Elden Hole, in the Peak of Derbyshire, a yawning cavity 200 feet deep, with an inner cave 65 feet deeper, has been descended several times recently. On the first occasion, through the inexperience of the party, I had the privilege of spending nine hours in the hole, in a state of uncertainty as to whether it was in the power of the other men to get me out. On the next occasion, we let down a dozen men safely. But there still remains the possibility that excavation might clear up the puzzle as to the connection of Elden Hole with other swallets and caves in the vicinity. The old miners believed that it had communication with the natural chambers in the Speedwell Mine; and that is a problem which will entail exploration in collapsible boats along the flooded levels. The great chasm in the Speedwell, which used to be reputed bottomless, has been proved to be only 90 feet deep. It has an upward extension, in the same steep rake, which has not been climbed, nor its top so much as caught sight of. It attains a height, most probably, of at least 400 feet. That is a problem worthy the mettle of our most skilful cragsmen. In the Blue John Mine, a vertical fissure has been climbed, by a party properly roped up, to the height of 130 feet, between walls splendidly adorned with polished and translucent stalagmite. Ladders may sometimes be rigged up, one above another, to reach hollows in the roof of caves. In this way a handsome grotto was discovered above Peak Cavern. When these vertical fissures are open to the sky, it is a simple matter to fix tackle, and even a windlass, for letting men down. When they open in the floor of a well-nigh impracticable gallery, as in the Eastwater Cavern, the difficulties of securing pulleys and ropes are serious. There our troubles are aggravated by the proximity of deep, gaping chasms at the foot of each pitch, lying in wait to receive falling bodies. Nevertheless, by an ingenious arrangement of life-line and pulley, the entire party gets safely to the bottom of the gulf and back again, although it is usual in such situations to leave a sentry behind at the top. Grandest of all these underground cavities in England is the great chamber of Lamb's Lair, in the Mendips. The approaches and subsidiary chambers of that marvellous cavern are magnificent in the richness of their incrustation and their colouring; but this mighty hall surpasses the rest by far. Floor, walls, and roof, of a dome-shaped chamber 110 feet high, are a mass of sculptured transparencies, fantastic reliefs and glowing enamel, all the colours of the rainbow being produced by the different veins of minerals. Only a strong party of experienced climbers or cave workers, fully equipped, should venture to explore this fine cavern in its present dangerous state.