would be accounted more easily, by supposing an implied licence. It has been said, in reference to sub-grants, that there can be no estates, no sub-infeudation of a patent (Sweet's Jarman's Conveyancing, vol. 7); but quære, as to the sense in which a patent is personalty. Real property, which was that common territory regulated by the State, has come to mean property subject to a particular kind of descent. In the latter sense, patents are without it, by the express terms of this grant. But they are analogous to it, as being a portion of the public domain of invention; of that which naturally is open to the world to discover, and the instrument itself was long employed for grants of land, or territorial privilege.

A patent is clearly an assignable thing; transferable voluntarily, or by act of law (Duveryier v. Fellow, 10 B. & C. 829; Hess v. Stevenson, 3 B. & P. 565; Bloxam v. Elsee, 6 B. & C. 169), and is disposed of by sale, for an annuity, or by mortgage. If it become the property of several persons, it is common to put it in trust, thus facilitating arrangements for sharing the profits, or exercising portions of the right, and without constituting a partnership. Primarily, each owner might use every part to an unlimited extent, both in person and by his licencees; but the patent may be severed in reference to use locally or for particular districts: the parties covenanting to keep within those limits, and to share in proceedings against infringers for disclaiming, obtaining confirmation, or extension, according to their respective interests; all such functions in the other case being exercised, and more commodiously, by the trustee. The mere joint enjoyment of the privilege would not amount to a partnership; and in a recent case the inventor managed the patent business, receiving a salary "equal to" a share of the profit, with a declaration of non-partnership: he was held not a partner.

The proviso against a transfer to more than twelve persons (arising out of the Bubble Act, and limited formerly to five persons) is evaded by a licence, however ample

F

(Protheroe v. May, 5 M. & W. 675), which retains a nominal right of revocation. Such a licence, however, (Jarman's Conveyancing, by Sweet, vol. 7) is suggested to be virtually a trust, which is expressly named and included in the proviso. A mortgage also escapes it (McAlpine v. Mangnall, 15 L. J. 298, C. P.), and an assignment for creditors (Bioxam v. Elsee, supra), who probably (like the executors mentioned in the proviso) only represent the patentee. When a company work a patent, they usually apply for an act of Parliament, which is seldom opposed. Any form effects a conveyance; as a declaration of transfer on a future event operated on its occurrence: (Cartwright v. Amatt, 2 B. & P. 43.) Personalty carries no warrant, which is seen in copyright: (Colburn v. — 1851), whence, and for estoppel, the recitals and covenants usually employed: (see Appendix.)

In a case of fraud in the sale of a patent, by exaggerating its value (Lovell v. Hicks, 2 Y. & Coll. 46, 472), the point arose how far the various owners participated in the effect not being parties to the deception.

A few remarks may be appended, on the mode of exercising the invention. Should this be much modified in practice, and parts are found unserviceable, these may be disclaimed; but if there be material addition or alteration, the expediency of patenting the improvement must be considered. Heath's patent (10 M. & W. 684) was for adding a compound substance to iron in a melted state; a beneficial effect resulted, but some practical inconvenience in the mode of working this plan, made it barely worth pursuing. Some years after, it was found that using the elements of the compound effected as good a result, without some of the demerits of the old plan, of which it was decidedly but a modification : there was strong evidence, in fact, that the elements did combine of themselves before they acted on the iron. But the patentee had not provided for such a variation, nor

could the public infer it as self-evident, à priori. The new plan was not patented, but left to the protection of the old patent, and lost; it is obvious that a new patent would have a longer term of enjoyment if the sub-invention were referred to; on the old plan, part of the fourteen years had run out. The case will be distinguished from improvements of detail, which more usually occur, keeping within the patent, and subject to it, whether themselves patented

or not.

A note-book of any scientific matters connected with the patent, including the history of the discovery, the opinion of contemporaries, &c., might be serviceable with a view to evidence for infringement or prolongation; and memorandums might be added of patents likely to prove hostile.

The inventor is more frequently neither wealthy nor a man of business, and wealth and enterprise are almost always needed, to such an extent sometimes as to amount to a risk better suited to a body of shareholders than an individual. This plan is somewhat hampered by the proviso previously alluded to, and an impression exists that a company is not so favourably dealt with by the Privy Council in extension cases as a single assignee.

Conflicts between patentees are often difficult and protracted; the result is thought to depend on the amount of legal ability pressed into the service, and the oyster simile has often been realised in such cases. The five or six pro

effected an amicable

peller patentees, after much litigation, coalescence, and avoided a similar fate. So, again, exorbitant royalties, or patent profits, would (if, indeed, they have any existence out of the brains of patent law opponents) be impolitic, not only in reducing sale, but in encouraging evasion and litigation, and rival expedients in invention. That fictitious inventions are patented to make a profit of litigation, or a black mail, by the threat of it (see Evid. Ho. of Com., of Mr. Ricardo, 1851), is not easy to believe. A patentee has no more facility for attacking a defective patent than any other member of the public; and as to

oppression of the trade generally, the patentee's game is an uphill one; he has to make and maintain a right, and, usually, against a superior force of capital.

The compulsory supply of the Government, on their terms, seems unfair; but only one case (Ex parte Pering, 4 A. & E. 949) has occurred under the proviso; which, it seems, does not apply to a use by the dockyards themselves; this would, therefore, be an infringement (Walker v. Congreve, Carpm. Rep. I. 356); but the Government in that case, or if a use by their own contractors were stopped, could resort to the proviso. Some conversation occurred in a Privy Council case as to screw propellers, but there a sum was paid to the inventor, which he allowed to be adequate.

Licenses.

This is an advantageous mode of remuneration to an inventor, who benefits in proportion to the development of the manufacture, without incurring the attendant risks. The term is usually co-extensive with the patent; a few days are sometimes reserved at the end, when it is apprehended that it may amount to an assignment. The application of the art to different purposes may be granted to different persons; but a more usual division is to licence (exclusively) for local districts. The distinction as to exclusiveness is material; without it, the licence only removes a prohibition; but with it confers a right. The latter may, in most cases, be properly made transferable, or have a power to sublicence to the extent of the district, &c. The consideration may be a definite sum or sums, subject to the success of the practice. A quarterly rent is common where the patent is for a process or machinery, or for certain parts of machinery, as for each loom or each spindle. When the product is the patent, it may be computed per set, or per pound, &c., or by a per centage on the gross proceeds, to exclude the creation of partnership. A minimum is often fixed, and, on the other hand, the payments reduced

as the amount produced increases. This is a more efficient mode of securing the cultivation of the patent than stipulation for diligent attention, or to embark a certain amount of capital, or employ so many hands, &c. As to all such points, however, and the provision (see Precedent) for mutual communication of improvements, and not taking up rival inventions, it must be recollected that the landlord and tenant are, to a great degree, in the same boat. The licencee cannot force the sale beyond a certain point; and to that point it is his interest to force it. Covenants are added for accounts of the above produce, and inspection of premises, and for marking all articles; this may be not only to check the sales, but sometimes to keep the patentee's name on the article. Title is not implied; if required, it must be provided for, as, where a premium is paid down, or a capital embarked; arrangements being made in such cases as to costs of prosecuting infringers. Covenants for payment are essential; and for annulling the licence on a certain extent of arrear; and as to covenants of assignees or sub-licencees, if such be contemplated.

On the other hand, the grantor should covenant not to use the invention himself, or grant licence to others, or only so far as may be stipulated; and it is usually arranged, that on the grant of any licence at lower terms, the rent of the one in question shall sink to the same level.

As arrangements are sometimes made while the success is evidently doubtful, the licence may be made voidable on the failure of a certain result, or it may take the shape of an agreement for a licence on the accomplishment of it ; and from similar motives, the royalty or rents are often remitted for the first twelve months, &c.

A licence, though usually, is not necessarily under seal, although inattention to what is said in the letters patent might be a contempt of the Great Seal (Chanter v. Dewhurst, 12 M. W. 823); and if sealed, is not necessarily a deed, or requires a stamp: (Chanter v. Johnson, 14 M. & W. 408.)