Hard Frost

hard frost

[′härd ¦frȯst]
(hydrology)
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Hard Frost

 

in meteorology, a solid white covering of minute ice crystals formed by the sublimation of water vapor on cold surfaces exposed to the wind. Hard frost is seen on the windward side of stone walls, columns, rocks and other massive objects having high heat capacity and rather good thermal conductivity. It forms in sub-zero (°C) air temperatures but only after the temperature has been rising and the objects mentioned above, which have been greatly cooled in the preceding period, have not yet taken on the temperature of the warmer surrounding air. The thickness of hard frost does not exceed several millimeters. Hard frost is to be distinguished from glaze ice.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in classic literature ?
Once, when there was a hard frost, he formed a scheme to cross the Charles River on the ice.
There must be deep snow, hard frost, no wind, and a cloudless sky; and when, on waking up, I see these conditions fulfilled, then it would need some very potent reason to keep me from having out a sleigh and going off.
I think it must have been a fully year after our hunt upon the marshes, for it was a long time after, and it was winter and a hard frost. With an alphabet on the hearth at my feet for reference, I contrived in an hour or two to print and smear this epistle:
Having spread the quilt and folded my night-dress, I went to the window-seat to put in order some picture-books and doll's house furniture scattered there; an abrupt command from Georgiana to let her playthings alone (for the tiny chairs and mirrors, the fairy plates and cups, were her property) stopped my proceedings; and then, for lack of other occupation, I fell to breathing on the frost-flowers with which the window was fretted, and thus clearing a space in the glass through which I might look out on the grounds, where all was still and petrified under the influence of a hard frost.
Fancy if it had been a hard frost! I never thought it would be so cold in the old country.
But the sun itself, however beneficent, generally, was less kind to Coketown than hard frost, and rarely looked intently into any of its closer regions without engendering more death than life.
I have my alarms, but they are quite in a different quarter; and if I could have altered the weather, you would have had a good sharp east wind blowing on you the whole time--for here are some of my plants which Robert will leave out because the nights are so mild, and I know the end of it will be, that we shall have a sudden change of weather, a hard frost setting in all at once, taking everybody (at least Robert) by surprise, and I shall lose every one; and what is worse, cook has just been telling me that the turkey, which I particularly wished not to be dressed till Sunday, because I know how much more Dr.
In the calm of the hard frost outside, the clear- cut strokes of the town clock counting off midnight penetrated the quietness of his suspended animation.
A sharp keen wind blew dead against us; a hard frost prevailed on shore; and the cold was most severe.
A hard frost too, or a fall of snow, was an Event; and it seemed to do him good, somehow or other--it would have been hard to say in what respect though, Toby!
They were to be picked late, when the hard frosts had set in, and put away for winter use.
It was a bitter cold winter, with long, hard frosts and heavy gales; and it was plain from the first that my poor father was little likely to see the spring.