“Your views in the matter,” replied Maitland, “are precisely those which first occurred to me, and I am not sure but I should still hold them, had I been obliged to decide solely from the evidence I have submitted to you.  It was clear to my mind from the first that some common purpose actuated both Weltz and Rizzi.  With a view to ascertaining where they lived as a preparatory step toward learning more of them, I consulted a Boston directory, only to learn that it contained no such names.  I was about to examine some of the directories of neighbouring towns when it occurred to me that the easiest way to find their places of residence would be to consult the green slips upon which they had procured their books, and I accordingly asked the attendant to kindly let me look at them.  While she was collecting the slips I re-examined the list of books taken by Weltz and Rizzi, especially those which had been taken by both men.  One thing at once struck my attention, and that was that most of these latter were large books which would take a long time to peruse and would require to be borrowed several times for hall use, were they to be examined with any care.  I put this fact down for future reference and gave my attention to the green slips, the whole twenty of which the attendant now placed before me.  The residence of Weltz was given as No. 15 Staniford Place, Boston, while that of Rizzi was No. 5 Oak Street, Boston.  I was about to walk over to Oak Street to see if Rizzi were still there when, in returning the slips to the attendant, I noticed a peculiarity in Weltz’s ‘z’ which I had thought I had seen in Rizzi’s signature.  I immediately compared the slips.  There was the same oddly shaped ‘z’ in both.  It was made like this”—­and he handed us a slip of paper with this z* upon it.

“You see,” he continued, “it is so unusual a way of making the letter that it at once attracted my attention, notwithstanding the fact that Rizzi wrote with his left hand.  Closer examination revealed other peculiarities, as in the r*’s, common to both hands.  Well, to make a long story short, I satisfied myself that the same person wrote the whole twenty slips and was, moreover, ambidextrous.  This I considered as a very promising discovery, so much so, indeed, that I gave up an engagement I had for the evening and decided to camp right there until the Library closed.  Happily the books I had been consulting were still on the table.  I picked out those borrowed under the names of Weltz and Rizzi, and began a most careful examination of them.  I had been working about two hours when I discovered something that fairly took my breath away.  I was not sure that I was right, but I knew that, if my microscope bore me out, I would be able to stake my life that the murderer of John Darrow had read that book.  I was aware, however, that even then I should not be able to name the man who had put his mark upon the book, but I could take oath that the record was made by the same hand that committed the murder.