profits were very considerably reduced. On these grounds he applied for a prolongation of the patent, and produced evidence to show the value and importance of the invention, the losses he had suffered from infringements, and the great reduction that would take place in the value of the premises and machinery (much of which was fitted only for the particular manufacture) if the patent were thrown open. He further showed that his life had been endangered by the anxiety of certain law proceedings. One witness stated that, if the manufacture were thrown open, it would hardly be worth following: the process was so beautifully simple, that it would almost be within the reach of any person of capital. The net profits amounted to about 13,000l.; but this was shown to be not much greater than the ordinary profits on stock without the protection of a patent. Taking all this into consideration, the Committee thought the patent ought to be extended for six years, the original patentee receiving 500l. a year out of the profits for that time (Whitehouse's l'atent, 1 W. P. C. 473).

A patent for forging and shaping small articles in metal was obtained by Mr. Ryder in 1841: when he applied for an extension, he pleaded that though the profits had been 7,000l., they had only been made during the last four years. This, however, was held to be no ground for the application in the face of the large sum realised, and the petition was dismissed (Ryder's Patent, Pract. Mech. Journ.' vol. vii. p. 238).

It will have been remarked that the maximum period of extension in these cases was seven years. To induce the Judicial Committee to recommend an extension for a longer time, a case of the strongest kind must be made out.

In Ruthven's Patent (Pract. Mech. Journ.' 2nd series, vol. viii. p. 159), which was a patent for improve

ments in the propulsion of vessels, the invention was proved to be of very great merit, and to have failed in being brought into general use through circumstances altogether independent of the will and without the fault. of the inventor, who had not merely derived no profit, but had suffered considerable loss from his patent. It was shown, moreover, that the Admiralty had then lately instituted experiments with a view to the adoption of the invention, and that several friends of the inventor were willing to provide large capital for working the invention, should a prolongation be obtained. Evidence was also given that from the nature of the invention it would necessarily be a long time before its merit could be properly brought before the public. Under these circumstances the Judicial Committee (stating that they considered the case exceptional) granted a prolongation for the unusual period of ten

years.

In the case of Sillar's Patent (Goodeve's Cases, p. 581) it appeared that the patent had been sold by the patentees to a Joint Stock Company, who had paid them a sum which seemed to be commensurate with the value of the invention. The Company had afterwards floated their shares in the market, and had thereby made considerable profit. They then applied for an extension of the patent, but it was refused, although they had been considerable losers by working the invention.

Major Childs obtained a patent in 1869 for improvements in the manufacture of bread and biscuits. By this invention a nutritious aërated bread could be made by machinery with regularity and certainty. Down to 1873 the inventor had failed in his endeavours to get the invention fairly worked, but in that year he became chairman of the Aerated Bread Company, and let them have the use of his patent. It was not until

1883 that a large central manufactory was started in London for the making of bread by his process. He received a salary of 600l. as chairman and managing director of the company, which was paying 8 per cent. on the shares, of which he held 12,000. The counsel appearing for the Crown estimated that the inventor had made a profit under the patent of between 20,000l. and 30,000l., including the rise in the value of the shares held by him. The Judicial Committee were satisfied that the invention possessed considerable merit, and although the inventor had made for the last five years a profit which was increasing, they came to the conclusion that he had not been sufficiently remunerated, and a prolongation for five years was granted. Childs' Patent. The Times,' Dec. 1883.

The recent case of Bailey's patent (1 R. P. C. 1), shows that the old views of the Judicial Committee as to manufacturers' profits, as distinguished from the profit which may be considered more directly to belong to the patent, will still be insisted upon. This case also shows that if the patentee wishes to claim an allowance for personal trouble it must appear in the

accounts.

Newton's patent (1 R. P. C. 177) shows that the practice of the Privy Council, as to the necessity for including profits derived from foreign patents in the accounts, has not been altered by the recent Act.

CHAPTER XII.

ASSIGNMENTS AND LICENCES.

POWER both to assign and to license is by implication given to the patentee by the patent. A patentee is empowered by the thirty-sixth section of the new Patent Act, 1883, to assign his patent for any place in or part of the United Kingdom or Isle of Man as effectually as if the patent were originally granted to extend to that place or part only.

Rules 65 to 69 prescribe a somewhat complicated system of registry for assignments and licences. In all cases there must be a request in writing to the Comptroller to register, and the original document to be registered, together with an examined copy, must be left with the Comptroller. The practice of registration under the Act of 1852 was quite as effective and much more simple.

To be a valid instrument, an assignment ought to be a deed under hand and seal. It is usual to introduce into assignments covenants on the part of the patentee that he is the true and first inventor, and that the patent is valid. And it may be well to insert a covenant binding the assignor not to seek leave to amend the specification or drawings without the written consent. of the assignee.

Under the twenty-fifth section of the Patent Act of 1852, a patent obtained in the United Kingdom for an invention previously patented in a foreign country, came

to an end at the expiration of the foreign patent. But as this provision has not been inserted in the Patent Act of 1883, it is not now of importance for an assignee to see that the foreign patent is kept on foot, although when the assignment deals with a British patent obtained under the Act of 1852 it is still incumbent upon him to see that the foreign patent had not expired prior to January 1, 1883.

It is no answer to an action to enforce a contract for the purchase of a patent for a stipulated sum (Hall v. Conder, 2 C. B. N. s. 22), to plead that the patent is wholly worthless and of no utility, and that the subjectmatter of the patent was not the novel invention of the plaintiff, there being no proof of fraud, and no express warranty. Such a contract was held merely to have the effect of placing the purchaser in the same situation as the seller was with reference to the patent, and the purchaser is bound to take it with all its faults. This being so, it is desirable to consider whether or not an express warranty of the patent should not be introduced. into contracts of this nature. See also Smith v. Neale (2 C. B. N. s. 67).

The purchaser, in addition, ought invariably to have a search made by a competent person at the Patent Office and elsewhere as to the novelty of the invention, prior to his entering into a contract for the purchase.

One of two joint patentees cannot assign more than his share of the patent (In Re Horsley and Knighton's Patent, L. R. 8 Eq. 475).

The assignee of part of a patent separate from other parts may bring his action for an infringement of such part without joining as plaintiffs those persons who have distinct interests in the other parts, but have no interest in the damages sought to be recovered (Dunnicliff v. Mallet, 7 C. B. N. s. 209). This decision was mentioned with approval by the Court when delivering

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