26. A Good, Old-Fashioned, Healthy, and Mighty Storm

These three instances are all I have time to give of the former conditions of serene weather, and of non-electric rain-cloud. But I must yet, to complete the sequence of my subject, show you one example of a good, old-fashioned, healthy, and mighty, storm.

In Diagram 4, Mr. Severn has beautifully enlarged my sketch of a July thunder-cloud of the year 1858, on the Alps of the Val d’Aosta, seen from Turin, that is to say, some twenty-five or thirty miles distant. You see that no mistake is possible here about what is good weather and what bad, or which is cloud and which is sky; but I show you this sketch especially to give you the scale of heights for such clouds in the atmosphere. These thunder cumuli entirely hide the higher Alps. It does not, however, follow that they have buried them, for most of their own aspect of height is owing to the approach of their nearer masses; but at all events, you have cumulus there rising from its base, at about three thousand feet above the plain, to a good ten thousand in the air.

White cirri, in reality parallel, but by perspective radiating, catch the sunshine above, at a height of from fifteen to twenty thousand feet; but the storm on the mountains gathers itself into a full mile’s depth of massy cloud,—every fold of it involved with thunder, but every form of it, every action, every colour, magnificent:—doing its mighty work in its own hour and its own dominion, nor snatching from you for an instant, nor defiling with a stain, the abiding blue of the transcendent sky, or the fretted silver of its passionless clouds.