The Torricellian column of mercury stands arrested at 29.86 inches, its silvery summit unwavering in the dim light of my observatory cell—a glassy sentinel over the valley's breathless repose. From the brass dial of the barometer, no tremor betrays the faintest fluctuation; the instrument is as still as the tomb, and the hair-hygrometer, that curious device of human hair and whalebone, reports the air's moisture at a dew point of 48 degrees Fahrenheit, though no fog clings to these heights. The copper weathercock above the turret swings but lazily, pointing southwest with a gentle four-knot br…