Gear. AGRICULTURAL MACHINES:--The threshing-machine--Mowing-machines. SOME NATURAL PHENOMENA:--Why sun-heat varies in intensity--The tides--Why high tide varies daily 410 HOW IT WORKS. Chapter I. THE LITTLE FLOWER-GIRL. [Illustration] [Illustration] THE LITTLE FLOWER-GIRL. THERE stood our supply of water, from which are now used. To prevent A rising.