VI INTRODUCTION. 



Lave however been consulted iu order to secure the necessary checks 

 upon accuracy. 



A considerable number of the works quoted are not to be obtained 

 in the United States, and in many cases I have had only incomplete 

 sets of periodicals at hand, which may explain possible omissions. 



Following, I give a list of all works on special astronomical 

 bibliography which are known to me, which may be of use to those 

 consulting this Catalogue. 



Among this list of works, the only one similar in purport to the 

 present, is the work of my friend E. B. Knobel, Esq., F. R. A. S., 

 etc. A careful comparison Avith § 4 of his work has assured me of 

 the accuracy both of his list and of the present one as it stood in 

 manuscript at the time of the publication of Mr. Knobel's paper. 



The present Index is somewhat wider in scope than §4 of Mr. 

 Knobel's, and it contains a special reference to the contents of 

 each paper, which is not given in the other list. As the two works 

 were done independently, each serves as a useful check upon the 

 other. 



LIST OF ASTRONOMICAL BIBLIOGRAPHIES. 



Belgian Academy of Sciences : Bibliographic Academique. 1875. 8vo. 

 [This work contains, beside brief biographies of the various 

 members of the Academy, a full list of those works of each 

 member which have been printed in the publications of this 

 Academy, as well as tolerably full lists of such works printed 

 elsewhere.] 



Carl, Ph.: Principien der Astronomischen Instrxcmentcnlcunde, p. 161. 

 [Literature of Micrometers.] 



: Repertorium der Cometcn-Astronomie. 8vo. 1864. 



[Contains references to observations, etc., of comets, and is 

 very complete.] 



Darboux and Houel : Bulletin des Sciences Mathematiques et Astrono- 

 miques. Periodical. 8vo. 



[Contains abstracts of, and criticisms upon, works and memoirs 

 on Astronomy, Mathematics, etc.] 



