ADVERTISEMENT. 



This volume forms the fourth of a series, composed of original memoirs on dif- 

 ferent branches of knowledge, published at the expense, and under the direction, of 

 the Smithsonian Institution. The publication of this series forms part of a general 

 plan adopted for carrying into effect the benevolent intentions of James Smithson, 

 Esq., of 'England. This gentleman left his property in trust to the United States 

 of America, to found at Washington an institution which should bear his own 

 name, and have for its objects the ^'■increase and diffusion of knowledge among 

 men." This trust was accepted by the Government of the United States, and an 

 Act of Congress was passed August 10th, 1846, constituting the President and the 

 other principal executive officers of the general government, the Chief Justice of 

 the Supreme Court, the Mayor of Washington, and such other persons as they might 

 elect, honorary members, an establishment under the name of the " Smithsonian 

 Institution for the increase and diffusion of knowledge among men." The 

 members and honorary members of this establishment are to hold stated and special 

 meetings for the supervision of the affairs of the Institution, and for the advice 

 and instruction of a Board of Regents, to whom the financial and other affairs are 

 entrusted. 



The Board of Eegents consists of three members ex officio of the establishment, 

 namely, the Vice-President of the United States, the Chief Justice of the Supreme 

 Court, and the Mayor of Washington, together with twelve other members, three of 

 whom are appointed by the Senate from its own body, three by the House of 

 Representatives from its members, and six persons appointed by a joint resolution 

 of both houses. To this board is given the power of electing a Secretary and other 

 officers, for conducting the active operations of the Institution. 



To carry into effect the purposes of the testator, the plan of organization evi- 

 dently should embrace two objects — one, the increase of knowledge by the addition 

 of new truths to the existing stock; the other, the diffusion of knowledge, thus 

 increased, among men. No restriction is made in favor of any kind of knowledge, 

 and hence each branch is entitled to, and should receive, a share of attention. 



