The attorney or solicitor general then summons the applicants to appear sepa rately before him ; and if he should be of opinion that the two patents will inter fere with each other, or are virtually the same, the usual course is not to grant any patent except to the two claimants con jointly, though if priori:: of invention can be proved by either, he who is prior is entitled to the patent.
If the invention is of such a nature that it can at once be produced or put into operation, no caveat is needed; and indeed a caveat may be the means of ex citing the very attention and opposition which it is intended to prevent. Where some experiments or operations which require assistance must be performed be fore a definite title can be given to the invention, as must be done in the de claration and petition, it is much better to avoid the caveat ; and by getting the different parts of the machinery or ope rations performed by difiereut persons, if possible, keep the invention a secret until thepatent is secured.
The next step is to draw up a petition to the crown, before doing which how ever the title of the patent must be settled. To those who have not considered the subject this may not seem a very difficult matter, but in fact it requires the greatest care ; for the least discrepancy between the title and the description contained in the specification will endanger the patent. (See the evidence of Mr. Farey and others before a committee of the House of Com mons upon this subject, 1829.) The title should set forth the subject of the patent in such terms that any one may see if a patent has been taken out or applied for in the case of any similar in vention.
The titles of patents collectively should form an index of the inventions thus pro.
tected. It is a common practice however to make the title as obscure as it can be made without endangering the patent, in order that the real object of it may be kept secret. But this is a matter of great difficulty, and has often justly vitiated a patent. The law requires all patented inventions to be open to public inspection, and the enterer of a caveat may be cheated by a title, for although the sub jects may be the same, a title may ex press the invention so faintly, or indeed so falsely, that the similarity of two in ventions may escape the notice of the attorney-general, and injustice may be done by granting a patent to one party while priority of invention belongs to another. By the 5 & 6 Wm. IV. c. 83, a
patentee is allowed to enter a disclaimer of any part of the title or specification, with the consent of the attorney-general or solicitor-general, who may order such disclaimant to publish his disclaimer. This act supplies a remedy for unin tentional errors, but is ineffectual where the title is purposely made obscure. Be sides this, the disclaimer does not operate retrospectively, so that if an action be commenced before the entry of the dis claimer, the title and specification must be adduced on the trial as they originally stood. A caveat may be entered against the granting of such disclaimer.
The following cases contain instances of patents being lost through defective titles :—King v. Metcalfe (2 Starkie, N. P. C., 249); Cochrane v. Smethurst (K. B., 1 Starkie, 205). In the case of Bloxam v. Elsee (6 Barn. and Cress., 169 and 178), the title of a patent which came in question was "A Machine for making Paper in Single Sheets, without seam or joining, from 1 to 12 feet and upwards in width, and from 1 to 45 feet and up wards in length." The specification however described a machine only capa ble of producing paper of one width or to a certain width. Now if an inventor who thought of taking a patent for a machine to make paper of a greater width than 12 feet had looked at the title only of this patent, he would have sup posed that such a patent already existed ; but if he had inspected the specification, he would have found that it did not bear out the title, as the machine therein de scribed was not capable of making paper of a width greater than 12 feet. The patent then was invalid, as tha title com prised more than the specification. This is the most common error that patentees fall into. Jessop's case, cited during the trial of Boulton and Watt against Bull, in 1795, by Mr. Justice Buller, is another instance. A patent was taken out for a " New Watch,' whereas the specification only described a particular movement in a watch, which was the real invention, and the patent was therefore void.