During the period of Fourteen Years which has elapsed since the business of procuring patents for inventors was commenced by MUNN & Co., in connection with the publication of this paper, the number of applications for patenta in this country and abroad has yearly increased until the number of patents issued at the United States Patent Office last year (1859) amounted to 4,538 ; while the number granted in the year 1845fourteen years ago numbered 502only about one-third as many as were granted to our own clients last year; there being patented, through the Scientific American Patent Agency, 1,440 during the year 185!). The increasing activity among Inventors has largely augmented the number of agencies for transacting such business. In this profession, tlie publisher of this paper have become identified with the universal brotherhood of Inventors and Patentees at home and abroad, at the North and the South; and with the increased activity of these men of genius we have kept apace up to i this time, when we find ourselves transacting a larger business in this profession than any other firm in the world. We may safely assert that no concern has the combined talent and facilities tlmt we possess for preparing carefully and correctly applications for patents, and attending to all business pertaining thereto. FREU EXAMINATION OF INVENTIONS. Persons having conceived an idea which they think may be patent-able are advised to make a sketch or model of their invention, and aubmii to us, with a full description, for advice. The points of novelty are carefully examined, and a reply written corresponding with the factsv free of charge. Address MUNN & CO., No. 37 Park-row, New York. PRELIMINARY EXAMINATIONS AT THE PATENT OFFICE. The advice we render gratuitously upon examining an invention does not extend toa search at the Patent Office, to see if alike invention has been presented there, but is an opinion baeed upon what knowledge we may acquire of a similar invention from our long experience, and the records in our Home Office. But for a fee of $5, accompanied with a model or drawing and description, we have a special search made at the United States Patent Office, and a report setting forth the prospects of obtaining a patent, fee, made up and mailed to the inventor, with a pamphlet, giving instructions for further proceedings. These preliminary examinations are made through our Brauch Office, corner of F and Seventh streets, "Washington, by experienced and competent persons. Over 1,500 of these examinations were made last year through this office, and as a measure of prudence and economy, wo usually advise inventors to have a preliminary examination made. Address MUNN fe CO., No. 37 Park-row, New York. CATEATS. Persons desiring to file a caveat can have the papers prepared on reasonable terms, by sending a sketch and description of the invention. The government fee for a caveat is $20. A pamphlet of advice regarding applications for patents and caveats furnished gratis on application by mail. Address MUNN & CO., No. 37 Park-row, New "York. HOW TO MAKE AN APPLICATION FOR A PATENT. Every applicant fora patent must furnish a model of his invention, if susceptible of one; or if tiie invention is a chemical production, he must furnish samples of the ingredients of which his composition is composed for the Patent Office. These should be securely packed, the inventor's name marked on them, and sent, with the government fee, by express. The express charges should be prepaid. Small models, from a distance, can often be sent cheaper by mail. The safest, way to remit money is by draft on New York, payable to Munn & Go. Persons who live in remote parts of the country can usually purchase drafts from their merchants on their New York correspondents ; but if not convenient to do so, there is tut little risk in sending bank bills b> mail, having the letter registered by the postmaster. Address MUNN & CO., No. 37 Park-row-Kew York. Circulars of information concerning the proper course to be pursued in obtaining patents in foreign countries through our Agency the requirements of the different Patent Offices, &c., may be had gratis upon application at our principal office, No. 37 Park-row, New York, or either of our branch offices. TESTIMONIALS. The annexed letters, from tlieast three Commissioners of Patenta, we commend to the perusal of all persons interested in obtaining Patents: Messrs. MNN*: CO.:I take pleasure in statin? that while I held the office of Commissioner of Patent?, MORE THAN ONE-FOURTH OF AIX THE BUSINESS OF TUB OFFICE CAME TIIROfTGII YOTJE HANDS. I have no doubt that the public confidence thus indicated has been fullv de-Hfvrved as I have always observed, in nil vour intercourse with the Office, a marked degree of promptness, skill and fidelity to the interests of your employers. Yours, very truly, ---- CHAS. MASON. Immediately after the appointment of Mr. Holt to the office of Postmaster-General of the United States, he addressed to us the Btih.fctined very gratifying testimonial: MPSSI'H. MDNN & Co.:Tt affords me much pleasure to bear testi-monv to the able and efficient manner in which von have discharged yrmr duties of Solicitors of Patents while I had the hnnor of holding the office of Commissioner. Your business was very large, and you sustained (and, T don ht, not, justly deserved) the reputation of en-ergv, imrkpd ahility and uncompromising fidelity in performing your yrofessional engagements. Very respectfully, Your obedient servant, J. HOLT. Mesar?. MUNN& Co.: Gentlemen : Tt give me much pleasure to snv tint, dnrinfr the time of mv holdine the office of Commissioner of Patent, a VPIT larpe proportion of the business of inventors before tlie Patent Office was transacted throuehyonr agency, and that I liave ever found ynn faithful and devoted to the interests of your clients, as welt as ^minentlv qualified to perform the duties of Patent Attorneys with skill and accuracy. Very respectfully, Your obedient servant, WM. D. BISHOP.