American Bell Tel Co. v. Dolbear

• Decision Date: 24 January 1883
• Citation: 15 F. 448
• Parties: AMERICAN BELL TELEPHONE CO. v. DOLBEAR and others.
• Court: U.S. District Court — District of Massachusetts

15 F. 448

AMERICAN BELL TELEPHONE CO. v. DOLBEAR and others.

United States Circuit Court, D. Massachusetts.

January 24, 1883

Chauncey Smith and James J. Storrow, for complainants.

Causten Browne and James E. Maynadier, for defendants.

GRAY Justice.

Few legal rules have been oftener misunderstood and misapplied than the maxim that you cannot patent a principle. But the confusion on this subject has been so effectually cleared up by the recent judgment of the supreme court, delivered by Mr Justice BRADLEY, in Tilghman v. Proctor, 102 U.S 707, that it will be sufficient for the purposes of this case to state the conclusions there announced. There can be no patent for a mere principle. The discoverer of a natural force or a scientific fact cannot have a patent for that. But if he invents for the first time a process by which a certain effect of one of the forces of nature is made useful to mankind, and fully describes and claims that process, and also describes a mode or apparatus by which it may be usefully applied, he is, within the meaning and the very words of the patent law, 'a person who has invented or discovered any new and useful art;' and he is entitled to a patent for the process of which he is the first inventor and is not restricted to that particular form of mechanism or apparatus by which he carries out that process. Another person, who afterwards invents an improved form of apparatus embodying the same process, may indeed obtain a patent for his improvement, but he has no right to use process, in his own or any other form of apparatus, without the consent of the first inventor of the process.

It was decided by this court in American Bell Telephone Co. v. Spencer, 8 F. 509, and is not denied by the present defendant, that Bell is the first inventor of a speaking telephone. The only controversy is the extent of his patent. The draughtsman of the specifications has exhibited as clear and accurate a comprehension of the rules of the patent law, as the inventor has of the force of nature with which he was dealing, and of the means by which he reduced that force to a practical use. The patent is clearly not intended to be limited to a form of apparatus, but embraces a method or process. This is apparent upon the face of the specification. The inventor begins by saying:

'My present invention consists in the employment of a vibratory or undulatory current of electricity in contradistinction to a merely intermittent or pulsatory current, and of a method of and apparatus for producing electrical undulations upon the line wire.'

After describing the advantages of an undulatory current, resulting from gradual changes of intensity, over a pulsatory current caused by sudden changes of intensity, he says:

'It has long been known that when a permanent magnet is caused to approach the pole of an electro-magnet, a current of electricity is induced in the coils of the latter, and that, when it is made to recede, a current of opposite polarity to the first appears upon the wire. When, therefore, a permanent magnet is caused to vibrate in front of the pole of an electro-magnet, an undulatory current of electricity is induced in the coils of the electro-magnet, the undulations of which correspond, in rapidity of succession, to the vibrations of the magnet, in polarity to the direction of its motion, and in intensity to the amplitude of its vibration.'

Or, as he afterwards repeats in fuller language:

'Electrical undulations, induced by the vibration of a body capable of inductive action, can be represented graphically, without error, by the same sinusoidal curve which expresses the vibration of the inducing body itself, and the effect of its vibration upon the air; or, as above stated, the rate of oscillation in the electrical current corresponds to the rate of vibration of the inducing body, that is, to the pitch of sound produced; the intensity of the current varies with the amplitude of the vibration, that is, with the loudness of the sound; and the polarity of the current corresponds to the direction of vibrating body, that is, to the condensations and rarefactions of air produced by the vibration.'

He further says:

'There are many ways of producing undulatory currents of electricity, dependent for effect upon the vibrations or motions of bodies capable of inductive action. A few of the methods that may be employed I shall here specify. When a wire, through which a continuous current of electricity is passing, is caused to vibrate in the neighborhood of another wire, an undulatory current of electricity, is induced in the latter. When a cylinder, upon which are arranged bar magnets, is made to rotate in front of the pole of an electromagnet, an undulatory current of electricity is induced in the coils of the electro-magnet.

'Undulations are caused in a continuous voltaic current by the vibration or motion of bodies capable of inductive action, or by the vibration of the conducting wire itself in the neighborhood of such bodies. Electrical undulations may also be caused by alternately increasing and diminishing the power of the battery. The internal resistance of a battery is diminished by bringing the voltaic elements nearer together, and increased by placing them further apart. The reciprocal vibration of the elements of a battery, therefore, occasions an undulatory action in the voltaic current. The external resistance may also be varied. For instance, let mercury or some other liquid form part of a voltaic circuit, then the more deeply the conducting wire is immersed in the mercury or other liquid, the less resistance does the liquid offer to the passage of the current. Hence the vibration of the conducting wire in mercury or other liquid included in the circuit occasions undulations in the current. The vertical vibration of the elements of a battery in the liquid in which they are immersed produces an undulatory action in the current by alternately increasing and diminishing the power of the battery.

'In illustration of the method of creating electrical undulations, I shall show and describe one form of apparatus for producing the effect. I prefer to employ for...