1884] self-induction of the galvanometer. 2YI 



induction of a ' sensitive mirror galvanometer ' experimentally. L 

 was 5£ earth quadrants, while g was 13,000 ohms. So g/L was 

 about 2400 in this case. Even if the time of charging were only 

 3<^jth of a second, the error in the value of the capacity produced 

 by treating the time constant as x instead of 2,400, would be less 

 than one part in a thousand. 



(4) On the future of naval warfare, with an exhibition and 

 account of a submarine boat. By H. Middleton. 



Abstract. 



It is not proposed in my paper — of which the following is a 

 very short abstract — to repeat the same comments and considera- 

 tions, on the subject of the present condition of the British navy, 

 with which the press has lately teemed. 



However, I have treated briefly of those general principles of 

 naval warfare which govern the design and construction of all 

 ships of war whatever. Because, on the knowledge of those prin- 

 ciples the utility of all inventions and innovations from established 

 forms and models entirely depends. 



In my paper I pointed out that in consequence of the applica- 

 tion of steam to fleets, together with the fact that each ironclad 

 can now carry so short store of coal that the operation of refilling 

 its bunkers has to be repeated every four or five days, while large 

 "bases" for the supply of the fleet's motive power have to be main- 

 tained, require the study of a set of conditions of a character 

 similar to those which give birth to what is known as "strategy" 

 when applied to the maintenance and conduct of armies on land. 



While the large fleet of coal ships which must now-a-days 

 always accompany ironclads operating on the "high seas" neces- 

 sitate the invention of a kind of naval tactics which differs 

 considerably from those applicable to the wooden ships with which 

 England maintained her sovereignty of the sea in her wars with 

 the great Napoleon. 



Now a knowledge, and a sound knowledge, of these matters 

 forms the only guide an inventor has in determining the channels 

 of thought into which he should direct his ingenuity. And this 

 knowledge teaches him the conditions of the problem he must 

 strive to solve; however, the recapitulation of them must be left 

 out of this abstract, and I but state briefly because of the difficulty — 

 if not impossibility — of fulfilling them by ships which move over 

 the surface of the sea. I propose to make them move under the 

 surface, and have thus carried out the problem I proposed to myself 

 for solution. 



Three different kinds of submarine boats have been designed, 

 which kinds I shall call Class (a), (b) and (c) respectively. 



VOL. V. PT. III. 15 ; " 



