ZERMATT, tser-miit'. A celebrated mountain resort in the southern part of the Canton of Valais, Switzerland, situated on the left bank of the Visp at an altitude of over 5000 feet (Map: Switzerland, II 2). II is the starting point. for ascents of the BilTelherg and the Gooier Grat, which are connected by an electric moun tain railway with Zermatt. as well as of the Matterhorn (q.v.) and the entire Monte Rosa group. Population, in 1900, 752.
ZERO (Fr, t:1(ro, from It., Sp. zero, from Ar. ,silr„safr, cipher, from salira, to be empty). In mathematics, a symbol written 0, and signifying the absence of quantity or number. The term is also applied to the infinitesimal. (See INFINITY AND TIIE INFINITESIMAL; NEGATIVE QUANTITY.) In thermometry the term is applied to certain fundamental points of temperature on the ther mometer scale. In the earliest thermometers (q.v.) the zero point was fixed at the normal temperature of a healthy man, and any varia tion from this point was indicated on an arbi trary scale. The temperature of spring water
was also selected as a fundamental point. A mixture of snow and salt furnished the zero point on Sagredo's thermometer, where the tempera ture of the hottest summer day was denoted by 360. Fahrenheit also used the mixture of ice and salt to determine the zero in his thermom eter, while Reaunmr put his zero at the tem perature of melting ice. About the same time De lisle constructed thermometers in which the zero was the temperature of freezing water, and also instruments where the zero was at the boil ing point. The zero of the modern centigrade thermometer is fixed at the temperature of melt ing ice and is marked by placing the thermom eter in a vessel containing cracked ice. For absolute zero, see THERMOMETER.