One of the specialties of the city is its rats. In my house-yard was a sink, or rather hole in the rock, covered by a wooden grating. A large cat, who made herself at home on the premises, would sit watching at the grating for hours, every now and then inserting her paw between the bars and hooking out leisurely a squeaking young rat, of which thirty or forty at a time showed themselves within the cavity. I was assured that these rats have underground communications, like those of the rock of Gibraltar, from every quarter of the city to the citadel, and so downward to the quays and river below. Besides the cat, there was a rough terrier dog named Cæsar, also exercising right of occupancy. To see him pouncing upon rats in the pantry, from which they could not be easily excluded by reason of a dozen entrances through the stone basement walls, was something to enchant sporting characters. I was not of that class, so stopped up the rock with broken bottles and mortar, and provided traps for stray intruders. The Laurentine mountains, distant a few miles north of the city, rise to a height of twenty-five hundred feet. By daylight they are bleak and barren enough; but at night, seen in the light of the glorious Aurora Borealis which so often irradiates that part of Canada, they are a vision of enchanting beauty. This reminds me of a conversation which I was privileged to have with the late Sir William Logan, who most kindly answered my many inquisitive questions on geological subjects. He explained that the mountains of Newfoundland, of Quebec, of the height of land between the St. Lawrence and Lake Nipissing, and of Manitoba and Keewatin in the North-West, are all links of one continuous chain, of nearly equal elevation, and marked throughout that vast extent by ancient sea-beaches at an uniform level of twelve hundred feet above the sea, with other ancient beaches seven hundred feet above the sea at various points; two remarkable examples of which latter class are the rock of Quebec and the Oak Ridges eighteen miles north of Toronto. He pointed out further, that those two points indicate precisely the level of the great ocean which covered North America in the glacial period, when Toronto was six hundred feet under salt water, and Quebec was the solitary rock visible above water for hundreds of miles east, west and south--the Laurentides then, as now, towering eighteen hundred feet higher, on the north.