bjection, but--"

"But what?"

"I pray to Heaven you will not undertake this experiment alone, will
you?"

"Oh dear, no; not alone."

"You will take a companion with good nerves, and reliable in case of
disaster, won't you?"

"I shall bring two companions," the doctor said.

"Ah, that's better. I feel easier. I am sure you must have among your
acquaintances men who--"

"I shall not think of bringing men, Mr. Pender."

The other looked up sharply.

"No, or women either; or children."

"I don't understand. Who will you bring, then?"

"Animals," explained the doctor, unable to prevent a smile at his
companion's expression of surprise--"two animals, a cat and a dog."

Pender stared as if his eyes would drop out upon the floor, and then led
the way without another word into the adjoining room where his wife was
awaiting them for tea.

II

A few days later the humorist and his wife, with minds greatly relieved,
moved into a small furnished house placed at their free disposal in
another part of London; and John Silence, intent upon his approaching
experiment, made ready to spend a night in the empty house on the top of
Putney Hill. Only two rooms were prepared for occupation: the study on
the ground floor and the bedroom immediately above it; all other doors
were to be locked, and no servant was to be left in the house. The motor
had orders to call for him at nine o'clock the following morning.

And, meanwhile, his secretary had instructions to look up the past
history and associations of the place, and learn everything he could
concerning the character of former occupants, recent or remote.

The animals, by whose sensitiveness he intended to test any unusual
conditions in the atmosphere of the building, Dr. Silence selected with
care and judgment. He believed (and had already made curious experiments
to prove it) that animals were more often, and more truly, clairvoyant
than human beings. Many of them, he felt convinced, possessed powers of
perception far superior to that mere keenness of the senses common to
all dwellers in the wilds where the senses grow specially alert; they
had what he termed "animal clairvoyance," and from his experiments with
horses, dogs, cats, and even birds, he had drawn certain deductions,
which, however, need not be referred to in detail here.

Cats, in particular, he believed, were almost continuously conscious of
a larger field of vision, too detailed even for a photograph