42 REPORT— 1869. 



the position of her -weights, as regards both centre of gravity and moment of 

 inertia, previously to the trial ? 



10. Force and direction of wind, and condition of ship as regards re- 

 sistance to it. 



11. FuU details as to manner in which, and the iastruments or calcida- 

 tions by which, these data have been ascertained. 



There is no doubt that for a comprehensive view of the subject, it would 

 be necessary that these things should be ascertained with care for a large 

 number of ships, of various classes, and under very varied conditions. Eut 

 this is too much to expect to get done, although we think it would be a 

 good thing for the Government, and other large shipowners, to keep in view 

 as an ultimate object. McauwhUe we think it would be a very great expe- 

 rimental aid to science if these things could be accurately settled for even 

 two or three ships, under different circumstances of weather and different 

 arrangements of weight, both in amount and distribution. 



Similar experiments should also be made with reference to pitching. 



The trials should be made with sails furled, and as little disturbance from 

 headway as possible. We have every wish to have parallel experiments 

 tried under any possible conditions of sail and propulsion, and, if it may be 

 done, on the same ships, consecutively with the simpler experiments ; but it 

 will be seen that the data are already sufficiently complex at the best, and 

 that they must be used clear of headway and leeway before they can be 

 discussed with reference to these. 



No experiments are of use for the purpose of inductive reasoning in which 

 any one of the data mentioned above are wanting. 



We think that the Government might fairly be asked to institute such a 

 set of calculations and experiments. We cannot find that the exact infor- 

 mation which we have suggested is in existence anywhere. We are certain 

 that it has not been published in any available form ; and we have reason to 

 believe that the knowledge is quite as much needed and desired by the 

 gentlemen responsible for the construction of the navj^ as by merchant 

 builders or by students of theorj'. 



We therefore recommend that the deputation previously mentioned with 

 reference to the experiments on resistance be also instructed to urge upon 

 the Admiralty the importance, both practical and theoretical, of instituting 

 such a set of experiments, of providing suitable instruments for recording 

 exact observations, and of publishing the results. We also recommend the 

 appointment by the Council of the Association of a committee of three mem- 

 bers to confer with the officers of the Admiralty as to the drawing up of 

 detailed instructions for conducting these experiments; and that the Lords 

 of the Admiralty, in the event of their assenting to the proposals, be 

 requested to nominate a committee to confer with the committee named by 

 the Association. 



In conclusion, we beg leave to recommend that this Report be officially 

 communicated to the Councils of the Institution of jS^aval Architects, the 

 Institution of Civil Engineers, and the Institution of Engineers in Scotland, 

 and the cooperation of those bodies sought, both in applying to the Govern- 

 ment and in making known among shijibuilders, and other persons con- 

 nected Avith Naval Architecture, as weU what is the state of our existing 

 knowledge as what are the immediate desiderata for its extension. 



Charles W. ILeeeifield. W. J. Macquorn Rankine. 



Geoege p. Biddee. W. Peoude (subject to the fol- 



DoTJGLAs Galton. lowlng exjjianaiions). 



