The Clockwork man is now ready for adjustment. The chart should be studied with care, and a choice made from one of the types indicated. Having made a selection, proceed to arrange indicators in accordance with detailed instructions, taking the utmost care to follow the directions with absolute accuracy, as the slightest error may lead to serious confusion. A good plan is to hold the chart in the left hand, and manipulate the regulators with the right, checking each adjustment as it is made. Now wind black central hand fourteen and a half times, press centre knob until bell rings, close lid, replace wig and hat, and Clockwork man is ready for action. * * * * * The expression on Gregg's face, as he read these amazing instructions, changed slowly from avid curiosity to puzzled alarm. He was frankly embarrassed by this sudden turn of events, and for a few moments he could make nothing at all of the matter. Yet the wording was intelligible enough, and its application to the Clockwork man only too obvious. The little piece of thin metal must have slipped from his pocket during the Doctor's examination, and its discovery was undoubtedly of supreme importance. But what could it mean? Gregg rather prided himself upon the resiliency of his mind, but not all the elasticity of which he was capable could enable him to overcome a sudden sense of uneasiness. Was the Clockwork man, after all, no more than a very elaborate and highly complex puppet? But how could that be, since he breathed and spoke and gave every sign of the possession of an individual consciousness? Considered in this new light he was even more difficult to explain. But when Gregg looked up, rather sheepishly, wary of meeting the Doctor's eye, he beheld a sight that sent an uncomfortable thrill down his spine. For the latter lay at full length upon the couch, his chest and stomach rising and falling in the convulsions of that excessive laughter that at first sight raises a doubt of danger in the mind of the beholder--for men have died of mirth. Gregg stared at his prostrate friend, and his own countenance was transfixed with alarm. Many minutes elapsed before any kind of definite sound brought a relief to the strain; for the Doctor's laugh was primæval; it racked his vitals, shook him from head to foot, began and stopped, proceeded in a series of explosions, not unlike those of the Clockwork man himself, until at last it reached the throat and found expression. "Ha! ha! ha!" broke at last upon the silence of the night (and Mrs. Masters in her top attic heard the noise and thought of the devil climbing over the roofs). "Ha! ha! ha! ha!"