432 THIRD REPORT 1833. 



These ships may be made to sail against each other under 

 ever possible circumstance of sailing, taking care always to ap- 

 ply the propelling force in the same way, that is, by bracing the 

 corresponding yards of all the ships to the same angle with a fore 

 and aft line, during every comparison, and by raking the masts 

 to the same degree. 



It is of importance that during the experiments the surface 

 of sail in each ship should be presented as nearly as possible 

 at the same angle to the action of the wind ; and this is perfectly 

 practicable, for it is easy to measure the angles of the yards by 

 an instrument for that purpose ; and the officer who commands 

 the squadron can take care, by means of frequent signals, to 

 have the yards of all the ships braced to the same angle at the 

 same time. 



These experiments would not be limited in their result to the 

 discovery merely of that form of a ship which is best calculated 

 for velocity, although this of itself is so important as to justify 

 almost any expense, but we might also be able to discover how 

 far the angle of leeway is affected by the form, which is also a 

 vei*y important question connected with the sailing of ships ; 

 and after having, by repeated and careful trials, discovered the 

 order of superiority of ships in respect of velocity, we might 

 then, by varying the angle of bracing the yards, discover also 

 the trim of the sails and the course of the ship by which to gain 

 most on a wind, a question which is not by any means satisfac- 

 torily settled, in as much as it involves all the uncertainty of our 

 present knowledge of the resistance of fluids. 



Experiments to determine this latter question might, however, 

 be made immediately on sister ships, of which thei'e are several 

 at present in His Majesty's service. 



Let two ships be selected of the same form, and let the ut- 

 most pains be taken to make the position and rake of the 

 masts, the seat in the water, the stowage of the ballast, and of 

 all the heavy weights, exactly the same in both ships, and let 

 them be compared together in sailing both on the wind and at 

 various points off the wind ; the angles of bracing the yards 

 being constantly varied, we should doubtless, from a series of 

 experiments of this nature, succeed in discovering the best trim 

 of the sails for every direction of the wind on every course. 



It may, perhaps, be urged against a series of experiments like 

 those which have been here recommended, that the expense of 

 building a ship is so great as to render it advisable not to run 

 the risk of building a bad one for the sake of experiment merely. 

 But the author suggests that our knowledge of naval architec- 

 ture is such as to enable us to construct ships which we can 



