Walsh. — 0)i a New Steamer-hraJcc. 643 



supply the obvious want, and which I offer in all becoming 

 modesty for the consideration of those who are interested in 

 the subject. 



The questions to be solved are two — (1) How to bring a 

 ship going at full speed to a standstill in the shortest possible 

 time; and (2) how to rapidly change her course at a com- 

 paratively acute angle. 



In a pulling-boat these objects are accomplished (1) by 

 the simultaneous backing of all the oars, and (2) by holding 

 water on one side, while her "way," or existing impetus, 

 maintained by the oars on the other side, carries her round. 

 And, though it is not, of course, to be expected that these 

 manoeuvres could be accomplished with the same ease and 

 perfection in the case of a ship of large tonnage as in that of 

 a small boat, still I think that by means of the apparatus I 

 propose they might be effected to such a degree as would be 

 of material assistance in attaining the desired result. 



The apparatus I propose consists of a system of strong 

 metal plates, set in pairs at the sides of the vessel, to which 

 they are attached by hinges at their forward ends, and which 

 could be forced outward to any desired angle. In order to be 

 effective in checking the way they should be placed at vari- 

 ous depths, and well below the water-line, where they would 

 encounter a maximum of resistance ; and to insure the 

 greatest steering-power one pair at least should be well aft of 

 amidships. These plates I have designated brake-fins, as the 

 name seems appropriately to describe their structure and 

 functions. To bring the fins into action would, of course, re- 

 quire the exercise of a very powerful pressure from within, 

 which should be capable of instant application. This I would 

 propose to supply by means of hydraulic chambers fitted with 

 pistons on the principle of the hydraulic jack, the water being 

 supplied by steam-pumps whose action could be controlled 

 from the bridge.''' 



The actual operation of the apparatus would be precisely 

 similar to that of the oars in the boat before described. The 

 fins would simply act as so many drags on the vessel, and 

 would serve either to assist in bringing her round, or in re- 

 ducing her speed, according as they were projected on one or 

 both sides. When not in use they could simply be shut back 

 in depressions made for the purpose, so that their outer sur- 

 faces would be flush with the external plating. 



There are several important questions which would have 

 to be worked out in order to insure the successful operation of 

 the apparatus — as, e.g., those regarding the best form, the 



* It is possible, also, that compressed air might be used for the pur- 

 pose. 



