A. S. Browne and A. Comstock, for appellant.

Howard Henderson, for appellee.

Mr. Justice SHIRAS delivered the opinion of the court.

This case comes here on appeal from the circuit court of the United States for the southern district of New York, whose decree dismissed complainants bill charging the defendants [149 U.S. 117, 118] with infringing letters patent of the United States, No. 203,604, granted to Charles E. Dobson, May 14, 1876, and letters patent No. 249,321, granted to Henry C. Dobson, November 8, 1881, both being for improvements in banjos.

The bill discloses that the several letters patent so as aforesaid issued to Charles E. Dobson and to Henry C. Dobson, by certain assignments in writing, became vested in the complainant, Catharine L. Dobson, and avers an infringement by the defendants, E. I. Cubley and George Van Zandt, of her rights under said letters patent.

The defendants, by their answer, admit that letters patent were issued, as alleged in the bill, to Charles E. Dobson and Henry C. Dobson, but deny that said patentees were original inventors of the devices described therein, and allege that each of the combinations or devices claimed in said several letters patent was a mere aggregation of mechanical features well known in the art, and hence contend that the claims for said devices should be declared null and void.

The answer further sets up that the defendant Edwin I. Cubley was himself the original inventor of certain improvements in banjos and other musical instruments, for which letters patent No. 253,849 were, on the 21st of February, 1882, granted to him, under which the defendants were carrying on the manufacture and sale of banjos, and denies that such manufacture and sale were infringements of any supposed or alleged rights of complainant, as assignee of the several letters patent described in the said bill.

Replication was duly filed, testimony taken, and, after hearing, the decree dismissing the bill of complaint was rendered.

The banjo is described as a musical instrument of the guitar class, having a neck with or without frets, and a circular body covered in front with tightly-stretched parchment. It has from five to nine strings, of which the melody string, the highest in pitch, but placed outside of the lowest of the others, is played by the thumb of the performer. As in the guitar, the pitch of the strings is fixed by stopping them with the left hand, while the right hand produces the tone by plucking or striking. Cent. Dict. art. Banjo. [149 U.S. 117, 119] The banjo of the Charles E. Dobson patent contained a dome-shaped ring, composed of metal, interposed between the parchment and a wooden rim; and what is claimed as new is this dome-shaped ring, in combination with the wooden rim and parchment head. The advantages claimed are that the rounded shape of the ring causes less wear of the parchment head than the more angular corner or edge previously in use, and that such combination materially improves the tone or resonance.

The banjo of Henry C. Dobson has also a metal ring, but the ring is formed with two downwardly projecting flanges, interposed between the parchment head and a rim composed of wood and metal. The outer flange passes down outside of the ring, and the inner one projects down inside the ring, and is free from contact with other parts of the instrument, so as to be capable of unrestrained vibration, and it is claimed that the effect is to give a clear, bell-like, ringing tone to the instrument.

The ring is an element of both of the Dobson patents, and its peculiar form is essential in each invention in producing the bell-like notes which are characteristic of the instruments. These effects are varied in each by the dimensions and form of the ring, and in the Henry C. Dobson patent the flanges and the combination of wood and metal in the rim are distinctive features.

The Cu