water surface lessens, a connection being maintained with each other and with the first or outer canal which carries the water to the sea or river. In Schermer Polder in North Holland are four canal levels, the land between them forming long parallelograms.

Pole'cat, a carnivourous animal with a long, slim body like a weasel. Four species inhabit the northern hemisphere. The common polecat of Europe is dark brown above and black below. Its fur is of little value. They sleep by day, and at night plunder poultry-yards and dove-cotes. They feed also on rabbits, rats, mice and birds. Very similar species are found in Siberia, Tibet and North America. These animals emit a foul odor when disturbed. The ferret is a domesticated variety of polecat. In the United States the name sometimes is applied to the skunk incorrectly.

Poles (Greek polos, a turning point), in geography are the two extremities of the axis round which the earth revolves, the north pole being 900 north of the equator and the south pole 90° south. In astronomy the poles, which for distinction are called celestial poles, are those points in the heavens to which the earth's axis is directed and round which the heavens seem to revolve. Unfortunately no stars mark the exact position of the celestial poles, and therefore the polestar is used for this purpose, its exact position being determined by noting the point between its upper and lower cidminations. The term poles also has a wider application as denoting the extremities of a line passing through the center of a great circle perpendicular to its plane. Thus we have the poles of the horizon (which are the zenith and the nadir), the poles of the ecliptic and the poles of a meridian. In the same sense the terrestial and celestial poles are spoken of as the poles of the equator and the equinoctial, respectively. Poles in physics denote those points of a body at which its attractive or repulsive force is concentrated.

Pole'star or Pola'ris, the star nearest to the northern pole of the celestial quarter. The star which at present goes under the name of the polestar is Alpha in the constellation of Ursa Minor. This star, however, is a little more than 1° from the north pole and has a sensible motion around it. This star will in about 2,100 A. D. come within 28' of the north pole of the heavens, and then recede. Two thousand years ago -Beta of Ursa Minor was the polestar, and about 2,300 B. C. Alpha in the constellation of the Dragon was not more than 10' from the north pole, while 12,000 years after the present time the bright star Vega in Lyra will be within 5° of it.

Pole-Vault'ing is one of the sports called field-events. It consists in leaping over

a bar by means of a pole. Usually this is 16 feet long. The contestant grasps the pole above his head, measures the height of the bar with his eye, and runs forward. At a certain distance from the bar he thrusts the pole into the ground, leaps up, and throws himself forward and. up over the bar, at the same time flinging the pole behind him. Generally three trials at different heights are made. The highest record is 12 feet nine inches.

Police {pô-lēs') are a& organized force —■ especially in towns and cities — for the preservation of peace and order and the prevention of crime. This definition applies more particularly to the police of the United States and of England, as the police of most European countries have much wider functions, and are often used by rulers and ministers for political purposes and in a more or less oppressive manner. The existing sytem of police administration in England is of recent origin, and many features of it were introduced during the reign of Queen Victoria. In the early periods of English history there was no such thing as a separate body of police, the responsibility for the maintenance of the peace being imposed on each hundred or tithing and the individuals composing these divisions being held jointly liable for the consequences of any violations of law which occurred within their limits. In the larger towns the inhabitants of the various wards kept watch within their limits, special watchmen being gradually introduced; but these duties of watch and ward were performed very inefficiently, and crimes were committed with marked impunity, especially in London and other large cities. During the 18th century various efforts were made to remedy this state of things in London and to secure a more efficient administration both in the prevention and detection of crime; but the results obtained were very unsatisfactory. In 1829 Sir Robert Peel organized the metropolitan police, placing the new force under the control of the secretary of state, and since that time the police of counties and boroughs have been organized upon the same principles as the metropolitan police, except that they are under the local authority. The strength of this body of metropolitan police is 14,954, comprising 31 superintendents, 578 inspectors, 1,930 sergeants and 13,155 constables. The City of London police-force numbers 1,062 men, exclusive of those on private service and detective duty and of those known as metropolitan police. The police-force throughout the kingdom is a civil, not a military body, with the exception of the royal Irish constabulary, which is more military than civil. This force is directly under the Irish government, and its members are armed and drilled as soldiers. It