Joseph P. Bradley

“ The pistons are prevented from coming into contact with the ends of the cylinders by means of adjusting stops, slightly projecting therefrom inside. Projecting stops for arresting the movement of the pistons, and much of the mechanical arrangement between the crank-shaft and the slots in the piston-rods, used for giving the proper motion to the crank-shaft, are to be found described in a patent granted to Mr. Ericsson in 1851 for a water-meter having slide valves instead of a rotary valve, but in which a rotary motion was communicated to the indicator. ”

“ But the meter of the defendant's has no crank-shaft, and no semblance of a crank-shaft, for imparting motion from the pistons to the rotary valve; on the contrary, their valve is connected directly with the piston-rods in the following manner: The piston-rods cross each other at right angles, having transverse slots, and being halved together, one lying immediately on the other, so that the axes of the pistons are in the same plane. ”

“ It may be observed, before concluding this opinion, that the courts of this country cannot always indulge the same latitude which is exercised by English judges in determining what parts of a machine are or are not material. ”

“ The meter manufactured by the defendants is different in several respects from that described in the complainant's patent. It has a rotary valve like the latter, but without any bevel-gear; it also has two cylinders, with an immaterial difference of position, being placed at right angles with each other instead of being parallel; each cylinder is likewise provided with two double-acting pistons, connected by a piston-rod, the same as in the complainant's meter ”