642 Transactions. — Miscellaneous. 



necessary suddenly to alter the course or to come to a full stop 

 the modern ship is at the greatest disadvantage. The sailing- 

 vessel, with anything hke a breeze, would come round on her 

 heel or could be hove-to in an instant, by a turn or two at the 

 wheel and a pull at the yards ; and the comparatively short and 

 wide build of the old paddle-steamer, especially if she were 

 fitted with side- wheels of independent action, gave her a great 

 advantage whenever any rapid manoeuvre was required. But 

 with the " greyhound " of the Atlantic or Pacific it is quite 

 different. Her immense length and the extreme fineness of 

 her lines cause her to forge ahead in spite of engines stopped 

 and reversed, and increase the radius of the arc on which she 

 will come round. In fact, the very qualities which give her a 

 proportionate advantage when all is clear and straightforward 

 become a corresponding element of inconvenience and danger 

 when it is necessary to navigate a tortuous channel or avoid 

 a suddenly-apprehended obstacle. 



In spite of every advance in the science and practice of 

 navigation, there will always be a certain number of dangers 

 to be avoided or overcome. These may be divided into two 

 classes — namely, those which are, so to speak, constant, and 

 those which are on the increase. To the former class belong 

 those which result from the ordinary vicissitudes of wind and 

 weather, and other natural causes, which will continue to tax 

 the skill and resources of the navigator to the end of time ; 

 while to the latter must be put down those which are inci- 

 dental to new modes of structure and equipment, and to the 

 growing extension of ocean traffic, of which the most important 

 is the risk of collision, which is daily becoming more imminent, 

 and which, from the build and tonnage of the ships, and their 

 increasing rate of speed, is fatal to a degree hitherto un- 

 known. 



The actual event of a collision has to some extent been 

 foreseen and provided for — that is to say, certain provisions 

 have been made in the structure and equipment of the ship 

 which are intended to reduce the damage and loss of such a 

 catastrophe to a minimum, as, e.g., watertight bulkheads, 

 deck-rafts, and improved boat-lowering arrangements. But, 

 so far as I am aware, beyond the careful use of the ordinary 

 appliances no steps have been taken for the avoidance of the 

 catastrophe itself ; and it seems to me that it is precisely here 

 that the weak spot is to be located.''' 



The object of the present paper is the suggestion of an 

 apparatus which I cannot but think will in some measure 



* The twin-screw may perhaps be quoted as forming an exception to 

 this statement. Its adoption, however, is by no means general, at least 

 in the merchant service, with which we are chiefly concerned at present, 

 nor is it materially effective in attaining the desired result. 



