American and European of Munn & Co., No. 37 Park How, New York. For a period ol nearly twenty-five years Munn Co. have occupied the position of leading tolicitors of American and European Patents, and during this extended exp erience of nearly a quarter of a century, they have examined not less than fifty thousand alleged new inventions, and have prosecuted upwards of thirty thousand applications for patents, and, in addition to this, they have made at the Patent Office over twenty thousand Preliminary Examinations into the novelty of inventions,with a careful report on the same. This wide experience has not been confined to any single class of inventions but has embraced the whole range of classification, such as Steam and Air Engines, Sewing Machiues, Looms and Spinning Machinery, Textile, Manufactures, Agriculture and Agricultural Implements, Builders' Hardware, Calorifics, Carriages, Chemical Processes, Civil Engineering, Brick Making, Compositions, Felting and Hat Making, Fine Arts, Fire-arms, Glass Manufacture, Grinding Mills, Harvesters, Household Furniture, Hydraulics and Pneumatics, Illumination, Leather Manufactures, Mechanical Engineering, Metallurgy, Metal Working, Navigation, Paper Making, Philosophical Instruments, Presses, Printing and Stationery,Railroads and Cars, Sports, Games, and Toys, Stone Working, Surgical Apparatus, Wearing Apparel, Wood Working. Munn Co. deem it safe to say that nearly one-third of the whole number of applications made for patents during the past fifteen years has passed through the r Agency. CONSULTATIONS AND OPINIONS FREE. Those who have made inventions and desire to consult with us are cordially in vi. cd to do so. We shall be happy to see them in person, at our office, or to advise them by letter. In all cases they may expect from us an honest opinion. For such consultation, opinion, and advice, we make no charge. A pen-and-ink sketch and a description of the invention should be sent. Write plainly, do not use pencil or pale ink. If a SPECIAL SEARCH at the Patent Office is required, which embraces a personal examination of all patented inventions and a report in writing, a fee of $5 is charged. This examination is only advised in doubtful cases. To Apply for a Patent, a model must be furnished, not over a foot in any dimension. Send model to Munn Co., 37 Park Row, New York, by express, charges paid, also a description of the improvement, and remit $16 to cover first Government fee, revenue and postage stamps. The model should be neatly made of any suitable materials, strongly fastened, without glue, and neatly painted. The name of the inventor should be engraved or painted uponit. When the invention consists of an improvement upon some other machine, a full working model of the whole machine will not be necessary. But the model must be sufficiently perfect to show, with clearness, the nature and operation of the improvement. THE GREAT ADVANTAGES OF MUNN CO.'S AGENCY are that their practice has been ten-fold greater than any other Agency in existence, with the additional advantage of having the assistance of the best professional skill in very department, and a Branch Office at Washington, which watches and supervises all their cases as they pass through official examination. If a case is rejected for any cause, or objections made to a claim, the reasons are inquired into and communicated to the applicant, with sketches and explanations of the references; and should it appear that the reasons given are insufficient, the claims are prosecuted immediately and the rejection set as ide and usually WITHO UTEXTRA CHAR GE. Munn Co. are determined to place within the reach of those who confide to them their business the highest professional skill and experience. Caveats are desirable if an inventor is not fully prepared to apply for Patent. A Caveat affords protection for one year against the issue of a patent to another for the same invention. Caveat papers should be carefully prepared. Reissues. A patent, when discovered to be defective, may be reissued, by the surrender of the original patent and the filing of amended papers This proceeding should be taken with great care. Patents can be Extended. All patents issued prior to 1861, and now in force, may be extended for a period of seven years upon the presentation of proper testimony. The extended term of a patent is frequently of much greater value than the firstterm, but an application for an extension, to be successful, must be carefully prepared. Munn Co. have had a large experience in obtaining extensions, and are prepared to give reliable advice. Interferences between pending applications before the Commissioners are managed and testimony taken; also Assignments, Agreements and Licenses prepared. In fact there is no branch ofthePatentBusiness which Munn Co, are not fully prepared to undertake and manage with fidelity and dispatch Designs, Trade Marks, and Compositions can be patented for a term of years; also new medicines er medical compounds, and useful mixtures of all kinds. When the invention consists oi a medicine or compound, or a new article of manufacture, or a new composition, samples of the article must be fur-nished, neatly put up. Also, send us a full statement of the ingredients, proportions, mode of preparation, uses, and merits.