Commonly the upper surfaces of cloud-strata appear like a peaceful silver-gray sea. They appear woolly and sometimes fluffy, level, and often so vast that they sweep away beyond the horizon. Peaks and ridges often pierce their interminable surface with romantic continents and islands; along their romantic shores, above the surface of the picturesque sea, the airship could sail in safe poetic flight, though the foggy depths below were too dense for any traveler to penetrate. One spring the snow fell continuously around my cabin for three days. Reports told that the storm was general over the Rocky Mountain region. Later investigations showed that that cloud and storm were spread over a quarter of a million square miles. Over this entire area there was made a comparatively even deposit of thirty inches of snow. All over the area, the bottom, or under surface, of the cloud was at an altitude of approximately nine thousand feet. My cabin, with an altitude of nine thousand, was immersed in cloud, though at times it was one hundred feet or so below it. Fully satisfied of the widespread and general nature of the storm, and convinced of the comparatively level line of the bottom surface of the cloud, I determined to measure its vertical depth and observe its slow movements by climbing above its silver lining. This was the third day of the storm. On snowshoes up the mountainside I went through this almost opaque sheep's-wool cloud. It was not bitterly cold, but cloud and snow combined were blinding, and only a ravine and instinct enabled me to make my way. At an altitude of about twelve thousand feet the depth of the snow became suddenly less, soon falling to only an inch or so. Within a few rods of where it began to grow shallow I burst through the upper surface of the cloud. Around me and above there was not a flake of snow. Over the entire storm-area of a quarter of a million square miles, all heights above twelve thousand had escaped both cloud and snow. The cloud, which thus lay between the altitudes of nine thousand and twelve thousand feet, was three thousand feet deep.