midnight
Occasionally , after prolonged labour in confined and bad air , a faint trace of the old complaint showed itself when he reached the top of the ladders , but he was not now depressed by that circumstance as he used to be . He was past his prime at the period of which we write , and a confirmed bachelor . To return from this digression : David Trevarrow made up his mind , as we have said , to `` go on , '' and , being a man of resolute purpose , he went on ; seized his hammer and chisel , and continued perseveringly to smite the flinty rock , surrounded by thick darkness , which was not dispelled but only rendered visible by the feeble light of the tallow candle that flared at his side . Over his head rolled the billows of the Atlantic ; the whistling wind howled among the wild cliffs of the Cornish coast , but they did not break the deep silence of the miner 's place of midnight toil . Heaven 's artillery was rending the sky , and causing the hearts of men to beat slow with awe . The great boulders ground the pebbles into sand as they crashed to and fro above him , but he heard them not -- or if he did , the sound reached him as a deep-toned mysterious murmur , for , being in one of the low levels , with many fathoms of solid rock between him and the bottom of the superincumbent sea , he was beyond the reach of such disturbing influences , tremendous though they were . The miner was making a final effort at his unproductive piece of rock , and had prolonged his toil far into the night .