Information about Caveats, Extensions, Interferences, Designs, Trade Marks; also, Foreign Patents. FOR a period of nearly twenty-five years, MUNN & CO. have occupied the position of leading Solicitors of American and European Patents, and duringthis extended experience of nearly a quarter of a century,they have examined not less than fifty thousand alleged new inventions, and have prosecuted upward of thirty thousand applieations 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 careful report on the same. The Important advantages of MUNN & CO.'S Agency are,that their practice has been ten-fold greater than that of any other Agency in existence, with the additional advantage of having the assistance of the best professional skill in every department, and a Branch Office at Washington, which watches and supervises, when necessary, cases as they pass through official examination. CONSULTATIONS AND OPINIONS FREE. Those who have made Inventions and desire a consultation are cordially Invited to advise with MUNN & CO.who will be happy to see them in person at the Office, or to advise them by letter. In all cases, they may expect an HONEST OPINION. For such consultations, opinion, and advice, NO CHARGE S made. A pen-and-ink sketch and a description of the invention should be sent. TO APPLY FOR A PATENT, A model must be furnished, not over a foot in any dimension. Send model to MUNN & CO., S7 Park Row. New York, by express, charges paid, also, a description of the improvement, and remit $16 to cover first Government fee, and revenue and postage stamps. The model should be neatly made, of any suitable materials, strongly'fas-tened, without glue, and neatly painted. The name of the inventor should be engraved or painted upon it. When the invention consists of an improve ment 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. PRELIMINARY EXAMINATION Is made into the patentability of anlnvention by personal search at the Patent Office, amoHg the models of the patents pertaining to the claes to which the improvement relates. For this special search, and a report in writing, a fee of $5 is charged. This search is made by a corps of examiners of long experience. Inventors who employ us are not required to incur the cost of a preliminary examination. But it is advised in doubtful cases. COST OF APPLICATIONS. When the model is received, and first Government fee paid, the drawings and specification are carefully prepared and forwarded to the applicant tor his signature and oath, at which time the agency fee is called for. This fee is generally not over $25. The cases are exceptionally complex ifa higher fee than $25 is called for,and,upon the return of the papers, they are filed at the Patent Office to await Official examination. If the case should 1!e rejected for any cause,or objections made to aeifti!p,tJle iieasons are inquired into and communicated to the applicant, with 8IptOes and ekplanations of the references ; and should it appear that the reasons given ar,insufflcient,the claims are prosecuted immediately, and the rejection set aside, and usually Without Extra Charge to the Applicant. MUNN & CO. are determined to place within the reach of those who confide to them their business, the best facmties and the highest professional skill and experience. The only cases ot this charaeter,in which MUNN & CO. expect an extra fee, are those wherein appeals are taken from the decision of the Examiner after a second rejection ; and MUNN & CO.wish to state very distinctly,that they have but few cases which can not be settled without the necessity of an appeal ; and before an appeal is taken, in any case, the applicant is fully advised of all facts and charges, and no proceedings are had without his sanction ; so that all inventors who employ MUNN & CO. know in advance what their applications and patents are to cost. MUNN & CO. make no charge for prosecuting the rejected claims oftheir own clients before the Examiners and when their patents are granted, the invention is noticed editorially in the SCIENTIFIC AMERICAN. REJECTED CASES. MUNN & CO. give very special attention to the examination and prosecution ofrejected cases filed by inventors and other attorneys. In such cases a fee of $5 is required for special examination and report, and in case ofprobable success by further prosecution, and the papers are found tolerably well prepared, MUNN & Co. will take np the case and endeavor to get t throngh for a reasonable fee,to be agreed upon inadvance ofprosecution. CAVEATS Are desirable ifan inventor is not fully prepared to applyfor a Patent. A Caveat affordsprotection, for one year, against the issue of a patent to another for the same invention. Caveat papers should be carefully prepared. The Government fee on filing a Caveat is $10, and MUNN & Co.'s charges for preparing the necessary papers are usually from $10 to $12. REISSlJES. 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 sho-ild he taken with great care. DESIGNS, TRADE MARKS, AND COMPOSITIONS Can be patented for a term of years, also,'new medicines or medical compounds, and usefulmixtures of all kinds. When the invention consists ofa medicine or compound, or a new article of manufacture, or a new compo-sltion, samples of the article must be furnished, neatly put up. Also, send a full statement of the ingredients, proportions, mode of preparation. Uses, and merits. PATENTS (JAN BE EXTENDED. All patents issued prior to 1861, and now in force, may be extended for a eriod of seven years upon the presentation of proper testimony. The extended term ofa patent is frequently of much greater valne than the first term; but an application for an extension, to be successful, must be care-lUlly prepared. MUNN & Co. have had a large experience in obtaining extensions, and are prepared to give reUable advice. INTERFERENCES etween pending applications before the Commissioners are managed and 'testimony taken; also, Assignments, Agreements, and Licenses prepared. In fact, there is no branch of the Patent Business which MUNN & Co. are not fully prepared to undertake and manage with fidelity and dispatch. FOREIGN PATENTS. American inventors should bear in mind that five Patents—Ameri-cau, English, French, Belgian, and Prnssian—will secure an inventor exclusive monopoly to his discovery among ONE HUNDRED AND THIRTY MILLIONS of he most intelligent people In the world. The facilities of business and steam communication are such, that patents can be obtained abroad by our citizens almost as easily as at home. MUNN & Co. have prepared and taken a larger number of European Patents than any other American Agency. They have Agents of great experience in London, Paris, Berlin, and other "Capitals. A Pamphlet, containing a synopsis of the Foreign Patent Laws, sent free. Address MUNN & CO., 87 Park Row. New York.