VIII PREFACE. 



the periodicals issued therefrom. Besides these cross references, an Index 

 of Subjects will be found at the close of the alphabetical list of periodicals. 



The Chronological Tables are designed to give the date of publication of 

 each volume of the periodicals entered, as explained on pages 618, 619. 

 They have been compiled on a plan proposed by Prof. James D. Dana 

 (System of Mineralogy, p. xxxiv, note), modified to meet typographical ex- 

 igencies. We are indebted to Professor Dana for useful hints and material 

 assistance in beginning the compilation of these Tables. It is hardly nec- 

 essary to point out their utility ; by them the date of a given volume in a 

 given series of a given work may be found, or the number of the volume 

 may be ascertained when the date only is known. Librarians will find the 

 Tables of service in determining bibliographical data of series not in their 

 collections. The alphabetical list of periodicals should always be consulted 

 in connection with the Chronological Tables. An Index to the periodicals 

 contained in these Tables will be found at their close. 



The Librai-y Check-List, showing in what American libraries the preced- 

 ing periodicals may l)e found, is an attempt to carry out on a continental 

 scale that which has been done in a smaller way by Librarians in several 

 localities. The data were gathered by means of proof-sheets and circulars 

 oistributed by the Smithsonian Institution, which gave its approval to the 

 scheme from the very outset. Circulars were sent to over 200 Libraries, 

 and 120 Librarians responded with great kindness and fullness; the returns 

 were classified and arranged for printing by the Smithsonian Institution. 

 This Check-List is however only a first attempt, and is far from being as 

 complete as is desirable; in a few cases the latter portion of the Catalogue 

 appears almost unrepresented where the earlier portion has a fair showing. 

 The number of periodicals noted is about 2,150 out of the 5,100 in the 

 Catalogue: a more elaborate census of a larger number of Libraries is there- 

 fore much to be desired. 



The material fi)r this work has been gathered from all available biblio- 

 graphies both general and special, and by personal examination of the 

 shelves and of the manuscript (or printed) Catalogues of many Libraries in 

 the United States, as well as of important Libraries in England, France, and 

 Gornuiny. As a last resort over one thousand circulars were sent (in part 

 through the Smithsonian Institution) direct to publishers throughout the 

 world, asking for specimen numbers of their periodicals ; the responses to 

 these requests were very ])rompt and satisfactory, and we were thus enabled 



