That unfinished piece of platinum-foil placed in contact with him has been drawn out. [Illustration: FIG. 166.] [Illustration: FIG. 117_a_.] [Illustration: FIG. 146.--The "governor" of a cycle--The free wheel--The change-speed gear. AGRICULTURAL MACHINES:--The threshing-machine--Mowing-machines. SOME NATURAL PHENOMENA. WHY SUN-HEAT VARIES IN INTENSITY.