CEZIMBRA, sti-zem'bra. A coast town of Portugal, in the Province of Estremadura. IS miles south of Lisbon (Map: Portugal. A 3). It has a good harbor and fisheries. Population of the commune, in 1890. S13S; in 1900, 9000.
C. G. S., or CENTIMETER-GRAM-SEC OND SYSTEM. That system of units or stand ards for the measurement. of physical quantities which is based upon the centimeter as the unit of length, the gram as the unit of mass. and the mean solar second as the unit of time duration.
It has been adopted by all scientific bodies, by most governments, and is in daily commercial 11-e at the present time (1902) by all the lead ing nations of the world except Russia, Great Britain, and the United States, The cent inlet( r has a length which is the one hundredth of that of a certain platinum bar kept in Paris. known as the des °rehires, the length being measured when the bar is at the temperature of 0° Centigrade. Its abbreviation is 'ern.' The gram has a mass which is the one thousandth of that of a piece of platinum kept in Paris, known as the kilogramme des archives. Its abl,reN iation is `gm.' The mean solar second is an interval of time such that 60 X 60 X 24 of them compose a mean solar day—that is, the length of time such that 365 of than compose a year. The abbreviation of the second] is 'see.' It should be noted that the meter is nearly one-ten-millionth of the distance from the pole of the earth to the equator, measured along any meridian on the earth's surface. Further, the grain has very exactly the same mass as one cubic centimeter of distilled water at 4° C. (its temperature of maximum density), and at normal atmospheric pressure, for the most ac s-orate results give for this mass 0.99996 grain.
.1 liter is the volume occupied by one kilogram of pure water at -1' and at clarion] pressure.
Various multiples and fractions of these units have received imines. (See :METRIC SYSTEM.) Thus, one thousand meters is called a I; ilometer ; one-tenth of a centimeter a millimeter; one thousandth of a millimeter a micron, whose abbreviation or symbol is '/.4' ; one-thousandth of a micron, or one-millionth of a millimeter, has the symbol 'pit.' The other divisions of the meter and those of the grain have the usual decimal names and notations. The words 'min liteS,. 'hours,' etc., redpiire no explanation. Units for the various ineehanical quantities are based directly on the centimeter, grain. and second. Thus, a unit velocity on the C'. C. S. system is a speed of one centimeter per second in a definite direction, etc. (See AlEcitAxics and AlEctiANIcAt. UNITS,) A unit force is called a dyne; a unit of energy an erg; but these units are incon veniently small, and so multiples of them are used in general. A megailyne is 1.000.000 or lir dynes; a /mile is 10,000.000, or lit' ergs. The practical unit of pressure is, therefore, I mega dyne per square centimeter, and is called a boric: the practical unit of power or activity is 1 10111C per second. and it is called a matt.
There are also several sets of electrical units (q.v.), based on these mechanical ones, as are also the ordinary units for measuring heat en ergy and phot011ietrie quantities. (See 1-1FAT: and l'intromETitv.) Consult Everett, Illustra tions of the Centimlire-G'rancme ,System (Lon don. 1875).