On the Marine Parade at Lyme Regis, Dorset stands a group of
attractive thatched cottages that look out over Lyme Bay. It was
here at Harville Cottage, the house of Thomas Clarke, a retired
Master Mariner, that Percy Carlyle Gilchrist was born on 27
December, 1851. His mother Anne (nee Burrows) was from an upper
class family and she and her barrister husband Alexander were of
independent means sharing the same writing, scholarly and
intellectual interests. Alex chose not to practice as a lawyer
and instead he pursued his life-long ambition of becoming a
writer. The early years of the marriage were nomadic ones, spent
travelling the country in search of information for the book
Alex was writing. Two years after Percy was born they made their
first home in an old manor house in Guildford.
Three more children were born to the Gilchrists who by 1856 had
settled in Cheyne Row, London, but in 1861 Percy contracted
scarlet fever which, in those days, was a life-threatening
disease. Through contact with his son, Alex also contracted the
disease to which he succumbed. With four children to support,
Anne continued with her writing while Percy attended Felsted
School, Essex, where he displayed an interest in the sciences.
From Felsted he studied at the Royal School of Mines, South
Kensington where he became a Murchison Medallist and obtained
his associateship of that school three years later. He also
became a member of both the Institution of Civil Engineers and
the Institution of Mechanical Engineers. In 1877 Percy married
Norah Fitzmaurice, the daughter of Captain L N Fitzmaurice, RN,
by whom he had a son Alexander, and a daughter Ellen.
Until the middle of the eighteenth century cast iron was the
most common metal used in construction work but it contained a
large number of impurities that made it brittle and liable to
failure under stress. Removal of these impurities from the iron
was a difficult process but when completed, it produced wrought
iron that was softer and easier to work. However, both cast and
wrought iron were prone to contain blowholes created during the
casting process which made them unable to withstand strong
tensile forces and it was this structural weakness that
contributed to the disastrous failure of the Tay Bridge in 1879.
By introducing carbon into the iron, steel could be created, a
metal that was strong, flexible and durable, possessing all the
qualities of cast and wrought iron but also capable of resisting
high tensile forces. However, the process was difficult and
expensive until Henry, later Sir Henry, Bessemer designed his
converter.
Steel was produced in the Bessemer converter from impure pig
iron smelted from the basic ores but sadly, it was not the
perfect answer and frequently produced steel that was of poor
quality and sometimes quite useless. The reason for this was
eventually found to be the presence of the phosphorous that
remained in the steel and which the converter had failed to
remove. The most phosphorous-free ore in this country was the
rich haematite discovered along the coast of Cumbria that led to
the establishment of iron and steelworks in the region, the
largest of which was at Barrow-in-Furness. But the deposits were
limited and expensive to extract, consequently ore speculators
moved to Spain where cheaper material was available.
After qualifying at the Royal School of Mines, Percy Gilchrist
took up a post of analytical chemist at Cwm Avon Ironworks in
South Wales and it was at this time that he was approached by
his cousin Sydney Gilchrist Thomas, about a theory the latter
had developed for eliminating phosphorous from Bessemer steel.
Sydney Gilchrist Thomas who was about nine months older than his
cousin, was a remarkable man. Due to financial difficulties
following the early death of his father, he was forced to
abandon his dream of studying medicine and instead, become a
clerk in the Metropolitan Police Courts. But his real interest
lay in chemistry which he studied with dedication in his spare
time. While attending a course of lectures at the Birkbeck
Institution he became fascinated in a particular lecture that
referred to the scarcity of low phosphoric ores in the steel
manufacturing industry. Mr George Chaloner, a lecturer in
inorganic chemistry and metallurgy, stated that 'the man who
succeeds in eliminating phosphorous in the Bessemer converter
would one day make his fortune' and it was this remark that
fired the imagination of the young Sydney Thomas. Thereafter he
dedicated himself to the study of the problem that eventually
led to the discovery of a process that became known as the
Thomas-Gilchrist Process and for which he and his cousin Percy
became famous.
In due course, Sydney Thomas also qualified as a chemist, but
whilst still a clerk to the police court, he pursued his
investigations by converting a room in his house into a
makeshift laboratory where he undertook experimental work.
However, the conditions were far from satisfactory and quite
dangerous.
He was encouraged in his research by Chaloner at the Birkbeck
Institution but being unable to carry out full-scale tests in a
converter, Sydney wrote to his cousin explaining his theory and
setting out the lines on which it could be tested.
Initially Percy Gilchrist was sceptical about his cousin's work
and having just obtained a new post at the Blaenavon Works, he
was reluctant to get involved in unofficial experiments.
Consequently the experimental work was slow to start. But
Sydney's enthusiasm gradually infected Percy and following a
further meeting between the two, it was agreed that experimental
work would commence, financed by Sydney Thomas out of his meagre
salary. Gilchrist started the work in a rough shed on a
mountainside but little was done until 1877 when the experiments
began in earnest. As Gilchrist began to anticipate the success
of the experiments the work advanced quite quickly,
necessitating Sydney Thomas's more active co-operation; this
required him to make frequent trips to Wales on the days he was
off duty.
Similar work was proceeding without success on the continent and
in America but the work that Percy Gilchrist was carrying out
did not go unnoticed by E P Martin, the manager of the Blaenavon
Works who became convinced that Gilchrist and Thomas were
working on the right lines. He was so impressed with the results
of their experiments that he arranged to relieve the cousins of
their pressing financial worries by agreeing to buy shares in
the patents for which they had applied, and to provide
facilities for their research work to continue.
Details of Gilchrist and Thomas's work were presented for
discussion at various meetings of learned institutions at home
and overseas but their claims to have devised a process for
successfully removing phosphorous from the Bessemer converter
were met with scepticism and a certain amount of incredulity.
However, a manager of a steelworks in Middlesbrough decided to
pursue the matter and visited Blaenavon where he arranged for
further tests that convinced him the dephosphorisation process
was a commercial possibility. When the results of the successful
tests became known Gilchrist and Thomas were besieged by steel
manufacturers wishing to obtain the patent rights and their
financial future was assured.
Sydney Thomas resigned his position at the police court and
devoted himself to promoting the new process as well as
negotiating patents and contracts with home and overseas
manufacturers. New companies were formed of which the cousins
were shareholders and Sydney travelled widely at home and abroad
in connection with the work. Sadly he had never enjoyed good
health and the strain of his early work, coupled with the
extensive travelling soon took its toll. He spent the last few
years of his life working on a project for converting the waste
slag from the Bessemer converters with its high phosphate
content into a basic fertilizer. He died, not yet thirty five
years old, having made a fortune but not living to see basic
slag become the highly valued fertilizer he had forecast.
Honours were bestowed on both men who were awarded the gold
medal of the Society of Arts and the Bessemer Medal of the Iron
and Steel Institute
Percy Gilchrist moved with his family to Redcar where he
continued his work in the steel industry as the managing
director of the Dephosphorising and Basic Patents Company Ltd.,
a company originally established to protect the rights of the
process he and his cousin had developed. He was also associated
with other companies in the steel industry.
The Thomas-Gilchrist process was taken up actively on the
continent and was duly extended to the Siemens open-hearth
process but for some reason, it gradually ceased to be employed
in this country until its revival by a British firm in the
mid-1930's. Percy Gilchrist may not have been aware of this for
after along illness, he died on 15 December, 1935 some fifty
years after his cousin with whom he had revolutionized the steel
manufacturing process.
Since his death improvements have taken place in the process and
although historically Gilchrist has been overshadowed by the
figure of Thomas, there is no doubt that Percy's contribution to
the invention of the basic process was just as great. He was the
practical chemist and metallurgist who proved by experiment what
his cousin had developed in theory. He was a member of the Iron
and Steel Institute, of which he became Vice President, for
sixty years and was elected a Fellow of the Royal Society in
1891, an honour that surely would have been bestowed also on his
cousin had he lived.
An obelisk erected on the site of the Blaenavon Ironworks in
Monmouthshire commemorates the experiments carried out by
Gilchrist and Thomas and the Retired Chartered Engineers' Club,
Exeter has fixed a plaque on the esplanade at Lyme Regis to
record Gilchrist's birth in the town.
This chapter embraces the combined work of both Thomas and
Gilchrist and shows that success also can be achieved by
independent dedication and hard work. Today we have cranes that
could lift the Eiffel Tower, buildings that soar 800 metres
skywards and vessels of 500,000 tonnes travelling the oceans,
all as a result of their pioneering work in developing the steel
manufacturing process. Sydney Thomas had the dream that Percy
Gilchrist made come true with the result that both men are
equally revered in the annals of steel manufacture.
A G Banks