Autobiography of Sir John Rennie, F.R.S. 33
During this period I was requested by the Commissioners of the Ancholme
Level, consisting of about 50,000 acres of low fen lands, bordering upon
the Ancholme in North Lincolnshire, to give them my advice as to the best
means of improving their drainage, and at the same time the navigation of
that river.
The Ancholme takes its rise near Market Rasen, in the highlands of the
north of Lincolnshire, and after a course of some miles it enters the
lowland district of the valley, and proceeds through it in a northerly
direction for a distance of about 18 miles, when it joins the Humber at
right angles to its course. The valley varies from one mile in width at
the upper end to three miles at the lower end, where it joins the Humber.
It is bounded on the south by a ridge of chalk hills of considerable
elevation, and on the north by a similar ridge of sandstone hills.
The Ancholme having very little fall where it enters the lowlands, and
being prevented from discharging its waters with facility into the Humber
on account of the great mass of water and high tides in the latter river,
was forced back upon the lowlands, and frequently inundated them, so
that they became little better than marshes, and the river itself was
necessarily extremely circuitous. In 1806 the Commissioners applied to my
father for advice, and he recommended, in the first place, that the river
should be straightened as far as practicable, in order to utilize the
fall of the current to the fullest extent; also that a sluice should be
constructed to exclude the tides at Terreby; and a catchwater drain made
on the south side, with separate sluice to discharge the highland waters
into the Humber. This advice was only partly followed: the river was
straightened; the catchwater drain only extended as far as Brigg; a lock
was made for the navigation at Hortestow Green, where the river entered
the lowlands; and a sluice with a lock was made at Terreby. In principle,
these works were correctly designed and well adapted for the purpose as
far as they went; but I am not exactly aware whether they were carried
out according to his plan, or under his immediate direction; and twenty
years had elapsed before I was invited to give my opinion.
When I visited them the level was very badly drained; the river was full
of shoals; the navigation, which was intended for the Yorkshire coasting
vessels up to Bishop’s Bridge, was only practicable a few miles beyond
Brigg, and that in a very imperfect manner; and the works generally were
in a very bad state.
After having inspected the works, I recommended, first, that the main
river should be deepened, widened, and enlarged throughout the entire
length of the level, so as to accommodate the full-sized Yorkshire
coasting vessels drawing 6 ft. 6 in.; and that the river should be of
ample capacity to contain the floods fully 2 to 3 feet below the level of
the lowlands, so that they could not be overflowed, and might always be
able to drain into it.
Secondly, that a lock should be made with a lift of 6 feet, so that
coasting vessels might be enabled to get up to Bishop’s Bridge; and that
as a great deal of sand was brought down by the upper part of the river,
which continually produced shoals and filled it up, I recommended that
at the upper end of the lock an overfall should be made, together with a
capacious reservoir, into which the sand might be discharged, in order to
prevent it from getting into the river; then it could be removed whenever
necessary.
Thirdly, that a new sluice and lock should be made at Terreby, where the
Ancholme joined the Humber; that all the new sluices should be laid 6
feet below the old one; and that new bridges should be made across the
main river to replace the old ones, which were not of sufficient capacity.
Fourthly, that the south catchwater drain should be drained out and
enlarged, and extended to the upper end of the level.
Fifthly, that a catchwater drain of the requisite dimensions should be
made on the north side of the level, from the new sluice to the farther
extremity of the level, and that the water should be discharged through a
separate opening in the new sluice.
Sixthly, that wherever a brook entered the catchwater drain on either
side, there should be corresponding weirs and reservoirs for receiving
the sand and other deposits, so as to prevent them from getting into the
drains.
These several works were executed, under my directions, by Messrs.
Jolliffe and Banks, as contractors; and Mr. Adam Smith, as resident
engineer, to whom the real credit is due for the very able, honest, and
zealous manner in which he discharged his duties, particularly for
the execution of the new sluice at Terreby, which was done without a
contractor, and is one of the cheapest and best works of the kind.
These works have answered their object completely; and the Ancholme
district is as well drained as any level in the kingdom, and the
navigation is complete of the kind.
Whilst carrying on these works I was the frequent guest of the Earl of
Yarborough, the Commodore of the Yacht Club, and received the greatest
kindness and attention from his lordship; without his support, ability,
and firmness, these works would never have been attempted, nor carried to
a successful conclusion.
[2] I have always heard this story in Cornwall; and a pamphlet
on the subject, now very scarce, was published at the time. Mr.
Fox, I have been told, was taken before a magistrate, and made
an affidavit concerning it the morning after the occurrence,
and before the mail came down.--C. G. C. R.
[3] I may mention here that before Telford built the suspension
bridge near Bangor, Mr. Rennie proposed a cast-iron bridge of
several arches, on the site of the present Britannia Bridge,
which would ultimately have carried the railway, but the scheme
was considered too bold at the time. The possibility of the
construction of the present magnificent bridge, which marks an
era in engineering, is of course due to the great improvements
in the manufacture of iron since Mr. Rennie’s time. Thus every
age has its specialty, and what cannot be done at one time
becomes practicable at another.
CHAPTER IV.
Sketch of the Risk and Progress of the Railway System--The
Manchester and Liverpool, London and Birmingham, and other
early Lines.
I will now proceed to a very important epoch in my life, namely, my
first introduction to railways upon the locomotive system. Railways of
wood were first introduced on the Tyne, for the purpose of bringing down
coal from the adjacent collieries, to be shipped from Newcastle and the
vicinity for exportation to London and other places. These were 4 feet 6½
inches wide from centre to centre, and the coal waggons were specially
adapted to them. The wooden rails wore out rapidly, and were subsequently
improved by having cast iron edge rails fixed upon the wooden ones, and
the wheels of the waggons were made of cast iron also, having a flange
on the inside to keep them in their places. It reduced materially the
friction of the road, enabled the horses by which the waggons were drawn
to take a greater load, and the expense of maintaining the ways was
greatly reduced. Matters proceeded in this manner until towards the end
of the last century. At that time, the celebrated James Watt began his
experiments upon steam, and then turned his attention to the improvement
of the steam engine, which had previously been so far perfected by
Savery, Newcomen, and Smeaton, as to be used for pumping water from mines
with considerable effect, by employing steam and atmospheric pressure
alternately, for raising and lowering the piston in the cylinder to which
the pumping apparatus was attached. The waste of fuel and the expense of
working these engines were very considerable, and they were inapplicable
to any other purpose but pumping. Watt saw these defects, and immediately
set about devising means for remedying them. He first enclosed the steam
cylinder at top and bottom, and elevated and depressed the piston by
means of steam only; and instead of allowing the spent steam to escape
into the atmosphere, it was discharged into a separate vessel, into
which a jet of cold water was constantly playing, so that the steam was
condensed there, and hence this vessel was called a “condenser.” In this
condenser there was an air pump constantly working, so that to some
extent a vacuum was produced, which facilitated the discharge of the
steam from above and below the piston, relieved the pressure upon it both
ways, and added considerably to the effect of the whole machine, as well
as economizing the fuel required to work it. He also added a crank to a
connecting rod at the opposite end of the beam to which the piston was
attached, and by means of this crank communicated rotary motion to any
machinery connected with it, adding still further to the value of the
steam engine, and rendering it universally applicable. The boiler also
he greatly improved, so as to produce a larger quantity of steam with
less fuel. The ingenious idea of the crank was pirated from him before he
could patent it, and he resorted to another invention to produce rotary
motion, which he called the sun and planet wheel; this consisted of a
toothed wheel attached to the lower end of the connecting rod fixed to
the end of the beam, which wheel worked into another attached to the
end of a horizontal shaft, upon which were fixed other wheels to give
motion to any system of machinery which might be required. It should be
observed that in this improved engine the connecting rod of the piston
was attached to one end of the beam, the connecting rod attached to the
crank, or sun and planet, was fixed to the other, and the air and cold
water pumps were attached to rods connected with the intermediate part
of the main beam, so that they were all worked together by the rising
and falling of the piston, and thus formed one whole compact machine.
He also added several minor contrivances, which it is unnecessary to
mention, and which rendered the steam engine still more complete. His
improvements did not end here, for he made numerous experiments upon the
expansibility or elasticity and effects of steam at various temperatures,
constructed a high pressure engine, and subsequently one with a condenser
mounted upon a carriage supported by wheels, which was nothing more than
the locomotive engine, a model of which still exists. Watt, however, as
I have already observed, did not like high-pressure steam: he was fully
aware of its importance; but at that time, from the backward state of
the iron manufacture, he did not see his way to controlling it with
safety, and he considered that his low-pressure condensing system was the
best and most economical, and he therefore gave up all idea of pursuing
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