Page:Edinburgh Review Volume 59.djvu/305

1834. rendered necessary by the addition which has just taken place.

The second quarter of a turn of the moving axis, will move forward through one division all the dials which in Fig. 2 are marked (*), and the scheme will be converted into the scheme expressed in Fig. 3.

Fig. 3.

In third quarter of a turn, the dial A1, fig. 3, will remain unmoved, since is at the index below it; the dial B1 will be moved forward through three divisions; C1 through nine divisions, and so on; and in like manner the dials of the row D3 will be moved