Gradually the excitement concerning the diamond robbery died away as do ripples in a pool and once more Christopher found himself settling down on the little wooden stool at McPhearson's elbow. The two had by this time become great friends, the boy preferring the companionship of the little Scotchman to that of any one else in the store. Perhaps this preference grew in a measure out of the fact that McPhearson appeared to like him and make more effort to entertain him than did the other clerks; perhaps also he had discovered that the clockmaker, when he did speak, was better worth listening to. Be that as it may, he sallied into the repair department very glad to be there again. "I feel as if I hadn't had a clock lesson for ages," observed he, as he sat down. "Clock lesson? What do you mean?" The man with the swift-moving hands shot him a quick, puzzled glance. "Oh, don't think I am here to steal your trade," retorted Christopher mischievously. "I only mean that so far as I am concerned the clock world stopped with Quare, Tompion, and Graham." "Indeed it didn't," contradicted the Scotchman, instantly bristling. "Though if it had, you would not need to be pitied for those makers would have bequeathed you some pretty fine products. And when you consider that Tompion, at least, began life as a blacksmith it is the more remarkable. Think what it meant to work out of such a crude, rough trade into one so delicate! Still, it was an age of marvels--a strange, fantastic, interesting era in which to have lived. Many members of the Clockmakers' Company were blacksmiths who had graduated into this higher calling and now boasted their own shops and apprentices. These latter men helped about under supervision, learning the trade and completing from eight to ten years of service before being taken in turn into the guild and permitted to make clocks. In the meantime they prepared simple parts of the work and made themselves useful in any direction they were able, even running errands or standing at the shop door and coaxing the passers-by to come in and purchase." "Pretty primitive advertising," smiled Christopher. "Advertising was primitive in those days," agreed McPhearson. "Sometimes when trade was dull the unfortunate apprentices were sent out to tour the streets and bring in customers. Or the present of a watch or clock would be made to the king or some nobleman of wealth and influence in the hope that such a gift would stimulate others to buy. No doubt even the celebrated Graham, in the days of his apprenticeship to Tompion, may have had some of these humble duties to perform. But if so they failed to dash his enthusiasm for his profession, for you see how well he profited by his teaching and what a master at clockmaking he finally became. He had always been an ingenious fellow interested in evolving mathematical instruments of all sorts." "Were his clocks as good as Tompion's?" queried Christopher.