A is a cutter, and B a collar, screwed upon the cutter bar, C. The edge of this collar fits into a notch on either end of the cutter, as shown at D, thus leaving the cutter as strong as possible at the center, and giving it a solid support at the point where support is needed, and at the same time insuring its always coming alike. Brooklyn, N.Y. THEODORE L. WEBSTER. [The device seems to be eminently well calculated for the support of the cutter on a boring bar, and is applicable, with but slight modification, to a pin or "teat" drill. Machinists will readily perceive its operation and excellencies.--EDS. * * * * * Tides and Their Causes. The phenomenon of the daily tides of our seacoasts and tidal rivers is attributed to the attraction of the moon upon the earth--that the moon draws the earth towards it, and that in drawing the earth towards it, it bulges up the water of the ocean on the side presented towards the moon, and drawing the earth and water thus on that side, also draws the earth _away_ from the water on the opposite side of it, and thus leaves the water bulged up on _that_ side, and in doing all this the effect comes after the cause some three hours, which is termed "the tide lagging behind." Now if we knew, _per se_, what attraction of gravitation was, and that it produced this anomaly of force, there would be nothing to question in the matter. But as we only know by attraction that it means _drawing to_, it is impossible to reconcile the theory of the tides as they run to the attraction of the moon. If the moon is so potent in drawing up, why does it not draw a bulge on the inland seas--our great lakes? I will not discuss the question of the moon's Apogee and Perigee--its different velocities in different parts[1] of its orbit, as laid down by the law of Kepler, or whether it turns once on its axis in a month, or not, as either theory will answer for its phases, as well as for the face of the "Man in the Moon," but I will endeavor to give a more rational theory for the phenomenon of the daily tides. [Transcribers note 1: typo fixed, changed from 'pasts' to 'parts']