INSTRUCTION?. 



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

 languages; (^) An Author Catalogue ; (c) A Subject Catalogue. 



The Author and the Subject Catalogue are paged separately. 



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. 



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 Indes. 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 l>y reference 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 1S06, but includes 

 those portions of the Hterature of 1901-1905 in regard to which the 

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

 the previous volumes. 



Topographical Symbols. 



Some of the sections are divided into sub-sections indicated by 

 topographical symbols. These are letters printed in italics. They 

 are explained in the Topographical Classification. 



