A Catalogue of Valuable Papers contained in SCIENTIFIC AMERICAN
SUPPLEMENT during the past ten years, sent _free of charge_ to any
address; also, a comprehensive catalogue of useful books by different
authors, on more than fifty different subjects, has recently been
published for free circulation, at the office of this paper. Subjects
classified with names of authors. Persons desiring a copy have only to
ask for it, and it will be mailed to them. Address