Once more I obeyed. Then came this message: "Doctor, have you a chair handy?" I said a chair was at the moment within arm's reach of me. "Excellent," said this person who professed to be in charge of the test. "Please draw the chair close up to the wall, climb upon it and, standing on tiptoe, say coo-coo clearly and distinctly and keep on saying it until I call out 'Enough.'" [Illustration: "SAY COO-COO CLEARLY AND DISTINCTLY AND KEEP ON SAYING IT UNTIL I CALL OUT 'ENOUGH'"] Marvelling that such a prolonged test should be deemed necessary, I nevertheless obliged by acting as instructed. I had repeated the word for what seemed to me an interminable space of time and was rapidly becoming wearied by the exertion of maintaining the position required when the voice said "Enough." I lost no time in dismounting to _terra firma_, or rather the floor. "Thank you so much," stated the unknown. "Just one more little test, doctor, and we'll be through. Have you a good singing voice?" In proper modesty but with a due regard for the truth, I admitted that although I never enjoyed the advantages of vocal culture, friends had more than once commented upon the quality of my voice when uplifted in song. "I sing tenor," I amplified, for as yet I suspected nothing. "Very well then," bade the stranger; "are you holding the receiver to your ear?" "I am." "Keep it there. And now stand on your head and sing 'Just as I am Without One Plea.'" I started back astounded. Instantly I divined, in a lightning flash of intuition, that apparently an effort was being made to perpetrate a hoax. In the same moment I arrived at the definite conclusion that the object of that hoax could be none other than myself. For a fleeting period my natural indignation was such that language almost failed me. Simultaneously I became aware of a sound as of suppressed laughter outside my study window. Releasing my hold upon the receiver which, until then, mechanically I had retained in my grasp, I stepped to my casement and peered out, first looking this way, then that. No one was in sight; I must have fancied I heard something. When I had in part recovered myself I lost no time in calling up the manager of the exchange, my intent being to explain the entire circumstance to him, with a view to demanding condign punishment of the person in his inspection department, whoever she might be, who with wilful design had sought to debase the organisation of his office to purposes of ill-timed merrymaking. He cut me short to say he had no such testing department whatsoever. From his tone I was impelled to accept his statement as a truthful one, all of which but served to confirm my suspicions without in the least explaining the mystery which at this hour remains unsolved. I am puzzled--nay, more, I am nettled, and did I not possess the power of holding my emotions under a well-nigh perfect control, I would go so far as to say that I have been outright irritated.