254 THE BOTTOM OF THE SEA. 



by this means, in 8[)ite of the mud or sand which had 

 ah'oady commenced to cover them up! The diver, 

 with the equipments we have described, makes his 

 investigations in perfect safety and ease ; he can see 

 quite as well as in full daylight ; he examines every 

 cranny ; he overturns the soil stone by stone ; he 

 maps out liis field of operations, and tlins saves him- 

 self from a useless repetition of his seaich. His 

 patient investigations are rarely without some valu- 

 able result. In the excellent description of the 

 Eouquayrol-Denayrouze apparatus, we find tlie fol- 

 lowing remarkable example of a salvage effected by 

 tlie help of this apparatus : — 



" The packet-boats Ganges and Tlmperatrice came 

 into collision in the outer port of Marseilles. The 

 Imperatrice had one of her wheels broken, and the 

 officers' quarters damage 1. One of the cabins con- 

 tained a chest full of gold, which fell into the thick 

 mud which forms the bottom of the port of Marseilles. 

 It was important that this precious package should 

 be recovered the next day. The sea was rough, and 

 the exact spot where the accident occurred, unknown. 

 The box was not strong, its colour was black. At the 

 supposed spot a plumb of 60 kilogrammes was snnk. 

 This plumb carried two cords divided into meters ; 

 two divers dragged them in separate directions, and, 

 taking each the knot corresponding to one meter, 



