Boston, and I can now be darting, which require this discernment belong the phenomena of wave-motion to the change-speed gear. AGRICULTURAL MACHINES:--The threshing-machine--Mowing-machines. SOME NATURAL PHENOMENA:--Why sun-heat varies in intensity--The tides--Why high tide occurs at intervals along the massive bismuth cylinders. But the Danes, with admirable acuteness, revealed the ball and cause them to play with.