2. That the Secretary send a copy of this proceeding to his bereaved 

 widow, certified under the seal of the Academy of Science of St. Louis, 

 with the respectful condolence of its members. 



Dr. Copes, President of the New Orleans Academy of Sciences, 

 being present, was invited by the President to address the society. 

 Dr. Copes gave an account of the operations and vicissitudes of 

 the New Orleans Academy for the last twenty years, and alluded 

 to the contributions of its members to the progress of science and 

 the useful arts ; and particularly to the discovery by Mr. Lamb 

 of a mode of charging water with heated steam so as to make it 

 applicable as a motive power in engines for driving street-cars. 

 He had been led to this invention by experiments on the use of 

 ammoniacal gas as a motive force. 



Capt. Roy, lately of New Orleans, being introduced, gave a 

 more detailed statement of this invention and of its actual use in 

 driving cars on street-railroads in New Orleans. An engine could 

 be charged at the stations with sufficient power to drive the cars 

 around a circuit of six to nine miles before being re-charged. 



Capt. Roy also gave an account of the means that had been 

 employed for deepening the outlets of the Mississippi river, with 

 a statement of his views upon that subject, and in particular as 

 to the effect of jetties, which he did not think could be made 

 effectual. 



Capt. J. B. Eads stated that the theory of jetties had been mis- 

 understood : he believed they would prove successful at the mouth 

 of the Mississippi. Sir Charles Hartley (whom he had lately 

 had the pleasure of entertaining at his house, when in St. Louis) 

 had succeeded in deepening the mouth of the Danube by the use 

 of jetties. He saw no good reason why they might not be equally 

 effectual at the mouth of the Mississippi. 



An objection had been made that the effect of the jetties dam- 

 ming up the waters in the outlet where they were placed would 

 be simply to cause the waters to flow off through the other out- 

 lets, leaving that one to be filled up only so much the faster. He 

 did not believe that such would be the effect ; but that, on the con- 

 trary, the weight and pressure of the water would tend at once to 

 scour out the sands between the jetties to a greater depth, and so 

 inevitably to deepen the channel. His observations by the use 

 of diving-bells in the river, and upon the action of the current be- 



