with a well-directed
clod.

Now the proceedings of Mr. H. Weiss resembled those of the tom-cat
aforesaid and invited an analogous reply. To a responsible professional
man his extraordinary precautions were at once an affront and a
challenge. Apart from graver considerations, I found myself dwelling
with unholy pleasure on the prospect of locating the secret hiding-place
from which he seemed to grin at me with such complacent defiance; and I
lost no time and spared no trouble in preparing myself for the
adventure. The very hansom which bore me from the Temple to Kennington
Lane was utilized for a preliminary test of Thorndyke's little
apparatus. During the whole of that brief journey I watched the compass
closely, noted the feel and sound of the road-material and timed the
trotting of the horse. And the result was quite encouraging. It is true
that the compass-needle oscillated wildly to the vibration of the cab,
but still its oscillations took place around a definite point which was
the average direction, and it was evident to me that the data it
furnished were very fairly reliable. I felt very little doubt, after the
preliminary trial, as to my being able to produce a moderately
intelligible track-chart if only I should get an opportunity to exercise
my skill.

But it looked as if I should not. Mr. Weiss's promise to send for me
again soon was not fulfilled. Three days passed and still he made no
sign. I began to fear that I had been too outspoken; that the shuttered
carriage had gone forth to seek some more confiding and easy-going
practitioner, and that our elaborate preparations had been made in vain.
When the fourth day drew towards a close and still no summons had come,
I was disposed reluctantly to write the case off as a lost opportunity.

And at that moment, in the midst of my regrets, the bottle-boy thrust an
uncomely head in at the door. His voice was coarse, his accent was
hideous, and his grammatical construction beneath contempt; but I
forgave him all when I gathered the import of his message.

"Mr. Weiss's carriage is waiting, and he says will you come as quickly
as you can because he's took very bad to-night."

I sprang from my chair and hastily collected the necessaries for the
journey. The little board and the lamp I put in my overcoat pocket; I
overhauled the emergency bag and added to its usual contents a bottle of
permanganate of potassium which I thought I might require. Then I tucked
the ev