Some one wrote, "Circumstances alter cases." Everybody knows how true that is, and how often we have illustrations in our own lives. Here is one: to catch hold of a rope after jumping to it is wonderfully easy, and in our young days the sensation of swinging to and fro in a sort of bird-like flight through the air is delightful--that is to say, if the ground is so near that we can drop on our feet at any moment; there is no thought of danger as we feel perfect confidence in our power to hold on. It is a gymnastic exercise. But change the scene: be hanging at the end of the same rope, with the knowledge that a friend and comrade is in deadly peril, and that, though resting against a rocky slope which gives you foothold and relieves the strain on your muscles, there is beneath you a horrible chasm full of black water, hidden by the darkness, but lapping and whispering as if waiting to receive the unfortunate. It is then that the nerves weaken and begin to communicate with and paralyse the muscles, unless there is sufficient strength of mind to counteract the horror, setting fear at defiance. The best thing under these circumstances is to get the body to work, and make brain take the second place. In other words, act and don't think. I must confess that my endeavours during those perilous moments were quite involuntary; for it was in a kind of desperation that I got my toes upon a solid piece of the slippery rock and pressed myself against the steep slope for a few moments, listening to the firing, some of which sounded close, some more distant. Then, shouting to Denham to hold on, I glanced at the lamp, which was flaring bravely and giving a good light, but only at the expense of the rapidly melting fat. The next minute I was climbing as quickly as I could by the rope, and shuddering as I heard stone after stone go down, any one of which I knew might crash full upon Denham. There was no time to think--I was too hard at work; and, to my surprise, I found myself just beneath the long bridge-like piece of stone which had been laid across the opening to the shaft; while, by holding on to the rope with one hand and, reaching up the other to grasp the stone, I could see by the light which rose from below--reflected from the glistening wall, for the lamp was out of sight--that the rope was one of the strong tethering-reins, fastened round the stone as if for the purpose of lowering a bucket.