president's address — SECTION H. 173- 



are accomplished are remarkable. These results are, doubtless, in 

 some measure due to an increased size of vessel, but chiefly to the 

 great advance which has been made in marine engine construction. 

 The adoption of high boiler pressures, triple expansion engines, 

 and the free use of steel has enabled the marine engineer to so 

 increase the efficiency of his machinery that we now find 2*4 indi- 

 cated horsepower per gross ton of vessel attained, as against the 

 one horsepower per ton of ten years since. An indicated horse- 

 power is produced for a consumption of a little over l|^lbs. of fuel,. 

 and the careful proportioning of details has rendered stoppages 

 from breakdowns of rare occurrence. 



To the active competition between the great English torpedo boat 

 builders much of this progression can be traced, and the new water 

 tube boiler of Mr. Thornycroft promises, from its comparative 

 lightness, to enable a further stride to be taken in high speed 

 navigation. But is advance in this direction to be completely 

 dependent on the engine-builder ? The naval architect has certainly 

 somewhat reduced the weight of the hull, but the form of vessel 

 has remained for many years practically unchanged. The great 

 improvement in the speed of our large racing yachts that (under 

 similar conditions of stiffness and displacement) has followed the 

 adoption of great beam, shallow body, and round linos, points to 

 the possibility of a beamy, pram-bowed vessel of moderate draught 

 being propelled with a less expenditure of power than is required 

 in the case of the pointed tanks now so common. Between the 

 seaworthiness and comfort of the two types there could be little 

 comparison. 



It is to submarine navigation we must look for the attainment 

 of extremely high velocities ; but if a submarine vessel — in every 

 way as desirable as the creation of Jules Verne's fertile brain — 

 were introduced to-morrow, it is extremely doubtful if it would 

 command a share of traffic sufficient for its profitable employ- 

 ment. 



Aerial navigation will in all probability be, before long, an 

 accomplished fact. Messrs. Maxim and Phillips have each suc- 

 ceeded in causing machines carrying their own motive power to 

 lift themselves from the ground, and move through the air at a 

 high velocity. This has been effected in the apparatus of the 

 former by the reaction of a single inclined plane ; whilst Mr. 

 Phillips has adopted a series of narrow planes arranged in much 

 the same manner as the laths of a Venetian blind. In both cases 

 the machine is propelled by a single stream-driven screw ; but it 

 is open to question if the aero-plane surface might not be mvicli 

 . reduced, and the manipidation of the contrivance made far more 

 easy, by so arranging the propeller shaft that its axle with the 

 horizontal could be varied at pleasure. The immediate use to 

 which the successful flying machine will undoubtedly be put will 

 be that of increasing the horrors of war, the character of which 



