ADVERTISEMENT. 



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

 Smithsonian Institution is to furnish brief accounts of scientific discov- 

 ery in particular directions; reports of investigations made by collab- 

 orators of the Institution; and memoirs of a geueral character or on 

 special toi:>ics that are of interest or value to the numerous correspond 

 ents of the Institution. 



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

 sonian Institution, from a very 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 ISSO the Secretary, induced in part by the discontinuance of an 

 annual summary of progress which lor thirty years previous had been 

 issued by well-known private publishing firms, had prepared by com- 

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

 nent features of recent scientific progress in astronomy, geology, meteor- 

 ology, physics, chemistry, mineralogy, botany, zoology, and anthropol- 

 ogy. This latter plan was continued, though not altogether satisfac- 

 torily, down 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 181)3. 



73 



