40 FEDERAL REPORTER.
original application was filed February 16, 1876. · Prior to the invention,
logs had been constructed with the registering mechanism in a circular or
drum. form, attached to the ship by means of a yoke or with gimbals,
like a compass or chronometer; they had also been made with an elon-
gated registering mechanism and the propeller in one apparatus, which
was fastened to a line and thrown overboard. These logs were found to
be expensive, inaccurate, and cumbersome. They were liable to get out
of order and to be lost. The object of the present invention was to pro-
vide a simple and inexpensive in-boa1·d log g the elongated case contain-
ing the registering apparatus being attached to the taffrail of the vessel,
and connected by a line with a distant propeller, rotating in the water.
The case is provided with a spindle or shaft, the end of which protrudes
to receive the line of the rotator. Motion is thus communicated to a.
series of wheels, which move the indexes on the dials, thus indicating
the vessel’s speed. The claims in controversy are as follows:
" (2) An elongated cylindrical case containing the registering mechanism,
with the shaft, o_, introduced axillary at one end, in combination with the anti-
friction rollers, h, eye, d, propeller, and connecting cord or wire, substantially
as set forth. (3) Theliorizontal attaching-yoke, m, in combination with the
gloplgated case, a, registering mechanism, b, and shaft, c, substantially as set
. or ." , . ·
In view of the disasters which usually befall reissues, it is curious to
note that, although the patent in suit was granted more than nine years
after thebriginal, no accusation is made against it as a reissue. The ob-
ject of the reissue was to correct a clerical error merely.
The defenses are lack of novelty and invention, and non-infringement.
The invention of the second claim is not anticipated by any of the
prior patents or exhibits. _ The English patent to Reynolds describes
. substantially the same combination, but, though prior to the complain-
- ants’ patent, it was not prior to their invention. This patent was sealed
July 27, 1875. It was therefore on that day that the invention was
made patent to the public. Smith v. Goodyear, 93 U. S. 486, 498. The
complainants, if they are to be credited, conceived their invention prior
to May 6 of that year. Their testimony in this regard is to some ex-
tent corroborated by other witnesses, and by presumptions drawn from
collateral facts and circumstances. It is true that this portion of the
proof is hardly susceptible of denial. It lies almost wholly within the
knowledge of the complainants. A direct attack upon a position founded
upon such evidence is, except in rare instances, out of the question.
But the diiiiculties which surround the defendants do not exonerate
them from presenting some satisfactory proof, either direct or circum-
stantial, to traverse the positive assertion of the complainants. Instead
of this, there is nothing but the intangible presumption arising from
the somewhat peculiar coincidence that the same idea, alike even in
minute details, should have occurred to two persons on different con-
tinents without one having seen the other’s device. But it is entirely
clear that the court would not be warranted in rejecting the positive testi-
mony of two respectable and unimpeached witnesses upon a mere sus-