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EXPLANATION OF THE PLATES.
equal her, except perhaps the Diamond, and the City of Canterbury, (running from
London to Herne Bay and Margate;) with these exceptions it is admitted that in
velocity the Star was unrivalled.
Vessels of the greatest speed will always command a decided preference ; hence
it is to the interest of proprietors to apply to the most skilful naval architects
and engineers, to procure vessels which shall combine speed with strength and
durability.
The Ruby built by the “Diamond” Company, at Mr. Wallis’s ship yard,
Black wall, in the early part of the summer of the year 1837, possesses the above es
sential qualities in an eminent degree, which has induced us to solicit the favour
of her plans for publication.
Mr. 0. W. Lang, who designed the Ruby, has obligingly presented us with the
lines, and put us in possession of many particulars respecting her.
Her length is 155 feet between the perpendiculars; 141 feet 9j inches on the keel
for tonnage; breadth for tonnage 19 feet, moulded 18 feet 5j inches; depth in hold 10
feet 2 inches; and burthen 272 tons. She is propelled by two engines of 50 horse power
each, made by Messrs. Seaward and Company, of which the following are some of the
most important particulars :—diameter of cylinder 40 inches ; length of stroke 3 feet 6
inches ; number of strokes per minute 30 ; diameter of paddle wheel 17 feet 6 inches;
length of paddle board 9 feet 2 inches, and depth 15 inches; dip or immersion 15
inches. The practical construction of the vessel is upon a principle recommended
by Mr. 0. W. Lang, and invented many years since by Mr. Johns, a clever practical
officer of Plymouth Dock-yard. It consists of an outer surface of plank, placed
horizontally in the usual manner, but of an inch and a quarter only in thickness, the
timbers being substituted by two other thicknesses of plank, laid diagonally to the
keel, but at right angles to each other, with felt introduced between the layers, the
whole three being fastened together by nailing, in the same manner as a clench work
boat. Vessels built in this manner have been found to be far less expensive (at least
20 per cent.) than vessels built in the usual way; they also possess greater strength,
and judging from the trials that have been made of ships’ launches and other large
boats for the Navy *, for several years past, there can be no doubt of their durability.
The comparative lightness of vessels built in this manner is also a great recommenda
tion. The Ruby, when launched, was found to displace only 65 tons of water. Her
draught, with her engines and fuel on board, complete in all respects, was only 4 feet
8 inches abaft, and 4 feet 1 inch forward ; her displacement 170 tons, and the area
* The boats built for the Navy are only of two thicknesses, the outer (fore and aft) planking being
deemed unnecessary. They are well known as Mr. Johns’ double bottomed diagonal built boats, and
are held in high estimation.