or 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 Porhoet 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
Porhoet 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.

The door was closed between this room and the next. Arthur opened it, and
they found themselves in a long, low attic, ceiled with great rafters, as
brilliantly lit and as hot as the first. Here too were broad tables laden
with retorts, instruments for heating, huge test-tubes, and all manner of
vessels. The furnace that warmed it gave a steady heat. Arthur's gaze
travelled slowly from table to table, and he wondered what Haddo's
experiments had really been. The air was heavy with an extraordinary
odour: it was not musty, like that of the closed rooms through which they
had passed, but singularly pungent, disagreeable and sickly. He asked
himself what it could spring from. Then his eyes fell upon a huge
receptacle that stood on the table nearest to the furnace. It was covered
with a white cl