Zaidie bowed her beautiful head in recognition of this ages-old devotion, and said as she passed him, more sweetly than he had ever heard human lips speak: "Thank you, Mr. Murgatroyd. You've taught me something in those few words that we have no knowledge of in the States. Good service is as honourable as good mastership. Thank you." Murgatroyd put up his lower lip and half smiled with his upper, for he was not yet quite sure of this radiant beauty, who, according to his ideas, should have been English and wasn't. Then, with a rather clumsy and yet eloquent gesture, he showed her the way down to the air-chamber. She nodded to him with a smile as she passed in through the air-tight door, and when she heard the levers swing to and the bolts shoot into their places she felt as though, for the time being, she had said goodbye to a friend. Her husband was waiting for her almost fully clad in his breathing-dress. He had hers all ready to put on, and when the necessary changes and investments had been made, Zaidie found herself clad in a costume which was not by any means unlike the diving-dresses of common use, save that they were very much lighter in construction. The helmets were smaller, and not having to withstand outside pressure they were made of welded aluminum, lined thickly with asbestos, not to keep the cold out, but the heat in. On the back of the dress there was a square case, looking like a knapsack, containing the expanding apparatus, which would furnish breathable air for an almost unlimited time as long as the liquefied air from a cylinder hung below it passed through the cells in which the breathed air had been deprived of its carbonic acid gas and other noxious ingredients. The pressure of air inside the helmet automatically regulated the supply, which was not permitted to circulate through the other portions of the dress. The reasons for this precaution were very simple. Granted the absence of atmosphere on the moon, any air in the dress, which was woven of a cunning compound of silk and asbestos, would instantly expand with irresistible force, burst the covering, and expose the limbs of the explorers to a cold which would be infinitely more destructive than the hottest of earthly fires. It would wither them to nothing in a moment. A human hand or foot--we won't say anything about faces--exposed to the summer or winter temperature of the moon--that is to say, to its sunlight and its darkness--would be shrivelled into dry bone in a moment, and therefore Lord Redgrave, foreseeing this, had provided the breathing-dresses. Lastly, the two helmets were connected, for purposes of conversation, by a light wire, the two ends of which were connected with a little telephonic receiver and transmitter inside each of the head-dresses. "Well, now I think we're ready," said Redgrave, putting his hand on the lever which opened the outer door.