244 A LIBRARIAN'S WORK. [xn. 



Here we enter upon a very wide subject, and one 

 that is not altogether easy to expound to the un- 

 initiated. A brief historical note is needed, to begin 

 with. In 1830 Harvard University published a 

 printed catalogue (in two volumes, octavo) of all the 

 works contained in its library at that date. In 1833 

 a supplement was published, containing all the acces- 

 sions since 1830, and these made a moderate-sized 

 volume. Here is the essential vice of printed cata- 

 logues. Where the number of books is fixed once 

 for all, as in the case of a private library, the owner 

 of which has just died, and which is to be sold at 

 auction, nothing is easier than to make a perfect 

 catalogue, whether of authors or of subjects. It is 

 very different when your library is continually grow- 

 ing. By the time your printed catalogue is completed 

 and published, it is already somewhat antiquated. 

 Several hundred books have come in which are not 

 comprised in it, and among these new books is very 

 likely to be the one you wish to consult, concerning 

 which the printed catalogue can give you no informa- 

 tion. If you publish an annual supplement, as the 

 Library of Congress does, then your catalogue will 

 become desperately cumbrous within five or six 

 years. When you are in a hurry to consult a book, 

 i t is very disheartening to have to look through half a 



