See also:

• FROST (a common Teutonic word, cf. Dutch, vorst, Ger. Frost, from the common Teutonic verb meaning " to freeze," Dutch, vriezcn, Ger. frieren; the Indo-European root is seen in Lat. pruina, hoar-frost, cf. prurire, to itch, burn, pruna, burning coal, Sans
• FROST, WILLIAM EDWARD (1810–1877)

FROST (a See also:

• COMMON

common See also:

• TEUTONIC
• TEUTONIC (GERMANIC) LANGUAGES

Teutonic word, cf. Dutch, vorst, Ger. Frost, from the common Teutonic verb meaning " to freeze," Dutch, vriezcn, Ger. frieren; the Indo-See also:

• EUROPEAN

European See also:

• ROOT (late O.E. rot, adopted from Scand., cf. Norw. and Swed. rot, Dan. rod; the true O.E. word was wyrt, plant, represented in Ger. Wurz or Wurzel; the ultimate root is the same in both words, and is seen in Lat. radix)
• ROOT, ELIHU (1845– )

root is seen in See also:

• LAT

Lat. pruina, See also:

• HOAR, SAMUEL (1778-1856)

hoar-frost, cf. prurire, to itch, See also:

• BURN, RICHARD (1709-1785)

burn, pruna, burning See also:

• COAL

coal, Sans  k. See also:

• PLUSH (Fr. peluche)

plush, to See also:

• BURN, RICHARD (1709-1785)

burn), in See also:

• METEOROLOGY (Gr. JerEwpa, and hb'yos, i.e. the science of things in the air)

meteorology, the See also:

• ACT (Lat. actus, actum)

act, or See also:

• AGENT (from Lat. agere, to act)

agent of the See also:

• PROCESS

process, of freezing; hence the terms " See also:

• HOAR, SAMUEL (1778-1856)

hoar-See also:

• FROST (a common Teutonic word, cf. Dutch, vorst, Ger. Frost, from the common Teutonic verb meaning " to freeze," Dutch, vriezcn, Ger. frieren; the Indo-European root is seen in Lat. pruina, hoar-frost, cf. prurire, to itch, burn, pruna, burning coal, Sans
• FROST, WILLIAM EDWARD (1810–1877)

frost " and " See also:

• WHITE
• WHITE, ANDREW DICKSON (1832– )
• WHITE, GILBERT (1720–1793)
• WHITE, HENRY KIRKE (1785-1806)
• WHITE, HUGH LAWSON (1773-1840)
• WHITE, JOSEPH BLANCO (1775-1841)
• WHITE, RICHARD GRANT (1822-1885)
• WHITE, ROBERT (1645-1704)
• WHITE, SIR GEORGE STUART (1835– )
• WHITE, SIR THOMAS (1492-1567)
• WHITE, SIR WILLIAM ARTHUR (1824--1891)
• WHITE, SIR WILLIAM HENRY (1845– )
• WHITE, THOMAS (1628-1698)
• WHITE, THOMAS (c. 1550-1624)

white-frost " applied to visible frozen vapourformed on exposed surfaces . A frost can only occur when the See also:

• SURFACE

surface temperature falls below 32° F., the freezing-point of See also:

• WATER

water; if the temperature be between 28° and 32° it is a " See also:

• LIGHT

light frost," if below 28° it is a " heavy," " killing " or " See also:

• BLACK
• BLACK, ADAM (1784-1874)
• BLACK, JEREMIAH SULLIVAN (1810–1883)
• BLACK, WILLIAM (1841-1898)

black frost "; the See also:

• TERM

term " black frost " is also used when no hoar-frost is See also:

• PRESENT

present . The number of degrees below freezing-point is termed " degrees of frost." As soon as a See also:

• MASS (O.E. maesse; Fr. messe; Ger. Messe; Ital. messa; from eccl. Lat. missa)
• MASS, IN

mass of See also:

• AIR (from an Indo-European root meaning " breathe," " blow ")
• AIR, or ASBEN

air is cooled to its See also:

• DEW

dew-point, water begins to be precipitated in the See also:

• FORM (Lat. forma)

form of See also:

• RAIN (O.E. regn; the word is common to Teutonic languages, cf. Ger. Regen, Swed. and Dan. regn; it has been connected with Lat. rigare, to wet, Gr. 13pixeav)

rain, dew, See also:

• SNOW (in O. Eng. sndw; a common Indo-European word; cf. in Teutonic languages, Ger. Schnee, Du. sneeuw; in Slavonic snieg', Lith. snegas; Gr. vi4a, Lat. nix, nivis, whence the Romanic forms, Ital. neve, Fr. neige, &c.; Ir. and Gael. sneachd; the original

snow or See also:

• HAIL (O. Eng. kcegl and hagol, 1 cf. the cognate Teutonic hagel, as in German, Dutch, Swedish, &c.; the Gr. K&XX17E, pebble, is probably allied)

hail . Hoar-frost is only formed at the immediate surface of the See also:

• LAND

land if the latter be at a temperature below 32°, and this may occur even when the temperature of the air a few feet above the ground is 12°-16° above the freezing-point . The heaviest hoar-frosts are formed under See also:

• WEATHER (O. Eng. weder; the word is common to Teutonic languages; cf. Du. weder, Dan. veir, Icel. ve8r, and Ger. Wetter and Gewitter, storm; the root is wa- to blow, from which is derived " wind ")

weather conditions similar to those under which the heaviest summer dews occur, namely, clear and See also:

• CALM

calm nights, when there is no See also:

• CLOUD (from the same root, if not the same word, as " clod," a word common in various forms to Teutonic languages for a mass or lump; it is first applied in the usual sense in the late 13th century; the Anglo-Saxon chid is only used in the sense of " a ma

cloud to impede the See also:

• RADIATION, THEORY OF

radiation of See also:

• HEAT (0. E. haktu, which like " hot," Old Eng. hat, is from the Teutonic type haita, hit, to be hot; cf. Ger. hitze, heiss; Dutch, hitte, heet, &c.)

heat from the surface of the land, which thereby becomes rapidly and completely cooled . The danger of frost is minimized when the See also:

• SOIL

soil is very moist, as for example after 10-12 mm. of rain; and it is a practice in See also:

• AMERICA

America to See also:

• FLOOD (in O. Eng. flod, a word common to Teutonic languages, cf. Ger. Flut, Dutch vloed, from the same root as is seen in " flow," " float ")
• FLOOD, HENRY (1732-1791)

flood See also:

• FIELDS, JAMES THOMAS (1817-1881)

fields on the See also:

• RECEIPT (M.E. receite, derived through Fr. from Lat. recepta, participle of recipere, to receive)

receipt of a frost warning, radiation being checked by the light See also:

• FOG

fog sheets which develop over moist soils, just as a cloud-layer in the upper See also:

• ATMOSPHERE (Gr. fir µ6r, vapour; orkaipa, a sphere)

atmosphere impedes radiation on a See also:

• GRAND

grand See also:

• SCALE
• SCALE (1) A

scale . A layer of See also:

• SMOKE (from O. Eng. smeocan, to smoke, reek, cf. Dutch meek, Ger. Schmauch, probably allied to Gr. vol9caiv)

smoke will also impede radiation locally, and to this end smoky fires are sometimes lit in such positions that the smoke may See also:

• DRIFT (from "drive ")

drift over planted ground which it is desirable to preserve from frost . Similarly, frost may occur in open See also:

• COUNTRY (from the Mid. Eng. contre or contrie, and O. Fr. cuntree; Late Lat. contrata, showing the derivation from contra, opposite, over against, thus the tract of land which fronts the sight, cf. Ger. Gegend, neighbourhood)

country when a See also:

• TOWN

town, protected by its smoke-cloud above, is See also:

• FREE

free of it . In a valley with fairly high and steep flanks frost sometimes occurs locally at the bottom, because the layer of air cooled by contact with the See also:

• COLD (in O. Eng. cald and ceald, a word coming ultimately from a root cognate with the Lat. gelu, gelidus, and common in the Teutonic languages, which usually have two distinct forms for the substantive and the adjective, cf. Ger. Kolte, kalt, Dutch koude

cold surface of the higher ground is heavier than that not so cooled, and therefore tends to flow or See also:

• SETTLE
• SETTLE, ELKANAH (1648–1724)

settle downwards along the slope of the land . When meteorological considerations point to a frost, an estimate of the See also:

• NIGHT

night temperature may be obtained by multiplying the difference between the readings of the wetand dry bulb thermometer by 2.5 and subtracting the result from the dry bulb temperature . This See also:

• RULE

rule applies when the evening air is at about 50° and 3o•1-in. pressure, the See also:

• SKY (M. Eng. skie, cloud; O. Eng. skua, shade; connected with an Indo-European root sku, cover, whence " scum," Lat. obscurus, dark, &c.)

sky being clear . An See also:

• INSTRUMENT (Lat. instrumentum, from insincere, to build up, furnish, arrange, prepare)

instrument has been devised in I ranee for the pre-diction of frost .

It consists of a wet bulb and a dry bulb thermometer, mounted on a See also:

• BOARD (O. Eng. bord)

board on which is also a scale of lines corresponding to degrees of the dry bulb, and a pointer traversing a scale graduated according to degrees of the wet bulb . Observations for the night are taken about See also:

• HALF

half an See also:

• HOUR

hour before sunset . By means of the pointer and scale, the point may be found at which the See also:

• LINE

line of the dry-bulb See also:

• READING

reading meets the pointer set to the reading of the wet bulb . The scale is further divided by See also:

• COLOURS, MILITARY

colours so that the observed point may fall within one of three zones, indicating certain frost, probable frost or no See also:

• PROBABILITY (Lat. probabilis, probable or credible)

probability of frost .