The Express.
London, England, 1857-11-06 00:00:00

TO TEL EDITOR O► TER REMUS.

Sla,—l have read with great interest your report
of the failure of the launch of the Great Eastern or
Leviathan. It seems clear to me that it was caused
by a needless and most uncalled for deviation from
the ordinary method of launching ships. Why the
old-faahioned mode of allowing the cradle to slide
down a well-greased inclined plane, where the
wooden surfaces are prevented from coming in con-
tact by grease, should have been departed from, is •
question Mr. Brunel is called upon to answer. From
the smallest sloop to the largest man-of-war that has
ever been launched, an inclined plebe, of a slope of
one foot in twelve, when lubricated with grease, has
always been found to answer and to insure perfect
uccess. The proportional difference betwecu the
bulk and weight of the Leviathan and the Duke of
Wellington is not greater than that which exists
between the largest man-of-war and a small
sloop or cutter. The Engineer of the Great
Eastern seems to have sought to immortalise himself
by a new method. Neglecting altogether a principle
be has made use of most suceelly in one pert
' of his works, he has introduced it into moats. in
such • manner as to frustrate his purposes.
Fearful only that his ship should elide down the
ways with too great a velocity, he sought to check
that velocity by bringing one ►urface of iron in
contact with another ander great pressure. This
was the method Mr. Brunel adopted to check the
revolution of his great drums, and to hold back the
great Leviathan, and it was successful. Is it not
astonishing that he should have felled to perceive
that upon the same principle his cradles would not
slide down his wavar; that the enormous premiere
even of the resole& portion of the weight of the
Leviathan on her ways would produce such a pres-
sure as not only to prevent the motion of her cradles,
but even to cause the rails to imbed themeelees into
the flit plates of iron at the bottom of the cradles ?
It may be said, however, in answer to this objec-
tion, that the monster ship did move. She did ; 'but
only when by the premature start, before her ways
were weaved with water, the surfsce of the rails was
thickly covered with blacklead. When this lubri-
cating material had been washed away by this rising
tide, every effort made to start the ship down the
inclines failed to make her budge an inch.
Mr. Brunel is a railway engineer; surely he must
know how absurd is the attempt to diminish friction
when one surface of iron is brought in contact with
another. Ilia rails were not even polished. The
surfaces of the plates of iron which formed the have
of the cradles, and which were intended to slide
down the rails, were, as I have been told, roughly
ground on a grindstone. Mr. Brunel has the satis-
faction of determining that a flat iron surface
gliding on longitudinal railway tails cannot launch
a ship, on en incline of one in twelve.
In all machinery where it is intended to obviate
friction, as your report truly states, iron is always
made to work in some other metal. Metals c f the
same kind are never brought in contact ; the neglect
et this established practice has caused the failure of
the launch.

Whether Mr. Brunel waits for the spring tides of
next month, or whether he waits for the Greek
/Calends, I do not believe he will be able to force the
Great Eastern down her present ways into thewater.
I cannot help regretting that the skilful bailder,who
has so admirably done his work in the construction
of the beautiful ship, was not intrusted with her
launch. I believe he would have been wise enough
to have worked on well-tried principles. The failure,
wlAich every well-wisher to a great and noble under-
taking moat regret, would not have been eau.ed by
an engineering blunder, arising from a neglect of
the Imes of practical meehanies.—l am, &c.,

A MECHANIC.