During the period of Fourteen Years which has elapsed since the business of procuring patents for inventors waa commenced by Munn & Co., in connection with the publication of this paper, the number of applications for patents in thiscountry 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, throughthe Scientific American Patent Agency, 1,440 during the rear 1859. The increasing activity among Inventors has largely augmented the numb er of agencies for transacting such business. In tliis profession, the publishers 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 i this profession than any other firm in the world. We may safely assert that no concern has the combined talent' and facilities that we possess for preparing carefully and correctly ' applications for patents, and attending to all business pertaining thereto. FREE EXAMINATION OF INVENTIONS. Persons having conceived an idea which they think may be patentable are advised te make a sketch or model of their invention, and submit to H9, with a full description,for advice. The points of novelty are carefully examined, and a reply written coiresponding I with the facta, free of charge. Address MUNN & CO., No. 37 Park-row, New York. PRELIMINARY EXAMINATIONS AT THE PATENT OFFICE. The ad vice we render gratuitously upon examining an invention does not extend to a search at the Patent Office, to see if a like invention has been presented there, but is an opinion based 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 I report setting forth the prospects of obtaining a patent, &c., made np and mailed to the inventor, with a pamphlet, giving instructions for further proceedings. These preliminary examinations are made through our Branch Office, corner of F and Seventh streets, Washington, by experienced and competent persons. Over 1,500 of these eliminations were made last year through this office, and as a mea- I sure of prudence and economy, we usually advise inventors to have a preliminary examination made. Address MUNN 4t CO-,No. 37 Park-roiv, New York. CAVEATS. 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 fora caveat is $20. Apamphletof" advice regarding applications for patents and caveats furnished gratis on application by mail. Address MUNN &, CO.jNo. 37 Park-row, New York. HOW TO MAKE AN APPLICATION FOR A PATENT. Every applicant for a patent must furnish a model of his invention, if susceptible of one; or if the invention is a chemical production, he must furnish samples of the ingredients of which his composition ia 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 seat cheaper by mail. The safest way to remit money is by draft on New York, payable to Munn & Co. 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 but little risk in sending bank bill3 by mailt having the letter registered by the postmaster. Address MUNN & CO., No, 37 Park-row-New 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, may be had gratis upon application at our principal office, No. 37 Park-row, New York, or either of our branch offices. TESTIMONIALS. i^The annexed letters, from tne last three Commissioners of.Patent*, we commend to the perusal of all persons interested in obtaining Patents : Messrs. Munn A Co.:I take pleasure in stating that while I held the office of Commissioner of Patent*, more than one-foubth of all THE BUSINESS OF THE OFFTPE CAME THROUGH TOT7B HANDS. I ll BVe no doubt that the public confidence thus indicated has been fully deserved as I have always observed, in all your intercourse with the Office, a marked degree of promptness, skill and fidelity to the inter. ests of your employers. Yours, very truly, ----- CHA.8. MASON. Immediately after the appointment of Mr. Holt to the office of Postmaster-General of the United States, he addressed to us the i subined very pratifyine testimonial: Mpssra. MonnA; Co.: Tt affords me much pleasure to bear testi-monv to the able and efficient manner in which von have discharged your duties of Solicitors of Patents while I had the honor of holding the fticft of Commissioner. Your business was very large, and you sustained (and, T doubt not, justly depervpd) the reputation of energy, marked ability and unenmpromisinsfidelityin performing your professional engagements. Very respectfully, Your obedient servant, J. HOLT. Messrs. Mnn Co.:Gentlemen : Tt eivea me much pleasure to aavthat,durinKth time of mvholdinsr the office of Commissioner of Patents, a verrl'arpe proportion of the business of inventors before the P:\tont Office was transacted through your agency, and that I have ever found you faithful and devoted to the interests of your clients, as well as eminently quaJdfiedto perform thr duties of Patent Attorns with