48 REPORT OF THE SECRETARY. 



sition by the publication of tbe classified index of all tbe physical 

 papers in the transactions of learned societies and in scientific peri- 

 odicals which has been in course of preparation for the last ten years 

 by the Royal Society of London, and of which the printing of the first 

 volume has just been completed. It may be recollected that the 

 preparation of this index resulted from a letter addressed to the Brit- 

 ish Association in 1855, by tbe Secretary of this Institution, setting 

 forth the advantages to science of such a work, that the matter was 

 referred to a committee of the Association, reported favorably upon, 

 and recommended for execution to the Royal Society. As soon as 

 this work is published copies will be procured by the principal libra- 

 ries and institutions in this country. Any person, then, desiring to 

 investigate a special point in any branch of science, will be able to 

 find a reference to the transactions, journals or proceedings in which 

 it is contained ; and as the most perfect set of these is to be found in 

 the National Library, it will become a centre of information on scien- 

 tific subjects. It may also be remarked that the National Library is 

 now accessible to all persons during every week-day in the year, with 

 the exception of one month devoted to cleaning and arranging. 



In the arrangement of the compound library the principal part of 

 the Smithsou collection, that is, the scientific transactions, will form a 

 department by itself in which works of a similar character previously 

 belonging to the library of Congress will be incorporated, while the 

 miscellaneous books of the Institution will be arranged with the works 

 of a similar class already in that library. A complete catalogue of 

 all the transactions belonging to the Smithson library up to 1866 was 

 prepared and published by the Institution, and a general catalogue 

 of the whole National Library is now in the press, in which the books 

 of the Institution are designated by the letter — S. 



Some idea may be formed of the value of the annual contributions 

 from the exchanges of the Institution, when it is mentioned that it 

 includes the publications of 1,081 societies, besides large donations 

 from governments, libraries, and individuals, and that these publica- 

 tions are principally of a very expensive character, illustrated by 

 costly engravings and in many cases by colored plates. The following 

 is a statement of the number of establishments in different parts of 

 the world which have contributed to the Smithson library, and which 

 it is expected will continue their contributions from year to year for 

 an indefinite period. 



