VI ADVERTISEMENT. 



The Annual Reports are presented to Congress, and printed at 

 its expense, copies being given to the Institution. They consist 

 of the reports of the Secretary to the Board of Regents of the 

 operations and condition of the Institution ; the reports of com- 

 mittees of the Board ; abstracts of lectures delivered before the 

 Institution ; extracts from correspondence ; original or translated 

 articles relating to the history and progress of science, etc. Over 

 the typography and general mechanical execution, as well as the 

 number of copies, of the Smithsonian Annual Reports the Institu- 

 tion has no control. 



In the first experiments of the Smithsonian system of publica- 

 tion, the proper magnitude of the editions necessary to meet the 

 immediate and future demand could not be accurately ascertained. 

 The number of copies of the Contributions then fixed upon, has 

 since been found inadequate, although it was larger than that 

 usually issued by other institutions. The edition has, therefore, 

 been augmented, until at the present time 1000 copies of each 

 article are set aside to be combined into volumes, and an extra 

 number, varying with the probable demand, from 500 to 1500, 

 struck off for separate distribution, and for sale. 



Each article is complete in itself, with separate paging, title, 

 and index, and without any necessary relationship to others com- 

 bined with it in the same volume. 



Of the first volume of Smithsonian Contributions, the edition, 

 for reasons already explained, is less than of the succeeding ones, 

 so that complete sets cannot now be always furnished. A consi- 

 derable number of the earlier articles in octavo, also, are out of 

 print, and cannot be furnished in series for the same reason; they 

 are, therefore, necessarily excluded from the "Smithsonian Mis- 

 cellaneous Collections." Most of such works, however, have been 

 or will be reproduced in later and improved editions. 



The regular series of volumes of Smithsonian Annual Reports 

 begins with 1853, those for previous years being pamphlets now 

 out of print. The essential portion of their contents is, however, 

 given in the above-mentioned volume for 1S53, so as to present a 

 complete summary of the history of operations of the Institutiou 

 from its commencement to the present time. 



The rules governing the distribution of the Smithsonian publi- 

 cations are appended. To enable institutions not coming within 

 their provisos, as well as individuals, to procure copies of such as 



