310 SCIENTIFIC RECORD FOR 1884. 



heat by Lanj^iey's, Fiirster's, aud Frolicb^s methods, he recognizes that 

 Forster's grauite pillar has a much more constant sensitivciu ss and 

 certainly changes very slowly; he has therefore undertaken a modifica- 

 tion of his own apparatus looking to an independence of the variations 

 of the temperature of the air. {Z. 0. G. M., xix, p. 400.) 



184. Dr. W. Koppen i)ublishes an interesting study of the effect of 

 hot, temperate, and cold weather on the organic world, and proposes a 

 new distribution of the limits of temi^erate zones, namely, the tropical 

 zonCj where every month the temperature is above 20° C; the subtropic 

 zone, where four to eleven months are hot, or above 20°; the temper- 

 ate zone, where from four to twelve months are temperate, namely, 

 from 10° to 20°, and this he divides into three subzones, the nmform 

 temperate, having hot summers and cool winters or temperate summers 

 and cold winters; the cold zone, where from one to four months are 

 moderate and the remainder cold ; and the polar climates, where all 

 months are cold, namely, under 10° C. He shows that this empirical 

 divi-sion (lower than 10°, from 10° to 20°, and above 20° C.) accords rea- 

 sonably well with phenomena of animal and vegetable life. Everywhere 

 the progress of civilization has been from the warmer into the cooler 

 countries. {D. M. S., i, p. 215.) 



185. Dr. A. Woeikof, on the dependence of the daily variations of 

 temijerature upon local circumstances, especially topograph}-, formu- 

 lates his views about as follows: 



1. A convex surface, such as a hill or mountain, is a cause that dimin- 

 ishes the daily range o( temperature, and by so much the more in pro- 

 portion to the ratio of tlie vertical to the horizontal dimensions. 



2. A concave surface, as a valley or hollow, increases the daily range, 

 of temperature, but only up to certain limiting ratio of vertical and hori- 

 zontal dimensions. 



3. As a normal condition in rcsi)ect to the daily amplitude he adopts 

 a perfect plane surface ; he gives numerous examples pf this, quoting the 

 data from Asia and Europe; he eliminates the effect of cloudiness and 

 winds, and leaves the outstanding daily amplitude to be explained as 

 due to the iutluence of the topography. Quantitatirely it would seem 

 that the daily amplitude iu the high valleys of the Indus, 3,500 meters' 

 above the sea, in January an<l February, is greater than in some of 

 the driest places on the low' plains of Northern India. {Z. 0. G. M., 

 XVIII, p,211.) 



186. G. J. Symons gives the first results of simultaneous thermometric 

 and hj-grometric observations at heights 4, 170, and 260 feet, which were 

 made on behalf of the Eoyal Meteorological Society on the cathedral 

 tower at Boston. During clear November weather the average temper- 

 ature at the highest point was greater than at the earth's surface by 

 reason of the excess of cold due to radiation at night, but on cloudy, 

 windy weather, the average temperature was lower above than below. 

 In foggy weather the temperature at the highest point was always higher 



