ADVERTISEMENT. 



The object of the General . Appendix to the Annual Report of the 

 Smithsonian Institution is to furnish brief accounts of scientific dis- 

 co\'ery in particular directions; reports of investigations made by col- 

 laborators of the Institution, and memoirs of a general character or 

 on special topics that are of interest or value to the numerous corre- 

 spondents of the Institution. 



It has heen a prominent object of the Board of Regents of the Smith- 

 sonian Institution, from a ver}' early date, to enrich the annual report 

 required of them by law with memoirs illustrating the more remarka- 

 ble and important developments in physical and biological discovery, 

 as well as showing the general character of the operations of the Insti- 

 tution; and this purpose has, during the greater part of its history, 

 been carried out largely by the publication of such papers as would 

 possess an interest to all attracted by scientific progress. 



In 1880 the Secretary, induced in part by the discontinuance of an 

 annual summary of progress which for thirty years previous had been 

 issued by well-known private pu])lishing firms, had prepared by com- 

 petent collaborators a series of abstracts, showing concisely the prom- 

 inent features of recent scientific progress in astronomy, geolog}^ 

 meteorology, yjhysics, chemistry, mineralogy, botany, zoology, and 

 anthropology. This latter plan was continued, though not altogether 

 satisfactorily, doAvn to and including the year 1888. 



In the report for 1889 a return was made to the earlier method of 

 presenting a miscellaneous selection of papers (some of them original) 

 embracing a considerable range of scientific investigation and discus 

 sion. This method has been continued in the present report, for 1899. 



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