WHO INVENTED THE STEAM BLAST?
To the Editor of the “Northern Echo”
By John Wesley Hackworth 1876
Sir – In answer to
the letters of Miss Gurney and Mr Smiles on the above subject, which appeared
in the Times 27th ult. And 1st inst., I beg to say that
16 years before Sir Goldsworthy Gurney professed to have discovered the “steam
jet” or “blast,” William Nicolson patented, illustrated, described
it in his specification No 2990, and dated 22nd November 1806. This
invention he applied to most of the purposes enumerated by Miss Gurney; but it
now almost entirely superseded by more economical and modern inventions. While
Nicholson’s specifications and Gurney’s pamphlet of 1859 prove that they
represent one and the same thing, they are equally conclusive as to the
locomotive steam-blast being essentially different. For example, we are
informed – “The steam must be high pressure, the steam draught cannot be
produced by exhaust steam” Now, as the exhaust steam is the agency employed
to produce the locomotive blast - the intermittent sound of which (only emitted
when the engine is in motion) is familiar to the ear of everyone, where as the
steam jet or ‘blower’ has a continuous sound, caused by steam issuing direct
from a boiler when at rest, as well as when in motion – it follows that they
are unquestionably two distinct things. It is equally certain that Miss Gurney
is in error in her supposition that “Timothy Hackworth conveyed her father’s
plan to the north of England” as will be clearly seen in the following
facts, which will likewise correct Mr Smiles’s statements. George Stephenson,
in his first locomotive at Killingworth in 1814, adopted Blenkinsop’s exhaust,
ejecting the steam vertically into the air from an inverted T pipe ; and in his
subsequent engines, Stephenson resorted to the plan used by Timothy Hackworth
in the Wylam locomotives four or five years before, the method being to carry
the exhaust pipes just within the circumference of the chimney, and allow the
steam to escape upwards. This became the established mode and the engines did
tolerably well in conveying coals at three to five miles an hour on short lines
of four and five miles, when due attention was paid to having plentiful supply
of steam and water in the boiler with which to commence the journey ; but even
with strict observance of these conditions, the engines not infrequently came to
a halt and had so to remain till steam was generated to complete the distance.
Matters were in this state when the Stockton and Darlington Railway approached
completion, and as the distance intended to be worked by horses or locomotives
was 20 miles, it was predicted by competent judges that it would be impractical
by the latter power, and such it proved to be, for after 18 months’ trial of
the locomotives the directors determined to abandon them, as horses were found
to do the work at less cost. Letters which I hold from George and Robert
Stephenson to my father show their disappointment at this decision. At this
juncture Timothy Hackworth proposed to make an engine to answer the purpose.
This proposition was considered, and the directors resolved, as a last
experiment, that Hackworth should be allowed to carry out his plan. This
engine, the “Royal George,” was started in 1827.We can not stop here to
enumerate the novelties in its construction ; suffice to say it had his
invention “the blast pipe” for the first time, and as used at the present day,
only that the contraction is doubled. The result of the working of this engine
may be asserted from data adduced from an experiment witnessed by Robert
Stephenson, Joseph Lock, my father and myself, which Robert Stephenson had
inserted in Rastrick and Walker’s report, which was laid before the directors
of the Liverpool and Manchester Railway in March, 1829, to show what a
locomotive could accomplish.
Report p.17 (Ed's note Robert Young quotes p21) “Hackworth’s
engine took 48 ¾ at 11 2 /10 miles an hour, on a level, and the steam was blowing
off when the experiment concluded” … “I state the preceding as it has
been given to us. Hackworth’s engine is undoubtedly the most powerful that has
yet been made, as the amount of tons that have been conveyed, compared with the
other engines, prove.”
In 1828, George
Stephenson being wishful to produce an equally powerful engine built the Lancashire
Witch, which, besides having the Wylam mode of exhaust, was provided with
two bellows – an arrangement he was sanguine would effect the desired result.
After the trial – he wrote the following to his friend, Timothy Hackworth –
“ Liverpool
July 25th 1828. We have tried the new locomotive engine at Bolton ;
we have also tried the blast to it for burning coke, and I believe it will
answer. There are two bellows worked by eccentrics underneath the tender.”
It did not answer,
and it is obvious at this date, Stephenson knew nothing of the blast pipe, nor
did he acquire a knowledge of it October 1829.At a preliminary trial of the Sanspareil,
Hackworth gave Stephenson a brisk run on his engine, when the latter made
his observations, and at length put the question – “Timothy, what makes the
sparks fly out of the chimney?” Mr Hackworth touched the exhaust pipe near
the cylinders and said – “It is the end of this little fellow that does the
business”
That night men
were sent to purloin Hackworth’s invention, and the Rocket was fitted
with a similar blast pipe for the race. I think it unfair on the part of
Nicholas Wood to have chronicled (p. 290 e., 1831) the fuel destroyed by a
disorganised engine working with an internally burst cylinder. However, after
the engine was fitted with a new cylinder, Wood, (in table V11., p. 387) shows
that, taking the difference of speed into account, she had the advantage of
fuel in the economy of fuel over her rival “Rocket” 14 miles per hour consumed
2,41lbs per ton per mile.
Moreover, the short
history sent by Mr John Hick, M.P., with the old engine, when he presented it
to the South Kensington Museum, shows the Sanspariel to have been a much
superior engine to the Rocket. William Gowland, an engine driver whom
George Stephenson brought from Killingworth to assist in opening the Stockton
and Darlington line in 1825, after having run the Royal George two
years, and been the driver of the Sanspariel at Rainhill, gives
testimony in a letter to The Engineer, 23rd October, 1857, to
the following effect :-
“ I was driver
of the Royal George on the Stockton and Darlington Railway for about two years,
it having come out of Shildon works in 1827 - the complete production of
Timothy Hackworth. It contained the blast pipe as perfect as any used at the
present day…I can solemnly assure you that when the
Sanspariel left Shildon it contained the blast pipe not only by accident
but by clear design, with a full knowledge of its value, as proved in the case
of the Royal George. Of course everybody knew that the Rocket had not the blast
pipe when it came to Rainhill. The Sanspariel had.”
Respecting
Nicholas Wood (in treatise 1825), noting the slightly increased draught
obtained from his colleague, George Stephenson, turning the exhaust steam into
the chimney at Killingworth, this was merely recording an old face known at
Wylam years before, which Wood and Stephenson were familiar with, though they
differed in opinion as to the utility of adopting it, the effect being so
slight. The same phenomenon was observed in Trevithick’s engine, and, although
noted in Nicholson’s journal, in 1806, there is no mention made of using the
exhaust steam to produce a blast in Trevithick’s minutely drawn patent
specification (No. 2,599), the omission proving beyond question that he neither
knew its value nor apprehended its principal. In further proof, he patented (Fanners,
&c., for creating an artificial draft in the chimney,)
The error in the Encyclopedia Britannica has been corrected in subsequent editions. Referring to the
quotations given by Mr Smiles, first, that –
“During the
construction of the Rocket a series of experiments was made with blast pipes of
different diameters, and their efficiency was tested by the amount of vacuum
that was found in the smoke-box.”
Secondly –
“The
contraction of the orifice in many of our best locomotives is totally
unnecessary, and rather disadvantageous, than otherwise, for since the speed of
the engines have been increased the velocity of the steam is quite sufficient
to produce the needful rarefaction in the chimney without any contraction
whatever.”
In the first
place, the smokebox had not then been introduced. The Rocket had not
one, she merely had a chimney with a right-angle bend to fix to the boiler end,
into which the copper tubes were inserted. And secondly, the early engine
exhausts at the cylinder faces and blast orifices were in proportion of three
or three and half to one. The present practice is six or seven to one. Hence
the contraction is doubled. Imagine an engine constructed with the modern blast
orifice - say 16 square inches – carried down uniformly to the cylinder faces -
that is eight inches to each, we need no philosopher to tell us that such an
engine could not run ; yet this is just what the world is asked to believe. It
seems incredible that Robert Stephenson should d have so committed himself, but
if on the authority of Mr Smiles we receive these statements they are almost as
damaging to Stephenson’s reputation as the Suez canal affair. Instead of Robert
Stephenson making such detrimental assertions, would it not have been wiser to have
honourably accepted my challenge (in the Engineer, August 14th,
1857) and settled this question on evidence before a properly constituted
tribunal?
I am, &c.,
John Wesley Hackworth
January 12th
1876
…………………………………………………………………………………
This letter
is published separately, owing to having been excluded from the Times. A copy
can be had on application to John W. Hackworth, Darlington, enclosing postage
stamp.
Darlington: Bell, Priestgate.
