T E M 



177 



T E M 



plaining of its inconvenient effects in deranging his tem- 

 per, is said by M. Segur to have added, ' Oependant sans 

 <~ette mauclite bile on ne gagne pas de grandes batailles.' 

 -aiine men, continues the writer above mentioned, are 

 fit for courtiers ; but individuals who have the misfortune 

 to be of the phlegmatic temperament, being quite incom- 

 petent to any elevated condition, must be made common 

 soMiers or labourers, and condemned to the lowest em- 

 ployments. (De Teiripi'ntnii'tttri l-'ii>i<l<tmp>ito Morborum, 

 i) 10, quoted by Dr. Prichard.) It is extremely improba- 

 ble that an opinion should have held its ground for so 

 many ages among men of observation, especially on a 

 subject requiring no abstruse research, without some foun- 

 dation at least in fact. The doctrine of temperaments is 

 true to a certain extent, and has ever been confirmed by 

 an appeal to experience. States of the mind are so con- 

 nected with affections of the body, that it is impossible for 

 any ptrson who considers all the physiological facts that 

 present themselves in connection with this subject to 

 doubt that with each temperament particular mental 

 qualities must be associated, although it is manifest that 

 many writers have indulged their fancy on this subject, 

 and have gone into more full and minute details than 

 experience will establish. Tile same may be said of phre- 

 nology, with which science the doctrine of the tempera- 

 is in this point of view closely connected, as modi- 

 fying in some degree the intellectual and moral qualities 

 rganization of the brain. This very 

 : subject is di<cu--i'd at some length in Dr. 

 Prichard's article on ' Temperament' in tli 



\[i><lii-ine, from which most of flic preceding i 

 vations are taken. See also Bostock, Richerand. and Miil- 

 ler's works on Physiology, and other writers there quoted. 



UPF.KA.MKXT. ""[Tt-MM;.] 

 TEMPERATURE. [ ATMOSPHERE; CLIMATE; Iso- 



THKKM U. ].: 



TEMPERATURE OF THE EARTH. [GEOLOGY, p. 

 133.] 



TEMPERATURE. It is intended under this head to 

 notice the law of the variations of temperature on the 

 earth so far only as to indicate its analogy with that of 

 the variations of terrestrial magnetism ; the formula' cx- 

 ng the mean temperatures at different places being, 

 BS yet, very far from affording satisfactory results, and ob- 

 servations being too few to serve as a basis for correct 

 theory. In CLIMATE there are given some general ob- 



linns concerning the distribution of heat at the sur- 



oi'the earth, and under ISOTHERMAL LINES there will 

 be found the estimated values of the mean temperatures 

 at the equator and at the geographical north pole. \Vith 

 respect to the former, it may be said to have been tolerably 

 well determined, and to be nearly uniform quito round the 

 world ; but the mean temperature at the pole can only be 

 surmised from the uncertain evidence afforded by an ap- 

 plication of the formula of temperature which has been 

 found to hold good in the north of Europe, and a correc- 



ounded on an estimated amount of the frigorifir: in- 

 fluence of ice : even the determination thus obtained is 

 rendered still further uncertain by the fact that the de- 



of temperature in proceeding from the equator 

 northv. iird-i is different on meridians which differ con- 



ily in lonn 



Before this difference of temperature on the same 

 parallel of latitude in the old and new continent 

 known or regarded, a simple formula was thought suffi- 

 cient to express the temperature at any parallel of terres- 

 trial latitude. The celebrated Tobias Mayer, from such 

 mean temperatures as had in bis time been observed, 

 found that the temperature t (on Fahrenheit's ,,eale) at 

 anyplace might be represented byT 5'2 sin.-' L, where T 

 is the mean temperature :it the equator, and L the geo- 

 graphical latitude of flu; place; and in 1810 M. l.'.Mibuisson 

 ('Trait*: dei e ') proposed the more 



/ = 27 cos.' L (centigrade scale) ; which being wlaptrd to 

 Fahrenheit's scale, considering the mean tem. 

 the equator to be 81, becomes 32- r -49 cos. 8 I.. This 

 formula ha.s been found to serve for temperatures in 

 Europe a.s far north a.s the latitude of 00 ; but. I 

 para!' less, and it supposes the temperature at the 



to be 32, which is much too high. 

 ;n above 4(HX) observations which were made by Sir 

 K'lv Harbour, in 74 



qy N. lat.. and in long. 250 (110 \V. long.), the mean 

 P. t'., No. 15Ki. 



temperature is as low as 1-33 ; and from above 600 ob- 

 servations at Spitzbergen (78 N. lat.) Mr.' Scoresty found 

 the*mean temperature to be 10'99 : a mean temperature 

 of 17 is also found on the American continent, in 65 

 N. lat. ; and hence it may be inferred that, between the 

 parallels of G5 and 78, and near the meridian of Winter 

 Island, there exists a pole of minimum temperature. The 

 mean temperatures of places in the eastern parts of Asia 

 have not been well ascertained ; but since at North Cape 

 in Lapland the mean temperature is that of freezing 

 water, and in Siberia, as low as the parallel of GO N. lat., 

 the surface of the ground is constantly frozen, it is evi- 

 dent that the isothermal line of 32 must form a curve about 

 some point as a focus in the northern part of the Asiatic 

 continent : hence, for determining the mean temperature 

 of any place, no formula which does not involve the posi- 

 tion of the place with respect to the two foci of coldness 

 can be expected to satisfy the phenomena. 



This circumstance has suggested to Sir David Brewster 

 the formula T = (f T) sin." S sin." t'+r for the mean 

 temperature at any place : T being that temperature, t 

 the mean temperature at the equator, T the temperature at 

 each of the foci of coldness, and S, I', the distances in de- 

 grees between the given place and those foci. A corre- 

 sponding expression will serve to determine the number of 

 vibrations which would be performed by a magnetized 

 needle in a given time if t and r be made to represent the 

 numbers performed, in an equal time, at the magnetic 

 equator and at either of the poles of magnetic intensity : 

 the exponent n, both for temperature and intensity, is to 

 be determined by means of observations, and Brewster 

 considers that the fraction g may be the value of it in 

 the formula for temperature. 



The similarity of character which is presented by the 

 isothermal lines and those of magnetic dip and intensity, 

 with respect to two polar points in one hemisphere of the 

 earth, and the fact that the poles of temperature and mag- 

 netism lie nearly in the same parts of the world, cannot 

 fail to suggest the idea that tiiere may be a connection 

 between the temperature and magnetism of the earth. It 

 is generally believed, also, that the temperature of the 

 western parts of Europe is now higher than it was nearly 

 two thousand years since ; and it has, hence, been inferred 

 that the poles of minimum temperature perform revolu- 

 tions about the geographical pole of the earth, so that the 

 terrestrial meridian on which the greatest cold prevails 

 gradually changes its position. If this opinion be well 

 founded, the circumstance will afford another argument 

 in favour of the hypothesis which assigns to the tempera- 

 ture and magnetism of the earth an intimate connection 

 with each other, by its correspondence to those motions of 

 the poles of magnetic dip which have been adduced from 

 observations by M. llansteen. [TERRESTRIAL MAGNETISM.] 



A^ the nit iin temperature at the surface of the earth U 

 an element of great importance in the present state of 

 physical science, it has been strongly recommended to 

 travellers and persons making distant voyages, if they 

 sre to remain only a few days at any place, that they 

 should, on arriving, lose no time in burying in the earth, 

 to the depth of from three to twelve feet, according to the 

 power of pi into the soil, bottles filled with water, 



or with spirits, if there should be any danger of water 

 freezing. These bottles should be packed in boxe- stuffed 

 with woollen cloths, pounded charcoal, or any other non- 

 conducting material, and should be allowed to remain 

 underground till the time of departure, in order that they 

 may acquire, as accurately as possible, the temperature of 

 the ground. On being taken up, the temperature of the 

 liquid should be ascertained by a good thermometer in- 

 i ill the bottle. 



TEMPERATURE OF PLANTS. The living processes 

 by which heat is so evidently developed in animals go on, 

 though much less actively, in plants, and give to them a 

 peculiar temperature, independent of the air in which they 

 The periods at which an increase in the temperature 

 of plants has been most evidently observed are those of 

 germination, flowering, and impregnation ; but it is only 

 , those chemical changes which produce In at. are 

 more active during the performance of those functions 

 that the heat becomes more evident. The great cause of 

 the development of heat in animals is the union or com- 

 bustion of carbon with oxygen, which is constantly taking 

 place during the process of nutrition in the various tissues of 



VOL. XXIV.-2 A 



