REPORT OF THE SECEETARY. 69 



other duties was devoted to the reproduction and extension of the re- 

 sults previously obtained. 



During the past year I devoted about three weeks, in connexion 

 with Commodore Powell and Mr. Lederle, of the light-house service, 

 to investigations in relation to sound as applicable to fog signals, 

 and obtained results of sujficieut practical value to determine with 

 considerable precision the policy of the Light-house Board in regard 

 to this branch of aids to navigation. 



As usual, various questions have been referred to the Institution by 

 different departments of the government for solution, and these have 

 in all cases received proper attention, and such reports have been 

 made as would suffice to an intelligent decision in regard to them. 



The Institution is constantly applied to for the examination and 

 analysis of specimens of ores. Where such examination requires no 

 special labor, the information has been gratuitously given; but where 

 quantitative analysis is desired, and the information is for the ad- 

 vancement of private interests, a charge is always made sufficient to 

 repay the actual cost of the investigation 



Exchanges. — The system of international scientific and literary 

 exchanges has been maintained and extended by the Institution dur- 

 ing the past year. Seventy-seven large boxes, containing 1, ITG par- 

 cels, were sent to our foreign agents in 1865, and 60 boxes, contain- 

 ing 5,000 parcels, received from them. 



These packages, as in former years, contain the publications of the 

 Institution, public documents, transactions of societies, and scientific 

 works, by individuals, besides specimens of natural history. The 

 cost of this branch of the general operations is very large, and would 

 indeed far exceed the means of the Institution were it not for the 

 liberal aid received from various parties interested in the advance of 

 science. For favors of this kind thanks continue to be due to the Bre- 

 men, the Hamburg, the Cunard, and the Pacific steamship lines, and 

 to the Panama Railroad Company: all these have generously transport- 

 ed the packages of the Institution free of cost. Acknowledgments are 

 due to the Adams, Harnden, and Wells & Fargo express lines for 

 the carriage without charge of smaller packages, and of larger ones 

 at a very reduced rate. To Sir E. Cunard, F. Probst & Co. , Oelrichs 

 & Co., and Kunhardt & Co., of New York, and to Lefiraan & Gut- 

 heil. of Vera Cruz, thanks have been tendered for important privi- 

 leges granted by them or through their influence. Mr. George Hiilier, 

 of New York, and Mr. Samuel Hubbard, of San Francisco, agents of 

 the Institution in those cities, have continued their valuable services. 



It may be proper to state that great care is exercised in the 



