delivered the opinion of the Court:
This appeal is from the decision of the Commissioner of Patents denying appellant, Frederick R. Yreeland, cei-tain claims in an application for a patent relating to a method of receiving wireless signals.
The rejected claims in issue are as follows:
“44. The method of detecting sustained alternating signal impulses, which consists in combining in a common element of a circuit the signal impulses and sustained oscillations from a local source of slightly different frequency and detecting tho beats thus produced, substantially as set forth.
“45. The method of detecting sustained high frequency signal impulses, which consists in breaking up the continuous signal impulses into an intermittent or pulsating one by combining it in a common element of a circuit with a locally generated sustained oscillation of slightly different frequency and detecting the beats thus produced, substantially as set forth.”
“49. The method of detecting signal impulses, which consists in setting up in a closed tuned oscillating circuit oscillations separate from the signal impulses, superimposing thereon the impulses to be detected and detecting the variations in these oscillations caused by the signal impulses, substantially as set forth.”
The issue relates to an improvement in receiving signals, as practised in the extremely complicated art of radio telegraphy. It consists in reducing the frequency of electrical oscillation^ within the, range of human audibility. This is accomplished by establishing a local circuit at the receiving station which produces electrical oscillations at a different frequency from that *453produced at the signaling station. For example, let it be assumed that the signal oscillations have a frequency of 100,000 per second, and the local oscillations have a frequency of 99,500 per second. A combination of these two oscillations will produce beats. These pulsations or beats always occur at a rate equal to the difference between the two frequencies. In other words, in the example stated, the frequency of the heats would he at the rate of 500 per second.
Counsel for appellant in his brief describes appellant’s invention as “combining in a local circuit, or at least in a part or common element of a local circuit, of the two continuous ox undamped oscillations of slightly different frequencies, one from the distant source and the other from the local source, whereby electric beats or surges or variations in amplitude will be set up, corresponding in frequency to the difference between the frequencies of the two oscillations, and in utilizing in connection with the local circuit suitable detecting means by which these electric beats or surges can be detected. The key to appellant’s invention is the local circuit in wbich the two oscillations aro combined, because by combining the two oscillations in the local circuit it becomes possible to utilize highly efficient devices for amplifying and detecting the heats.”
The tribunals of the Patent Office justify their rejection of the claims by reference to a patent to one Fessenden. Fessenden, in his specification, after stating that he lias a “variety of forms of receiving device,” says that “it is preferred, therefore, to have the frequency of the dynamo producing a field * * * different from the frequency of the received oscillations, and (his difference may amount preferably to about one fifth (A) of 1 per cent (1%), though a larger or a smaller difference may he used.” Fessenden uses an example of two frequencies, one of 100,000 and the other one fifth of 1 per cent different, and states that “beats vdll be produced which will cause the telephone diaphragm to vibrate and emit a musical note. * * * The pitch of the note may he altered at will so as to produce mechanical resonance with the telephone diaphragm. * * Another advantage of the heats method herein described, as *454against having the same frequency-at the sending end, is that if the frequency at the receiving end were the same as that at the sending end (though this is commercially impracticable) the fixed coil would generate by induction current in the moving coil many thousand times greater than the current to be received, and hence the effect of the received impulses would be drowned by the current generated by the local or fixed coils. * * * Where desired, all or any of the circuits may be electrically tuned in accordance with methods well-known in the' art, the advantages and effects of such tuning being well-known.” An examination of the claims of the Fessenden patent discloses, we think, a complete anticipation of the claims in issue. His claim 19 reads as follows: “In a high frequency signaling system the combination at the receiving station of two fixed coils, one operatively connected to antenna and the other operatively connected to a frequency determining element of slightly different frequency, a ring arranged in the fields of said coils, and an indicating mechanism controlled by said ring.”
The specification points out that the oscillations on the antenna, or the receiving wire of the signal circuit at the receiving station, are in themselves too rapid to affect the ring, and consequently have no influence upon the detecting mechanism or indicating instrument, and likewise that the oscillations of different frequency in the local circuit have independently no effect upon the ring or detecting devices. But, by combining the oscillations of different frequency, the ring readily responds to the pulsations or beats, which can be detected by placing the indicating instrument in proximity to the ring.
The improvement attained, if any, by appellant over Fessenden, is in degree, not invention. We, therefore, agree with the Commissioner that appellant in the allowed claims has been awarded everything to which he is entitled.
The decision of the Commissioner of Patents is affirmed, and the clerk is directed to certify these proceedings as by law required; Affirmed.
Mr. Justice Staotoed, of the Supreme Court of the District *455of Columbia, sat with the Court in the hearing and determinaturn of this appeal in the place of Mr. Chief Justice Shepard.