So the Maori set to work, building houses and forts, and hewing out canoes. For the last, those who dwelt in the north chose the great trunks of the _kauri_, often forty feet in circumference, and of such diameter that a tall man with outspread arms could not stretch from rim to rim of the cross section. In the south they used the _totara_, likewise a pine, and great, but a pigmy beside the imperial _kauri_. While the builders built, explorers traced the swiftly flowing rivers from source to sea, or gazed with awe at the snow-capped peaks and glimmering glaciers. Others moved northwards towards those giant mountains from whose cones poured tall pillars of smoke, threatening shadows of dire events to come, or stood upon the shore of a lake, marvelling to find the water hot instead of cold. Imagine one, agape with curiosity, holding in his hand a dead _kuri_, designed for dinner. Suddenly, with hiss and roar, a column of water shoots hundreds of feet into the air, almost at his elbow. With a cry of terror he starts back, losing his grip of the dog, which drops into an adjacent pool. Too much afraid to run, our Maori stands trembling, and the spouting column presently falls back into the bowels of the earth. Marvelling, he gropes in the pool for his dinner, and with another yell withdraws his hand and arm, badly scalded. But he has got his dog and, to his amazement, it is cooked to perfection. Small wonder if the Maori muttered a _karakia_, deeming the miracle the work of the demon of the lake. But their fear departed as time went on, and the hot springs and lakes became health-resorts, where they bathed and strove to be rid of the pains and aches their flesh was heir to. Those who dwelt within reach of this marvellous region soon became familiar with its phenomena, and made full use of the natural sanatorium and kitchen. Other immigrants gathered for ornament the precious greenstone from the Middle Island, with blocks of jade and serpentine; the snow-white breast of the albatross; the wings of birds; the tail plumes of the infrequent _huia_;[41] the cruel teeth of the shark. They found another use for the greenstone, fashioning it with infinite toil into war-clubs, or _mere_, too valuable to be used in the shock of battle without safeguard against possible loss. So a hole was drilled through the handle, and a loop of flax passed through, by which the club was secured to the wrist. How in the world could they pierce that defiant mineral--they, who had neither iron nor diamonds with which to drill a hole? Their method was as ingenious as it was simple. They took a sharp-pointed stick of hard wood and half-way up secured two stones, which acted after the manner of a flywheel. Above the stones two pieces of string were attached, and these, alternately pulled, imparted a rotatory movement to the stick, whose sharpened point at length pierced the sullen stone.