16 NINTH ANNUAL REPORT OP 



and forwarded them to the Institution. Mr. Barry took northern Wis- 

 consin for the field of his labors, and spent several months in traversing 

 the State, penetrating into various regions scarcely visited before by the 

 white man. Several lakes and streams, not on the map, were discov- 

 ered, and named by him. His most important results consisted in very 

 full series of fishes from many localities. Professor Baird spent six 

 weeks on the coast of New Jersey, at Beesley's Point, collecting speci- 

 mens, and studying the habits of the marine fishes of the neighborhood. 

 Thence he proceeded to several places on Long Island, especially to 

 Greenport and Riverhead ; and afterwards made explorations at various 

 points on and near the Hudson river, as far north as Sing Sing. Full 

 series of fishes and Crustacea were procured at all these places, and 

 sent to the Smithsonian Institution. 



" (2.) Terrestrial Magnetism. — The observatory established at the 

 joint expense of the Coast Survey and the Institution, described in the 

 last report, for determining the changes in the different elements of the 

 magnetic force, has not yet been fully supplied with all the necessary 

 instruments. This has been occasioned by the illness of Mr. Brooks, of 

 England, the inventor, who has not been able to furnish the apparatus 

 for recording the variations in the dip and intensity. The only part of 

 the system which has been in partial operation, is that of the variation 

 or declination instrument; and in this, the glass cylinder which sup- 

 ports the sensitive paper, and which is needed to render the record 

 more perfect, is wanting. 



An attempt was made to supply this deficiency by means of a copper 

 cylinder, coated with gold by the electrotype process. It was found r 

 however, that the porosity of the gold allowed the acid to act upon the 

 copper below, and thus to produce stains upon the paper. It is hoped 

 this observatory will be fully equipped in the course of the present 

 spring, and that a continued record will hereafter be kept up. 



It was mentioned in the last report, that a set of instruments had 

 been furnished the Grinnell expedition under command of Dr. Kane. 

 No intelligence, however, has yet been received from this expedition ; 

 but should our most anxious hopes be realized in reference to this enter- 

 prise, we doubt not a series of results will Be obtained which will well 

 repay the cost of the instruments. If not, the Institution should receive 

 some degree of commendation for aiding in an undertaking which re- 

 flects so much honor on the intelligence and liberality of one of our 

 citizens, and the gallantry and enterprise of a young officer of our navy. 



Four complete sets of instruments have been constructed in London 

 for the Institution ; three of these have been purchased by the general 

 government, and have been employed in the different surveying expe- 

 ditions. The fourth has been lent, in succession, to different individu- 

 als, for the purpose of accumulating magnetic observations in different 

 parts of the United States. 



A simple instrument for determining the minute changes in the direc- 

 tion of the magnetic needle, devised by Mr. J. E.Hilgard of the United 

 States Coast Survey, is now in the process of construction, under the 

 direction of this Institution, for the Academy of Natural Sciences 

 California. The cost of this instrument is defrayed by the liberality 

 of the President of the Academy, Dr. A. Randall. 



