with Mr. Jessop) was engaged, was the Ellesmere Canal, a series of
navigations intended to unite the Severn, the Dee, and the Mersey,
and extending altogether to a length of nearly one hundred and twenty
miles. From the date of this engagement, about 1793, Telford directed
his attention almost entirely to civil engineering. In the execution of
the immense aqueducts, required on this work, which cross the valleys
of the Ceroig or Chirk, and of the Dee, at an elevation of 70 and 120
feet respectively, cast iron was first introduced as a material for
forming the water-troughs of the canal, in place of the usual puddled
clay confined in masonry, a practice which involved great expense, and
some danger in times of frost, from the expansion of the moist clay. In
the locks of this canal Telford also introduced cast iron framing in
place of timber; and in one instance, where the lock was formed in a
quicksand, he made every part of the above material.
The Caledonian Canal, of which Mr. Jessop was consulting engineer,
was another of Mr. Telford's principal works. This canal was opened
throughout its course in the year 1823, and it forms a noble monument
of the skill of the engineer. The locks are stated by Telford to be the
largest ever constructed at that time, being 40 feet wide, and from 170
to 180 feet long. Of other canals constructed wholly or partially under
his superintendance, it is sufficient to mention the Glasgow, Paisley,
and Androssan; the Macclesfield; the Birmingham and Liverpool Junction;
the Gloucester and Berkeley; the Birmingham, which was completely
remodelled by him and adapted to the conduct of a very extensive
traffic, and the Weaver navigation in Cheshire. On the Continent he
likewise superintended the construction of the Gotha Canal in Sweden,
a navigation of about 125 English miles, of which 55 are artificial
canal. From the Lake Wener at one extremity, this navigation rises
162 feet to the summit level, and falls 370 feet to the Baltic at the
other; the rise and fall are effected by fifty-six locks, and the canal
is 42 feet wide at the bottom and 10 feet deep. Upon its completion
Telford received a Swedish order of knighthood, and as a farther mark
of the royal approbation, received the King of Sweden's portrait set in
diamonds.
The works executed by Telford under the Commissioners of Highland Roads
and Bridges are of great importance. The practical operations under
this commission, appointed in 1803, embraced about a thousand miles
of new road, with nearly 1,200 new bridges, which caused the whole of
Scotland, from its southern boundary near Carlisle, to the northern
extremity of Caithness, and from Aberdeenshire on the east, to the
Argyleshire islands on the west, to be intersected by roads; and its
largest rivers and even inferior streams to be crossed by bridges. The
execution of this undertaking occupied a period of twenty-five years,
and all was done under the sole direction of Telford. The great road
from London to Holyhead remains, perhaps, one of the most perfect
specimens of his skill as an engineer; the improvements in it were
executed by him, under another Parliamentary Commission appointed in
1815, and Telford himself appears to have regarded this work with
peculiar satisfaction.
The Menai suspension bridge is, however, unquestionably one of the
noblest monuments of Mr. Telford's fame, and it may be said to have
inaugurated the era of the extensive introduction of wrought iron into
great permanent structures exposed to heavy strains.[39] This bridge
was commenced in 1819, and opened for traffic in 1826. The distance
between the two piers is 550 feet, and the whole roadway, which is
carried over four arches on the one side, and three on the other, has
a length of 1000 feet, and a breadth of 30 feet. The total cost of the
work was 120,000_l._
Mr. Telford also built many other bridges of considerable size, and
executed some important harbour works at Aberdeen and Dundee; but his
most striking performance of this latter class is the St. Katharine
Docks, London. One of his latest engagements was the survey of Dover
harbour, undertaken in January, 1834, at the request of the Duke
of Wellington, (as Warden of the Cinque Ports,) with a view to the
adoption of measures to check the accumulation of shingle at the
entrance.
During the course of his life Mr. Telford taught himself Latin, French,
and German, so as to be able to read those languages with fluency, and
to be able to converse freely in French. He is likewise said to have
been well acquainted with algebra, but to have placed more reliance
upon experiment, than on mathematical investigation. He contributed
to the 'Edinburgh Encyclopædia' the articles--'Architecture,' 'Bridge
Building,' and 'Canal Making.' Besides the above, he wrote an account
of his own life, giving elaborate descriptions of his various
professional undertakings. (Life of Thomas Telford, written by himself.
Edited by John Rickman. London, 1833, 4to.)
Although Telford was not connected with the Institution of Civil
Engineers at its formation, he accepted their invitation in 1820, and
became their President; and from that time he was unremitting in his
attention to the duties of the office, having become by his partial
retirement from business, a pretty regular resident in the metropolis.
Telford was possessed of a robust frame, and till he had reached the
age of seventy, had never been visited with any serious illness. While
at Cambridge, in the year 1827, he was afflicted with a severe and
dangerous disorder; and although he gradually recovered a certain
degree of health, he never regained his former vigour. He died a
few years afterwards at his house in Abingdon Street, Westminster,
having completed the seventy-seventh year of his age. His remains were
deposited in Westminster Abbey, where there is a statue erected to his
memory.--_Encyclopædia Britannica._--_English Cyclopædia._
CHARLES TENNANT.
Born May 3, 1768. Died October 1, 1838.
Charles Tennant, the founder of the celebrated chemical works at St.
Rollox, Glasgow, was born at Ochiltree, Ayrshire. His father, John
Tennant, was factor or steward to the Countess of Glencairn, and also
rented a farm on her estate, in the culture of which he displayed great
practical and scientific ability. John Tennant married twice; after
the death of his first wife, by whom he had two sons and one daughter,
he married, in the year 1757, Margaret McLure, who, in the course of
time, brought him a numerous family of six sons and seven daughters.
John Tennant's second wife possessed very superior abilities, which
she earnestly directed to the education and advancement of her family,
ultimately having the satisfaction of seeing all her children turn out
men of energy and success in life. Charles Tennant, the subject of our
memoir, was the fifth son; he received his early education at home,
afterwards attending the parish school of Ochiltree. When still very
young, Charles left home and went to Kilbarhan, with the intention
of learning the manufacture of silk. After remaining at this place a
short time, Tennant removed to Wellmeadow bleachfield, where he studied
the methods of bleaching at that time in use, and ultimately went to
Darnly (the place from which the unfortunate husband of Mary, Queen of
Scots, took his title), and established there an extensive bleachfield,
taking into partnership with him Mr. Cochrane of Paisley. Mr. Tennant
now devoted himself to the study of chemistry, feeling that the process
of bleaching could only be effected by true chemical agency, whatever
might be the particular method or operation, and that, therefore, the
bleacher must in the first case look to the chemist for the discovery
of more potent agents to effect his object. Before Mr. Tennant's time
the operation of bleaching was of a very tedious and expensive nature.
The cloth was steeped in alkaline lye, which was called 'bucking.' The
subsequent process of bleaching was done by exposure on the grass,
called 'crofting;' these operations were repeated five or six times,
and extended over a period of eight or ten weeks. In the year 1787 an
important change took place, in consequence of the discovery, by Mr.
Scheele, of Sweden, of chlorine, which was used as a substitute for
exposure to the atmosphere. The repeated experiments of Berthollet
added considerably to the facts already known, while the practical
effects of these discoveries were still more fully shown by Mr. Watt,
and Dr. Henry of Manchester. In 1798 Mr. Tennant made his first great
discovery, viz., a method of making saturated chloride of lime, an
article which was found to answer perfectly all the purposes required
by the bleacher. This invention, for which he took out a patent,
consisted in the substitution of lime for potash. His patent right
was, however, resisted by certain of the bleachers of Lancashire,
and was set aside by the verdict of a jury, on the grounds that the
patent included a mode of 'bucking' with quicklime and water, which
was not a new invention; and because one part of the patent was not
new, the whole of the claim must be set aside. By this decision the use
of liquid chloride of lime in bleaching was thrown open to all; and
through an unfortunate error of expression in describing his process,
Mr. Tennant was deprived of the fruits of a laborious investigation
extending over a period of several years. This subsequently caused a
strong feeling of sympathy to be manifested for him by many of the
bleachers of Lancashire, who, as an expression of their grateful
acknowledgment, presented him with a service of plate, which he
accepted. Mr. Tennant, however, in accordance with the character of his
original design, determined to press onward with his discoveries, and
to bring, if possible, his first invention to a still more practical
issue. He therefore adopted a new method, and at length completed and
secured by patent a process for impregnating quicklime in a dry state
with chlorine, which proved perfectly successful; this, his second
patent, remained uncontested, and he lived to secure a large pecuniary
reward.
Mr. Tennant's discoveries, together with the introduction of
soda-ash or 'British soda,' in place of potash, greatly facilitated
and cheapened the process of bleaching, while the introduction of
mechanical appliances and the power of the steam-engine superseded
the previous laborious operations by hand. The result has been that
the same amount of bleaching is now performed in as many days as was
formerly performed in weeks, while the price has been reduced from 7s.
6d. (1803) to 6d. (1861) for a piece of cloth of 28 yards.
In the year 1800 Mr. Tennant removed from Darnly to St. Rollox,
Glasgow, where he commenced business as a large manufacturing chemist,
taking into partnership Mr. Charles Mackintosh, Mr. William Cowper, and
Mr. James Knox. During the remainder of his life Mr. Tennant devoted
himself with energy to the forwarding of his business, and ultimately
caused his manufactory to become the largest and most extensive of its
kind in Europe. He also took considerable interest in the politics of
the day. His principles were those of an intelligent and liberal-minded
reformer, and he was long looked up to as one of the leading men of his
party, although the least tainted by mere party spirit or selfishness.
Mr. Tennant was likewise conspicuous in his promotion of many public
undertakings. He took a deep interest in the furtherance of the railway
system; the Garnkirk and Glasgow Railway may be said to owe its origin
and completion almost entirely to him, while his invincible industry
and perseverance contributed greatly towards the establishment of
the Edinburgh and Glasgow Railway. He was a great friend of George
Stephenson's, and was present with him at the opening of the Liverpool
and Manchester Railroad when the unfortunate accident occurred which
resulted in the melancholy death of Mr. Huskisson.
Mr. Tennant died rather suddenly, in his seventy-first year, at
his house in Abercrombie Place, Glasgow. He was possessed of a
constitutional nervousness, rather remarkable in one of a large and
healthy frame, allied to a peculiar sensitiveness to the beautiful.
In after life he would often talk with pleasure of his youthful
reminiscences of the poet Burns, who was at that time on terms of
considerable intimacy with his family. Mr. Tennant was an earnest and
indefatigable promoter of economical and educational improvement; an
uncompromising friend of civil and religious liberty; while his own
inborn energy of character and clear intellect placed him among the
foremost of those men who, by uniting science to manufactures, have at
once extended their fields of action, and entitled their occupations to
be classed among the ranks of the liberal professions.--_The Progress
of Science and Art as developed in the Bleaching of Cotton, by Henry
Ashworth, Paper read before the British Association at Manchester_,
September 5, 1861; _and_, _Particulars communicated by the Family_.
THOMAS THOMSON, M.D., F.R.S.
Born April 12, 1773. Died July 2, 1852.
Dr. Thomas Thomson, Regius Professor of Chemistry in the University of
Glasgow, who exercised a remarkable influence in the development and
extension of the science of chemistry during the present age, was born
at Crieff, in Perthshire. He received his early education at the parish
school of that place, and after remaining for a time under the care of
Dr. Doig, of Stirling, went to the University of St. Andrews, where he
remained for a period of three years.
Thomson entered upon his medical studies at the University of
Edinburgh, and during the session of 1795-96 attended the lectures of
the celebrated Dr. Black, who first awoke in him the latent taste for
that science of which he was destined to become so bright an ornament.
In 1796 he became connected with the _Encyclopædia Britannica_, for an
early edition of which he wrote the articles--Chemistry, Mineralogy,
Vegetable Substances, Animal Substances, and Dyeing Substances, &c.
These articles formed the basis of his system of chemistry, which
he published at Edinburgh in the year 1804, in four volumes, and
afterwards greatly enlarged and improved as the demand for the book
increased. Dr. Thomson commenced delivering a series of lectures on
chemistry at Edinburgh in 1800, which were continued with increasing
popularity until 1810. Meanwhile he invented the system of chemical
symbols now generally adopted by all men of science (with variations
as the time demands), and without which chemical language would be
unintelligible. He was also the first to open a laboratory in Great
Britain for practical manipulation in chemistry. In 1810 he published
his 'Elements of Chemistry,' and in 1812 visited Sweden, and on his
return wrote a description of that country. The following year to this
Dr. Thomson started in London the 'Annals of Philosophy,' a scientific
journal, which he continued to edit until the year 1822, and which
a few years afterwards was merged in the 'Philosophical Magazine.'
He also about this time conducted for the Board of Excise a series
of investigations on brewing, which formed the basis of Scottish
legislation on that subject.
In the year 1817 Thomson was elected lecturer on chemistry in the
University of Glasgow, and in the following year received the title
of Professor. This chair he held until his death, being assisted in
his latter years by his nephew and son-in-law, Dr. R. D. Thomson.
When Dalton had worked out his grand discovery of the Atomic Theory,
he communicated the result of his researches to Thomson, who at once
perceived the value and importance of the discovery, and in the year
1807 was the first to publish it to the world. He gave a sketch of this
grand theory in the third edition of his 'System of Chemistry;' and we
are chiefly indebted to the labours of Professor Thomson, conjointly
with Dr. Henry of Manchester, and Dr. Wollaston, for luminous views on
this important subject. In 1825 Dr. Thomson wrote, in two volumes, 'An
Attempt to Establish the First Principles of Chemistry by Experiment.'
In 1830-31 he published his 'History of Chemistry,' a work which has
been described as a masterpiece of learning and research. In 1836
appeared his 'Outlines of Mineralogy and Geology;' and in 1849 he
issued his last work, 'On Brewing and Distillation.'
Thomson performed in science, and its history and literature, a
very great amount of valuable labour, and acquired a distinguished
reputation both as an original discoverer, and as a practical
teacher of his favourite science. He died in 1852, at the age of
seventy-nine, and has left behind him a son who bears his name, now
(1860) superintendent of the East India Company's Botanic Gardens at
Calcutta, and one of the most distinguished scientific botanists of the
day.--_Encyclopædia Britannica_, Eighth Edition.--_English Cyclopædia._
London, 1858.
RICHARD TREVITHICK.
Born April 13, 1771. Died April 22, 1833.
Richard Trevithick, inventor of the first high pressure steam-engine,
and the first steam-carriage used in England, was born in the parish
of Illogan, in Cornwall. He was the son of a purser of the mines in
the district, and although he received but little early education,
his talents were great in his own special subject, mechanics. When
a boy he had no taste for school exercises, and being an only son,
was allowed by his parents to do much as he pleased; so that most of
his time was passed either in strolling over the mines amidst which
he lived, or in working out schemes which had already begun to fill
his youthful imagination, seated under a hedge, with a slate in his
hand. Trevithick was a pupil of William Bull, an engineer practising
at that time in Cornwall, employed in erecting Watt's engines, and
who afterwards accompanied Trevithick to South America. When he had
attained the age of twenty-one, Trevithick was appointed engineer to
several mines, a more responsible situation than the one held by his
father, who, on hearing of his son's appointment, expressed great
surprise, and even considered it his duty to remonstrate with the
gentlemen who had proposed the appointment. About this period (in 1792)
he was also employed to test one of Hornblower's engines, and even
before this, had, with the assistance of William Bull, constructed
several engines which did not come under Watt's patent. Trevithick's
duties, as engineer, at this time, frequently required him to visit
Mr. Harvey's iron foundry at Hayle, who was in the habit of inviting
him to his house; this ultimately resulted in his becoming attached to
Mr. Harvey's daughter, to whom he was married on the 7th of November,
1797. After his marriage Trevithick lived at Plane-an-quary in Redruth
for a few months, then at Camborne for ten years. From about 1808
to 1810 he resided in London; but after his unfortunate failure in
attempting to tunnel the Thames, returned to Penponds in the parish of
Camborne, where he lived for five or six years, at the house of his
mother, afterwards living at Penzance, from which town he sailed for
Peru on the 20th October, 1816. While residing at Camborne, Trevithick
influenced perhaps by the success of Murdock's model steam-carriage,
determined to build one adapted to ordinary road traffic. One Andrew
Vivian supplied the pecuniary means and joined him in the project, for
which, on its completion, a patent was taken out in 1802, and in the
same year a small one was erected at Marazion, which was worked by
steam of at least thirty pounds on the square inch above atmospheric
pressure.[40] Their steam-carriage presented the appearance of an
ordinary stage-coach on four wheels, having one horizontal cylinder,
which, together with the boiler and fire-box, were placed at the back
of the hind axle. Mr. Michael Williams, late M.P. for Cornwall, in a
letter to Mr. E. Watkins, dated the 5th of January, 1853, mentions
having been present at the first trial of Trevithick's locomotive,
and says "the experiments made on the public road close by Camborne
were perfectly successful, and although many improvements in the
details of such description of engines have been since effected, the
leading principles of construction and arrangement are continued, I
believe, with little alteration in the magnificent railroad engines
of the present day." After making several satisfactory trials in the
neighbourhood of Plymouth, Trevithick and Vivian exhibited their
invention publicly in London, first at Lord's Cricket-ground, and
afterwards on the spot of ground now occupied by Euston Square.[41]
At this latter place, however, Trevithick, influenced by some curious
whim, suddenly closed the exhibition on the second day, leaving
hundreds waiting outside in a state of great wrath. Mrs. Humblestone,
an old inhabitant of London, who at that period used to keep a shop
near to the present Pantheon, Oxford Street, relates that she well
remembers witnessing a public trial of Trevithick's steam-carriage. On
this occasion the shops were shut, no horses or carriages were allowed
in the streets, and the roofs of the houses in the neighbourhood were
crowded with people, who hurraed and waived their handkerchiefs as the
'steam monster' was seen coming along Oxford Street at a rapid pace.[42]
Two years afterwards Trevithick constructed the first successful
railway locomotive, which was used on the Merthyr Tydvil Railway in
the year 1804. This engine had an eight-inch cylinder, of four feet
six inches stroke, placed horizontally as at present, and working on a
cranked axle; while, in order to secure a continuous rotatory motion,
a fly-wheel was placed on the end of the axle. When we add to this,
that the fly-wheel was furnished with a break, that the boiler had a
safety-valve or a fusible plug beyond the reach of the engineer, and
that the patent includes the production of a more equable rotatory
motion--"by causing the piston rods of _two_ cylinders to work on
the said axis by means of cranks at a quarter of a turn asunder"--it
is scarcely too much to say that nothing material was added to the
design of the locomotive until the invention of the tubular boiler
in 1829.[43] On the occasion of its first trial, on the 21st of
February, 1804, this engine drew carriages containing ten tons of
bar iron for a distance of nine miles, at the rate of five miles an
hour. The specification of the patent for Trevithick's steam-carriage
mentions a plan for causing the wheels, _in certain cases_, to take a
stronger hold of the ground by means of sundry rough projections, but
it also adds that, _in general, the ordinary structure or figure of the
external surface of these wheels will be found to answer the intended
purpose_, which appears to have been the case in the above-mentioned
engine.[44] After making a few experiments with his engine, Trevithick
forsook the locomotive for other projects of his versatile genius, and
this great invention was left to be perfected and carried into general
use by George Stephenson.