Thornycroft, in place of the massive cast-iron bedplates and columns of
the ordinary engines of commerce. The same may be said of the moving
parts. In fine, the hull and engines should be as much as possible one
structure; rigidity in one place and elasticity in others are the
cause of most of the accidents so costly to the ship-owner; under such
conditions mass and solidity cease to be virtues, and the sooner their
place is taken by careful design, and the use of the smallest weight
of material--of the very best kind for the purpose--consistent with
thorough efficiency, the better for all concerned.
CONSUMPTION OF FUEL IN MARINE ENGINES.
Coming to the question of the consumption of fuel, a considerable saving
has been effected in nine years, as shown in the following table:
Item. 1872. 1881.
Working pressure, lb. per sq. in......... 52.5 77.4
Heating surface per I. H. P., sq. ft.... 4.64 3.919
Piston speed, feet per min.............. 376 467
Coal burnt per I. H. P., lb.............. 2.11 1.828
This shows a saving equal to 13.38 per cent, in quantity of fuel
consumed. Mr. Marshall then read a letter from Mr. Alfred Holt, of
Liverpool, bearing on this subject, in which Mr.
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