DISTRIBUTION IN THE ATMOSPHERE OVER ENGLAND. 263 



Tin- vi-ry Host- ri.imi'c'tion (hat exists between the temperature of the upper air and 

 the height of the barometer is plainly shown in these tables. One can form an idea 

 of the reliability of the figures by taking the surface temperature, where the relation 

 is fairly well known. The value 83 C. for the mean barometric pressure of 754 mm. 

 is probably too high, and would be reduced if sufficient observations were available. The 

 mean temperature of the South of England is close to 83 C., but Pyrton Hill is at 

 an elevation of 500 ft., so that its mean temperature is about 82 C., so also is that 

 of Manchester. Thus the mean of these 124 observations is close to the value it 

 ought to have. Also at the surface the temperature, taking the year through, is 

 below its average in times of low barometer, for in winter, the statements in text- 

 books notwithstanding, in England the height of the barometer has but little, if any, 

 effect upon the temperature, but in summer cold is nearly always associated with a 

 low barometer. Thus the values at the surface are and should be below the mean in 

 cyclonic weather. 



It is probable that if a very large number of observations were available, the 

 roughness shown in the gradients for the first few kilometres with pressures of 754 

 and 760 mm. would be smoothed out, but taking the table as a whole the values are 

 remarkably smooth. 



These tables show how the lower strata are cold in a cyclone and warm in an 

 anticyclone, and how this is reversed above ; how at 10 km. the intermediate type of 

 weather has the lowest temperatures, and how the temperature gradient ceases at 

 8 km. in the cyclone but not till 12 km. in the anticyclone. 



All these particulars have been noted in the Continental results, but not in so 

 pronounced a manner. It will be seen in the line " A-C," in Table VII., that in 

 England at a height of 7 km. the difference amounts to 15 C. In Messrs. GOLD and 

 HARWOOD'S report the greatest difference occurs rather lower and only reaches 8 C. 

 This is for barometric heights of below 750, and over 770, but the number of 

 observations on which the figures depend is not stated. Dr. WAGNER gives 18 C. at 

 8 km., but his values for the centre of a cyclone depend on two ascents only. 

 M. RYKATCHEW gives much smaller differences, but the barometric heights are not 

 defined in either case, the tables being simply headed " cyclonic" and " anticyclonic." 



About the actual fact there is no doubt ; it was stated by M. TEISSERENC DE BORT 

 long since. It would be of interest to know if the distinction is more pronounced in 

 England than on the Continent, but the question is somewhat involved. Cyloues of 

 any depth are rare on the Continent, except perhaps at Hamburg and Pawlowsk, so 

 that the opportunities for studying it are not so good there as here. 



The Isothermal Region. 



It will be noticed in the tables previously given that the decrease of temperature 

 mostly ceases at a height of about 10 or 11 km., but tables showing mean values do 

 not fairly indicate the nature of the phenomenon. In nearly every individual ascent 



