Fig 90 287 CONTRIVANCES FOR CHANGING THE DIRECTION, or MOTION.

Changefrom one direction to another.

Two wedges, fig 90, may be used for this purpose.

When the lower one is driven in the direction AL, the upper one raises any thing, placed upon it, in the direction FIX 288 Two racks and segments.

When the rack H, fig 91 is raised, or depressed, the rack B, will be depressed, or raised, by the segment D.