MESSRS. Munn & Co. in connection with the publication of the SCIENTIFIC AMERICAN.continue to examine Improvements, and to act as Solicitors of Patents for Inventors. In this line of business they liave had thirty-eight years' experience, and now have iitwqualea facilities for the preparation of Patent; Drawings, Specifications, and the prosecution of Applications for Patents in the United States, Canada, and Foreign Countries. Messrs. Munn Co. also attend to the preparation of Caveats, Copyrights for Books, Labels, Keissues, Assignments, and Reports on Infringements of Patents. All business intrusted to them is done with special care and promptness, on very reasonable terms. A pamphlet sent free of charge, on application, containing full information about Patents and how to procure them; directions concerning Labels, Copyrights, Designs. Patents, Appeals. Keissues, Infringements, Assignments, Rejected Cases, Hints on the Sale of Patents, etc. We also send, free of charge, a Synopsis of Foreign Patent Laws, showing the cost and method of securing patents in ail the principal countries of the world. MUNN CO., Solicitors of Patents, 261 Broadway, New York. BRANCH OFFICE.--Comer of P and 7th Streets, Washington, D. C.