1785,Patrick Wilson, “[Account of Some Experiments on Cold]”, inAndrew Duncan, compiler,Medical Commentaries, for the Years 1783–84.[…], volume IX, London:[…]J[ohn] Murray,[…], andC[harles] Dilly,[…]; Edinburgh: W. Gordon and C. Elliott,→OCLC, section III (Medical News),page426:
[…] It is moſt remarkable on the ſurface of ſnovv, vvhen covered vvithhoarfroſt, and on other bodies vvherehoarfroſt moſt abounds. In ſuch caſes, I have often found the ſurface to be ſeven degrees colder than the air at the diſtance of tvvo feet;[…]
1817,John Murray, “Of Caloric”, inElements of Chemistry.[…], 4th edition, volume I, Edinburgh:[…] Francis Pillans,[…]; London:Longman, Hurst, Rees, Orme, & Brown,→OCLC, book II (Of Repulsion, and the Powers by which It is Produced), section III (Of the Communication and Diffusion of Caloric),page146:
This striking fact, of the lower temperature of the surface on which dew andhoarfrost are forming, it was always found difficult to explain; for the transition of a body from the state of vapour to the fluid or solid form is always accompanied with an evolution of heat,[…] The surface is not warmer in consequence of the formation of the dew orhoarfrost, but the dew orhoarfrost is deposited because the surface is previously cold; and its low temperature, compared with that of the air above, is owing to the discharge of heat by radiation.
2005, Manh-Cuong Pham, “Conclusions and Policy Implications”, inLand-use Change in the Northwestern Uplands of Vietnam: Empirical Evidence from Spatial Econometric Models and Geo-referenced Analyses and Policy Implications for Sustainable Rural Development, Göttingen:Cuvillier Verlag,→ISBN,page331:
However, high mountains with a long winter and long dry spells,hoarfrosts and infertile soils are not an ideal environment for some annual crops but are well suited for perennial industrial crops and forest species.
