PREFACE 



TN the Preface to the Volume forming the Subject Index to the papers on 



Pure Mathematics for the nineteenth century, published in 1908, an outline 

 of the history of the Royal Society's Catalogue of Scientific Papers is given ; 

 it is not necessary to repeat that account. 



Volume II of the Subject Index, dealing with the papers on Mechanics, 

 was published in 1909. 



The present volume deals with the papers on Physics, as classified in the 

 schedule of the International Catalogue of Scientific Literature. As it was 

 found that the number of entries in this subject was too large for a single 

 volume, the Committee decided that it should be published in two Parts, the 

 first volume containing the entries classed under Generalities, Heat, Light and 

 Sound, and the second those on Electricity and Magnetism. Part I contains 

 33344 entries referring to the papers contained in 1261 serial publications. 



This order differs from that of the International Catalogue, in which 

 Sound follows Electricity and Magnetism ; the Registration Numbers are 

 here retained, but the numbers 8990 to 9520, dealing with Sound, are inter- 

 polated between 4470 and 4900. 



The Index titles were prepared in the same manner as those for Volumes 

 I and II. Papers published from 1884 to 1900 inclusive were consulted by 

 Referees familiar with the subjects, so that the Index titles were made from 

 the contents of the papers and not merely from the headings. For the years 

 from 1800 to 1883, it had been intended that the Index entries should be 

 made from the titles in the published twelve volumes of the Catalogue 

 arranged according to Authors' names; but it has been found necessary in 

 a large number of cases to refer to the original papers, as the headings of the 

 papers were not sufficiently definite to enable the Referees to classify the 

 contents. 



With the object of expediting the publication of the Physics volume, 

 three of the Referees who assisted in the preparation of the Index titles 

 were invited to help in sorting the slips for the Press. Mr R. Hargreaves 



