“You notice the thermometer.”
“Exactly.”
“Those knobs you see on the wall have various uses.”
“Quite.”
They examined the knobs with an air of profound seriousness, Mrs. Porter erect and complacent, the other leaning forward and peering through her spectacles. Mamie took advantage of their backs and turned to cast a hurried glance at the water-proof curtain. It was certainly an admirable screen; no sign of Steve was visible; but nevertheless she did not cease to quake.
“This,” said Mrs. Porter, “controls the heat. This, this, and this are for the ventilation.”
“Just so, just so, just so,” said the doctor. “And this, of course, is for the shower-bath? I understand!”
And, extending a firm finger, she gave the knob a forceful push.
Mrs. Porter nodded.
“That is the cold shower,” she said. “This is the hot. It is a very ingenious arrangement, one of Malcolmson’s patents. There is a regulator at the side of the bath which enables the nurse to get just the correct temperature. I will turn on both, and then——”