353 POPULAR LECTURES AND ADDRESSES. 



slower hauling must be practised. An arrange- 

 ment by Professor Jenkin can very readily 

 be applied, by which the men or engine can 

 haul in as fast as they please, and be unable 

 to put more than a certain force on the 

 wire. Thus will be realised in speed the 

 benefit of abundance of power. The wire 

 will come in fast when the strain is easy, 

 and not come in at all when the ship is 

 rising and producing such a pull on the wire 

 as might break it if being hauled in at the 

 moment. 



The advantages of the pianoforte-wire method 

 are very obvious. You see the simplicity of 

 the apparatus, and the comparative inexpen- 

 siveness of it ; no donkey-engine required, no 

 three or four hundred pounds of iron cast 

 away every time, as in the ordinary method 

 of deep-sea soundings : and withal there is a 

 very much surer sounding than the ordinary 

 process can give at the same depths. The 

 apparatus at present in use in our navy, 

 which is better than that of any other navy 



