Page:EB1911 - Volume 14.djvu/254

 generally made hollow for racing-yachts and the rigging is pliable steel wire. The sails are of 10-oz. duck for a boat carrying 400 sq. ft. of canvas. They have very high peaks, short hoists and long booms. The mainsail and jib rig is general, but a double-masted lateen rig has been found advantageous. The foremost ice-yacht builder of America is G. E. Buckhout of Poughkeepsie.

An ice-yacht about 40 ft. in length will carry 6 or 7 passengers or crew, who are distributed in such a manner as to preserve the balance of the boat. In a good breeze the crew lie out on the windward side of the runner-plank to balance the boat and reduce the pressure on the leeward runner. A course of 20 m. with many turns has been sailed on the Hudson in less than 48 minutes, the record for a measured mile with flying start being at the rate of about 72 m. an hour. In a high wind, however, ice-yachts often move at the rate of 85 and even 90 m. an hour.

Several of the laws of ice navigation seem marvellous to the uninitiated. Commodore Irving Grinnell, who has made a scientific study of the sport, says: “The two marked peculiarities of ice-yachting which cause it to differ materially from yachting on the sea are: (1) Sailing faster than the wind. (2) Sheets flat aft under all circumstances.” Mr H. A. Buck, in the “Badminton Library,” Skating, Curling, Tobogganing, &c., thus explains these paradoxes. An ice-boat sails faster than the wind because she invariably sails at some angle to it. The momentum is increased by every puff of wind striking the sails obliquely, until it is finally equalled by the increase of friction engendered. Thus the continued bursts of wind against the sails cause a greater accumulation of speed in the ice-yacht than is possessed by the wind itself. When the boat sails directly before the wind she is, like a balloon, at its mercy, and thus does not sail faster than the wind. The ice-yacht always sails with its sheets flat aft, because the greater speed of the boat changes the angle at which the wind strikes the sail from that at which it would strike if the yacht were stationary to such a degree that, in whatever direction the yacht is sailing, the result is always the same as if the yacht were close-hauled to the wind. It follows that the yacht is actually overhauling the wind, and her canvas shivers as if in the wind’s eye. When eased off her momentum becomes less and less until it drops to the velocity of the wind, when she can readily be stopped by being spun round and brought head to the wind. The latter method is one way of “coming to,” instead of luffing up in the usual way from a beam wind. In beating to windward an ice-boat is handled like a water yacht, though she points more closely.

On the bays near New York a peculiar kind of ice-boat has developed, called scooter, which may be described as a toboggan with a sail. A typical scooter is about 15 ft. long with an extreme beam of 5 ft., perfectly oval in form and flat. It has mainsail and jib carried on a mast 9 or 10 ft. long and set well aft, and is provided with two long parallel metal runners. There is no rudder, the scooter being steered entirely by trimming the sails, particularly the jib. As the craft is flat and buoyant it sails well in water, and can thus be used on very thin ice without danger. A speed of 50 m. an hour has been attained by a scooter (see Outing for March 1905).

I-CHʽANG (, anciently known as Yi-ling), a town of China in the province of Hu-peh, one of the four ports opened to foreign trade by treaty in 1877. It is situated in 30° 42′ N. and (approximately) 111° 20′ E., on the Yangtsze-Kiang, 1000 m. from Shanghai. Built on the left bank of the river where it escapes from the ravines and gorges which for 350 m. have imprisoned its channel, I-chʽang is exposed to considerable risk of floods; in 1870 the waters rose 20 ft. in one day, and the town had many of its houses and about half of its wall swept away. The first English vessels to ascend the river as far as I-chʽang were those of Admiral Sir James Hope’s expedition in 1861. All cargo to or from Szechʽuen is here transhipped from steamer to junk, or vice versâ. About 10 m. above I-chʽang the famed scenery of the Yangtsze gorges begins. Through these the great river runs in a series of rapids, which make navigation by vessels of any size extremely difficult. A very large trade, nevertheless, is carried on by this route between Chungkʽing and I-chʽang. As a local centre of distribution this port is of no great consequence, the transhipment trade with Szechʽuen being almost its sole business. The population is estimated at 35,000. The number of foreign residents is very small, trade being carried on by Chinese agents. Before the anti-opium campaign of 1906 (see ) opium was much grown. The trade of the port amounted in 1899 to £531,229, and in 1904 to £424,442, the principal import being cotton yarn and the principal export opium.

  ICHNEUMON (Gr. , from  , to track out), the common name of the North African representative of a number of small weasel-shaped mammals belonging to the carnivorous family Viverridae; the Indian representatives of the group being known as mongooses. A large number of species of the type genus are known, and range over southern Asia and all Africa, the typical Herpestes ichneumon also occurring in the south of Spain. The latter is an inhabitant of Egypt and the north of Africa, where it is known to foreign residents as “Pharaoh’s rat.” It is covered with long harsh fur of a tawny-grey colour, darker on the head and along the middle of the back, its legs reddish and its feet and tail black. It lives largely on rats and mice, birds and reptiles, and for this reason it is domesticated. It is, however, fond of poultry and their eggs, and its depredations among fowls detract from its merits as a vermin-killer. During the inundations of the Nile it is said to approach the habitations of man, but at other seasons it keeps to the fields and to the banks of the river. The Indian mongoose (H. mungo) is considerably smaller than the Egyptian animal, with fur of a pale-grey colour, the hairs being largely white-ringed, while the cheeks and throat are more or less reddish. Like the former it is frequently domesticated. It is especially serviceable in India as a serpent-killer, destroying not only the eggs and young of these creatures, but killing the most venomous adult snakes. The fact that it survives those encounters has led to the belief that it either enjoys immunity from the effects of snake poison, or that after being bitten it has recourse, as the Hindus maintain, to the root of a plant as an antidote. It has been found, however, that when actually bitten it falls a victim to the poison as rapidly as other mammals, while there is no evidence of its seeking a vegetable antidote. The truth seems to be that the mongoose, by its exceeding agility and quickness of eye, avoids the fangs of the snake while fixing its own teeth in the back of the reptile’s neck. Moreover, when excited, the mongoose erects its long stiff hair, and it must be very difficult for a snake to drive its fangs through this and the thick skin which all the members of the genus possess. The mongoose never hesitates to attack a snake; the moment he sees his enemy, “his whole nature,” writes a spectator of one of those fights, “appears to be changed. His fur stands on end, and he presents the incarnation of intense rage. The snake invariably attempts to escape, but, finding it impossible to evade the rapid onslaught of the mongoose, raises his crest and lashes out fiercely at his little persecutor, who seems to delight in dodging out of the way just in time. This goes on until the mongoose sees his opportunity, when like lightning he rushes in and seizes the snake with his teeth by the back of the neck close to the head, shaking him as a terrier does a rat. These tactics are repeated until the snake is killed.” The mongoose is equally dexterous in killing rats and other four-footed vermin.

 ICHNEUMON-FLY, a general name applied to parasitic insects of the section Ichneumonoidea (or Entomophaga), order 