Publisher's Synopsis
This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1886 edition. Excerpt: ... Amsler's apparatus for examining this case, in which, if the edge of the roller has any width, there must be slipping action, even though the force always acts in theMirection of the plane of rotation. The roller m which rests on the upper surface of the disk, which latter has its edge divided, and is in juxtaposition with a vernier (v). The axis of the roller is fixed, and its edge is thus kept always vertically under a microscope (K). The position of the disk is noted, and it is then moved forward about 8 revolutions (or exactly 2,900), which gives the roller about 130 revolutions, and a mark is ob-served on the latter. Then in theory the result of giving 8 more revolutions to the disk in the same direction should be to bring the same mark of the roller under the microscope, Practically the succes-sive motions of the disk will be a little different, so that the second advance of the disk will not be exactly the same as in the first case. The same mark on the roller is, however, always brought under the microscope, and the difference in turning of the disk is what is noted. In the following table--i=number of experiment, (p--angle by which the disk differs from last reading, so that the second column gives the positions of the disk at the end of successive advances in which the roller is made to take 130 complete revolutions, the third column shows the travel of disk in minutes (2,900 having, of course, to be added to the readings). The fourth gives the difference between these and a mean value. The last gives the ratio of these differences to the travel. Case ii. To test the results when a roller partly rolls and partly slips, Dr. Amsler used the apparatus shown (Fig. 56) in plan and elevation. In this C is a carriage, running upon...