Page:Federal Reporter, 1st Series, Volume 1.djvu/329

PAGE V. HOLMES BUBGLAB ALABM TELEOBAPH CO. 321 �with references to the drawing and to the letters on it, whioh description is substantially the same as the description in the plaintifs patent of what is shown by figure 10 of the draw- ings of the patent. The same description and drawing set forth and show the combination covered by the twelfth claim of the plaintifïs' patent, as it is described in that patent. �Figure 1 of the drawings of the application of February 2, 1854, was, undoubtedly, the same as figure 9 of the drawings of the patent. Such application describes, by references to letters which must have been on such figure 1, the same apparatus, and by substantially the same description, wMch is described in the patent by references to letters on figure 9 of the drawings of that patent. The thirteenth claim claims the regulation of the length of vibration of the armature of an electro-magnet by a set-screw or its mechanical equivalent for that purpose. The specification of the re-issue says that the set-screw in figure 9 regulates the proximity of the arma- ture to the magnat. It does so. As the set-screw is turned so as to press down further the spring which carries the armature, the armature is brought nearer to the magnet. Thus, its proximity to the magnet is regulated. Such prox- imity is a difl'erent thing from the tension of the spring, and a different thing from the rapidity of the vibrations of the spring. Nothing is claimed in the thirteenth claim as to reg- ulating such tension or such rapidity. It is such tension and such rapidity which are stated in the specification to be reg- ulated only to some extent by the set-screw, so that the regulation of them is imperfect. When the proximity of the armature to the magnet is regulated, its- length of vibration is regulated, although the consequence of pressing down the spring and bringing the armature nearer to the magnet is, that the attractive force of the magnet on the armature inoreases more rapidly, as the distance between them is lessened, than the force of the spring increases, and thus the same relation is not maintained between the tension or force of the spring and the attractive force of the magnet on the armature which the spring carries, as the spring and the �T.l,no.5— 21 ��� �