The horrid gibbering was drowned by the noise he made. Quickly, without pausing, he began to hack at the oak door with all his might. In rapid succession his heavy blows rained down, and the sound echoed through the empty house. There was a crash, and the door swung back. They had been so long in almost total darkness that they were blinded for an instant by the dazzling light. And then instinctively they started back, for, as the door opened, a wave of heat came out upon them so that they could hardly breathe. The place was like an oven. They entered. It was lit by enormous lamps, the light of which was increased by reflectors, and warmed by a great furnace. They could not understand why so intense a heat was necessary. The narrow windows were closed. Dr Porhoët caught sight of a thermometer and was astounded at the temperature it indicated. The room was used evidently as a laboratory. On broad tables were test-tubes, basins and baths of white porcelain, measuring-glasses, and utensils of all sorts; but the surprising thing was the great scale upon which everything was. Neither Arthur nor Dr Porhoët had ever seen such gigantic measures nor such large test-tubes. There were rows of bottles, like those in the dispensary of a hospital, each containing great quantities of a different chemical. The three friends stood in silence. The emptiness of the room contrasted so oddly with its appearance of being in immediate use that it was uncanny. Susie felt that he who worked there was in the midst of his labours, and might return at any moment; he could have only gone for an instant into another chamber in order to see the progress of some experiment. It was quite silent. Whatever had made those vague, unearthly noises was hushed by their approach.