My London Exhibit, its Success, but what was the matter? Remarkable
Sale of the Engine.
Thus, as the result of a remarkable combination of circumstances,
upon which I look back with feelings more of awe than of wonder, the
high-speed system made its appearance in the London International
Exhibition of 1862, installed in the midst of the British machinery
exhibit, under conditions more advantageous than any which I could have
imagined.
But the engine had a weak feature: it was wanting in an essential
respect, of which I was, and remained to the end, quite unconscious, as
will presently appear. Before entering on this subject I will give the
reader an idea of what the exhibit was like. The accompanying half-tone
from a photograph will, with the help of a little explanation, make
this quite real.
The location was in a narrow space between a side aisle and the wall
of the temporary wooden structure, 300 feet wide by nearly 1000 feet
long, which formed the machinery hall. The engine was crowded closely
by looms on both sides. Here were shown together the first high-speed
engine, the first high-speed governor, and the first high-speed
indicator. My marine governor could not be accommodated there, and had
to be shown elsewhere. I was so much afraid of deflection or vibration
of the shaft that I shortened up the length between the bearings and
placed the driving-pulley on the overhanging end of the shaft, which
for the light work to be done there answered sufficiently well. I
showed also the largest and the smallest sizes of my stationary-engine
governors. These were belted from the shaft to revolve so as to
stand always in positions coincident with those of the governor which
regulated the engine.
On a table between the railing and the head of the engine I showed
mahogany sectional models of the valves at one end of the cylinder in
the engine exhibited, and of the now well-known Allen slide valve, with
double opening for admission made by a passage over the exhaust-cup.
The Richards indicator is seen placed on the cylinder midway of its
length, and connected by pipes with the ends over the clearances, so
that in the familiar manner by means of a three-way cock the opposite
diagrams could be taken on the same sheet. After a few days’ use I
mistrusted that the lead lines were not correctly drawn, and I took
away these pipes, placing the indicator on the cylinder itself, at the
opposite ends alternately. The diagrams then taken showed that the
error from transmission through these pipes had been even greater than
I had feared. I have, of course, employed the close connection ever
since.
This identifies the time when the photograph was taken. It must have
been within a few days after starting.
The center of the eccentric coinciding with the crank, as already
stated, and the center line of the link being in the same horizontal
plane with that of the engine, I was able to take the motion of the
paper drum from the sustaining arms of the link instead of from the
cross-head. This was very convenient.
During the first two or three weeks the steam pressure was kept up to
75 pounds, as intended, and I was able to get diagrams cutting off
quite early, which were then erroneously supposed to show superior
economy. But when all the steam-eaters had got in their work the
pressure could not be maintained much above 40 pounds, and for that
exhibition the day of fancy diagrams was over. Gwynne & Co. showed
a large centrifugal pump driven by a pair of engines which always
brought the pressure down at the rate of a pound a minute. They were
not allowed to run longer than fifteen minutes at a time, but it took
a long time after they stopped before the pressure could be got up
again even to 40 pounds. Whenever I took a diagram somebody was always
standing ready to take it away, and so among my mementoes I have been
able to find none cutting off earlier than the one here represented.
On the wall at the back I hung the largest United States flag I could
find, with a portrait of President Lincoln. This seems all that needs
to be said about the photograph and the diagram.
[Illustration:
INTERNATIONAL EXHIBITION, UNITED STATES DEPARTMENT
1862 DIAGRAM TAKEN FROM 1862
THE ALLEN ENGINE BY THE RICHARDS INDICATOR.
ENGINE, 8 INCHES BY 24 INCHES, REVOLUTIONS PER MINUTE, 150.
SCALE, 40 LBS. TO THE INCH.]
But what was the matter? I will clear the way to answering this
question by relating the following incident: Six months later, with a
feeling of bitter disappointment, I contemplated my engine standing
alone where the place had been thronged with surging life. All the
other exhibits had been removed. This was left in stillness and
desolation, and I was making up my mind to the necessity of shipping it
home again, its exhibition to all appearance absolutely fruitless--a
failure, which I was utterly at a loss to comprehend, when I had a
call from Mr. James Easton, the same man who had first welcomed me in
England. His firm had perhaps the largest exhibit in the Machinery
Hall, of a waterfall supplied by a centrifugal pump, and they had been
frequent observers of the running of my engine, which was quite near
them. Mr. Easton bluntly asked me if I thought my engine could be run
50 per cent. faster or at 225 revolutions per minute, because they
had concluded that it could be, and if I agreed with them they had
a use for it themselves. Under the circumstances I did not hesitate
long about agreeing with them in respect to both ability and price,
and the sale was quickly concluded. I noted an entire absence of any
disposition to take an undue advantage. Mr. Easton then told me that
they were troubled with lack of power every afternoon when the foundry
blower was on, and had long wanted to drive this blower independently.
It needed to make 2025 revolutions per minute to give the blast they
required, and they had planned to drive it by a frictional gearing,
nine to one, if my engine could run at the necessary speed. So
this most peculiar and exceptional opportunity for its application,
absolutely the only chance for its sale that had appeared, and that at
the very last moment, prevented my returning home in disappointment.
It is hardly necessary to add that the engine proved completely
successful. I shall refer to it again.
The point of the incident is this: It established the fact, the
statement of which otherwise no one from the result would credit for an
instant, that, from the afternoon when the black and averted looks of
my loom exhibitors were changed to smiling congratulations down to the
close of the exhibition, the engine never once had a warm bearing or
was interrupted for a single moment. It was visited by every engineer
in England, and by a multitude of engine users, was admired by every
one, and won the entire confidence of all observers in its speed, its
regulation, and the perfection of its diagrams; and yet in all that
six months not a builder ever said a word about building it, nor a
user said a word about using it; and, as week after week and month
after month passed without a sign, I became almost stupefied with
astonishment and distress.
The explanation of this phenomenon was entirely simple, but I did not
know it, and there was no one to even hint it to me. I was among a
people whose fundamental ideas respecting steam-engines were entirely
different from those to which I had been accustomed, and I knew nothing
about them, and so could not address myself to them. In the view of
every Englishman a non-condensing engine was rubbish. Those which were
made were small, cheap affairs, mostly for export. Neither a builder
nor a user could regard a non-condensing engine with the slightest
interest.
Now I do not think that in my limited sphere of observation at home
I had ever seen a condensing stationary engine, except the engine
which pumped out the dry-dock at the Brooklyn Navy Yard. In my mind
condensing engines were associated with ships and steamboats. At this
exhibition also there were shown only non-condensing engines. I did not
think of the reason for this, that in this part of London, far away
from the Thames, no water could be had for condensing purposes. I took
it all as a matter of course, though I was astonished at the queer lot
of engines in the company of which I found myself.
I was, of course, familiar with the development of the stationary
engine in England from the original type, in which the pressure of
steam below that of the atmosphere, and sometimes the pressure of the
atmosphere itself furnished the larger proportion of the power exerted;
but after all I carried with me my American ideas, which were limited
to non-condensing engines, and had no conception of the gulf that
separated my thoughts from those of the men about me.
My visitors always wound up with the same question, “How do you drive
your air-pump?” And in my innocence I uniformly replied, “The engine
is a non-condensing engine; it has no air-pump”; all unconscious that
every time I said that I was consigning the engine to the rubbish
heap. This reply was taken necessarily as a frank admission that the
high-speed engine was not adapted for condensing. Of course, then, it
had no interest for them. No doubt many wondered why I should have
troubled myself to show it there at all. If I had thought more deeply
I must have been struck by the unvarying form of this question, always
assuming the air-pump to be a part of the engine, but which, of course,
could not be used there, and only inquiring how I worked it; and also
by the fact that after getting my answer the questioner soon departed,
and I scarcely ever saw the same visitor again. But I did not think
deeply. Perhaps the conditions of excitement were not favorable to
reflection. All I thought was that this same everlasting question,
which at home I would never have heard, was getting awfully monotonous.
After a while this annoying question came to be asked less and less
frequently, and also the engine attracted less and less attention. The
engine had failed in a vital respect, and I did not know it. That the
fact of the engine being non-condensing should have been an objection
to it never once entered my mind.
But I doubt if I could have bettered the matter, however alive to this
difficulty I might have been. I showed all I had yet accomplished.
In the minds of my visitors it no doubt appeared impossible to run
an air-pump successfully at such a speed; the water and air would
be churned into foam, and the valves would not close in time. This
objection I was not prepared to meet, for I had not thought on the
subject at all. Moreover, it could not have been met in any way except
by a practical demonstration. For that demonstration I had yet to wait
five years.
There were many things connected with this season which were well worth
remembering. One of these was the visit of the jury. It was the only
time I ever met Professor Rankine. There were two or three Frenchmen on
the jury, and they engaged in an animated discussion of the question
whether the steam could follow the piston at so great a speed. I well
remember the sharp exclamation with which Professor Rankine put an end
to this nonsense, when he had got tired of it. “There is no limit to
the speed at which steam will follow a piston.”
One day I had a call from Mr. John Penn, Mr. William Fairbairn, and Mr.
Robert Napier, who came together on a visit of ceremony, and presented
me their cards. In return I presented to them the cards of the engine.
But their visit, like most others, closed with the same inevitable
question.
It was a delightful hour that Mr. F. W. Webb spent with me. He was
then assistant engineer of the London & Northwestern Railway under Mr.
Ramsbottom, afterwards Mr. Ramsbottom’s successor, and the pioneer
builder of compound-cylinder locomotives. He told me about the new form
of traveling-crane invented by Mr. Ramsbottom for the shops at Crewe,
which was driven by a flying-rope, a ³⁄₄-inch cotton cord, and also of
other inventions of Mr. Ramsbottom--among these the automatic cylinder
lubricator, in which the condensation of the steam was so rapid, from
the locomotive rushing through the atmosphere, that only the water
formed on the conical end of a bolt was permitted to drop into the oil,
other condensation running into a circular trough and back through an
external gooseneck pipe to the steam-chest; and of their experiments
to observe the rate of this condensation. For this purpose they used
soda-water bottles, which they found capable of resisting a pressure of
200 pounds on the square inch, and in which they could see the rapidity
with which the condensed water displaced the oil, thus leading to the
above device for limiting this action; also about the Ramsbottom piston
rings, which came to be, and still are, so largely used. These consist,
as is well known, of square wrought-iron rods, say ¹⁄₂ inch square,
two for each piston, sprung into grooves. What is not so generally
known is the way in which these rings were originated, which Mr. Webb
then described to me. As sold, these are not circular rings, but when
compressed in the cylinder they become truly circular and exert the
same pressure at every point. The original form was found for each size
in this way: A circular iron table was prepared, provided with a large
number of pulleys located radially and equidistant around its edge. A
ring having the section of the proposed rings, turned to the size of
the cylinder, and cut on one side, was laid on this table, and cords
were attached to it at equal distances passing over these pulleys.
Equal weights were hung on these cords, sufficient to expand this ring
to the extent desired. The form of the expanded ring was then marked on
the table, and to the lines thus obtained the rings were then rolled.
He told me also of the trough and scoop invented by Mr. Ramsbottom, and
now used the world over, for refilling locomotive tanks while running
at full speed. Being a locomotive man, Mr. Webb did not ask about the
way I drove my air-pump.
Mr. Clark formed a scheme to indicate all the engines in the
exhibition, twenty-four in number, all English except mine, so far as I
remember, and employed my indicator for the purpose, the diagrams being
taken by myself. Only two exhibitors declined to have their engines
indicated. As I afterwards learned, most of the engines were bought for
use there, as exhibitors would not exhibit non-condensing engines.
One of those who refused permission were Gwynne & Co., the principal
partner a nephew of my centrifugal-force friend of earlier days. They
exhibited a centrifugal pump supplying a waterfall. They employed Mr.
Zerah Colburn, then editor of _The Engineer_, to investigate their pair
of non-condensing engines and find out why they used so much steam. He
borrowed my indicator to make a private test. Of course, I never saw
the diagrams, but Mr. Colburn informed me that by making some changes
he had reduced the back pressure to 7 pounds above the atmosphere,
which he claimed to be as good as could be expected. No material
improvement in the engines was to be observed, however.
Some of the diagrams taken on these tests exhibited almost incredible
faults. The only really good ones were from a pair of engines made by
Easton, Amos & Sons, also to drive a large centrifugal pump, built
for drainage purposes in Demerara, and sustaining another waterfall.
These showed the steam cut off sharply at one third of the stroke by
separately driven valves on the back of the main slides. A mortifying
feature of this work for myself was that on testing the indicator Mr.
Clark found that the area of the piston, which was represented to be
one quarter of a square inch, was really considerably less than this,
showing lamentable inaccuracy on the part of the makers, as well as my
own neglect to discover it. This rendered the instrument valueless for
measuring power, but it showed the character of the diagrams all right.
The finest mechanical drawing I ever saw--or any one else, I think--was
shown in this exhibition. It was a drawing of the steamship “Persia,”
then the pride of the Cunard fleet, and was the only mechanical
drawing ever admitted to the walls of the National Gallery, where it
had appeared the year before. It represented side and end elevations
and plan, as well as longitudinal and cross-sections, was painted
and shaded in water-colors, and involved an almost incredible amount
of work. It was made by Mr. Kirkaldy, then a draftsman in the employ
of the Napiers, of Glasgow, the builders of the vessel. I am tempted
to refer to this, as it forms a prominent datum point from which to
measure the development of steam navigation in the brief space of forty
years. The vessel did not possess a single feature, large or small,
that now exists. It was of only about 3000 tons burden. It was an iron
ship built in the days of the rapid transition from wood to steel.
It was propelled by paddle-wheels. These were driven by a pair of
side-lever engines. The engines had each a single cylinder. The steam
pressure carried was nominally 25 pounds above the atmosphere, but
practically only from 15 to 20 pounds. Full pressure was not pretended
to be maintained. They had jet condensers. All forged work was of
iron. The vessel was steered by hand. The rigging, standing as well as
running, was of hemp. It was full bark-rigged.
[Illustration: FREDERICK E. SICKELS]
There I first met Mr. Frederick E. Sickels, the inventor of the trip
cut-off; that immortal man who conceived the idea of tripping the valve
mechanism of a steam-engine at any point in its opening movement,
thus releasing the valve and permitting it to be suddenly closed. He
had come over to exhibit his steam steering gear, which is now used
throughout the world. It was astonishing how little attention it
attracted. He had it connected and showed it in operation. While he
turned the wheel precisely as the steersman did, the steam did all
the work of moving the rudder and holding it in any position. Nobody
seemed to take the slightest interest in it. I attributed this largely
to his mistake in showing a very rough affair, the very thing which
he thought would add to its effect. He had an apparatus that had been
used on a coasting steamer which was captured by the Confederates and
employed by them as a blockade-runner, and afterwards captured by our
cruisers, taken into New York and condemned. He bought this gear out of
it at auction and sent it to the exhibition just as it was. He believed
that the more evidences of neglect and rough usage it showed, the
greater admiration its perfect action would inspire. He learned better.
Polished iron and brass and mahogany would have led people to believe
that he himself thought it was worth showing properly.
The picture gallery in the second story of the main building of this
exhibition was really wonderful. Its most prominent feature was a
collection of paintings representing the progress of British art from
the days of Hogarth. All Europe was represented. I was told that the
entire wall surface was seven eighths of a mile long.
We also had a gallery of American art, consisting of a number of
remarkable large photographs of the Yosemite Valley, California, and
one painting. Mr. J. F. Cropsey, an American landscape artist of
considerable celebrity at home, had formed a scheme for establishing
himself in London. He took with him a number of his works. His _pièce
de résistance_ was “Autumn on the Hudson,” which was greatly admired
and for which he was offered a large price, but he preferred to show
it in London. He had sent it to the National Gallery, and, to his
consternation, it was refused, the committee declaring that there were
no such colors in nature. It also offended the English taste, by which
our autumnal tints are regarded as “very gaudy,” so he hung it in Mr.
Holmes’ office at the exhibition. He and I had each a lot to learn
about the way things look to our cousins.