POLAR REGIONS. 



15 



Pohr ice, to the severities of this intense cold, for fifty hours. 

 Regions. One man fell a victim tothecoltl while on the ice, and 

 "^"^r-^" another dii-d .-oon after he reached his ship. All of 

 them suffered from the severity of the exposure more 

 or less. Some lost their fingers ; others their toes ; 

 some lost their hands, and others their feet. Thirty- five 

 fingers and toes were amputated in one day. An ex- 

 ample was given of the severity of the cold, by one of 

 the King George's sailors, who stated, that a quantity 

 of beef that was sent in a boat to the men upon the 

 ice, when they first saw them, was taken hot out of the 

 coppers, but, before they reached the ice, though at no 

 great distance, it was frozen so hard that they had to 

 cut it in pieces with hatchets. It is an observation 

 of several arctic voyagers, that the sensible effect of 

 cold depends in a great measure on the strength 

 of the wind ; for it appears very probable that the 

 lowest temperature experienced by Captain Parry, 

 54, is as tolerable to the feelings in perfectly calm 

 weather, as a temperature 40 or 50 degrees higher, un- 

 der exposure to a severe gale. In the former case, 

 there is a warm atmosphere of partially stagnant air 

 formed in the clothing and about the person of every 

 individual ; but, in the latter, the warm air derived 

 from the animal heat is carried off as rapidly as given out. 

 Until the observations on the temperature of the 

 atmosphere in the Greenland Sea, by Captain Scores- 

 by, made between the years 1807 and 181&, the seve- 

 rity of the cold of the Arctic regions was extremely 

 underrated by meteorologists. The celebrated astro- 

 nomer Tobias Mayer, of Gottingen, who was the first 

 person that attempted to deduce from observation a 

 general expression for the mean temperature of all la- 

 titudes, calculated the mean temperature of the north 

 pole to be 31. But Captain Scoresby, by an analogi- 

 cal process, has shown that the cold at the pole must 

 be as low as about 10. By observations made in the 

 months of April, May, June, and July, near the coast 

 of Spitzbergen, he found the mean annual temperature 

 of the parallel of 76 45' N. (derived from a satisfactory 

 formula for calculating the mean temperature of the 

 year, from observations made in a part of the year,*) 

 to be 18.86. Mayer's formula, however, which had 

 been followed by almost all meteorologists up to this 

 period, gives the temperature of this parallel 33 J .8, 

 being nearly 15 too high. Dr. Brewster, who had be- 

 stowed a good deal of attention on the subject of the 

 mean temperature of the globe, even before the publi- 

 cation of Mr. Scoresby's results, was induced, from the 

 'comparison of Mayer's formula with observations on 

 temperature made in high latitudes, to reject it as not 

 being applicable to the phenomena. He found on in- 

 vestigation, that the temperature varied pretty nearly 

 with the co-sine of the latitude, and obtained the ge- 

 neral expression 



T=81$ cos. lat. 



T being the mean temperature of any place, and 8l^ 



the mean temperature of the equator. This formula, 



applied to thirty different places, situated between the 



"equator and latitude C5 a 3', agreed with the results de- 



termined by observation within ,',ths of a degree, at an 

 average, upon each observation, t And applied to the 

 Arctic parallels, it give* the temperature of 76" 45', IS 1 

 6'8', differing only AMh of a degree from the tempe- 

 rature observed by Captain Scoresby. This striking 

 coincidence, was indeed general in all places situate- 1 

 about the meridian of England and western Europe, but 

 the formula required a modification for the new world ; 

 the mean temperature of the American continent, and 

 the regions to the northward of it, being found to be 

 lower than that of Europe. This is particularly the case 

 in high latitudes. Thus, the thermometric curve of 1 7 . 

 Dr. Brewster observes, which rises in the meridian of 

 Spitzbergen to 78 of north latitude, descends in the 

 meridian of Melville Island to 65 ; and, we may add, 

 that the 75th parallel at Spitzbergen, which has a mean 

 temperature of about 20% has, at Melville Island, as 

 ascertained by Captain Parry with great accuracy, 

 during twelve successive months, a mean temperature 

 of zero, or one or two degrees below it. Hence Dr. 

 Brewster concludes, and with the best reason imagin- 

 able, " that the pole of the globe is not the coldest point 

 of the arctic hemisphere ;" but " that there are in o 

 points of greatest cold, not many degrees from the pole, 

 and in meridians nearly at right angles to that which 

 passes through the west of Europe." These points Dr. 

 Brewster supposes to be situated about the 80th parallel, 

 and in the meridian of 95 east, and 100 3 west longi- 

 tude. A general expression for calculating the tempe- 

 rature, applicable to all parts of the northern hemi- 

 sphere, referring to these isothermal poles is, 



Mean temp. = 86 3 sin. D S, 

 upon the supposition that the greatest cold is S^ of 

 Fahrenheit ; ' 82 8 being the mean temperature of 

 the equator in the warmest meridian, and D the dis- 

 tance of the place from the nearest isothermal pole." J 

 This formula, applied to the conclusions obtained by 

 Humboldt, and to the observations of Captain Scoresby 

 and Captain Parry, gives very satisfactory and consist- 

 ent results. And by the further application of this 

 formula, the mean temperature of the north pole comes 

 out 11% which differs only one degree from the ana- 

 logical result obtained by Captain Scoresby. $ The 

 near coincidence of the isothermal poles, and of the 

 magnetic poles of the earth, led Dr. Brewster to sup- 

 pose that they might have some other connexion be- 

 sides their accidental locality. If so, if the centres of 

 greatest cold be also precisely the centres of magnetic 

 attraction, and if from some unknown but necessary con- 

 nexion they are always coincident, then we derive from 

 the known motion of the magnetic poles, an explanation 

 of some of the most remarkable revolutions that have 

 taken place on the surface of the globe. ' There is no 

 fact in the natural history of the earth better ascertain- 

 ed," observes Dr. Brewster in his interesting paper that 

 we have already quoted, " than that the climate of the 

 west of Europe was much colder in ancient than in 

 modern times. When we learn that the Tyber was 

 often frozen ; that snow lay at Rome for forty days; 

 that grapes would not ripen to the north of the Ce- 



* Account of Arctic Regions, Vol. I. Appendix, No. II.; and Vol. I. p. 358. 



fr Edinburgh Philosophical Trantactiont for 1820. 



' The distance D from the isothermal pole la in the coldest meridian D = 80 latitude; and in the warmest meridian cos. D = 



cos. 10 x sin. lat. In all intermediate meridians, we have cos. D = "~ ' , and tang, t cos. M. Un. L, where M is the dit- 



cos. S 



ference of longitude between the place and the pole, L the co-latitude of the isothermal pole or 10*, and / the co-latitude of the 

 place." Ibid. 



Account of Arctic Region*, i. 36*. 



