fifteen minutes past six
A darkness which no eye could penetrate surrounded him as he lay in bed . Absolute obscurity was essential to the repose of that singular brain , and he had perfected arrangements for supplying the deficiencies of Nature 's night . He touched a switch , and in front of him at a distance of thirty feet the ivory dial of a clock became momentarily visible under the soft yellow of a shaded electric globe . It was fifteen minutes past six . At the same moment a bell sounded the quarter in delicate tones , which fell on the ear as lightly as dew . In the upper gloom could be discerned the contours of a vast dome , decorated in turquoise-blue and gold . He pressed a button near the switch .