TUKFACE. XI 



In America assistance has been received from so many persons 

 that it would occupy too much space to mention them all ; but I must 

 acknowledge the willing aid of Mr. Spofford, Librarian of Congress, 

 Prof. Baird, of the Smithsonian Institution, Dr. Hilgard, Mr. Baker 

 and Lt. Dall, of the U. S. Coast Survey, Prof. Cleveland Abbe, of 

 the Weather Bureau, Prof. Lesley and Mr. Prime, of the Pennsylva- 

 nia Geological Survey, and Miss Slack, Librarian of the Cambridge 

 Museum. Proofs of the work have also been submitted to the assis- 

 tants in the libraries of the Natural History Society and of the Acad- 

 envy of Sciences, in Boston, who have kindly compared every entry 

 of a work on the shelves of these institutions with the originals, and 

 to them, and especially to Miss Foster, of the Natural History Society, 

 I am indebted for many emendations. 



A few minor explanations are necessary. The words "royal," 

 " imperial " and " national " (or their equivalents in Latin or in any 

 of the languages of modern Europe) are left entirely out of account in 

 alphabetising, and in the index of titles are altogether omitted ; the 

 only exceptions to this are where societies have no other distinc- 

 tive title, as the Royal Societies of London, Edinburgh, etc. But 

 words like " cantonal," " churfiirstlich" or " grossherzoglich," being 

 rare and seldom changed by political events, have been treated like 

 any other words. Many academies entered in this catalogue issue 

 series which find no place here, because not embraced within the scope 

 of the catalogue, and all works published by societies or academies 

 which have not a serial character are also purposely omitted ; such are. 

 all proceedings published upon festive or anniversary occasions at in- 

 tervals of twenty-five, fifty or one hundred }*ears. Annuals are in all 

 cases entered ; and even the yearly financial and statistical reports, 

 as often including matters of purely scientific interest or at any rate 

 of special interest in connection with the histories of scientific institu- 

 tions, have been included, wherever information concerning them 

 could be procured. Changes in a title are indicated by the enclosure 

 of the altered portions in parentheses ; when several changes have oc- 

 curred in a minor title, these are shown by their separation within the 

 parentheses by a dash. When a serial is published by a society or 

 other institution, editor's names are not given ; nor, in any independ- 

 dent journal, more than one name (and that the first mentioned), 

 where there are several editors. Where dates included in parentheses 

 follow dates not in parentheses, the former indicate the years for 

 which, and the latter the years in which the work was published. 



The names of the towns are written as in the country to which they 

 belong ; but in the Index of Towns, they appear in all the forms by 

 which they are known in different languages ; and to the names of 

 towns of the United States, the states are there appended in italics. 

 In the Index of Titles, independent journals appear by the first word 

 of their title not an article or a preposition ; serials published by so- 



