So, the final depôt having been constructed, the work on the last series of galleries was begun and carried on with greatly increased vigour, till an altitude only a few yards lower than the under surface of the cloud was gained. At this place the angle of inclination of the cliff had eased off to sixty-three degrees, and it was thought advisable, in view of the unknown possibilities of the mountain inside this thick screen, to establish, by blasting away the rock, a level surface of sufficient extent to enable them to build yet another storehouse, before venturing to proceed with the sloping gallery. CHAPTER VIII. Of the great courage of three engineers—How they passed the Screen and saw the Host of Heaven—How they further discovered a Disk of Unknown Fire—Of the reception of the news throughout the world—Of the construction of a mountain Observatory; and of the rapid growth of Astronomical knowledge. The levelling of the rock was necessarily a work which required a good deal of time; and, while it was proceeding, three of the engineers formed the daring project of scrambling up the cliff, into the cloud, and endeavouring to penetrate through it by themselves. All the three were in the stationary period of life, and, consequently, in the possession of full bodily strength and activity. The cliff was in most places rough enough to give good hold for both hands and feet. Still, to venture on a climb through a dense mist, on the face of a nearly precipitous and wholly unknown mountain, where a single slip would be certainly followed by immediate destruction, was regarded by their comrades as too hazardous to be thought of. But the three were not to be dissuaded—I ought, perhaps, to mention that it is to one of these daring men I am indebted for the account of the whole expedition. Their preparations were soon complete, for their equipment was very simple; each of them took about one pound weight of some sort of food in a highly concentrated form, and a flask containing a pint of water. Water, it may be observed, was valuable at this elevation, for every drop had to be carried up from the glacier region. Each man also carried a coil of about five hundred yards of fine, but very strong twine. This was intended to be used as a clue to guide them back to the camp. Fixing an end of one of these coils to the wall of their store, they started on their perilous journey at two o’clock in the afternoon. Without very much difficulty they scrambled up to the edge of the cloud, and there disappeared from the sight of their friends, most of whom believed that they had gone mad.