The better to hear this grand uproar, I advanced to the western edge of the summit. Here my hat was torn off, but not quite grasped, by the upshooting blast. It fell into the swirl above the summit and in large circles floated upward at slow speed, rising directly above the top of the peak. It rose and circled so slowly that I threw several stones at it, trying to knock it down before it rose out of range. The diameter of the circle through which it floated was about one hundred and fifty feet; when it had risen five, or perhaps six, hundred feet above the summit it suddenly tumbled over and over as though about to fall, but instead of falling it sailed off toward the east as though a carrier pigeon hurrying for a known and definite place in the horizon. Some of the gulf-streams, hell-gates, whirlpools, rough channels, and dangerous tides in the sea of air either are in fixed places or adjust themselves to winds from a different quarter so definitely that their location can be told by considering them in connection with the direction of the wind. Thus the sea of air may be partly charted and the position of some of its dangerous places, even in mountain-top oceans, positively known. However, there are dangerous mountain-top winds of one kind, or, more properly, numerous local air-blasts, that are sometimes created within these high winds, that do not appear to have any habits. It would be easier to tell where the next thunderbolt would fall than where the next one of these would explode. One of these might be called a cannon wind. An old prospector, who had experienced countless high winds among the crags, once stated that high, gusty winds on mountain-slopes "sometimes shoot off a cannon." These explosive blasts touch only a short, narrow space, but in this they are almost irresistible. Isolated clouds often soften and beautify the stern heights as they silently float and drift among peaks and passes. Flocks of these sky birds frequently float about together. On sunny days, in addition to giving a charm to the peaks, their restless shadows never tire of readjusting themselves and are ever trying to find a foundation or a place of rest upon the tempestuous topography of the heights below. Now and then a deep, dense cloud-stratum will cover the crests and envelop the summit slopes for days. These vapory strata usually feel but little wind and they vary in thickness from a few hundred to a few thousand feet. Sometimes one of these rests so serenely that it suggests an aggregation of clouds pushed off to one side because temporarily the sky does not need them elsewhere for either decorative or precipitative purposes. Now and then they do drop rain or snow, but most of the time they appear to be in a procrastinating mood and unable to decide whether to precipitate or to move on.