Vlll 



INSTRUCTIONS. 



The present volume contains (a) Schedules and Indexes in four 

 languages; {b) An Author Catalogue ; (c) A Subject Catalogue. 



The Schedules have been revised in accordance with the decisions 

 of the International Convention of 1905. 



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



denoted by a four-figure number between 0000 and 9999 called 



a Registration number. These numbers follow one another in 

 numerical order. 



In each section the final arrangement of papers is in the 

 alphabetical order of authors' names. 



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 numbeis, 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 right-hand top corners 

 of the pages. 



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 reference to the Schedule. 



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

 to these is provided at the cud of the volume. 



The literature indexed is mainly that of 1911, but includes 

 those portions of the literature of 1901-1910 in regard to which the 

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

 the previous volumes. There are also entries dated 1912. 



Topographical Symbols. 



These symbols are letters printed in italics. They are explained in 

 the Topographical Classification. They are not used instead of 

 Registration numbers, but for sub-dividing the sections. 



