INSTRUCTIONS. 



The present \oliiine consists of three parts : — (a) Schedules aud 

 Indexes in four lang-uaj^es ; {b) An Author Catalogue ; (c) A Subject 

 Catalog-ue. 



The Subject Catalogue is divided into sections, each of which is 

 denoted b/ a four-fig'ure number between 0000 and 9999 called 

 a Registration number. These follow one another in numerical order. 



To find the papers dealing with a particular subject the reader 

 may consult either the Schedule or the Index to the Schedule. 

 The numbers given in the index are Registration numbers, and can be 

 used at once for turning to the proper page of the Subject Index. This 

 is done by looking at the numbers at the outer top corners of the pages. 



In each section the final arrangement of entries is in the 

 alphabetical order of authors' names. 



In the Author Catalogue the numbers placed within square brackets 

 at the end of each entry are Registration numbers, and serve to 

 indicate the scope of each paper indexed. The meaning of these 

 numbers will at once be found by refei'ence to the Schedule. 



In case the abbreviated titles of Journals are not understood, a key 

 to these is provided at the end of the volume. 



The literature indexed is mainly that of 1904, but includes those 

 portions of the literature of 1901, 1902 and 1903 in regard to which 

 the index slips were received by the Central Bureau too late for 

 inclusion in the previous volumes. 



Some of the sections are sub-divided into a number of sub-sections 

 by means of topographical symbols. These symbols are letters printed 

 in italics. They are explained in the Topographical Classification. 



