If you become thoroughly conversant with priced catalogues, you will make fewer mistakes than most private buyers. Not only catalogues of notable collections, with the prices obtained at auction, but the large and very copious catalogues of such London book-dealers as Quaritch and Sotheran, are accessible in the great city libraries. These are of the highest use in suggesting the proximate prices at which important books have been or may be acquired. Since 1895, annual volumes entitled "American Book Prices Current" have been issued, giving the figures at which books have been sold at all the principal auction sales of the year. There is no word so much abused as the term _rare_, when applied to books. Librarians know well the unsophisticated citizen who wants to sell at a high price a "rare" volume of divinity "a hundred and fifty years old" (worth possibly twenty-five cents to half a dollar,) and the persistent woman who has the rarest old bible in the country, which she values anywhere from fifty to five hundred dollars, and which turns out on inspection to be an imperfect copy of one of Barker's multitudinous editions of 1612 to '18, which may be picked up at five to eight shillings in any old London book-shop. The confident assertions so often paraded, even in catalogues, "only three copies known," and the like, are to be received with absolute incredulity, and the claims of ignorant owners of books who fancy that their little pet goose is a fine swan, because they never saw another, are as ridiculous as the laudation bestowed by a sapient collector upon two of his most valued nuggets. "This, sir, is unique, but not so unique as the other." Buying books by actual inspection at the book-shops is even more fascinating employment than buying them through catalogues. You thus come upon the most unexpected volumes unawares. You open the covers, scan the title-pages, get a glimpse of the plates, and flit from book to book, like a bee gathering honey for its hive. It is a good way to recruit your library economically, to run through the stock of a book-dealer systematically--neglecting no shelf, but selecting throughout the whole stock, and laying aside what you think you may want. When this is done, you will have quite a pile of literature upon which to negotiate with the proprietor. It is cheaper to buy thus at wholesale than by piecemeal, because the bookseller will make you a larger discount on a round lot of which you relieve his shelves. Another method of recruiting your library is the examination of books "on approval." Most book-dealers will be so obliging as to send in parcels of books for the inspection of a librarian or collector, who can thus examine them leisurely and with more thoroughness than in a book store, without leaving his business.