Humboldt, at Caraccas , in South-America ,has made ſome intereſting obſervations onthe motion of the barometer near the equa-tor. “I have read,” ſays he, “In the tranſ-actions of the Bengal Society, that the baro-meter riſes and falls there regularly every 24hours. Here, in South-America , its motionis more aſtoniſhing aſtoniſhing. There are four atmoſ-pherical tides every 24 hours, which dependonly on the attraction of the ſun. The mer-cury falls from nine o’clock in the morningtill four o’clock in the evening. It riſes fromfour till eleven o’clock; it falls from eleveno’clock till half paſt four in the morning;it reaſcends from that time till nine o’clock:neither winds, ſtorms, nor earthquakes, haveany influence on this motion.”