'44 , REPORT OF THE SECRETARY. 



his field-work may bo fully elaborated in illustration of the flora and 

 fauna of a portion of the United States of which comparatively little is 

 known. 



MISCELLANEOUS. 



The Institution, as in former years, has been in harmonious co-operation 

 with the Department of Agriculture, the Army Medical Museum, and the 

 Corcoran Art Gallery. With the first it has deposited plants and other 

 articles relating to agriculture ; to the Medical Museum it has transferred 

 a large number of articles pertaining to comparative anatomy and mate- 

 ria medica, and has received in return ethnological specimens; in the 

 third, the Corcoran Art Gallery, it has deposited a number of paintings, 

 aiticles of statuary, engravings, i&c. A list of these several deposits 

 will be found in the appendix. 



It may be mentioned that the present Secretary of the Institution 

 has been chosen one of the trustees of the Corcoran Art Gallery, and 

 thus the connexion between these two establishments has become more 

 intimate. The Gallery has been opened during the past year under very 

 favorable auspices, and bids fair to be an important means of improving 

 the intellectual and moral condition of the citizens of Washington, as 

 well as a perpetual monument of the beneficent liberality of its founder. 

 Since its first opening to the public on the 19th January, 1874, it has been 

 visited by 75,000 persons. It has an endowment of $900,000, and had 

 an income last year of upward of $02,000. 



Fog-Signals. — During the last summer I devoted a considerable por- 

 tion of my vacation to investigations in regard to sound in its applica- 

 tion to fog-signals, the results of which have been published in an ap- 

 pendix to the Light-House Eeport for 1874. 



These investigations, which were a continuation of those of former 

 years, tend to establish the fact that sound is susceptible of a kind of 

 refraction, due to the unequal velocity of the upper and lower current 

 of the air, by which the sound-ray is in some cases bent upward, and 

 consequently passes far above the head of the distant auditor, and in 

 others is refracted downward to the surface of the earth, and is thus 

 perceived at a much greater distance. This principle explains the pe- 

 culiar action of the wind on sound, as well as various abnormal phe- 

 nomena which have been observed from time to time in the operation 

 of fog signals; also the discharge of cannon during battles, of which 

 the sound was heard at remote points, though inaudible at those much 

 nearer the explosion. 



Fish inquiry and propagation. — It may be remembered that an act of 

 Congress was passed in February, 1871, directing an inquiry to be made 

 into the causes of the decrease of the food-fishes of the United States, 

 to be i)rosecuted by a commissioner appointed by the President, from 

 the civilian employ6s of the Government, and to serve without salary. 

 Professor Baird, of this Institution, received this appointment and en- 

 tered upon his duties. 



