This was a serious difficulty; in fact, it was an impossibility.  The courage of the men began to waver immediately; once more we were threatened with a panic.  But when the danger was most imminent, we were saved in a mysterious way.  A mule which had attracted attention from the beginning by its disposition to experiment, tried to eat a five-pound can of nitroglycerin.  This happened right alongside the rock.  The explosion threw us all to the ground, and covered us with dirt and debris; it frightened us extremely, too, for the crash it made was deafening, and the violence of the shock made the ground tremble.  However, we were grateful, for the rock was gone.  Its place was occupied by a new cellar, about thirty feet across, by fifteen feet deep.  The explosion was heard as far as Zermatt; and an hour and a half afterward, many citizens of that town were knocked down and quite seriously injured by descending portions of mule meat, frozen solid.  This shows, better than any estimate in figures, how high the experimenter went.

We had nothing to do, now, but bridge the cellar and proceed on our way.  With a cheer the men went at their work.  I attended to the engineering, myself.  I appointed a strong detail to cut down trees with ice-axes and trim them for piers to support the bridge.  This was a slow business, for ice-axes are not good to cut wood with.  I caused my piers to be firmly set up in ranks in the cellar, and upon them I laid six of my forty-foot ladders, side by side, and laid six more on top of them.  Upon this bridge I caused a bed of boughs to be spread, and on top of the boughs a bed of earth six inches deep.  I stretched ropes upon either side to serve as railings, and then my bridge was complete.  A train of elephants could have crossed it in safety and comfort.  By nightfall the caravan was on the other side and the ladders were taken up.

Next morning we went on in good spirits for a while, though our way was slow and difficult, by reason of the steep and rocky nature of the ground and the thickness of the forest; but at last a dull despondency crept into the men’s faces and it was apparent that not only they, but even the guides, were now convinced that we were lost.  The fact that we still met no tourists was a circumstance that was but too significant.  Another thing seemed to suggest that we were not only lost, but very badly lost; for there must surely be searching-parties on the road before this time, yet we had seen no sign of them.

Demoralization was spreading; something must be done, and done quickly, too.  Fortunately, I am not unfertile in expedients.  I contrived one now which commended itself to all, for it promised well.  I took three-quarters of a mile of rope and fastened one end of it around the waist of a guide, and told him to go find the road, while the caravan waited.  I instructed him to guide himself back by the rope, in case of failure; in case of success, he was to