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 have had over thirty years' experience, and now have unequaled facilities foi 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, Registration of Label., Copyrights for Books, Labels, Reissues, Assignments, and Reports on Infringements of Patent.. All business intrusted to them is done with special care and promptness, on very moderate term. We send, free of charge. on application, a pamphlet containing further information about Patents, and how to procure them; directions concerning Labels, Copyrights, Designs, i'atents, Appeal., Reissues, Infringements, Assignments, Rejected Cases, Hints on the Sale of Patents, etc. Foreiyn Patef.*.-We also eendfree Qf charge, s Synopsis oi Foreigii Patent Laws, showing the cost and method of securing patents in all the principal countries of the world. American inventors ehonld bear in mind that, as a general rule, any invention that is valuable to the patentee, in this country is worth equally as much in England and some other foreign countries. Five patents-embracing Canadian, English, German, French, and Belgian-will secure to an inventor the exclusive monopoly to his discovery .among about onb HTODRED anp fifty MILLIONS of the most intelligent people in the world. The facUities of business and steam communication are such that patents can be obtained abroad by our citizens almost as easily .l at home. The expense to apply for an English patent is 75; German, 100; Freuch, 100; Belgian, 100; Can.. dian, 50. Copies of Pafent.-Persons desiring any patent issued from 1836 t.o November 20, 1866, can be supplied with official copies at reasonable cost, the price depending upon the extent of drawings and length o1 specifications. Any patent issued since November 20, 1866, at which time the Parent Office commenced printing the drawings and specifications, may be had by remitting to this office 1. A copy of the claims of any patent issued since 1836 will be furnished foi 1. When ordering copies, please to remit for the same as above. and state name of patentee, title of invention, and date of patent. A pamphlet. containing full directions for obtaining United States patents, sent free. A handsomely bound Reference Book, gilt edges, contains 140 pages and many engravings and tables important to every pat. entee and mechanic, and is a useful handbook of reference everybody. Price 25cents mailed free. Munn & Co., Publishers Scientific American 37, Park Row, New York. BRANCH OFFICE--Corner of F and 7th Street, Washington D.C.