262 Prof. S. Arrhenius on the Influence of Carbonic Acid 



where c is a constant with the values 1*88, 1*58, and 1*37 

 respectively for the three cases *. In this way we find the 

 following corrected values which represent the variation of 

 temperature, if the solid ground changes its temperature 1° C. 

 in consequence of a variation of fi as calculated by means of 

 formula (3). 



Table Y. — Correction Factors for the Radiation. 



0= 



Solid 



ground, 



v=l. 



Water, 



Snow, 

 v=0-5. 



Clouds (v^ 0-22) at aheight of 



v= 0-925. 



m. 



2000 m. 



4000 m. 



0-37 

 0-35 

 0-33 

 0-31 

 030 



0-65 

 0-75 

 0-85 

 095 

 1-00 



1-53 

 1-60 

 1-69 

 1-81 

 ]-88 



1-46 

 1-52 

 1-59 

 1-68 

 1-74 



0-95 

 0-95 

 0-95 

 094 

 0-94 



049 

 0-47 

 0-46 

 0-43 

 0-41 



0-42 

 040 

 0-38 

 0-36 

 0-35 



If we now assume as a mean for the whole earth K=l and 

 W = l, we get /3 = 0*785, and taking the clouded part to be 

 52*5 p. c. and the clouds to have a height of 2000 metres, 

 further assuming the unclouded remainder of the earth's 

 surface to consist equally of land and water, we find as average 

 variation of temperature 



1-63 X 0-2385 + 1-54 x 0*2385 + 0-39 x 0*525 = 0-979, 



or very nearly the same effect as we may calculate directly 

 from the formula (3). On this ground I have used the 

 simpler formula. 



In the foregoing I have remarked that according to my 

 estimation the air is less transparent for dark heat than on 

 Langley's estimate and nearly in the proportion 37*2 : 44. 

 How great an influence this difference may exercise is very 

 easily calculated with the help of formula (3) or (4). Ac- 

 cording to Langley's valuation, the effect should be nearly 

 15 p. c. greater than according to mine. Now I think that my 

 estimate agrees better with the great absorption that Langley 

 has found for heat from terrestrial radiating bodies (see p. 260) , 

 and in all circumstances I have preferred to slightly under- 

 estimate than to overrate the effect in question. 



* 1- 



Absolute temperature of the higher radiating layer of the air, 



