can publish his invention with greater safety. "Notice to proceed" having been given in due form, it is advertised in the Commissioners of Patents Journal, with a notification to any persons desirous of opposing the application to leave particulars in writing of their objections to same, at the office of the Commissioners, within twenty-one days of the date of the Journal containing said advertisement. If there be no opposition, the entire cost of this step (including £5 stamp) is usually £6 10s. ($324). Should, however, an opposition be entered (which does not take place in one case out of twenty), the additional expenses of the defence will be from nine guineas ($47) upwards, according to the nature of the case.

WARRANT AND SEAL.

Not later than twenty-one clear days before the expiration of the provisional protection, application for the law officers' warrant and the great seal must be made. A special extension of the time is sometimes granted by the Lord Chancellor, but only in exceptional

cases.

At this point again, an opposition can be entered against the granting of a patent, but except in those cases where it is an appeal from the decision of the law officer, in an opposition filed during the twenty-one days after the notice to proceed was advertised, or evidence not accessible on that occasion be brought forward, or the invention be proved to be identical with a patent already sealed, the Lord Chancellor almost invariably grants the application for a patent. The

* Patents can be opposed on the ground that the opposer believes the alleged invention to be not new, not useful, a mere colourable imitation or infringement of another patent already granted, or that the applicant is not the true and first inventor or importer, or that he obtained his knowledge of the invention by fraud. The case is heard before the Law Officer of the Crown, who has the power to refuse the patent, or allow it, and to grant costs to either party.

cost of this step, should no opposition occur-(and oppositions at this stage are extremely rare)-including £10 stamp duties, the letters patent, and a leather case to hold them, is usually £12 ($60).

FINAL SPECIFICATION.

Previous to the termination of the six months' protection (unless a complete specification was filed at first), a final specification must be entered. This document requires the greatest care to make it comply with the decisions of the courts. It must fully describe the invention that was set forth roughly in the provisional specification, and the manner of carrying it into effect, pointing out exactly what is claimed as new. If drawings are required, they must be made in duplicate, and so neatly and artistically drawn that they can be photolithographed direct, and present a creditable appearance in the printed copies. One set is attached to the specification and the other left at the office of the Commissioners. The specification must be signed and sealed by the inventor. Cost of drawing up, engrossing, and filing the final specification (including stamps, drawings, copy of specification for Queen's printer, &c.) varies from £12 to £20 ($60 to $100).

The patent is now secured for fourteen years from the date of application, subject, however, to a stamp, at the end of three years, of £50 ($250), and at the end of seven years of £100 ($500). These duties must be stamped on the letters patent themselves, before the expiration of the respective periods, otherwise the patent becomes null and void. There have been instances where inventors, having accidentally allowed the time to pass, have obtained private acts of Parliament, at the expense of several hundred pounds, to be allowed to pay the stamp duties and renew their patents. Agents' fees for stamping the patent with the above-mentioned stamps are usually from two to

three guineas ($12 to $18, including postage to America).

It may be well here to state that at any stage of the proceedings, if further cost be found undesirable, a patent can be allowed to lapse.

PROLONGATIONS.

All patents expire at the end of fourteen years, unless they be prolonged by a special fiat of the Judicial Committee of the Privy Council. A prolongation is granted occasionally in cases where patents of great utility have not sufficiently rewarded their inventors. A licence to use the original patent does not necessarily give the licensee a right to use the invention during the prolonged term. The prolongation cannot exceed another term of fourteen years, is rarely granted for more than seven, and cannot be again renewed.

CONFIRMATIONS.

Should a patentee discover that his patent is invalid because of some obscure publication or use of the invention within the realm prior to the date of his patent, and of which he had been ignorant at the date of his application, the Act of 1835 gives to the Judicial Committee of the Privy Council the right to ratify and validate his patent, notwithstanding such publication. This right has, however, unfortunately been rarely exercised, and not at all during the last twenty years, every application during that period having been refused.

LICENCES AND ASSIGNMENTS.

A patentee can assign his patent in whole or in part, not only as regards its duration, but its subject matter and its territorial limits. He can also grant licences to use it on royalty, either exclusive or concurrent, and over the whole or only some part of the United King

dom. All licences and assignments must be stamped, and must be registered in the Registry of Proprietors, in London, before they are valid against third parties.

Copies of this register are open to the public in London, Edinburgh, and Dublin, on payment of a small fee, but the want of an index to the Dublin copy renders it of little use. Copies of any particular entry can also always be obtained from the department at the cost of making them,

In licensing an invention to a manufacturer, the patentee should take care to guard himself on the following points:-1st. He should have quarterly statements of the number or quantity of the patented article manufactured, and of their destinations. 2nd. A right of inspection of the books and works of the licensee. 3rd. All machines manufactured under the patent should be numbered with consecutive numbers, and be stamped with the inventor's name and word "Patent (to unlawfully affix this subjects the offender to a fine of £50). 4th. The patentee should either have a part of the royalties in advance, or a guarantee of a certain minimum royalty each quarter, so as to make it to the interest of the licensee not to let the patent lie idle.

On the other hand, the licensee should have the following protective covenants in his licence:-1st. That all further improvements in the said invention made by the patentee, or his other licensees, shall be as free to him as the original inventor (he also should agree to reciprocate in this matter). 2nd. That all disputes on the meaning or intention of the licence hereafter shall be put to arbitration in the usual way, and the award of such arbitrators be made a rule of court by either party. 3rd. That the licensee shall be allowed to sue in the name of the patentee in cases of infringement (this is not so important since the new Adjudicature Act came into force). 4th. That the patentee shall maintain the patent by paying the stamp

duties as they become due. A licensee cannot successfully plead the invalidity of a patent as a ground for refusing to pay royalty, except in a case of scire facias.

If in a licence it be stated that unless a certain minimum royalty be paid yearly, the licence can be cancelled by the patentee, and if for one or more years the patentee accepts a less royalty, he cannot afterwards cancel the licence on the ground that the minimum royalty stipulated has not been paid, his having accepted the smaller royalty being held to be equivalent to cancelling this particular clause in the licence.

DISCLAIMERS.

It very frequently happens, when no search has been instituted before patenting, that something has been claimed in the specification that had been previously secured by another patentee, or which was in public use, or published in this country, before the date of application. Such a claim makes the whole patent null and void in law. When, therefore, a patentee finds such a flaw, he should immediately apply to the law officer for permission to enter a disclaimer discarding said claim. The disclaimer must in no case extend the scope of the invention, otherwise it would be null and void. The application being made, it must be duly advertised in such newspapers and periodicals as the law officer may select. For ten days after the publication of the advertisement in all these journals (and, indeed, afterwards until the actual fiat of the law officer has been given), anyone is at liberty to enter an opposition. Infringers opposing are frequently allowed by the court to continue to work the invention as one of the conditions of granting the disclaimer. Hence we see the great advantage of a thorough previous search, and the consequent preparation of accurate claims to start with, over the plan usually adopted, of blindly

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