The book has been appreciated by numerous learners and users of Lathes, and many letters of approval have been received. It will be found in the principal libraries in England, Canada, and Australia. Having been successful in our book on Elementary Turning, we are encouraged to bring out others to suit the practical engineer, the first of which — ou 'screws and screw-cutting will shortly appear. Our opinion as to the best books on various technical subjects having so frequently been requested, we have (to save much time and correspondence) compiled a Catalogue of Technical Books, giving their price, size, contents, &c., which we trust may be useful to the English-speaking world.