‘I venture to suppose that you never had a correspondent who at the time of writing was situated as your present one is. I am at this moment sitting in a small cavern deep in the recesses of the earth, separated by 1,200 feet of rock from the surface on which you mortals tread. I am close to a wooden partition which has been fixed here by human hands, through which I ever and anon look, by means of two telescopes, into a larger cavern. That larger den has got various strange-looking machines, illumined here and there by unseen lamps, among which is visible a clock with a face most unlike common clocks, and a brass bar which swings to and fro with a small but never-ceasing motion. I am clad in the garb of a miner, which is probably more dirty and scanty than anything you may have happened to see in the way of dress. The stillness of this subterranean solitude is interrupted by the noise, most strange to its walls, of the ticking of my clock, and the chirping of seven watches. But besides these sounds it has noises of its own which my ear catches now and then. A huge iron vessel is every quarter of an hour let down through the rock by a chain above a thousand feet long, and in its descent and ascent dashes itself against the sides of the pit with a violence and a din like thunder; and at intervals, louder and deeper still, I hear the heavy burst of an explosion when gunpowder has been used to rend the rock, which seems to pervade every part of the earth like the noise of a huge gong, and to shake the air within my prison. I have sat here for some hours, and shall sit five or six more, at the end of which time I shall climb up to the light of the sky in which you live, by about sixty ladders, which form the weary upward path from hence to your world. I ought not to omit, by way of completing the picturesque, that I have a barrel of porter close to my elbow, and a miner stretched on the granite at my feet, whose yawns at being kept here so many hours, watching my inscrutable proceedings, are most pathetic. This has been my situation and employment every day for some time, and will be so for some while longer, with the alternation of putting myself in a situation as much as possible similar, in a small hut on the surface of the earth. Is not this a curious way of spending one’s leisure time? I assure you I often think of Sir John’s favourite quotation from Leyden, “Slave of the dark and dirty mine! What vanity has brought thee here?” and sometimes doubt whether sunshine be not better than science.