and must, on the request of either of the parties to the proceeding, call in the aid of an assessor specially qualified, and try and hear the case wholly or partially with his assistance; the action is tried without a jury unless the court otherwise direct.

The Court of Appeal or the Judicial Committee of the Privy Council may, if they see fit, in any proceeding before them respectively, call in the aid of a specially qualified assessor.

The remuneration, if any, paid to the assessor, is determined by the court or the Court of Appeal or Judicial Committee, as the case may be, and is paid by Government, and forms no part of the costs of the action.

In an action for infringement of a patent the plaintiff (the owner of the patent) must deliver with his statement of claim, or, by order of the court or the judge, at any subsequent time, particulars of the infringements complained of.

The defendant (the person accused of infringing) must deliver with his statement of defence, or, by order of the court or a judge, at any subsequent time, particulars of any objections on which he relies in support of his case.

If the defendant disputes the validity of the patent, the particulars delivered by him must state on what grounds he disputes it, and if one of the grounds be want of novelty, must state the time and place

of the previous publication or "user" alleged

by him.

At the hearing no evidence can, except by leave of the court or a judge, be admitted in proof of any alleged infringement or objection of which particulars were not so delivered.

Particulars delivered may be from time to time amended, by leave of the court or a judge, but in such case the payment of costs of the opposite party

up to that date is frequently a condition of leave to amend.

In an action for infringement of a patent, the court or a judge may certify that the validity of the patent came in question; and if the court or a judge so certifies, then, in any subsequent action for infringement, the plaintiff in that action, on obtaining a final order or judgment in his favour, shall have his full costs, charges, and expenses 66 as between solicitor and client," unless the court or judge trying the action certifies that he ought not to have the same.

On taxation of costs, regard will be had to the particulars delivered by the plaintiff and by the defendant; and they respectively cannot be allowed any costs in respect of any particular delivered by them, unless the same be certified by the court or a judge to have been proven, or to have been reasonable and proper, without regard to the general costs of the case.

LICENSES AND ASSIGNMENTS.

A patentee can assign his patent in whole or in part, not only as regards its duration, but also its subject-matter and its territorial limits. But a patentee assigning any (say one-hundredth) part of a patent, unless there be a special agreement in writing, is giving the assignee in every respect an equal share with himself in the invention and patent, as they are simply co-owners of the patent. A patentee can grant licenses to use this patent on royalty, either exclusive or concurrent, and over the whole or only some part of the United Kingdom.

All licenses and assignments must be stamped, and must be registered in the Register of Patents in London; and copies of entries in this register, duly certified by the officials, are primâ facie evidence in

court of the facts therein set forth, only controvertible by direct proof of their incorrectness.

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, and should have the right of requiring the licensee to certify to the correctness of his returns under oath by statutory declaration. (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 or trade-mark, and the word "Patent." To unlawfully affix these, subjects the offender to a fine of £5 for each offence. (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 license :-(1st) That all further improvements in the said invention made by the patentee, or his other licensees, shall be considered as included in his license (he also should agree to reciprocate in this matter). (2nd) That all disputes hereafter on the meaning or intention of the license shall be put to arbitration in a given way, and the award of the arbitrator 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 present Judicature Act came into force). (4th) That the patentce shall maintain the patent by paying the stamp duties as they become due.

A person while a licensee of a patent cannot successfully plead the invalidity of that patent as a ground for refusing to pay royalty, except in a case of an action for revocation.

If in a license it be stated that, unless a certain minimum royalty be paid yearly, the license can be cancelled by the patentee, and if for one or more years the patentee accepts a less royalty, he cannot afterwards cancel the license 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 license.

HOW TO SELL A PATENT.

Brokers of stocks and shares, houses and land, cotton, sugar, etc., abound, yet there is hardly a single firm in the world who are really brokers of patents. The inventor who has not sufficient leisure or capital to work his own invention, has therefore usually to do his patent brokering himself. How should he go about it?

(1) Go to the greatest centre of the particular industry where that business is carried on with which the invention is most nearly connected. (2) If the invention be for a small object, get some specimens made and finished in the most pleasing style. .(3) Issue a neatly printed prospectus. Many inventors start on their travels with a coarse, broken-down model, showing defects rather than virtues, or a dirty, ill-got-up drawing, whose very appearance is enough

to set the capitalist at first sight against it; whereas a pretty working model, showing the actual performance, and a nicely printed explanation, are prepossessing, and tend to carry conviction with them. It is often very desirable to have the invention well illustrated in the technical journals before offering it for sale, but great care should be taken to secure its appearance in journals of high standing and large circulation, as these will not usually insert it after it has appeared in the smaller fry. (4) If, as is usually the wisest plan, the inventor wishes to still retain an interest in and assist in introducing his invention, a limited company, with the patentee as managing director, is frequently his best resource. It is far easier to sell a thousand shares in a patent at 10 each, than the whole for £10,000. The main business is to get a few good names as directors, and the rest is comparatively easy if the invention has already come into successful use. Until this latter is made evident, it is utterly useless to attempt to float a company to purchase a patent. A small syndicate can frequently be formed to prove an invention first.

CAUTION TO INVESTORS IN PATENTS.

The ease, however, with which limited companies can be raised to purchase and work patents, has given a handle to sundry unscrupulous adventurers to palm off on the public numerous patents, good, bad, and indifferent, at prices enormously exceeding their real value.

Nothing is easier than to get glowing testimonials for the most worthless invention, and capitalists, before investing in any patent, would do well to refer to a responsible Patent Agent, to discover by an examination and search whether it be really valid.