Beneath the ridge, on the farther side of this great bed of sulphur, an abundance of vapor escaped with a loud noise. Having crossed to the side of the mountain opposite, they walked to what is called the principal spring. This was a task of much apparent danger, as the side of the mountain to the extent of about half a mile, was covered with loose clay, into which the feet of our travelers sunk at every step. In many places there was a thin crust, beneath which the clay was wet, and extremely hot. Good fortune attended them; and without any serious inconvenience, they reached the object they had in view. A dense column of steam, mixed with a small portion of water, forced its way impetuously through a crevice in a rock, at the head of a narrow valley, or break in the mountain. The violence with which it rushed out was so great, that the noise, thus occasioned, might often be heard at the distance of several miles. During the night while the party lay in their tent at Krisuvik, they more than once listened to it with mingled awe and astonishment. Behind the column of vapor was a dark-colored rock, which added to the sublimity of the effect. “It is quite beyond my power,” observes Sir George Mackenzie, “to offer such a description of this extraordinary place, as would convey adequate ideas of its wonders, or of its terrors. The sensations of a person, even of firm nerves, standing on a support which feebly sustains him, over an abyss where, literally, fire and brimstone are in dreadful and incessant action; having before his eyes tremendous proofs of what is going on beneath him; enveloped in thick vapors; his ears stunned with thundering noises—must be experienced before they can be understood.” MONT BLANC. [See cut, page 38.] “When mid the lifeless summits proud Of Alpine cliffs, where to the gelid sky Snows piled on snows in wint’ry torpor lie, The rays divine of vernal Phœbus play; Th’ awakened heaps, in streamlets from on high, Roused into action, lively leap away, Glad warbling through the vales, in their new being gay.”—THOMSON. [Illustration: MONT BLANC AND THE GLACIERS.]