A quality secondhand book shop is the best bet, where they would make you an offer. Early editions like these are quite collectible. If you have a considerable number of books, it would be advisable to make a detailed list in the first instance, rather than take all the books to the shop. It is as well to check if they are first editions, which of course are more valuable. Sometimes with these older books, it doesn't say 1st Edition, but 'Copyright' instead. Also it is important that they are in reasonably good condition. Mainly the inner pages need to be good, with little or no foxing, (that is little brown spots). If the covers are worn and the book is quite scarce, then the bookseller will sometimes have them rebound. Hope this helps. Which area are you in.