“There was one other most important discovery which I made after I had divided the impressions into two classes—­according as they were produced by the right or left board—­which was that when the right foot was thrown forward the stride was from three to four inches longer than when the left foot led.  Directly under the window there was a deep impression in the sand.  I took a plaster cast of it, and here it is,” he said, producing an excellent facsimile of a closed hand.  “There can be little doubt,” he continued, “from the position occupied by the depression, of which this is a reverse copy, that it was either accidentally made by someone who, stooping before the east window to avoid obstructing its light, suddenly lost his balance and regained his equilibrium by thus thrusting out his hand, or—­and this seems far more likely to me—­that the hand was deliberately placed in the gravel in order to steady its possessor while he performed some peculiar operation.”

At this point I ventured to ask why he regarded the latter view as so much more tenable than the former.  “There are several reasons,” he replied, “which render the view I prefer to take all but certain.  First, the impression was made by the left hand.  Second, it is the impression of a closed hand, with the upper joints of the fingers undermost.  Did you ever know one to save himself from falling by thrusting out a closed hand?  Certainly not.  There is a certain amount of fear, however slight, invariably associated with losing one’s balance.  This sentiment, so far as the hand is concerned, is expressed by opening it and spreading the fingers.  This he would instinctively have done, if falling.  Then there is the position of the impression relative to the window and some slight testimony upon the sill and glass, for the thorough investigation of which I have been obliged to await my microscope.  I have worked diligently, but that is all I have been able to accomplish.”

“All!” exclaimed Gwen, regarding him with ill-concealed admiration.  “It seems to me a very great deal.  The thoroughness, the minuteness of it all, overwhelms me; but, tell me, have your discoveries led you to any conclusion?” “No,” he replied, “nothing definite yet; I must not allow myself to become wedded to any theory, so long as there is anything further to be learned.  If I were to hazard a few idle guesses, I should say your father was murdered in some mysterious way—­by a person about five feet five inches tall, weighing, say, one hundred and thirty-five pounds, and having a lame leg, or, perhaps, one limb shorter than the other,—­at all events having some deformity or ailment causing a variation in the length of the strides.  I should guess also that this person’s feet had some marked peculiarity, since such pains had been taken to conceal the footprints.  Then the cast of the hand here encourages speculation.  Fingers long, slim, and delicate, save at the nails, where, with the exception of the little finger, are