an ex parte affidavit under Rule 75. However, in analyzing the testimony adduced at the trial, the court found that the only credible evidence of work done prior to the date of the Kratz lecture, the substance of which was communicated to the patentee on the next day, was that of two inconclusive tests which were not sufficient to carry the date of invention back to overcome the effect of the Kratz disclosure. The other ground of invalidity of the patent was predicated upon the work Kratz did prior to the presentation of his paper. The evidence showed that several years before the reading of the paper, Kratz prepared some diphenylguanidine and established its efficacy as an accelerator in the manufacture of 300 tires. The plaintiff urged that this was merely an abandoned experiment since the discovery was not used after that. However, the reason for non-use was merely that at the time of reduction to practice diphenylguanidine was too expensive. It was only after Weiss discovered a method of making this substance cheaply that its use as an accelerator was feasible. However, this invention of process of making the substance economically for which Weiss received a patent did not give him the right to the monopoly for its use as an accelerator when such use was known before. C. W. L., WEISER ET AL v. PORTABLE ELEVATOR MFG. CO. C. C. A. 7th Circuit 11 F (2d) 918. This involved an appeal from a decision holding both the Caldwell reissue patent 15217 covering a ventilated grain crib stave and the Caldwell patent 1,421,763 to a grain crib including as an element the stave defined in patent 15217, valid and infringed. The lower court was reversed it being held that the reissue patent was not infringed, and that patent 1,421,763 was invalid for want of patentable novelty. It is of interest to note that in considering the broadest claim (claim 7) of the reissue patent the court directed attention to the fact that this claim was presented under the provisions of rule 78 and "upon the representation by applicant's solicitor that the proposed correction was merely formal, it was ordered that the amendment (the addition of claim 7) be allowed under rule 78". The court held that the representations made as well as the recital of the examiner precluded any broad construction of claim 7 without which there was no infringement. DE FOREST RADIO TELEPHONE & TELEGRAPH CO. v. WESTINGHOUSE ELECTRIC & MFG. CO. U. S. District Court for Eastern District of Penn This is a suit in equity under section 4918 R. S. brought by the De Forest Co. against the Westinghouse Co. in which it was alleged that the much litigated and valuable Armstrong patent 1,113,149 interfered with two De Forest patents 1,507,016 and 017. The bill prayed that an interference be declared between certain claims of Armstrong and of De Forest and called for the usual prayer of declaring the interfering claims of Armstrong void. The subject of the patents is the well known regenerative feed back using an audion. As is well known to most radio enthusiasts a three element vacuum tube having its grid plate circuits independent outside of the tube, no attempt being made to transfer any energy from the plate circuit to the grid circuit, acts as a pure amplifier. But if the electrical constants of the plate circuit and grid circuits are adjusted and if some energy from the plate circuit be transfered to the grid circuit by any well known way, as inductive or capacitative coupling between the two circuits, this energy transferred to the grid acts to control the plate current with the final result that the original weak grid signals coming from an antenna, for example, are greatly reinforced by currents from the plate circuit, the successive and cumulative reinforcements becoming very powerful currents compared to the original currents. This action can be so controlled that a continuous train of oscillatory currents are generated, the frequency of which can be varied from one cycle every few seconds to millions per second. The question of priority of this invention as between De Forest and Armstrong has been considered in the District Court (Southern) of N. Y. in Armstrong v. De Forest Radio Telephone & Telegraph Co. (279 Fed. 445) affirmed on appeal in 280 Fed. 584. The New York decision gave Armstrong priority. In an interference between De Forest, Armstrong, Meissner and Langmuir, the Court of Appeals of D. C. awarded priority to De Forest. In the decision by the District Judge in the case at hand, the above interference is described as involving the "applications for the Armstrong patent and for De Forest patent No. 1,507,016" with others. This appears to be an error since "the Armstrong patent" presumably 1,113,149 was not involved. What was probably meant was that the same invention in an Armstrong application was involved and supported by the same evidence as "The Armstrong patent." The defendant Westinghouse Co. cited the N. Y. decisions in its favor and contended the question was now res adjudicata. Practically, the question was res adjudicata but as a matter of law it was not, since a final decree had not been entered in the N. Y. case, there remaining the purely commercial but very important accounting between the parties to be made. Since the N. Y. decisions were not res adjudicata, the court considered the decision of the D. C. Court of Appeals in the interference as controlling and did not think that the evidence was convincing enough to go contrary to the D. C. Court of Appeals decision. Priority of invention was therefore given to De Forest and most of Armstrong's claims were held invalid. To really understand this decision, the N. Y. decisions must be considered as a background. The whole ground of contention is whether De Forest's original circuit sketches disclose the invention. If they do and the D. C. Court of Appeals as well as the Pennsylvania District Court believed they did-then De Forest is truly the first inventor. De Forest was working for a telephone repeater, a pure amplifier. Since messages must go in both directions, "singing" is unavoidably obtained. This is merely the tube acting as an oscillator due to the unavoidable concateriation of the grid and plate circuits, since it must be remembered that amplification in both directions is required. The N. Y. decisions regard De Forest as having accidentally discovered the tubes as an oscillator at audio frequencies but that he neither understood nor appreciated what was happening and in fact did not want it in a repeater. Armstrong had been deliberately working on the problem, and when he made his invention realized what an important role the circuit constants play and realized the regenerative feed back operation as applied to receiving and detecting the radio frequency waves in wireless telegraphy and telephony. The N. Y. court considered the early tubes with their relatively high gas content possibly as the cause of the oscillations at audio frequency in the straight audion hook up sketched. Since the invention involved is used in many of the best receiving circuits, the final disposition of this contest between Armstrong and De Forest is of interest to the trade and to the radio public. If De Forest is finally adjudged the first inventor of the regenerative feed back as applied to radio then the monopoly on this invention will run till Sept, 2, 1941 instead of Oct. 6, 1931. Truly it is an ill wind that blows no one some good. KAHN, DIV. 16 ELECTRIC-BLEACHING GAS CO. v. PARADON ENGINEERING CO. A. Ct. of Appeals 2nd Ct. May 17, 1926, 12 Fed (2nd) 511. Appeal from a holding by the lower court that the defendant in manufacturing an apparatus for chlorinating water was a contributory infringer of Pat. 1,142,361 for a process of sterlizing water with chlorine. The decision and opinion are given in 8 Fed. (2nd) 890 and is reviewed in 8 J. P. O. S. 502-503 by the present writer. Defendant in the lower court contended that a process claim should be limited to the specific means disclosed for carrying out the process and that since the defendant had substituted an injector for the scrubbing and absorbing tower of the patent, the defendant had avoided contributory infringement. The defendant now argues that in rejecting this contention, the lower court had gone beyond any formula hitherto applied to one called a contributory infringer and that under this precedent the owner of a process patent can enjoy a monopoly of all and every device for the utilization of the patented process. The upper court refused to put such a broad interpretation upon the lower court's decision and held as did the lower court, that the inventor of a substantial improvement in an art is entitled to a commensurate range of equivalents, and that since the injector is a mechanical equivalent of the tower described by the patentee, the defendant was infringing upon the rights of the plaintiff. CHARLES W. RIVISE, UNIVERSAL OIL PRODUCTS CO. v. SKELLY OIL CO. D. C. D. Delaware Morris Dis. J. 12 F. (2nd) 271. Bill of Particulars. The plaintiff filed his bill of complaint citing five patents and alleging that the defendant "did unlawfully and wrongfully practice the inventions of said letters patent and each of them described and claimed in the claims thereof." The defendant, after making an offer to allow plaintiff to make a complete examination of defendant's plant, moved for an order requiring the plaintiff to set out in a bill of particulars (a) the particular steps charged to embody the steps of the process claims relied on, and (b) the particular elements charged to embody the elements of a particular claim of one of the patents sued on. The question at issue was to what degree of definiteness and certainty may a plaintiff be required to plead infringement of a patent. Rule 25 of the Court stated that the equity bill should contain "a short and simple statement of the ultimate facts upon which the plaintiff asks |