I never met a man possessed of a more thoroughly mathematical head than this ancient mason. I know not that he ever saw a copy of Euclid; but the principles of the work seemed to lie as self-evident truths in his mind. In the ability, too, of drawing shrewd inferences from natural phenomena, old John Fraser excelled all the other untaught men I ever knew. Until my acquaintance with him commenced, I had been accustomed to hear the removal of what was widely known in the north of Scotland as "the travelled stone of Petty," attributed to supernatural agency. An enormous boulder had been carried in the night-time by the fairies, it was said, from its resting place on the sea-beach, into the middle of a little bay--a journey of several hundred feet; but old John, though he had not been on the spot at the time, at once inferred that it had been carried, not by the fairies, but by a thick cake of ice, considerable enough, when firmly clasped round it, to float it away. He had seen, he told me, stones of considerable size floated off by ice on the shore opposite his cottage, in the upper reaches of the Cromarty Firth: ice was an agent that sometimes "walked off with great stones;" whereas he had no evidence whatever that the fairies had any powers that way; and so he accepted the agent which he knew, as the true one in the removal of the travelled stone, and not the hypothetical agents of which he knew nothing. Such was the natural philosophy of old John; and in this special instance geologic science has since fully confirmed his decision. He was chiefly a favourite among us, however, from his even and cheerful temper, and his ability of telling humorous stories, that used to set the barrack in a roar, and in which he never spared himself, if the exhibition of a weakness or absurdity gave but point to the fun. His narrative of a visit to Inverness, which he had made when an apprentice lad, to see a sheep-stealer hung, and his description of the terrors of a night-journey back, in which he fancied he saw men waving in the wind on almost every tree, till on reaching his solitary barrack he was utterly prostrated by the apparition of his own great-coat suspended from a pin, has oftener than once convulsed us with laughter. But John's humorous confessions, based as they always were on a strong good sense, that always saw the early folly in its most ludicrous aspect, never lowered him in our eyes. Of his wonderful skill as a workman, much was incommunicable; but it was at least something to know the principles on which he directed the operations of what a phrenologist would perhaps term his extraordinary faculties of _form_ and _size_; and so I recognise old John as one of not the least useful nor able of my many teachers. Some of his professional lessons were of a kind which the south and east country masons would be the better for knowing. In that rainy district of Scotland of which we at this time