73 REPORT — 1876. 



So far as the capabilities of each individual ship are concerned, there is no 

 insuperable difficulty or risk about the experiments, and to have determined 

 these will be a great point. When the officers know exactly what can be 

 done in the way of tui-niug their ships, and how to do it, the chances of 

 accidents must be greatly reduced. 



But at all events for fighting ships it is desirable that the officers should 

 have experience beyond the mere turning powers of their own ships. AVhen 

 two ships are mana3uvring so as to avoid or bring about a collision, each 

 commander has to take into account the movements of his opponent. To 

 enable him to do this with readiness, it would be necessary to have friendly 

 encounters. A fight between two ships Avhose captains had never before 

 fought, would be like a tournament between two novice knights who had 

 never practiced with pointless spears ; and such a contest, although not un- 

 equal, must be decided by chance rather than skill. 



Unfortunately sham fights or tournaments between ships with blunt rams 

 would bo about as dangerous as a real fight ; and the chance of an accident 

 would be far too great for such friendly tournament, however important, 

 ever to become an essential part of the training of a naval officer, as they 

 were of the knights of old. Por although, should war arise, the danger from 

 want of experience may be even greater than the danger of an accident in 

 gaining such experience by friendly fights, yet, as the chance of. war is 

 always remote, the former risk would be preferred ; and this is not all. 



As yet there has been no such thing as a ramming fight between steam- 

 ships ; so that not only are our officers without actual experience, but even 

 the rules by which they are instructed to act (the rules of naval tactics) aro 

 based entirely on theoretical considerations, and hence are very imperfect. 



Now there appears to me to be a means by which experience of the 

 counter-manoeuvring powers of ships, as well as the manoeuvring powers of 

 single ships, could be ascertained without any of the risk and but little of 

 the cost attending on the trials of large ships, and which, if not equal to an 

 actual fight, would be verj^ useful as a means of training the officers. 



If small steam-launches were constructed similar to the ships, so that 

 they represented these ships on a given scale (say one tenth linear measure), 

 and tlieir engines wei'c so adjusted that they could only steam at what we 

 may call the speed corresponding to that of the larger ships, then two 

 launches would manoeuvre in an exactly similar manner to the large ships, 

 turning in one tenth the room ; and the time which the manoeuvres with 

 the launches would take would only be about half that occuined by similar 

 manoeuvres with full-sized ships. The only points in which it would bo 

 necessary that the model should represent the ship would be in its shape 

 under water and as regards the longitudinal disposition of its weights. The 

 centre of gravity should occupy the same position amidships, and the longi- 

 tudinal radius of gyration of the model should bear the same proportion to 

 that of the ship as the other linear dimensions. In other respects the model 

 might be made as was most convenient. It might be made of wood, and so 

 strengthened that two models might run into each other with impunity. 



There would not be much difficulty in so strengthening the models, as the 

 speed of the models would be very small. For instance, if the speed of the 

 ship were 13| knots, then that of the model would be 4| knots. 



The study of the quahties of ships from experiments on their models has 

 not until recent years led to any important results. But this in great part 

 was owing to the fact that proper account had not been taken of the effect 

 of the Avave caused by the ship and the consequent resistance. It was not 



