130 On a change of Climate, 



relation to the quantity of the fluid, were quite as large in size. They 

 remained thirty-six hours in an atmosphere, whose temperature was 

 increasing from 46° to 58° Fah. ; some fluid oil then collected in 

 globules, and the exact temperature of a half fluid mass was 51^° F, 

 Roxbury Laboratory, 5th March, 1831. 



Art, 'XV.— 'On a change of Climate.^ 

 (fhom the writings of the i^ate bishop heber.) 



" The principal apprehension at present [in Norway] arises from 

 the too rapid destruction of their forests, to the existence of which 

 they attribute, with apparent reason, the superior mildness of their 

 chmate to countries under the same latitude." — Life of Bishop He- 

 ber, Vol. I. p. 80. 



" The resemblance of the Tanais to the Nile has been remarked 

 by many writers ; but that these ample downs, whither its fertilizing 

 waters cannot extend, have not since degenerated into a desert, like 

 those of the Thebais, must be ascribed to the difference of latitude^ 

 and the beneficial effects of a four months continued snow. 



" This rigor of climate is so greatly at variance with those inter- 

 ested reports which, in the hope of attracting settlers to her new do- 

 minion, v/ere circulated by the empress Catharine ; and it differs so 

 widely from that temperature which might be supposed to exist in 

 the latitude of forty-six, in the same parallel with Lyons and Gene- 

 va, — that though the ancients observed and recorded it, the fact has 

 been very slowly admitted by the generality of modern inquirers. 

 Even among those who yielded a respectful attention to the authority 



* Extract of a letter from David Thomas, Esq. to Prof. J. Griscom, dated, 



" Greatfield, 12th Mo. 10, 1830. 



" Since my last letter was written, I have read with much interest and satisfac- 

 tion, some remarks of the late Bishop Heber on physical climate, which differ in 

 point of fg.ct from several writers on this subject. His opinion will command the 

 greatest deference, not only on account of his eminent talents, but because he was 

 on the spot to observe and to inquire. I copy such parts as appear pertinent to our 

 present discussion. 



" As much has been written 07i a change of climate, and, in my view, many er^ 

 roneoiis notions widely diffused, perhaps it would subserve the interests of scieucej, 

 to offer Heber's rennarks for a place in Prof. Silliman's Journal," 



