this stage the matrices are no longer pressed together, but are
separated by short intervals SO as to allow them to drop succes- sively as they come above their respective magazines. At several parts in the traverse, then, the matrices present a con- tinuous surface, and are close to the wall of the channel through which they are passing, but at the final stage they are separated, and their edges are not in contact with the channel.
In the course of use the edges carrying the indicating letters are apt to become dirty, SO that the letters are scarcely legible, and means have been devised for cleaning them by means of brushes fixed SO as to project through the walls of the channels or conduits and come in contact with the letters as they pass before them.
All this is common knowledge, i.e., to persons conversant with linotype machines, which, however, differ in detail from one another, the general principle being as above stated.
I come now to Mounsey's application, which, as already said, is for "an improved matrix cleaner." The complete specification begins by saying that "the invention is for the purpose of automatically cleaning the matrices of linotype machines every time they have been used and before they are placed in the magazine, and consists of two pair of brushes, one pair being fixed on to the intermediate elevator channel plate, and another pair being fixed on to the distributor box, in such manner that the matrices in being distributed from each line shall pass the brushes, one of each pair of which will rub against and clean the front side and the other the back side."
The "intermediate elevator channel referred to is a part of the machine through which the matrices pass, supported by the projecting shoulders as above described, immediately before reaching the place of distribution or distributor box.
The specification describes the means of the attachment of the brushes, which, shortly stated, is as follows:-An oblong slit is cut in the wall of the channel, through which a brush projects for a small distance into the channel itself, SO that the edges of the matrices are rubbed by it in passing, two such brushes being affixed opposite to each other at the two points mentioned.
The claim is as follows :-" In linotype machines two or more