Practically the same dictum is stated by the Supreme Court in their analysis of R. S. 4886 in Chapman and Chapman v. Wintroath, 272 O. G. 913. This practice is followed even when the applicant can not make the exact claims of the patent, due to immaterial imitations therein which are not present in the disclosure of the application. Claims of the application which omit such unessential limitations are used for the issue of the interference. Parker v. Craft, 265 O. G. 305; Bonine v. Bliss, 265 O. G. 306. When one includes in his claims an element which is a substantial equivalent of an element present in the claim of the other, an interference will be declared upon an issue using a common term. Read v. Scott, 14 Gour. 2-4; Speer v. Morgan, 15 Gour. 52-7. If the patentee and applicant claim distinct species which are not separately patentable, the Office will suggest a generic claim to the applicant for the issue of an interference, even though there be no corresponding generic claim in the patent. Behan, 353 O. G. 8.

If the limitations in the patent claims are material, or if the application and patent stand in the relation of genus and species, respectively, based upon different species, the two are not claiming the same invention and there is no interference. Williams v. Perl, 87 O. G. 1607. If both the generic claim of one and the specific claim of the other are based upon the same species, a strict construction as called for by Williams v. Perl holds that there is no interference. When the generic claim is presented in the one earlier filed (whether patent or application) this construction would undoubtedly be adhered to; but if the generic claim were in the later one to be filed, the discretion vested in the Examiner by Hammond v. Hart, 83 0. G. 843 would undoubtedly be exercised by suggesting claims in such a way as to offer an opportunity for interference.

Where the application was filed before the patent, the mere fact that claims which will dominate the patent are asserted in the application in seasonable time after the patent has issued is not per se an indication of an inter

ference-in-fact, unless they are claiming the same invention. An applicant in such a case is within his rights in making such broad claims. Cloyes 328 O. G. 3.

Another practice authorized by Card and Card and extended in Weber and Woodford (cited) involves the speeding up of actions which might have a bearing on the validity of an interfering patent. Since the patent carries a prima facie validity which presumes that the patentee is the first inventor of the subject matter of all his claims, and the patent has a fixed term, it is public policy to require any one who challenges this presumption to act diligently. A time limit is therefore set by the Office (usually about 30 days) in which the applicant must make response to Office actions preparing for an interference, under Card and Card; and a similar time limit for response is imposed under Weber and Woodford upon an applicant who is making claims of a patent, but whose right to make them is questioned by an examining tribunal of the Office.

The practice followed in most of the examining divisions is not the simple rejection referred to, but utilizes the principles of Card and Card. Those claims which are copied from the patent are grouped, and if no affidavit under Rule 94 has been furnished, these claims are rejected upon the patent, and the applicant advised that such affidavit must be filed before an interference will be declared. It is thought that Weber and Woodford authorizes the setting of a time limit for the filing of such affidavit. If there are no claims copied from the patent but an interference exists, steps are taken to develop an issue for interference, taking the claims of the patent if possible, and suggesting them, under Card and Card, to the applicant, or in one of the other ways above mentioned, utilizing one of the claims of the application for the issue. In any action in the application a time limit is set for response. In declaring an interference the importance of indicating what claims are held "subject to the outcome of the interference" as unpatentable over the issue can not be overestimated.

An interference can not properly be instituted unless the issue would be rejectable on the patent in case the affidavit under Rule 94 were not furnished (Massicks v. Crooke, 38 O. G. 1439); and conversely, if the Office is willing to allow the claims of the application over the patent they are not claiming the same invention and no interference exists. Gibboney, 105 O. G. 976.

There have been efforts of late made by a few parties. to challenge the right of the Office to set a time limit for response, on the theory that R. S. 4894 gives a statutory right to a year for response to any Office action. They also point to the Chapman and Chapman decision holding that failure to copy a claim from a patent for purpose of interference does not result in estoppel until the delay has exceeded two years from the grant of the patent. Either of these rules, taken by itself, seems to support their contention, but the situations and reasons applying can be distinguished.

The right of the office to set a time limit when only two applications are involved, has never been successfully questioned. It is authorized by Rule 96 which has the force of law, so long as not inconsistent with statute. The penalty for failure to respond within the time limit or to furnish a good excuse for the delay, is not abandonment of the application, since that would be in violation of the statutory right conferred by R. S. 4894, but is that of implied disclaimer of the invention covered by the claim involved. See Hellmund, 141 O. G. 565; Ferris, 114 0. G. 541. This penalty is never harshly enforced and extensions of time for response are commonly granted upon a reasonable showing.

The reason behind this practice of requiring promptness when applications are involved applies all the more strongly when a patent is involved. It is desirable that any attacks on its validity be made promptly; and it is equally desirable that after the expiration of its monopoly another patent be not in force which will extend its monopoly on the same invention.

In the closing paragraphs of the Chapman and Chapman decision distinctions were made which apply equally well to the problem under discussion. There the distinction was made between the time (one year) allowed for response under R. S. 4894 to an actual notice given applicant of an action made on his case by the Patent Office, and the time to be allowed for taking action following the constructive notice he receives by the publication of a patent which claims an invention to which he may be able to lay claim. Of this latter constructive notice it was said to

"necessarily be precarious and indefinite to a degree to be justification for allowing the longer two year period to inventors, who must, at their peril derive from such notice their knowledge of any conflict with their applications."

The notice given an applicant when the possibility of an interference is discovered is definite and certain and actual. Logic and public policy require that it be acted upon within a reasonable time, since no time is fixed by statute. The letter sent an applicant preparing for interference is not a notice of an action which has been taken by the Office as is contemplated by R. S. 4894, but is a notice for him to take action, and at the same time a warning that an estoppel will be created if he neglects. or fails to take such action. A rejection on the ground of disclaimer of the invention, or estoppel is made only after the estoppel has arisen; and applicant is then entitled to the year period of R. S. 4894 for response. Until a contrary rule is enunciated by competent authority it must be assumed that the right to set a time limit under Rule 96 is also applicable by analogy when a patent is involved.

Closing the discussion with a hypothetical case, an earlier-filed application has claims to the same invention claimed by a later-filed patent. The Examiner suggests claims of the patent to the applicant, setting a time limit.

Applicant refuses to make the claims within that limit maintaining that he prefers to rely on those claims he has in his own wording. The Examiner then rejects his claims on the implied disclaimer, and the applicant replies that he has not disclaimed the invention since he has always had prior claims to that invention in his application; also that the patent, not being prior art offers no basis for rejection, and that therefore the Examiner has no valid basis of rejection on any ground. How would the appellate tribunals rule?

EXPERT WITNESSES AND LAWYERS.

(From Eng. News Rec., December 6, 1926.)

Expert witnesses do not have too good a standing in the common mind, mainly it would seem, because of the readiness with which opposing sides in a legal controversy can find experts to expound the opposing view. This particular basis of disregard is not so well founded as it might be, for in few things there is an incontrovertable truth. Engineers called to be experts before the court and jury, however, will do well to remember that they are facing hostile thoughts and that regardless of their professional standing they are suspected of bending their knowledge to meet a demand. Judge Hough, of the U. S. Circuit Court, in effect told the members of the American Institute of Consulting Engineers that at their meeting last month. The judge, from his long experience in patent causes, where the whole issue frequently rests on the expert's testimony, warned the prospective expert that the average jury is not so simple or so ignorant as it often appears, and that while anxious for enlightenment it distrusts too assertive instruction. Opinion, not advocacy, is what judge and jury want from the expert, but it is better advice to the lawyer who retains him. The honest expert assures himself of the righteousness of his cause before he associates himself