The air was bad enough at the start, but seemed to get worse as we proceeded. I trusted, however, to finding a distinct improvement in the neighbourhood of the shafts, but to my dismay each one in turn proved to be hermetically sealed with masses of rock just above its junction with the tunnel, and there was not the slightest suspicion of any circulation of air, so that the only relief they afforded was the possibility of resting in an upright position. Three hundred metres, as I afterwards calculated the total distance to be, may seem little enough in the open, but to grope one’s way this distance by the light of a feeble candle along a passage so restricted that one has to proceed not only with bent head and shoulders, but half sideways, in a hot, steamy, stagnant atmosphere, is quite a different matter. My companion, being of small build and stature, was able to walk upright in comparative comfort, without continually bumping his head and bruising his shoulders, so that the want of air did not tell on him to the same extent; while I became more and more fatigued, owing to the difficulty experienced of getting sufficient oxygen from such an atmosphere in the cramped position I had of necessity to assume. On more than one occasion I sank exhausted into the water, the huge gasps of breath which I took seeming powerless to relieve the horrible sensation of stifling, and with the unpleasant prospect of getting drowned if I escaped suffocation. Yet there seemed to be ten thousand devils tempting me onwards, and although I did not know how long life could be supported under such conditions, a mad desire possessed me to see the thing through; so that whenever I was able to progress a few yards it was towards the head of the tunnel.