The personal appearance of Henry Maudslay was in correspondence with
his character.  He was of a commanding presence, for he stood full six
feet two inches in height, a massive and portly man.  His face was
round, full, and lit up with good humour.  A fine, large, and square
forehead, of the grand constructive order, dominated over all, and his
bright keen eye gave energy and life to his countenance.  He was
thoroughly "jolly" and good-natured, yet full of force and character.
It was a positive delight to hear his cheerful, ringing laugh.  He was
cordial in manner, and his frankness set everybody at their ease who
had occasion to meet him, even for the first time.  No one could be
more faithful and consistent in his friendships, nor more firm in the
hour of adversity.  In fine, Henry Maudslay was, as described by his
friend Mr. Nasmyth, the very beau ideal of an honest, upright,
straight-forward, hard-working, intelligent Englishman.

A severe cold which he caught on his way home from one of his visits to
France, was the cause of his death, which occurred on the 14th of
February, 1831.  The void which his decease caused was long and deeply
felt, not only by his family and his large circle of friends, but by
his workmen, who admired him for his industrial skill, and loved him
because of his invariably manly, generous, and upright conduct towards
them.  He directed that he should be buried in Woolwich
parish-churchyard, where a cast-iron tomb, made to his own design, was
erected over his remains.  He had ever a warm heart for Woolwich, where
he had been born and brought up.  He often returned to it, sometimes to
carry his mother a share of his week's wages while she lived, and
afterwards to refresh himself with a sight of the neighbourhood with
which he had been so familiar when a boy.  He liked its green common,
with the soldiers about it; Shooter's Hill, with its out-look over Kent
and down the valley of the Thames; the river busy with shipping, and
the royal craft loading and unloading their armaments at the dockyard
wharves.  He liked the clangour of the Arsenal smithy where he had
first learned his art, and all the busy industry of the place.  It was
natural, therefore, that, being proud of his early connection with
Woolwich, he should wish to lie there; and Woolwich, on its part, let
us add, has equal reason to be proud of Henry Maudslay.



[1] The words Bramah uses in describing this part of his patent of 1795
are these--"The piston must be made perfectly watertight by leather or
other materials, as used in pump-making."  He elsewhere speaks of the
piston-rod "working through the stuffing-box."  But in practice, as we
have above shown, these methods were found to be altogether inefficient.

[2] In this lathe the slide rest and frame were moveable along the
traversing-bar, according to the length of the work, and could be
placed in any position and secured by a handle and screw underneath.
The Rest, however, afterwards underwent many important modifications;
but the principle of the whole machine was there.

[3] PLUMIER, L'Art de Tourner, Paris, 1754, p. 155.

[4] Machines approuvees par l' Academie, 1719.

[5] Machines approuvees par l' Academie, 1733.

[6] L'Art de Tourner en perfection, 49.

[7] It consisted of two parallel bars of wood or iron connected
together at both extremities by bolts or keys of sufficient width to
admit of the article required to be planed.  A moveable frame was
placed between the two bars, motion being given to it by a long
cylindrical thread acting on any tool put into the sliding frame, and,
consequently, causing the screw, by means of a handle at each end of
it, to push or draw the point or cutting-edge of the tool either
way.--Mr. George Rennie's Preface to Buchanan's Practical Essays on
Mill Work, 3rd Ed. xli.

[8] Turning was a favourite amusement amongst the French nobles of last
century, many of whom acquired great dexterity in the art, which they
turned to account when compelled to emigrate at the Revolution.  Louis
XVI. himself was a very good locksmith, and could have earned a fair
living at the trade.  Our own George III. was a good turner, and was
learned in wheels and treadles, chucks and chisels.  Henry Mayhew says,
on the authority of an old working turner, that, with average industry,
the King might have made from 40s. to 50s. a-week as a hard wood and
ivory turner.  Lord John Hay, though one-armed, was an adept at the
latter, and Lord Gray was another capital turner.  Indeed the late Mr.
Holtzapffel's elaborately illustrated treatise was written quite as
much for amateurs as for working mechanics.  Among other noble
handicraftsmen we may mention the late Lord Douglas, who cultivated
bookbinding.  Lord Traquair's fancy was cutlery, and one could not come
to him in a more welcome fashion than with a pair of old razors to set
up.

[9] Professor WILLIS, Lectures on the Results of the Great Exhibition
of 1851, 1st series, p. 306.

[10] Address delivered before the British Association at Manchester in
1861; and Useful Information for Engineers, 1st series, p. 22.

[11] Life of Sir Samuel Bentham, 97-8.

[12] Remarks on the Introduction of the Slide Principle in Tools and
Machines employed in the Production of Machinery, in Buchanan's
Practical Essays on Mill Work and other Machinery.  3rd ed. p. 397.

[13] So far as words and drawings can serve to describe the
block-making machinery, it will be found very ably described by Mr.
Farey in his article under this head in Rees's Cyclopaedia, and by Dr.
Brewster in the Edinburgh Cyclopaedia.  A very good account will also
be found in Tomlinson's Cyclopaedia of the Useful Arts, Art. "Block."

[14] The remuneration paid to Mr. Brunel for his share in the invention
was only one year's savings, which, however, were estimated by Sir
Samuel Bentham at 17,663L.; besides which a grant of 5000L. was
afterwards made to Brunel when labouring under pecuniary difficulties.
But the ANNUAL saving to the nation by the adoption of the block-making
machinery was probably more than the entire sum paid to the engineer.
Brunel afterwards invented other wood-working machinery, but none to
compare in merit and excellence with the above, For further particulars
of his career, see BEAMISH'S Memoirs of Sir Marc Isambard Brunel, C.E.
London.  1862.

[15] Among the last works executed by the firm during Mr. Maudslay's
lifetime was the famous Shield employed by his friend Brunel in
carrying forward the excavation of the Thames Tunnel.  He also supplied
the pumping-engines for the same great work, the completion of which he
did not live to see.

[16] His principal patent's were--two, taken out in 1805 and 1808,
while in Margaret Street, for printing calicoes (Nos. 2872 and 3117);
one taken out in 1806, in conjunction with Mr. Donkin, for lifting
heavy weights (2948); one taken out in 1807, while still in Margaret
Street, for improvements in the steam-engine, reducing its parts and
rendering it more compact and portable (3050); another, taken out in
conjunction with Robert Dickinson in 1812, for sweetening water and
other liquids (3538); and, lastly, a patent taken out in conjunction
with Joshua Field in 1824 for preventing concentration of brine in
boilers (5021).




CHAPTER XIII.

JOSEPH CLEMENT.

"It is almost impossible to over-estimate the importance of these
inventions.  The Greeks would have elevated their authors among the
gods; nor will the enlightened judgment of modern times deny them the
place among their fellow-men which is so undeniably their
due."--Edinburgh Review.


That Skill in mechanical contrivance is a matter of education and
training as well as of inborn faculty, is clear from the fact of so
many of our distinguished mechanics undergoing the same kind of
practical discipline, and perhaps still more so from the circumstance
of so many of them passing through the same workshops.  Thus Maudslay
and Clement were trained in the workshops of Bramah; and Roberts,
Whitworth, Nasmyth, and others, were trained in those of Maudslay.

Joseph Clement was born at Great Ashby in Westmoreland, in the year
1779.  His father was a hand-loom weaver, and a man of remarkable
culture considering his humble station in life.  He was an ardent
student of natural history, and possessed a much more complete
knowledge of several sub-branches of that science than was to have been
looked for in a common working-man.  One of the departments which he
specially studied was Entomology.  In his leisure hours he was
accustomed to traverse the country searching the hedge-bottoms for
beetles and other insects, of which he formed a remarkably complete
collection; and the capture of a rare specimen was quite an event in
his life.  In order more deliberately to study the habits of the bee
tribe, he had a number of hives constructed for the purpose of enabling
him to watch their proceedings without leaving his work; and the
pursuit was a source of the greatest pleasure to him.  He was a lover
of all dumb creatures; his cottage was haunted by birds which flew in
and out at his door, and some of them became so tame as to hop up to
him and feed out of his hand.  "Old Clement" was also a bit of a
mechanic, and such of his leisure moments as he did not devote to
insect-hunting, were employed in working a lathe of his own
construction, which he used to turn his bobbing on, and also in various
kinds of amateur mechanics.

His boy Joseph, like other poor men's sons, was early set to work.  He
received very little education, and learnt only the merest rudiments of
reading and writing at the village school.  The rest of his education
he gave to himself as he grew older.  His father needed his help at the
loom, where he worked with him for some years; but, as handloom weaving
was gradually being driven out by improved mechanism, the father
prudently resolved to put his son to a better trade.  They have a
saying in Cumberland that when the bairns reach a certain age, they are
thrown on to the house-rigg, and that those who stick on are made
thatchers of, while those who fall off are sent to St.  Bees to be made
parsons of.  Joseph must have been one of those that stuck on--at all
events his father decided to make him a thatcher, afterwards a slater,
and he worked at that trade for five years, between eighteen and
twenty-three.

The son, like the father, had a strong liking for mechanics, and as the
slating trade did not keep him in regular employment, especially in
winter time, he had plenty of opportunity for following the bent of his
inclinations.  He made a friend of the village blacksmith, whose smithy
he was accustomed to frequent, and there he learned to work at the
forge, to handle the hammer and file, and in a short time to shoe
horses with considerable expertness.  A cousin of his named Farer, a
clock and watchmaker by trade, having returned to the village from
London, brought with him some books on mechanics, which he lent to
Joseph to read; and they kindled in him an ardent desire to be a
mechanic instead of a slater.  He nevertheless continued to maintain
himself by the latter trade for some time longer, until his skill had
grown; and, by way of cultivating it, he determined, with the aid of
his friend the village blacksmith, to make a turning-lathe.  The two
set to work, and the result was the production of an article in every
way superior to that made by Clement's father, which was accordingly
displaced to make room for the new machine.  It was found to work very
satisfactorily, and by its means Joseph proceeded to turn fifes,
flutes, clarinets, and hautboys; for to his other accomplishments he
joined that of music, and could play upon the instruments that he made.
One of his most ambitious efforts was the making of a pair of
Northumberland bagpipes, which he finished to his satisfaction, and
performed upon to the great delight of the villagers.  To assist his
father in his entomological studies, he even contrived, with the aid of
the descriptions given in the books borrowed from his cousin the
watchmaker, to make for him a microscope, from which he proceeded to
make a reflecting telescope, which proved a very good instrument.  At
this early period (1804) he also seems to have directed his attention
to screw-making--a branch of mechanics in which he afterwards became
famous; and he proceeded to make a pair of very satisfactory
die-stocks, though it is said that he had not before seen or even heard
of such a contrivance for making screws.

So clever a workman was not likely to remain long a village slater.
Although the ingenious pieces of work which he turned out by his lathe
did not bring him in much money, he liked the occupation so much better
than slating that he was gradually giving up that trade.  His father
urged him to stick to slating as "a safe thing;" but his own mind was
in favour of following his instinct to be a mechanic; and at length he
determined to leave his village and seek work in a new line.  He
succeeded in finding employment in a small factory at Kirby Stephen, a
town some thirteen miles from Great Ashby, where he worked at making
power-looms.  From an old statement of account against his employer
which we have seen, in his own handwriting, dated the 6th September,
1805, it appears that his earnings at such work as "fitting the first
set of iron loames," "fitting up shittles," and "making moddles," were
3s. 6d. a day; and he must, during the same time, have lived with his
employer, who charged him as a set-off "14 weaks bord at 8s. per weak."
He afterwards seems to have worked at piece-work in partnership with
one Andrew Gamble supplying the materials as well as the workmanship
for the looms and shuttles.  His employer, Mr. George Dickinson, also
seems to have bought his reflecting telescope from him for the sum of
12L.

From Kirby Stephen Clement removed to Carlisle, where he was employed
by Forster and Sons during the next two years at the same description
of work; and he conducted himself, according; to their certificate on
his leaving their employment to proceed to Glasgow in 1807, "with great
sobriety and industry, entirely to their satisfaction."  While working
at Glasgow as a turner, he took lessons in drawing from Peter
Nicholson, the well-known writer on carpentry--a highly ingenious man.
Nicholson happened to call at the shop at which Clement worked in order
to make a drawing of a power-loom; and Clement's expressions of
admiration at his expertness were so enthusiastic, that Nicholson,
pleased with the youth's praise, asked if he could be of service to him
in any way.  Emboldened by the offer, Clement requested, as the
greatest favour he could confer upon him, to have the loan of the
drawing he had just made, in order that he might copy it.  The request
was at once complied with; and Clement, though very poor at the time,
and scarcely able to buy candle for the long winter evenings, sat up
late every night until he had finished it.  Though the first drawing he
had ever made, he handed it back to Nicholson instead of the original,
and at first the draughtsman did not recognise that the drawing was not
his own.  When Clement told him that it was only the copy, Nicholson's
brief but emphatic praise was--"Young man, YOU'LL DO!"  Proud to have
such a pupil, Nicholson generously offered to give him gratuitous
lessons in drawing, which were thankfully accepted; and Clement,
working at nights with great ardour, soon made rapid progress, and
became an expert draughtsman.

Trade being very slack in Glasgow at the time, Clement, after about a
year's stay in the place, accepted a situation with Messrs. Leys,
Masson, and Co., of Aberdeen, with whom he began at a guinea and a half
a week, from which he gradually rose to two guineas, and ultimately to
three guineas.  His principal work consisted in designing and making
power-looms for his employers, and fitting them up in different parts
of the country.  He continued to devote himself to the study of
practical mechanics, and made many improvements in the tools with which
he worked.  While at Glasgow he had made an improved pair of die-stocks
for screws; and, at Aberdeen, he made a turning-lathe with a sliding
mandrill and guide-screws, for cutting screws, furnished also with the
means for correcting guide-screws.  In the same machine he introduced a
small slide rest, into which he fixed the tool for cutting the
screws,--having never before seen a slide rest, though it is very
probable he may have heard of what Maudslay had already done in the
same direction.  Clement continued during this period of his life an
industrious self-cultivator, occupying most of his spare hours in
mechanical and landscape drawing, and in various studies.  Among the
papers left behind him we find a ticket to a course of instruction on
Natural Philosophy given by Professor Copland in the Marischal College
at Aberdeen, which Clement attended in the session of 1812-13; and we
do not doubt that our mechanic was among the most diligent of his
pupils.  Towards the end of 1813, after saving about 100L. out of his
wages, Clement resolved to proceed to London for the purpose of
improving himself in his trade and pushing his way in the world.  The
coach by which he travelled set him down in Snow Hill, Holborn; and his
first thought was of finding work.  He had no friend in town to consult
on the matter, so he made inquiry of the coach-guard whether he knew of
any person in the mechanical line in that neighbourhood.  The guard
said, "Yes; there was Alexander Galloway's show shop, just round the
corner, and he employed a large number of hands."  Running round the
corner, Clement looked in at Galloway's window, through which he saw
some lathes and other articles used in machine shops.  Next morning he
called upon the owner of the shop to ask employment.  "What can you
do?" asked Galloway.  "I can work at the forge," said Clement.
"Anything else?"  "I can turn."  "What else?"  "I can draw."  "What!"
said Galloway, "can you draw? Then I will engage you."  A man who could
draw or work to a drawing in those days was regarded as a superior sort
of mechanic.  Though Galloway was one of the leading tradesmen of his
time, and had excellent opportunities for advancement, he missed them
all.  As Clement afterwards said of him, "He was only a mouthing
common-council man, the height of whose ambition was to be an
alderman;" and, like most corporation celebrities, he held a low rank
in his own business.  He very rarely went into his workshops to
superintend or direct his workmen, leaving this to his foremen--a
sufficient indication of the causes of his failure as a mechanic.[1]

On entering Galloway's shop, Clement was first employed in working at
the lathe; but finding the tools so bad that it was impossible to
execute satisfactory work with them, he at once went to the forge, and
began making a new set of tools for himself.  The other men, to whom
such a proceeding was entirely new, came round him to observe his
operations, and they were much struck with his manual dexterity.  The
tools made, he proceeded to use them, displaying what seemed to the
other workmen an unusual degree of energy and intelligence; and some of
the old hands did not hesitate already to pronounce Clement to be the
best mechanic in the shop.  When Saturday night came round, the other
men were curious to know what wages Galloway would allow the new hand;
and when he had been paid, they asked him.  "A guinea," was the reply.
"A guinea!  Why, you are worth two if you are worth a shilling," said
an old man who came out of the rank--an excellent mechanic, who, though
comparatively worthless through his devotion to drink, knew Clement's
money value to his employer better than any man there; and he added,
"Wait for a week or two, and if you are not better paid than this, I
can tell you of a master who will give you a fairer wage."  Several
Saturdays came round, but no advance was made on the guinea a week; and
then the old workman recommended Clement to offer himself to Bramah at
Pimlico, who was always on the look out for first-rate mechanics.

Clement acted on the advice, and took with him some of his drawings, at
sight of which Bramah immediately engaged him for a month; and at the
end of that time he had given so much satisfaction, that it was agreed
he should continue for three months longer at two guineas a week.
Clement was placed in charge of the tools of the shop, and he showed
himself so apt at introducing improvements in them, as well as in
organizing the work with a view to despatch and economy, that at the
end of the term Bramah made him a handsome present, adding, "if I had
secured your services five years since, I would now have been a richer
man by many thousands of pounds."  A formal agreement for a term of
five years was then entered into between Bramah and Clement, dated the
1st of April, 1814, by which the latter undertook to fill the office of
chief-draughtsman and superintendent of the Pimlico Works, in
consideration of a salary of three guineas a week, with an advance of
four shillings a week in each succeeding year of the engagement.  This
arrangement proved of mutual advantage to both.  Clement devoted
himself with increased zeal to the improvement of the mechanical
arrangements of the concern, exhibiting his ingenuity in many ways, and
taking; a genuine pride in upholding the character of his master for
turning out first-class work.

On the death of Bramah, his sons returned from college and entered into
possession of the business.  They found Clement the ruling mind there
and grew jealous of him to such an extent that his situation became
uncomfortable; and by mutual consent he was allowed to leave before the
expiry of his term of agreement.  He had no difficulty in finding
employment; and was at once taken on as chief draughtsman at Maudslay
and Field's where he was of much assistance in proportioning the early
marine engines, for the manufacture of which that firm were becoming
celebrated.  After a short time, he became desirous of beginning
business on his own account as a mechanical engineer.  He was
encouraged to do this by the Duke of Northumberland, who, being a great
lover of mechanics and himself a capital turner, used often to visit
Maudslay's, and thus became acquainted with Clement, whose expertness
as a draughtsman and mechanic he greatly admired.  Being a man of
frugal and sober habits, always keeping his expenditure very
considerably within his income, Clement had been enabled to accumulate
about 500L., which he thought would be enough for his purpose; and he
accordingly proceeded, in 1817, to take a small workshop in Prospect
Place, Newington Butts, where he began business as a mechanical
draughtsman and manufacturer of small machinery requiring first-class
workmanship.

From the time when he took his first gratuitous lessons in drawing from
Peter Nicholson, at Glasgow, in 1807, he had been steadily improving in
this art, the knowledge of which is indispensable to whoever aspires to
eminence as a mechanical engineer,--until by general consent Clement
was confessed to stand unrivalled as a draughtsman.  Some of the very
best drawings contained in the Transactions of the Society of Arts,
from the year 1817 downwards,--especially those requiring the
delineation of any unusually elaborate piece of machinery,--proceeded
from the hand of Clement.  In some of these, he reached a degree of
truth in mechanical perspective which has never been surpassed.[2]  To
facilitate his labours, he invented an extremely ingenious instrument,
by means of which ellipses of all proportions, as well as circles and
right lines, might be geometrically drawn on paper or on copper.  He
took his idea of this instrument from the trammel used by carpenters
for drawing imperfect ellipses; and when he had succeeded in avoiding
the crossing of the points, he proceeded to invent the straight-line
motion.  For this invention the Society of Arts awarded him their gold
medal in 1818.  Some years later, he submitted to the same Society his
invention of a stand for drawings of large size.  He had experienced
considerable difficulty in making such drawings, and with his
accustomed readiness to overcome obstacles, he forthwith set to work
and brought out his new drawing-table.

As with many other original-minded mechanics, invention became a habit
with him, and by study and labour he rarely failed in attaining the
object which he had bent his mind upon accomplishing.  Indeed, nothing
pleased him better than to have what he called "a tough job;" as it
stimulated his inventive faculty, in the exercise of which he took the
highest pleasure.  Hence mechanical schemers of all kinds were
accustomed to resort to Clement for help when they had found an idea
which they desired to embody in a machine.  If there was any value in
their idea, none could be more ready than he to recognise its merit,
and to work it into shape; but if worthless, he spoke out his mind at
once, dissuading the projector from wasting upon it further labour or
expense.

One of the important branches of practical mechanics to which Clement
continued through life to devote himself, was the improvement of
self-acting tools, more especially of the slide-lathe.  He introduced
various improvements in its construction and arrangement, until in his
hands it became as nearly perfect as it was possible to be.  In 1818,
he furnished the lathe with a slide rest twenty-two inches long, for
the purpose of cutting screws, provided with the means of
self-correction; and some years later, in 1827, the Society of Arts
awarded him their gold Isis medal for his improved turning-lathe, which
embodied many ingenious contrivances calculated to increase its
precision and accuracy in large surface-turning.

The beautiful arrangements embodied in Mr. Clement's improved lathe can
with difficulty be described in words; but its ingenuity may be
inferred from a brief statement of the defects which it was invented to
remedy, and which it successfully overcame.  When the mandrill of a
lathe, having a metal plate fixed to it, turns round with a uniform
motion, and the slide rest which carries the cutter is moving from the
circumference of the work to the centre, it will be obvious that the
quantity of metal passing over the edge of the cutter at each
revolution, and therefore at equal intervals of time, is continually
diminishing, in exact proportion to the spiral line described by the
cutter on the face of the work.  But in turning metal plates it is
found very in expedient to increase the speed of the work beyond a
certain quantity; for when this happens, and the tool passes the work
at too great a velocity, it heats, softens, and is ground away, the
edge of the cutter becomes dull, and the surface of the plate is
indented and burnished, instead of being turned.  Hence loss of time on
the part of the workman, and diminished work on the part of the tool,
results which, considering the wages of the one and the capital
expended on the construction of the other, are of no small importance;
for the prime objects of all improvement of tools are, economy of time
and economy of capital--to minimize labour and cost, and maximize
result.

The defect to which we have referred was almost the only remaining
imperfection in the lathe, and Mr. Clement overcame it by making the
machine self-regulating; so that, whatever might be the situation of
the cutter, equal quantities of metal should pass over it in equal
times,--the speed at the centre not exceeding that suited to the work
at the circumference,--while the workman was enabled to convert the
varying rate of the mandrill into a uniform one whenever he chose.
Thus the expedients of wheels, riggers, and drums, of different
diameters, by which it had been endeavoured to alter the speed of the
lathe-mandrill, according to the hardness of the metal and the diameter
of the thing to be turned, were effectually disposed of.  These, though
answering very well where cylinders of equal diameter had to be bored,
and a uniform motion was all that was required, were found very
inefficient where a Plane surface had to be turned; and it was in such
cases that Mr. Clement's lathe was found so valuable.  By its means
surfaces of unrivalled correctness were produced, and the slide-lathe,
so improved, became recognised and adopted as the most accurate and
extensively applicable of all machine-tools.

The year after Mr. Clement brought out his improved turning-lathe, he
added to it his self-adjusting double driving centre-chuck, for which
the Society of Arts awarded him their silver medal in 1828.  In
introducing this invention to the notice of the Society, Mr. Clement
said, "Although I have been in the habit of turning and making
turning-lathes and other machinery for upwards of thirty-five years,
and have examined the best turning-lathes in the principal
manufactories throughout Great Britain, I find it universally regretted
by all practical men that they cannot turn anything perfectly true
between the centres of the lathe."  It was found by experience, that
there was a degree of eccentricity, and consequently of imperfection,
in the figure of any long cylinder turned while suspended between the
centres of the lathe, and made to revolve by the action of a single
driver.  Under such circumstances the pressure of the tool tended to
force the work out of the right line and to distribute the strain
between the driver and the adjacent centre, so that one end of the
cylinder became eccentric with respect to the other.  By Mr. Clement's
invention of the two-armed driver, which was self-adjusting, the strain
was taken from the centre and divided between the two arms, which being
equidistant from the centre, effectually corrected all eccentricity in
the work.  This invention was found of great importance in ensuring the
true turning of large machinery, which before had been found a matter
of considerable difficulty.

In the same year (1828) Mr. Clement began the making of fluted taps and
dies, and he established a mechanical practice with reference to the
pitch of the screw, which proved of the greatest importance in the
economics of manufacture.  Before his time, each mechanical engineer
adopted a thread of his own; so that when a piece of work came under
repair, the screw-hob had usually to be drilled out, and a new thread
was introduced according to the usage which prevailed in the shop in
which the work was executed.  Mr. Clement saw a great waste of labour
in this practice, and he promulgated the idea that every screw of a
particular length ought to be furnished with its appointed number of
threads of a settled pitch.  Taking the inch as the basis of his
calculations, he determined the number of threads in each case; and the
practice thus initiated by him, recommended as it was by convenience
and economy, was very shortly adopted throughout the trade.  It may be
mentioned that one of Clement's ablest journeymen, Mr. Whitworth, has,
since his time, been mainly instrumental in establishing the settled
practice; and Whitworth's thread (initiated by Clement) has become
recognised throughout the mechanical world.  To carry out his idea,
Clement invented his screw-engine lathe, with gearing, mandrill, and
sliding-table wheel-work, by means of which he first cut the inside
screw-tools from the left-handed hobs--the reverse mode having before
been adopted,--while in shaping machines he was the first to use the
revolving cutter attached to the slide rest.  Then, in 1828, he fluted
the taps for the first time with a revolving cutter,--other makers
having up to that time only notched them.  Among his other inventions
in screws may be mentioned his headless tap, which, according to Mr.
Nasmyth, is so valuable an invention, that, "if he had done nothing
else, it ought to immortalize him among mechanics.  It passed right
through the hole to be tapped, and was thus enabled to do the duty of
three ordinary screws."  By these improvements much greater precision
was secured in the manufacture of tools and machinery, accompanied by a
greatly reduced cost of production; the results of which are felt to
this day.

Another of Mr. Clement's ingenious inventions was his Planing Machine,
by means of which metal plates of large dimensions were planed with
perfect truth and finished with beautiful accuracy.  There is perhaps
scarcely a machine about which there has been more controversy than
this; and we do not pretend to be able to determine the respective
merits of the many able mechanics who have had a hand in its invention.
It is exceedingly probable that others besides Clement worked out the
problem in their own way, by independent methods; and this is confirmed
by the circumstance that though the results achieved by the respective
inventors were the same, the methods employed by them were in many
respects different.  As regards Clement, we find that previous to the
year 1820 he had a machine in regular use for planing the triangular
bars of lathes and the sides of weaving-looms.  This instrument was
found so useful and so economical in its working, that Clement
proceeded to elaborate a planing machine of a more complete kind, which
he finished and set to work in the year 1825.  He prepared no model of
it, but made it direct from the working drawings; and it was so nicely
constructed, that when put together it went without a hitch, and has
continued steadily working for more than thirty years down to the
present day.

Clement took out no patent for his invention, relying for protection
mainly on his own and his workmen's skill in using it.  We therefore
find no specification of his machine at the Patent Office, as in the
case of most other capital inventions; but a very complete account of
it is to be found in the Transactions of the Society of Arts for 1832,
as described by Mr. Varley.  The practical value of the Planing Machine
induced the Society to apply to Mr. Clement for liberty to publish a
full description of it; and Mr. Varley's paper was the result.[3]  It
may be briefly stated that this engineer's plane differs greatly from
the carpenter's plane, the cutter of which is only allowed to project
so far as to admit of a thin shaving to be sliced off,--the plane
working flat in proportion to the width of the tool, and its length and
straightness preventing the cutter from descending into any hollows in
the wood.  The engineer's plane more resembles the turning-lathe, of
which indeed it is but a modification, working up on the same
principle, on flat surfaces.  The tools or cutters in Clement's machine
were similar to those used in the lathe, varying in like manner, but
performing their work in right lines,--the tool being stationary and
the work moving under it, the tool only travelling when making lateral
cuts.  To save time two cutters were mounted, one to cut the work while
going, the other while returning, both being so arranged and held as to
be presented to the work in the firmest manner, and with the least
possible friction.  The bed of the machine, on which the work was laid,
passed under the cutters on perfectly true rollers or wheels, lodged
and held in their bearings as accurately as the best mandrill could be,
and having set-screws acting against their ends totally preventing all
end-motion.  The machine was bedded on a massive and solid foundation
of masonry in heavy blocks, the support at all points being so complete
as effectually to destroy all tendency to vibration, with the object of
securing full, round, and quiet cuts.  The rollers on which the
planing-machine travelled were so true, that Clement himself used to
say of them, "If you were to put but a paper shaving under one of the
rollers, it would at once stop all the rest."  Nor was this any
exaggeration--the entire mechanism, notwithstanding its great size,
being as true and accurate as that of a watch.

By an ingenious adaptation of the apparatus, which will also be found
described in the Society of Arts paper, the planing machine might be
fitted with a lathe-bed, either to hold two centres, or a head with a
suitable mandrill.  When so fitted, the machine was enabled to do the
work of a turning-lathe, though in a different way, cutting cylinders
or cones in their longitudinal direction perfectly straight, as well as
solids or prisms of any angle, either by the longitudinal or lateral
motion of the cutter; whilst by making the work revolve, it might be
turned as in any other lathe.  This ingenious machine, as contrived by
Mr. Clement, therefore represented a complete union of the
turning-lathe with the planing machine and dividing engine, by which
turning of the most complicated kind might readily be executed.  For
ten years after it was set in motion, Clement's was the only machine of
the sort available for planing large work; and being consequently very
much in request, it was often kept going night and day,--the earnings
by the planing machine alone during that time forming the principal
income of its inventor.  As it took in a piece of work six feet square,
and as his charge for planing was three-halfpence the square inch, or
eighteen shillings the square foot, he could thus earn by his machine
alone some ten pounds for every day's work of twelve hours.  We may add
that since planing machines in various forms have become common in
mechanical workshops, the cost of planing does not amount to more than
three-halfpence the square foot.

The excellence of Mr. Clement's tools, and his well-known skill in
designing and executing work requiring unusual accuracy and finish, led
to his being employed by Mr. Babbage to make his celebrated Calculating
or Difference Engine.  The contrivance of a machine that should work
out complicated sums in arithmetic with perfect precision, was, as may
readily be imagined, one of the most difficult feats of the mechanical
intellect.  To do this was in an especial sense to stamp matter with
the impress of mind, and render it subservient to the highest thinking
faculty.  Attempts had been made at an early period to perform
arithmetical calculations by mechanical aids more rapidly and precisely
than it was possible to do by the operations of the individual mind.
The preparation of arithmetical tables of high numbers involved a vast
deal of labour, and even with the greatest care errors were unavoidable
and numerous.  Thus in a multipltcation-table prepared by a man so
eminent as Dr. Hutton for the Board of Longitude, no fewer than forty
errors were discovered in a single page taken at random.  In the tables
of the Nautical Almanac, where the greatest possible precision was
desirable and necessary, more than five hundred errors were detected by
one person; and the Tables of the Board of Longitude were found equally
incorrect.  But such errors were impossible to be avoided so long as
the ordinary modes of calculating, transcribing, and printing continued
in use.

The earliest and simplest form of calculating apparatus was that
employed by the schoolboys of ancient Greece, called the Abacus;
consisting of a smooth board with a narrow rim, on which they were
taught to compute by means of progressive rows of pebbles, bits of bone
or ivory, or pieces of silver coin, used as counters.  The same board,
strewn over with sand, was used for teaching the rudiments of writing
and the principles of geometry.  The Romans subsequently adopted the
Abacus, dividing it by means of perpendicular lines or bars, and from
the designation of calculus which they gave to each pebble or counter
employed on the board, we have derived our English word to calculate.
The same instrument continued to be employed during the middle ages,
and the table used by the English Court of Exchequer was but a modified
form of the Greek Abacus, the chequered lines across it giving the
designation to the Court, which still survives.  Tallies, from the
French word tailler to cut, were another of the mechanical methods
employed to record computations, though in a very rude way.  Step by
step improvements were made; the most important being that invented by
Napier of Merchiston, the inventor of logarithms, commonly called
Napier's bones, consisting of a number of rods divided into ten equal
squares and numbered, so that the whole when placed together formed the
common multiplication table.  By these means various operations in
multiplication and division were performed.  Sir Samuel Morland,
Gunter, and Lamb introduced other contrivances, applicable to
trigonometry; Gunter's scale being still in common use.  The
calculating machines of Gersten and Pascal were of a different kind,
working out arithmetical calculations by means of trains of wheels and
other arrangements; and that contrived by Lord Stanhope for the purpose
of verifying his calculations with respect to the National Debt was of
like character.  But none of these will bear for a moment to be
compared with the machine designed by Mr. Babbage for performing
arithmetical calculations and mathematical analyses, as well as for
recording the calculations when made, thereby getting rid entirely of
individual error in the operations of calculation, transcription, and
printing.

The French government, in their desire to promote the extension of the
decimal system, had ordered the construction of logarithmical tables of
vast extent; but the great labour and expense involved in the
undertaking prevented the design from being carried out.  It was
reserved for Mr. Babbage to develope the idea by means of a machine
which he called the Difference Engine.  This machine is of so
complicated a character that it would be impossible for us to give any
intelligible description of it in words.  Although Dr. Lardner was
unrivalled in the art of describing mechanism, he occupied twenty-five
pages of the 'Edinburgh Review' (vol.59) in endeavouring to describe
its action, and there were several features in it which he gave up as
hopeless.  Some parts of the apparatus and modes of action are indeed
extraordinary and perhaps none more so than that for ensuring accuracy
in the calculated results,--the machine actually correcting itself, and
rubbing itself back into accuracy, when the disposition to err occurs,
by the friction of the adjacent machinery!  When an error is made, the
wheels become locked and refuse to proceed; thus the machine must go
rightly or not at all,--an arrangement as nearly resembling volition as
anything that brass and steel are likely to accomplish.

This intricate subject was taken up by Mr. Babbage in 1821, when he
undertook to superintend for the British government the construction of
a machine for calculating and printing mathematical and astronomical
tables.  The model first constructed to illustrate the nature of his
invention produced figures at the rate of 44 a minute.  In 1823 the
Royal Society was requested to report upon the invention, and after
full inquiry the committee recommended it as one highly deserving of
public encouragement.  A sum of 1500L. was then placed at Mr. Babbage's
disposal by the Lords of the Treasury for the purpose of enabling him
to perfect his invention.  It was at this time that he engaged Mr.
Clement as draughtsman and mechanic to embody his ideas in a working
machine.  Numerous tools were expressly contrived by the latter for
executing the several parts, and workmen were specially educated for
the purpose of using them.  Some idea of the elaborate character of the
drawings may be formed from the fact that those required for the
calculating machinery alone--not to mention the printing machinery,
which was almost equally elaborate--covered not less than four hundred
square feet of surface!  The cost of executing the calculating machine
was of course very great, and the progress of the work was necessarily
slow.  The consequence was that the government first became impatient,
and then began to grumble at the expense.  At the end of seven years
the engineer's bills alone were found to amount to nearly 7200L., and
Mr. Babbage's costs out of pocket to 7000L. more.  In order to make
more satisfactory progress, it was determined to remove the works to
the neighbourhood of Mr. Babbage's own residence; but as Clement's
claims for conducting the operations in the new premises were thought
exorbitant, and as he himself considered that the work did not yield
him the average profit of ordinary employment in his own trade, he
eventually withdrew from the enterprise, taking with him the tools
which he had constructed for executing the machine.  The government
also shortly after withdrew from it, and from that time the scheme was
suspended, the Calculating Engine remaining a beautiful but unfinished
fragment of a great work.  Though originally intended to go as far as
twenty figures, it was only completed to the extent of being capable of
calculating to the depth of five figures, and two orders of
differences; and only a small part of the proposed printing machinery
was ever made.  The engine was placed in the museum of King's College
in 1843, enclosed in a glass case, until the year 1862, when it was
removed for a time to the Great Exhibition, where it formed perhaps the
most remarkable and beautifully executed piece of mechanism the
combined result of intellectual and mechanical contrivance--in the
entire collection.[4]

Clement was on various other occasions invited to undertake work
requiring extra skill, which other mechanics were unwilling or unable
to execute.  He was thus always full of employment, never being under
the necessity of canvassing for customers.  He was almost constantly in
his workshop, in which he took great pride.  His dwelling was over the
office in the yard, and it was with difficulty he could be induced to
leave the premises.  On one occasion Mr. Brunel of the Great Western
Railway called upon him to ask if he could supply him with a superior
steam-whistle for his locomotives, the whistles which they were using
giving forth very little sound.  Clement examined the specimen brought
by Brunel, and pronounced it to be "mere tallow-chandler's work."  He
undertook to supply a proper article, and after his usual fashion he
proceeded to contrive a machine or tool for the express purpose of
making steam-whistles.  They were made and supplied, and when mounted
on the locomotive the effect was indeed "screaming."  They were heard
miles off, and Brunel, delighted, ordered a hundred.  But when the bill
came in, it was found that the charge made for them was very high--as
much as 40L. the set.  The company demurred at the price,--Brunel
declaring it to be six times more than the price they had before been
paying.  "That may be;" rejoined Clement, "but mine are more than six
times better.  You ordered a first-rate article, and you must be
content to pay for it." The matter was referred to an arbitrator, who
awarded the full sum claimed.  Mr. Weld mentions a similar case of an
order which Clement received from America to make a large screw of
given dimensions "in the best possible manner," and he accordingly
proceeded to make one with the greatest mathematical accuracy.  But his
bill amounted to some hundreds of pounds, which completely staggered
the American, who did not calculate on having to pay more than 20L. at
the utmost for the screw.  The matter was, however, referred to
arbitrators, who gave their decision, as in the former case, in favour
of the mechanic.[5]

One of the last works which Clement executed as a matter of pleasure,
was the building of an organ for his own use.  It will be remembered
that when working as a slater at Great Ashby, he had made flutes and
clarinets, and now in his old age he determined to try his skill at
making an organ--in his opinion the king of musical instruments.  The
building of it became his hobby, and his greatest delight was in
superintending its progress.  It cost him about two thousand pounds in
labour alone, but he lived to finish it, and we have been informed that
it was pronounced a very excellent instrument.

Clement was a heavy-browed man, without any polish of manner or speech;
for to the last he continued to use his strong Westmoreland dialect.
He was not educated in a literary sense; for he read but little, and
could write with difficulty.  He was eminently a mechanic, and had
achieved his exquisite skill by observation, experience, and
reflection.  His head was a complete repertory of inventions, on which
he was constantly drawing for the improvement of mechanical practice.
Though he had never more than thirty workmen in his factory, they were
all of the first class; and the example which Clement set before them
of extreme carefulness and accuracy in execution rendered his shop one
of the best schools of its time for the training of thoroughly
accomplished mechanics.  Mr. Clement died in 1844, in his sixty-fifth
year; after which his works were carried on by Mr. Wilkinson, one of
his nephews; and his planing machine still continues in useful work.



[1] On one occasion Galloway had a cast-iron roof made for his
workshop, so flat and so independent of ties that the wonder was that
it should have stood an hour.  One day Peter Keir, an engineer much
employed by the government--a clever man, though some what
eccentric--was taken into the shop by Galloway to admire the new roof.
Keir, on glancing up at it, immediately exclaimed, "Come outside, and
let us speak about it there!"  All that he could say to Galloway
respecting the unsoundness of its construction was of no avail.  The
fact was that, however Keir might argue about its not being able to
stand, there it was actually standing, and that was enough for
Galloway.  Keir went home, his mind filled with Galloway's most
unprincipled roof.  "If that stands," said he to himself, "all that I
have been learning and doing for thirty years has been wrong."  That
night he could not sleep for thinking about it.  In the morning he
strolled up Primrose Hill, and returned home still muttering to himself
about "that roof."  "What," said his wife to him, "are you thinking of
Galloway's roof?"  "Yes," said he.  "Then you have seen the papers?"
"No--what about them?"  "Galloway's roof has fallen in this morning,
and killed eight or ten of the men!" Keir immediately went to bed, and
slept soundly till next morning.