CAPTAIN SAVERY--HIS FIRE-ENGINE.
The attempts hitherto made to invent a working steam-engine, it will
be observed, had not been attended with much success. The most that
could be said of them was, that, by demonstrating the impracticable,
they were gradually leading other experimenters in the direction of
the practicable. Although the progress made seemed but slow, the amount
of net result was by no means inconsiderable. Men were becoming better
acquainted with the elastic force of steam. The vacuum produced by its
condensation in a closed vessel, and the consequent atmospheric pressure,
had been illustrated by repeated experiments; and many separate and minor
inventions, which afterwards proved of great value, had been made, such as
the four-way cock, the safety-valve, and the piston moving in a cylinder.
The principle of a true steam-engine had not only been demonstrated, but
most of the separate parts of such an engine had been contrived by various
inventors. It seemed as if all that was now wanting was a genius of more
than ordinary power to combine them in a complete and effective whole.
To Thomas Savery is usually accorded the merit of having constructed the
first actual working steam-engine. Little is known of his early history;
and various surmises have been formed as to his origin and calling.
Some writers have described him as the captain of a tin-mine; others as
a naval captain; while a third says he was an immigrant Frenchman.[21]
We are, however, enabled to state, from information communicated by his
descendants, that he was the scion of a well-known Devonshire family.
John Savery, of Halberton, or Harberton, afterwards of Great Totness,
was a gentleman of considerable property in the reign of Henry VIII. In
the sixteenth century the Saverys became connected by marriage with the
Servingtons of Tavistock, another old county family, one of whom served as
sheriff in the reign of Edward III. In 1588, Christopher Savery, the head
of the family, resided in Totness Castle, of which he was the owner; and
for a period of nearly forty years the town was represented in Parliament
by members of the Savery family. Sir Charles served as Sheriff of Devon in
1619. Though the Saverys took the side of the Parliament, in resisting the
despotic power assumed by Charles I., they nevertheless held a moderate
course; for we find Colonel Savery, in 1643, attaching his name to the
famous “round robin” presented to Parliament. Richard Savery, the youngest
son of the Colonel, was father of Thomas Savery, the inventor of the
“fire-engine.” Other members of the Savery family, besides Thomas, were
distinguished for their prosecution of physical science. Thus we find from
the family MSS., Servington Savery corresponding with Dr. Jurin, Secretary
to the Royal Society, respecting an improvement which he had made in the
barometer, and communicating the results of some magnetic experiments of
a novel kind, which he had recently performed.[22]
[21] Burn, ‘History of Foreign Protestant Refugees,’ 261.
[22] In a letter, dated Shilston, August 9th, 1727, he
writes:--“The late Mr. Thomas Savery, inventor of the engines
for rowing, and raising water by fire, was, I believe, well
known to several of the Royal Society, perhaps to the President;
but as I am a perfect stranger, do acquaint you that his father
was youngest brother to my grandfather. The late Servington
Savery, M.D., of Marlborough, was one of my family, viz., a
brother to my deceased father.”
[Illustration: THOMAS SAVERY, F.R.S.]
Thomas Savery was born at Shilston, near Modbury, in Devon, about
the year 1650. Nothing is known of his early life, beyond that he was
educated to the profession of a military engineer, and in course of time
duly reached the rank of Trench-master. The corps of engineers was not,
however, regarded as an essential part of the military force until the
year 1787, when the officers ranked with those of the Royal Artillery.
The pursuit of his profession, as well as his natural disposition, led
Savery to the study of mechanics, and he became well accomplished in the
physical knowledge of his time. He occupied much of his spare time in
mechanical experiments, and in projecting and executing contrivances of
various sorts. One of his early works was a clock, still preserved in the
family,[23] which until lately kept very good time; and when last repaired
by a watchmaker of Modbury was pronounced to be a piece of very good work,
of a peculiar construction, displaying much ingenuity.
Another of Savery’s early contrivances was a machine for polishing
plate-glass, for which he obtained a patent. He was occupied about the
same time with an invention for rowing ships in calms by the mechanical
apparatus subsequently described in his treatise, entitled ‘Navigation
Improved.’ He there relates how it troubled his thoughts and racked
his brains to find out this invention, which he accomplished after many
experiments, conducted “with great charge.” He naturally set much value
on the product of so much study and labour; and he was proportionately
vexed on finding that others regarded it with indifference. He professed
to have had “promises of a great reward from the Court, if the thing would
answer the end for which he proposed it;” but instead of a reward, Savery
received only contumely and scorn. He attributed his want of success to
the ill-humour of the then Surveyor of the Navy, who reported against
his engine, because, said he, “it’s the nature of some men to decry all
inventions that are not the product of their own brains.” He only asked
for a fair trial of his paddle-boat, believing in its efficiency and
utility; declaring, that it was not his “fondness for his own bratt that
made him think so,” but the favourable opinions of several very judicious
persons in town, that encouraged him to urge his invention for public
adoption.
[23] It is now in the possession of Capt. Lowe, of the 26th
Regiment, whose grand-aunt was a Miss Savery of Shilston.
The invention in question consisted of a boat mounted with two
paddle-wheels, one on each side, worked by a capstan placed in the centre
of the vessel. The annexed cut will show the nature of the arrangement,
which probably did not differ much from the scheme of Blasco Garay, above
referred to.
[Illustration: SECTION OF SAVERY’S PADDLE-BOAT.]
Savery says he was led to make the invention through the difficulty
which had been experienced in getting ships in motion so as to place them
alongside of the enemy in sea-fights, especially during calm weather. He
thought that if our fighting-ships could be made to move independent of
the winds, we should thereby possess an advantage of essential consequence
to the public service. “The gentlemen,” said he, “that were on the Brest
expedition with my Lord Caermarthen must know how useful this engine would
have been; for had they had them there on board each ship, they might have
moved themselves where they had pleased.” He also urged the usefulness of
the engine for packet-boats, bomb-vessels, and sloops, and especially for
use in sea-fights, in bringing off disabled ships. When he had completed
his invention, he took steps to bring it under the notice of Mr. Secretary
Trenchard. The plan was shown to the King, who thought highly of it, and
referred Savery to the Admiralty. When he went there he was told that he
should have gone to the Navy Board. At the Navy Board he was told that
certain objections to the adoption of his scheme had already been sent to
the Admiralty.
Savery having ascertained that the Surveyor was himself the author of the
objections, proceeded to discuss the matter with him. But the Surveyor
was not a man to be argued out of his views by an inventor; and he shut
up Savery with the remark: “What have interloping people, that have no
concern with us, to do to pretend to contrive or invent things for us?”
Savery was highly indignant at the official snub, and published the
conversation in his Treatise. “Though one has found out,” said he, “an
improvement as great to shipping as turning to windward or the Compass,
unless you can sit round the Green Table in Crutched Friars, your
invention is damned, of course;” and the testy inventor concluded: “All I
have now to add is, that whoever is angry with the Truth for appearing in
mean language may as well be angry with an honest man for his plain habit;
for, indeed, it is as common for Lyes and Nonsense to be disguised by a
jingle of words as for a Blockhead to be hid by abundance of Peruke.”[24]
[24] ‘Navigation Improved; or the Art of Rowing Ships of all rates
in calms, with a more easy, swift and steady motion than oars
can. Also, a description of the engine that performs it; and the
Author’s answer to all Mr. Drummer’s objections that have been
made against it. By Tho. Savery, Gent. London, 1698.’
Notwithstanding his rebuff by the Navy Surveyor, Savery proceeded to
fit up a small yacht with his engine, and tried an experiment with it
on the Thames, in sight of many thousands of spectators. The experiment
was, in his opinion, entirely successful. The yacht, manned by eight
sailors working the capstan, passed a ketch with all its sails spread,
as well as other vessels. “All people,” said Savery, “seemed to like the
demonstration of the use of my engine, the public newspapers speaking
very largely of it, yet all to no purpose.” Savery had already expended
200_l._ in his experiments on the paddle-wheel boat, and was not disposed
to go any further, now that Government had decided not to take up the
invention. Indeed, its practical utility was doubtful. The power of the
wind was, after all, better than hand-labour for working large ships;
and it continued to maintain its superiority until the steam-engine was
brought to perfection.
It is curious that it should not have occurred to Savery, who invented
both a paddle-wheel boat and a steam-engine, to combine the two in one
machine; but he was probably sick of the former invention, which had given
him so much vexation and annoyance, and gave it up in disgust, leaving
it to Papin, who saw both his inventions at work, to hit upon the grand
idea of combining the two in a steam-vessel,--the only machine capable
of effectually and satisfactorily rowing ships in a calm, or against wind
and tide.
It is probable that Savery was led to enter upon his next and most
important invention by the circumstance of his having been brought up
in the neighbourhood of the mining districts, and being well aware
of the great difficulty experienced by the miners in keeping their
pits clear of water, to enable them to proceed with their underground
operations. The early tin-mining of Cornwall was for the most part
what was called “stream-work,” being confined mainly to washing and
collecting the diluvial deposits of the ore. Mines usually grew out of
these stream-works; the ground was laid open at the back of the lodes,
and the ore was dug out as from a quarry. Some of these old openings,
called “coffins,” are still to be met with in different parts of Cornwall.
The miners did not venture much below the surface, for fear of the
water, by which they were constantly liable to be drowned out. But as
the upper strata became exhausted, they were tempted to go deeper in
search of the richer ores. Shafts were sunk to the lodes, and they were
followed underground. Then it was that the difficulty of water had to be
encountered and overcome; for unless it could be got rid of, the deeper
ores of Cornwall were as so much buried treasure. When the mines were of
no great depth, it was possible to bale out the water by hand-buckets.
But this expedient was soon exhausted; and the power of horses was then
employed to draw the buckets. Where the lodes ran along a hill-side, it
was possible, by driving an adit from a lower point, to let off the water
by natural drainage. But this was not often found practicable, and in most
cases it had to be raised directly from the shafts by artificial methods.
As the quantity increased, a whim or gin moving on a perpendicular axis
was employed to draw the water.[25] An improvement on this was the rack
and chain pump, consisting of an endless iron chain mounted with knobs
of cloth stiffened with leather, inclosed in a wooden pump of from six
to eight inches bore, the lower part of which rested in the well of the
mine. The chain was turned round by a wheel two or three feet in diameter,
usually worked by men, and the knobs with which it was mounted brought up
a stream of water according to the dimensions of the pump. Another method,
considered the most effectual of all, was known as “the water-wheel and
bobs,” consisting of a powerful pump, or series of pumps, worked by
a water-wheel. But although there is no want of water underground in
Cornwall, and no want of rain above ground, there are few or no great
water-courses capable of driving machinery; besides, as the mines are for
the most part situated on high ground, it will be obvious that water-power
was available to only a very limited extent for this purpose.
[25] Mr. Davies Gilbert says even this method was comparatively
modern, as he remembered a carpenter who used to boast that
he had assisted in making the first whim ever seen westward of
Hayle.--Davies, ‘Parochial History of Cornwall,’ London, 1838,
ii. 83.
It is also worthy of notice that the early mining of Cornwall was carried
on by men of small capital, principally by working men, who were unable
to expend any large amount of money in forming artificial reservoirs,
or in erecting the powerful pumping machinery necessary for keeping the
deeper mines clear of water. The Cornish miners, like the Whitstable
oyster-dredgers, worked upon the principle of co-operation. This doctrine,
now taught as a modern one, was practised by them almost time out of mind.
The owner of the land gave the use of his land, the adventurers gave their
money, and the miners their labour; all sharing in the proceeds according
to ancient custom. For the use of his land, and for the ore taken from
the mine, the lord usually took a sixth part; but in consideration of
draining the mine, and in order to encourage the adventure, he was often
content with an eighth, or it might be only a tenth part of the produce.
The miners, on their part, agreed to divide in the proportions in which
they took part in the work. Their shares of the ore raised were measured
by barrows, and parcelled into heaps; “and it is surprising,” says
Borlase, “to see how ready and exact the reckoners are in dividing, though
oftentimes they can neither write nor read. The parcels being laid forth,
lots are cast, and then every parcel has a distinct mark laid on it with
one, two, or three stones, and sometimes a bit of stick or turf stuck up
in the middle or side of the pile; and when these marks are laid on, the
parcels may continue there half a year or more unmolested.”[26]
[26] Borlase, ‘Natural History of Cornwall,’ 175–6.
These were, however, the early and primitive days of mining, when the
operations were carried on comparatively near the surface, and the capital
invested in pumping-machinery was comparatively small in amount. As the
miners went deeper and deeper into the ground, and the richer lodes were
struck and followed, the character of mining became considerably changed.
Larger capitals were required to sink the shafts and keep them clear
of water until the ore was reached; and a new class of men, outside the
mining districts, was induced to venture their money in the mines as a
speculation. Yet the system above described, though greatly modified by
altered circumstances, continues to this day; and the mining of Cornwall
continues to be carried on mainly upon the co-operative or joint-stock
system.
When the surface lodes became exhausted, the necessity of employing some
more efficient method of pumping the water became more and more urgent.
In one pit after another the miners were being drowned out, and the
operations of an important branch of national industry were in danger of
being brought to a complete standstill. It was under these circumstances
that Captain Savery turned his attention to the contrivance of a more
powerful engine for the raising of water; and after various experiments,
he became persuaded that the most effective agency for the purpose was
the power of steam. It is very probable that he was aware of the attempts
that had been previously made in the same direction, and he may have
gathered many useful and suggestive hints from the Marquis of Worcester’s
‘Century;’ but as that book contained no plans nor precise definitions
of the methods by which the Marquis had accomplished his objects, it
could have helped him but little towards the contrivance of a practicable
working engine.[27]
[27] The absurd story is told by Dr. Desaguliers (‘Experimental
Philosophy,’ ii. 465) that Savery, having read the Marquis’s
book, “was the first to put in practice the raising of water by
fire, which he proposed for the draining of mines;” and having
copied the Marquis’s engine, “the better to conceal the matter,
bought up all the Marquis of Worcester’s books that he could
purchase in Paternoster-row and elsewhere, and burned ’em in
the presence of the gentleman, his friend, who told me this!”
It need scarcely be said that it was very unlikely that Savery
should have attempted thus to conceal an invention recorded in
a printed book which had been in circulation for more than forty
years.
How Savery was led to the study of the power of steam has been differently
stated. Desaguliers says his own account was this,--that having drunk a
flask of Florence at a tavern, and thrown the empty flask on the fire, he
called for a basin of water to wash his hands, and perceiving that the
little wine left in the flask had changed to steam, he took the vessel
by the neck and plunged its mouth into the water in the basin, when, the
steam being condensed, the water was immediately driven up into the flask
by the pressure of the atmosphere. Desaguliers disbelieved this account,
but admits that Savery made many experiments upon the powers of steam,
and eventually succeeded in making several engines “which raised water
very well.” Switzer, who was on intimate terms with Savery, gives another
account. He says the first hint from which he took the engine was from
a tobacco-pipe, which he immersed in water to wash or cool it; when he
discovered by the rarefaction of the air in the tube by the heat or steam,
and the gravitation or pressure of the exterior air on the condensation
of the latter, that the water was made to spring through the tube of the
pipe in a most surprising manner;[28] and that this phenomenon induced
him to search for the rationale, and to prosecute a series of experiments
which issued in the invention of his fire-engine.
However Savery may have obtained his first idea of the expansion and
condensation of steam, and of atmospheric pressure, it is certain that
the subject occupied his attention for many years. He had the usual
difficulties to encounter in dealing with a wholly new and untried power,
in contriving the novel mechanism through which it was to work, and of
getting his contrivances executed by the hands of mechanics necessarily
unaccustomed to such kind of work. “Though I was obliged,” he says, “to
encounter the oddest and almost insuperable difficulties, I spared neither
time, pains, nor money, till I had absolutely conquered them.”
[28] Switzer, ‘System of Hydrostaticks and Hydraulicks,’ London,
1729.
Having sufficiently matured his design, he had a model of his new “Fire
Engine,” as he termed it, made for exhibition before the King at Hampton
Court in 1698. William III., who was himself of a mechanical turn, was
highly pleased with the ingenuity displayed in Savery’s engine, as well as
with its efficient action, and he permitted the inventor to dedicate to
him ‘The Miner’s Friend,’ containing the first published description of
his invention. The King also promoted Savery’s application for a Patent,
which was secured in July, 1698,[29] and an Act confirming it was passed
in the following year.
Savery’s next step was to bring his invention under the notice of the
Royal Society, whose opinion on all matters of science was listened to
with profound respect. He accordingly exhibited his model at a meeting
held on the 14th of June, 1699, and it is recorded in the minutes of that
date, that “Mr. Savery entertained the Society with showing his engine
to raise water by the force of fire. He was thanked for showing the
experiment, which succeeded according to expectation, and was approved
of.” The inventor presented the Society with a drawing of his engine,
accompanied by a description, which was printed in the ‘Transactions.’[30]
[29] The patent is dated the 25th July, 1698, and is entitled,
“A grant to Thomas Savery, Gentl., of the sole exercise of
a new invenc̃on, by him invented, for raiseing of water, and
occasioning moc̃on to all sort of mill works, by the impellant
force of fire, which will be of great use for draining mines,
serving towns with water, and for the working of all sorts
of mills when they have not the benefit of water nor constant
winds; to hold for 14 years; with usual clauses.”
[30] ‘Philosophical Transactions,’ No. 252. Weld’s ‘Royal
Society,’ i. 357.
Savery next endeavoured to bring his invention into practical use, but
this was a matter of much greater difficulty. So many schemes with a like
object had been brought out and failed, that the mining interest came to
regard new projects with increasing suspicion. To persuade them that he
was no mere projector, but the inventor of a practicable working engine,
Savery wrote and published his ‘Miner’s Friend.’ “I am not very fond,” he
there said, “of lying under the scandal of a bare projector, and therefore
present you here with a draught of my machine, and lay before you the uses
of it, and leave it to your consideration whether it be worth your while
to make use of it or no.”
Inventors before Savery’s time were wont to make a great mystery of their
inventions; but he proclaimed that there was no mystery whatever about
his machine, and he believed that the more clearly it was understood,
the better it would be appreciated. He acknowledged that there had been
many pretenders to new inventions of the same sort, who had excited hopes
which had never been fulfilled; but this invention which he had made was
a thing the uses of which were capable of actual demonstration. He urged
that the old methods of raising water could not be carried further; and
that an entirely new power was needed to enable the miner to prosecute
his underground labours. “I fear,” said he, “that whoever by the old
causes of motion pretends to improvements within the last century does
betray his knowledge and judgment. For more than a hundred years since,
men and horses would raise by engines then made as much water as they
have ever done since, or I believe ever will, or, according to the law of
nature, ever can do. And, though my thoughts have been long employed about
water-works, I should never have pretended to any invention of that kind,
had I not happily found out this new, but yet a much stronger and cheaper
force or cause of motion than any before made use of.” He proceeded to
show how easy it was to work his engine,--boys of thirteen or fourteen
years being able to attend and work it to perfection after a few days’
teaching,--and how he had at length, after great difficulty, instructed
handicraft artificers to construct the engine according to his design, so
that, after much experience, said he, “they are become such masters of
the thing that they oblige themselves to deliver what engines they make
exactly tight and fit for service, and as such I dare warrant them to
anybody that has occasion for them.”[31]
Savery’s engine, as described by himself, consisted of a series of
boilers, condensing vessels, and tubes, the action of which will be
readily understood with the help of the annexed drawing.[32]
[Illustration: SAVERY’S ENGINE.]
[31] ‘The Miner’s Friend, or an Engine to Raise Water by Fire,
described, and of the manner of fixing it in Mines, with an
account of the several uses it is applicable unto; and an
answer to the objections made against it. By Tho. Savery, Gent.’
London, 1702.
[32] Two boilers, a large, A, and a smaller, B, were fixed in
a furnace, and connected together at the top by a pipe, C.
The larger boiler was filled two-thirds full, and the smaller
quite full of water. When that in the larger one was raised to
the boiling-point, the handle of the regulator, D, was thrust
back as far as it would go, by which the steam forced itself
through the pipe connected with the vessel E, expelling the
air it contained through the clack at F. The handle of the
regulator being then drawn towards you, the communication
between the boiler and the vessel, E, was closed, and that
between the boiler and the second vessel, G, was opened, which
latter was also filled with steam, the air being in like manner
discharged through the clack, H. Cold water was then poured
from the water-cock, I, on to the vessel E, by which the steam
was suddenly condensed, and a vacuum being thereby caused, the
water to be raised was drawn up through the sucking-pipe, J,
its return being prevented by a clack or valve at K. The handle
of the regulator D being again thrust back, the steam was again
admitted, and pressing upon the surface of the water in E,
forced it out at the bottom of the vessel and up through the
pipe L, from which it was driven into the open air. The handle
of the regulator was then reversed, on which the steam was again
admitted to G, and the water in like manner expelled from it,
while E, being again dashed with cold water, was refilling from
below. Then the cold water was turned upon G, and thus alternate
filling and forcing went on, and a continuous stream of cold
water kept flowing from the upper opening. The large boiler was
replenished with water by shutting off the connection of the
small boiler with the cold water pipe, M, which supplied it from
above, on which the steam contained in the latter forced the
water through the connecting pipe, C, into the large boiler,
and kept it running in a continuous stream until the surface of
the water in the smaller boiler was depressed below the opening
of the connecting pipe, which was indicated by the noise of
the clack, when it was refilled from the cold water pipe, M, as
before.
Its principal features were two large cylindrical vessels, which were
alternately filled with steam from an adjoining boiler and with cold water
from the well or mine out of which the water had to be raised. When either
of the hollow vessels was filled with steam, and then suddenly cooled by
a dash of cold water, a vacuum was thereby created, and, the vessel being
closed at the top and open at the bottom, the water was at once forced
up into it from the well by the pressure of the atmosphere. The steam,
being then let into the vessel from the top, pressed upon the surface of
the water, and forced it out at the bottom by another pipe (its return
into the well being prevented by a clack), and so up the perpendicular
pipe which opened into the outer air. The second vessel being treated in
the same manner, the same result followed; and thus, by alternate filling
and forcing, a continuous stream of water was poured out from the upper
opening. The whole of the labour required to work the engine was capable
of being performed by a single man, or even by a boy, after very little
teaching.
Although Savery’s plans and descriptions of the arrangement and working
of his engines are clear and explicit, he does not give any information as
to their proportions, beyond stating that an engine employed in raising a
column of water 3½ inches in diameter 60 feet high, requires a fireplace
20 inches deep. Speaking of their performances, he says, “I have known,
in Cornwall, a work with three lifts of about 18 feet each, lift and
carry a 3½-inch bore, that cost 42_s._ a day (reckoning 24 a day) for
labour, besides the wear and tear of engines, each pump having four men
working eight hours, at 14_d._ a man, and the men obliged to rest at
least a third part of that time.” He pointed out that at least one-third
part of the then cost of raising water might be saved by the adoption
of his invention, which on many mines would amount to “a brave estate”
in the course of a year. In estimating the power of his engine, Savery
was accustomed to compare it with the quantity of work that horses could
perform, and hence he introduced the term “horse power,” which is still
in use.
Although, in the treatise referred to, Savery describes an engine with
two furnaces, the drawing which he presented to the Royal Society showed
only one; and it appears that in another of his designs he showed only
one cylindrical vessel instead of two. In order to exhibit the working
of his engine on a larger scale than in the model, he proceeded to erect
one in a potter’s house at Lambeth, where, Switzer says, though it was a
small engine, the water struck up the tiles and forced its way through the
roof in a manner that surprised all the spectators. Switzer mentions other
engines erected after Savery’s designs for the raising of water at Camden
House and Sion House, which proved quite successful. The former, he says,
was the plainest and best proportioned engine he had seen: it had only a
single condensing vessel; and “though but a small one in comparison with
many others of the kind that are made for coal-works, it is sufficient for
any reasonable family, and other uses required for it in watering middling
gardens.”[33] Four receivers full of water, or equal to 52 gallons, were
raised every minute, or 3110 gallons in the hour; whilst, in the case
of the larger engines with double receivers, 6240 gallons an hour might
easily be raised. The cost of the smaller engine was about fifty pounds,
and the consumption of coal about a bushel in the twenty-four hours,
supposing it was kept constantly at work during that time.
[33] Switzer, ‘Introduction to a General System of Hydrostaticks
and Hydraulicks,’ 237.
[Illustration: HUEL VOR, WITH REMAINS OF THE OLD WORKS.
[By R. P. Leitch.]]
The uses to which Savery proposed to apply his engine were various.
One was to pump water into a reservoir, from which, by falling on a
water-wheel, it might produce a continuous rotary motion. Another was to
raise water into cisterns for the supply of gentlemen’s houses, and for
use in fountains and as an extinguisher in case of fire. A third was to
raise water for the supply of towns, and a fourth to drain fens and marsh
lands. But the most important, in the inventor’s estimation, was its
employment in clearing drowned mines and coal-pits of water. He showed
how water might be raised from deep mines by using several engines, placed
at different depths, one over the other. Thus by three lifts, each of 80
feet, water might be raised from a mine about 240 feet--then considered a
very great depth. From Savery’s own account, it is evident that several
of his engines were erected in Cornwall; and it is said that the first
was tried at Huel Vor, or “The Great Work in Breage,” a few miles from
Helstone, then considered the richest tin mine in the county. The engine
was found to be an improvement on the methods formerly employed for
draining the mine, and sent the miners to considerably greater depths. But
the great pressure of steam required to force up a high column of water
was such as to strain to the utmost the imperfect boilers and receivers
of those early days; and the frequent explosions which attended its use
eventually led to its discontinuance in favour of the superior engine of
Newcomen, which was shortly after invented.
Savery also endeavoured to introduce his engine in the coal-mining
districts, but without success, and for the same reason. The demand for
coal in connection with the iron manufacture having greatly increased
in the county of Stafford, and the coal which lay nearest the surface
having been for the most part “won,” the mining interest became very
desirous of obtaining some more efficient means of clearing the pits of
water, in order to send the miners deeper into the ground. Windlass and
buckets, wind-mills, horse-gins, rack-and-chain pumps, adits, and all
sorts of contrivances had been tried, and the limit of their powers had
been reached. The pits were fast becoming drowned out, and the ironmasters
began to fear lest their manufacture should become lost through want of
fuel. Under these circumstances they were ready to hail the invention of
Captain Savery, which promised to relieve them of their difficulty. He
was accordingly invited to erect one of his engines over a coal-mine at
the Broadwaters, near Wednesbury. The influx of water, however, proved
too much for the engine; the springs were so many and so strong, that all
the means which Savery could employ failed to clear the mine of water. To
increase the forcing power he increased the pressure of steam; but neither
boiler nor receiver could endure it, and the steam “tore the engine to
pieces; so that, after much time, labour, and expense, Mr. Savery gave up
the undertaking, and the engine was laid aside as useless.”[34]
[34] Dr. Wilkes in ‘Shaw’s History of Staffordshire,’ i. 85, 119.
He was no more successful with the engine which he erected at
York-buildings to pump water from the Thames for the supply of the western
parts of London. Bradley says that to increase its power he doubled
every part, but “it was liable to so many disorders, if a single mistake
happened in the working of it, that at length it was looked upon as a
useless piece of work, and rejected.”[35] Savery’s later engines thus
lost him much of the credit which he had gained by those of an earlier
and simpler construction. It became clear that their application was
very limited. They involved much waste of fuel through the condensation
of the hot steam pressing upon the surface of the cold water, previous
to the expulsion of the latter from the vessel; and eventually their
use was confined to the pumping of water for fountains and the supply
of gentlemen’s houses, and in some cases to the raising of water for the
purpose of working an overshot water-wheel. Various attempts were made to
improve the engine by Bradley, by Papin, by Desaguliers, and others; but
no great advance was made in its construction and method of working until
it was taken in hand by Newcomen and Calley, whose conjoint invention
marks an important epoch in the history of the steam-engine.
[35] Bradley, ‘Discourses on Earth and Water, &c.’ Westminster,
1727.
Not much is known of the later years of Savery’s life. We find him a
Captain of Military Engineers in 1702;[36] and in 1705, with the view
of advancing knowledge in his special branch of military science, he
gave to the world a translation, in folio, of Cohorn’s celebrated work
on fortification. The book was dedicated to Prince George of Denmark,
to whom he was indebted, in the same year, for his appointment to the
office of Treasurer of the Hospital for Sick and Wounded Seamen. Various
letters and documents are still to be found in the Transport Office,
Somerset House, addressed to him in that capacity.[37] In 1714 he was
further indebted to Prince George for the appointment of Surveyor to
the Waterworks at Hampton Court; but he did not live to enjoy it, as he
died in the course of the following year. He is said to have accumulated
considerable property, which he bequeathed to his wife, together with all
interest in his inventions. His will was executed on the day of his death,
the 15th of May, 1715, and was proved four days after in the Prerogative
Court of Canterbury. He there described himself as “of the parish of Saint
Margaret, at Westminster, Esquire.” His widow herself died before all his
effects were administered. There was a considerable amount of unclaimed
stock, which the Savery family were prevented from claiming, as it had
passed to the widow; and it has since been transferred to the credit of
the National Debt.
[36] We are informed by Quartermaster Conolly, R.E., who has given
much attention to the early history of the Royal Engineers,
that the book of Warrants and Appointments, anno 1712, No. 172½,
in the Tower Record-room, contains the following memorandum in
pencil on the inside cover:--[Thomas] “Savery, Engineer officer,
1702–14.”
[37] A pamphlet published in 1712, entitled ‘An Impartial Inquiry
into the Management of the War in Spain,’ contains the following
reference to Savery:--“Sums allowed by Parliament for carrying
on the war in Spain ... for the year 1710. To Thomas Savery,
Esq., for Thomas Cale, surgeon, for care of disabled soldiers,
306_l._ 6_s._ 4_d._”