs at a certain hour.
This clue has been missed because Thacker’s proposal took a different form,
with no mention of erecting new “poles”. But the letter shows that Arbuthnot
had planned a Scriblerian pamphlet on this very topic. Another pointer
towards the author’s background may lie in a self-debunking Latin quotation
that Thacker placed on his title-page: “quid non mortalia pectora cogis,
auri sacri fames!” (to what lengths does this damned lust for gold drive the
human spirit). It was a familiar tag from the third book of the Aeneid, but
not the sort of thing that rolled off the tongues of other projectors.
Those who have taken Thacker literally have all failed to explore his
intricate set of allusions. The writer evidently had a close familiarity
with the published projects: he refers to their authors by initials or
abbreviated forms, but each can be identified. Among the hopefuls we find
Robert Browne, “the Corrector of the Moon’s Motion”; Isaac Hawkins, promoter
of a barometric scheme; and Francis Haldanby, who drafted an abject appeal
to the rising politician James Stanhope. One individual who promised to make
the secret of the longitude “known to the meanest capacity” turns out to be
Samuel Watson, a clockmaker on Long Acre in Covent Garden. (He also claimed
to have sold a moving ephemeris to Charles II and a chronological automaton
to Mary II.) We can also spot Sebastiano Ricci, who had acted as publicist
for a new method devised by the Venetian mathematician Dorotheo Alimari with
an unsubtle dedication to the commissioners, dated August 31, 1714.
Alimari’s proposal used an instrument outwardly resembling both an astrolabe
and a sundial. The most interesting of those named is Case Billingsley, an
archetypal projector later involved in South Sea scams and the fraudulent
York Buildings Company. His presence indicates that the chase for the prize
attracted not just scientific charlatans, but also a sprinkling of routine
conmen.
Whiston may have offered a soft target, but the pamphlet extracts some equally
effective comedy from lesser known participants in the quest for the
longitude. Among these is one writer who prefaced his effort with fulsome
dedications to the King, the Prince of Wales, the Royal Society and his
ingenious reader. Thacker obviously meant Benjamin Habakkuk Jackson, later
patentee of a swimming engine, and author of a miscellaneous tract entitled
Some New Thoughts Founded upon New Principles, concerning a Threefold Motion
of the Earth, intended as the prelude to a great new scientific excursion.
The title-page lists a series of topics ranging from the rectification of
the calendar to “the finding out the true place of the moon”. They all
receive skimpy treatment, and only in the final paragraph does the writer
address the last named of his topics, “facilitating the discovery of the
longitude”. In the manner of Swift’s narrator in A Tale of a Tub, Jackson
merely promises that he has something on the subject “to offer to the
Publick hereafter”. So feeble an effort might almost be a hoax; but Thacker
has fun in showing up the absurdities of the confused Thoughts. “The Body of
the Book was wrote in a Language that I could not understand”, he writes,
“and so I must suspend my Judgment, till I have sent it to be perus’d by my
learned Friend Mr. Gr–n, of Cambridge; for this Book may contain some of the
Conclusions which follow from the Principles of his new Philosophy.” This is
a feline sideswipe at The Principles of Natural Philosophy, in which is
shewn the Insufficiency of the Present Systems, to give us any just Account
of that Science (1712), by the eccentric natural philosopher Robert Greene.
At the start of his work Thacker unconvincingly claimed that most of the
longitude pamphlets were sold off before they reached “our Northern
Booksellers”. In reality an efficient book distribution system ensured that
advertisements for hot items appeared in the provincial press within days of
their launch in London. The author’s pose as an isolated yokel is undermined
by a wide range of references to the scientific community, from Leibniz
down. We can identify one of the commissioners, John Keill, another Scot
whose work Arbuthnot had long supported. In 1708 Keill sought the Savilian
chair, with the backing of both Halley and Arbuthnot, though opposed by
Flamsteed. Another acquaintance was John’s brother Dr James Keill, whose
“iatro-mathematical” works Arbuthnot cited in his own publications.
A less kindly reference to “my Friend K–th” points to James Keith (1685–1726),
another London physician from Scotland, and an early advocate of inoculation
for smallpox. He was a product of Aberdeen University, like Arbuthnot in all
probability. The two men came into contact in 1712, when they were rival
candidates for the post of physician to Chelsea Hospital. Keith had
presented a paper on the longitude to the Royal Society in 1710. A
provincial philomath, however able, would scarcely have had information of
this kind at his fingertips. The presence of these Scotsmen may or may not
provide a reliable clue. “Thacker”, an obsolete and dialect variant for
“thatcher”, survived longer in the Scots language: Allan Ramsay, who
completed his apprenticeship to a wig-maker in Edinburgh about 1709, later
spoke of himself as a “skull-thacker”, and he uses the expression
“thack-house” in The Gentle Shepherd, his most popular work. Thacker appears
in the attached glossary of Scots words “which are rarely or never found in
the modern English language”. Was Jeremy stitching up the credulous public
with a hidden Scottish pun?
Only one who was close to events could have picked off so many targets.
Arbuthnot’s friends included Halley and Newton, with both of whom he
currently served on boards such as the commission for building the fifty new
“Queen Anne” churches in London. As far back as 1701, in his Essay on the
Usefulness of Mathematical Learning, Arbuthnot had stressed the need to find
a practicable means of finding the longitude at sea, and commended Halley’s
expertise in this branch of study. This was more than an empty compliment:
in this very year, 1714, Halley published a brief article in the
Philosophical Transactions in which he tried to fix the longitude of the
Straits of Magellan more accurately. Moreover, in 1712 Arbuthnot had been
appointed along with Halley to a committee of the Royal Society, charged
with the task of determining the priority of Newton and Leibniz in
developing calculus. It was Keill who had mainly fomented this acrimonious
debate.
One more piece of evidence bears on the issue. The Longitudes Examin’d carries
the name of James Roberts in its imprint, but he was a distributor who
seldom owned copyrights. The real instigator, it now emerges, was the
notorious Edmund Curll. His name appears at the head of four booksellers in
a press advertisement on November 9, 1714; and the last leaf of the pamphlet
displays announcements for two of his characteristic works on impotence.
Whereas Roberts’s name is found in further items, including a second edition
of the Whiston–Ditton proposal in 1715, Curll did not publish any other
tract on longitude. It was not like him to miss out on such a hot topic. Of
course, Dr Arbuthnot would coin the most famous one-line appraisal of Curll,
whose biographies he described as a new terror of death. But the Scriblerian
group never showed any reluctance to use Curll’s services when it suited
them.
Since historians took the linguistic turn some two decades back, they have
been more scrupulous in looking at rhetorical features of a text. But the
case of Jeremy Thacker shows that they need to inspect the full array of
evidence, decipher cultural allusions, and consider the publishing history.
If The Longitudes Examin’d can no longer be regarded as a serious attempt to
win the prize, it deserves notice as an amusing response by a privileged
insider – most likely Dr John Arbuthnot – to the mania set off by the Act of
1714.
Pat Rogers is completing a biography, Hangman: The Earl of Coningsby
and his victims.
