HANDBOOK OF PATENT LAW, ETC.

The granting of Letters Patent, or exclusive privileges, to an inventor for a limited period, is, in reality, a contract between the crown, on behalf of the nation at large, and the inventor. The latter gives to the public what it did not possess before-the full details of a new invention; the crown in return gives the inventor the exclusive right of working that invention for a limited period, at the end of which time the full benefit of the discovery reverts to the public.

BRITISH PATENTS.

There are two kinds of protection for an invention,— Letters Patent, and Registration.

If protection be not desired for a longer period than from three to five years, and if the practical benefits arising from the invention are due simply to some particular shape or configuration of a part or the whole of a machine or apparatus,--then the cheaper form of protection, "Registration," is all that is desirable. (This form of protection is more fully gone into on page 20.)

If, however, as is generally the case, one particular shape or configuration is not absolutely essential to the practical application of the invention,-if, in fact, the invention be susceptible of more than one modification, or it consists of a process of manufacture, or a composition of matter,-the only form of protection is by Letters Patent.

B

LETTERS PATENT.

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. The invention, in order to come under the term new, must be unknown to the public in the United Kingdom, but may have been publicly known and used in foreign countries, or the colonies, at the date of application. An invention patented abroad can be patented in England at any time during the continuance of the foreign patent, provided the same has not been published in this country. But the sale, or public exhibition of the article in any portion of the British Isles, or a complete and accurate description of the invention in a journal or book, printed or circulating in the kingdom, would invalidate a patent afterwards obtained. Copies of the specifications and drawings of American and of some continental patents are now forwarded to the British Patent Office Library, where they are open to free inspection. This constitutes a legal publication, though they may not have been examined by the public. however, the invention be not sufficiently described as to enable a man, skilled in the line of business to which it relates, to work it successfully without experiments or invention on his part, such a partial or defective publication would not invalidate a patent afterwards applied for.

If,

In order that a patent may be sustained, it is also essential that it should be useful; but this point, though usually all-important as regards its value to the inventor, is never investigated in practice by the officials, unless the patent be opposed.

Any person, native or foreigner, may obtain a patent. He must be the true and first inventor, the first