abroad have taken out patents in their own names, and the office freely grants such and so far their legality has not been questioned. For the above and for other reasons, however, it is safer and better for foreigners residing abroad to apply for patents through a resident in this country as communications. An exception to this is made expressly when the inventor is a citizen of or resident in one of the countries forming the Union for the Protection of Industrial Property (see page 29), and the patent is applied for within twelve months of the date of the earliest foreign patent and under the rules of the Convention. must then be taken out in the name of the foreign patentee.

It

Where, however, a patent has been applied for by a resident in this country as a communication from a foreigner resident abroad, and that patent is afterwards assigned to a foreigner, there is no doubt that the latter can legally hold such patent, and carry on actions for infringement thereof.

In case of a patent being lost or destroyed, a duplicate will be issued to the inventor or owner on his proving the facts of the case to the satisfaction of the Comptroller, and paying the prescribed fees.

JOINT INVENTION.

When an invention is the joint production of two minds, it should be patented in their joint names; for should it be proved that the patentee obtained from another individual a material part of the invention, the patent will be invalid.

Should, however, an inventor employ another individual to perform experiments with a view to making a specific discovery, the discovery so made is in the eye of the law made by the employer, and can be patented by him without using the name of the afore

said employé, the latter being looked upon as merely an instrument employed by the inventor.

An employer has no right or title to the inventions of his employés, except such as those mentioned in the previous paragraph, where the employé has been employed purposely to work out the details of a general idea unfolded to him by his employer. Even should there be a special agreement between master and servant, that all inventions of the latter made during the period of service shall become the property of the former, the patents securing said inventions must be applied for in the name of the employé, alone or conjointly with that of the employer, but can be afterwards assigned to the employer.

Two or more individuals obtaining a patent in their joint names, or joint owners in a patent without a special agreement, are not partners, but each has an equal and co-extensive right to work the patent to his own individual advantage, or to license others, or to sell his entire share but not a part thereof, and neither is responsible for the liabilities of the other, but all owners have a joint interest in all royalties received by any one of them. It is therefore very desirable in all cases of dual ownership, that there should be a definite written agreement between the parties.

A patent can be seized by a sheriff, and in case of bankruptcy of owner it forms part of the estate, and can be sold for the benefit of the creditors.

WHAT CAN BE PATENTED.

Any new art, manufacture, or composition of matter, new combination of two or more known things producing an advantageous result, or any new chemical or other process, or improvement on existing processes or manufactures, can be patented.

Two substantially distinct inventions cannot legally be combined in one patent, and if, in the opinion of the Comptroller of the Patent Office, an application cover more than one invention, the grant is refused, subject to an appeal to the Attorney or Solicitor-General; but the applicant has the option of a patent for one of the inventions set forth in his specification, and of making a fresh application or applications for the others. These, if he desire it, and if they be made within six months of the original application, are dated as of the day of the original application, or such later date as the Comptroller may direct.

From various decisions of the Law Officers, the unwritten rule adopted by the examiners appears to be as follows:-Any two or more distinct inventions, dependent for their successful operation upon each other, and tending together to produce one result, can be covered by one application; also two or more ways of accomplishing the same result, if they have apparently novel points in common, can be covered by one application. Practically, where two inventions are allowed in one provisional protection, they are not afterwards required to be divided, except at the request of the inventor.

A patent once granted cannot be objected to at law, on the ground of its covering more than one invention. A new application of a known thing can be patented, provided it be not analogous to any existing application thereof, or a similar material has not already been so applied. Thus, the new application of vulcanised india-rubber in place of iron in the tyres of traction engines was the subject of a valid patent, while the employment of vulcanised india-rubber, then a known substance, for a purpose to which nonvulcanised rubber had been already applied, was held to be no invention, and the patent for it invalid.

The new combination of two known means to effect an improved result can be patented. Thus, the hot blast and anthracite had both been used separately in the smelting of iron; yet a patent for using the hot blast in combination with anthracite was decided to be valid, the combination producing great commercial advantage.

A patent specification may refer to subject-matter of another prior unexpired patent, but the patentee cannot of course work the previous patent without a license from the owner thereof. This license, however, he can under some circumstances obtain from the patentee (or should the latter be unwilling to grant it otherwise), by petition to the Board of Trade and the Judicial Committee of the Privy Council, as hereafter explained, under the head Compulsory Licenses, page 28.

WHAT INVENTIONS ARE MOST
PROFITABLE.

Patents for improvements on small objects in common use, or in the manufacture thereof are usually much more profitable than those for steam-engines, blast furnaces, ships, or other large and costly structures. Bessemer, who made more than a million sterling out of his steel-making patents, is a comparatively rare exception to this rule. In an official report of a chief examiner of the United States Patent Office appears the following:-"A patent, if it is worth anything, when properly managed, is worth, and can easily be sold for, from ten to fifty thousand dollars. These remarks only apply to patents of minor or ordinary value. They do not include such as the telegraph, the planing machine, and the rubber patents, which were worth millions of dollars each.

A few cases of the first kind will better illustrate my meaning.

"A man obtained a patent for a slight improvement in straw-cutters, took a model of his invention through the Western States, and, after a tour of eight months, returned with forty thousand dollars (£8000) in cash, or its equivalent.

"Another inventor obtained extension of a patent for a machine to thrash and clean grain, and sold it in about fifteen months for sixty thousand dollars (£12,000). A third obtained a patent for printers' ink, and refused fifty thousand dollars (10,000), and finally sold it for about sixty thousand dollars (£12,000).

"These are ordinary cases of minor inventions, involving no very considerable inventive powers, and of which hundreds go out of the Patent Office every year. Experience shows that the most profitable patents are those which contain very little invention, and are, to a superficial observer, of little value."

Another species of patent, almost always highly profitable, is that of small improvements on existing processes in the arts. Almost all the principal manufacturing firms that have risen and become eminent during the last fifty years, date their prosperity from some occasion when, making an improvement upon the then existing methods of manufacture (frequently only in some insignificant detail), they obtained for a time almost a monopoly of the trade. Thus a firm in Birmingham are believed to have made more than a million sterling out of their patent for making screws pointed, so that they may enter the wood more easily.

A firm of London candle manufacturers took out a patent for making the lower ends of candles taper, instead of parallel, so as to more easily fit the sockets, and to this small improvement, "which any fool might have invented," but did not, a large part of their present enormous business is owing.