CLOTHO 25 CLOUDS perature, thus preventing the disturb- ance of the important excretory func- tions of the skin by the influence of heat or cold. Hence in a changeable climate the question of Clothing becomes of spe- cial importance. The chief end pro- posed by Clothing ought to be protection from the cold. A degree of cold amount- ing to shivering cannot be felt without injury to the health, and the strongest constitution cannot resist the benumbing influence of a sensation of cold constant- ly present, even though it be so moderate as not to occasion immediate complaint, or to induce the sufferer to seek protec- tion from it. This degree of cold often lays the foundation of the whole host of chronic diseases, foremost among which are found scrofula and consumption. The only kind of dress that can afford the protection required by the changes of temperature to which the cooler or tem- perate climates itre liable is woolen. Those who would receive the advantage which the wearing of woolen is capable of affording must wear it next the skin; for it is in this situation only that its health-preserving power can be felt. The great advantages of woolen cloth are briefly these: — the readiness with which it allows the escape of sweat through its texture; its power of preserving the sen- sation of warmth to the skin under all circumstances; the slowness with which it conducts heat; the softness, lightness, and pliancy of its texture. Cotton cloth, though it differs but little from linen, approaches nearer to the nature of wool- en, and on that account must be esteemed as the next best substance of which Clothing may be made. Silk is the next in point of excellence, but it i^ very in- ferior to cotton in every respect. Linen possesses the contrary of most of the properties enumerated as excellencies in woolen. It retains the matter of per- spiration in its texture, and speedily be- comes imbued with it; it gives an un- pleasant sensation of cold to the skin ; it is very readily saturated with moisture, and it conducts heat too rapidly. Clothes should be so made as to allow the body the full exercise of all its mo- tions. The neglect of this precaution is productive of more mischief than is gen- erally believed. CLOTHO, one of the three Fates or Destinies who are represented by the an- cient classical writers as spinning the thread of life. Clotho held the distaff, Lachesis spun the thread of life, Atropos cut the thread when the man was to die. CLOTILDA, ST., the daughter of Chilperic, King of Burgundy; born in 47.5, and in 493 became wife of Clovis, King of the Franks. She was the chief means of securing the conversion of her husband to Christianity, and largely in- fluenced his life. After his death she lived a life of austerity at Tours, where she died in 545. She was canonized a few years after. Her remains were buried in the church of St. Genevieve at Paris, and burnt at the Revolution to prevent their desecration ; the ashes are still in the church of St. Leu. CLOUDS, formations owing their origin to aqueous vapor diffused in the atmosphere. The vapor is supplied from the evaporation of the sea and other water surfaces, under the influence of solar heat, and is diffused through the agency of winds. Air — under a given pressure and temperature — can absorb, or hold, only a certain amount of invisible vapor; when charged with this maximum amount it is said to be saturated. Should the temperature, under this condition, be lowered, as, for instance, when a current is ascending into colder regions, or ex- panding, condensation takes place, and clouds are formed, appearing suspended at a certain level above the surface. Should the cooling continue, these glo- bules unite and are finely precipitated in the form of rain, and, with sufficiently reduced temperatui'e, as snow, or perhaps hail or sleet. Mists and fogs are simply incipient states of clouds, and when in contact with cold bodies produce, by de- position of moisture, dew, and hoar-frost. The whole subject is comprised under the name hygrometry. The forms of clouds have been observed to depend greatly on altitude, and have been classified ac- cordingly. The nomenclature proposed by Howard, at the beginning of the 19th century, is still generally adhered to, owing to its simplicity and appropriateness, though a few minor subdivisions have been added. He divides clouds into three primary modifications, named cumulus, stratus, and cirrus, with the intermediate compos- ite forms — cumulo-stratzts, cii'^y-stratus , cirro-cumulus, and, lastly, nimbus, or rain-cloud. These varieties, and the con- ditions accompanying them, may be brief- ly described as follows: Cumulus — Con- vex or conical masses, generally resting on a horizontal base of apparently dense structure, and of globular shape or rolls (so-called cotton bale) ; they form in the lower atmosphere under the influence of ascending heated air, and are most de- veloped during the hottest part of the day; a fair-weather cloud. Stratus — Consists of continuous hoi'izontal sheets, a fine-weather sign, appearing mostly during the night and at no great eleva- tion. It forms dense clouds when mixed with smoke or dust. Cirrus — A lofty
