16 John Eliot— On the occasional Inversion of the Temperature [No. 1, 



emaller average difference of tlie minimum temperature at the hills and 

 at the adjacent plain stations (or of the small night vertical range of 

 temperature compared with the day) must recognize : — 



(a.) That the air is on the average less humid at the hills than at 



the adjacent plain stations in Upper India. 

 (6.) That there is on the average more cloud at the hill stations. 

 (c.) That the intensity of solar radiation is considerably greater at 



the hill stations, probably at least 20 per cent, greater. 

 (d.) And that the intensity of radiation from the earth's surface 

 at night is very considerably greater at the hills than the 

 adjacent plains. 



We now proceed to give data for the same pairs of stations for 

 January 1889. 



The following tables give the comparative temperature data of eight 

 hill stations in Northern India and of the eight nearest plain stations at 

 which there are observations for that month. 



The first table gives the maximum temperature of each day of the 

 montli of January 1889 and the variation from the normal. The 

 variations are obtained from the daily means of the past eleven years 

 (1878-88) smoothed so as to give a fairly regular series. The positive 

 sign afiixed to a number in this table indicates that the actual tempera- 

 ture was above the normal and a minus sign that it was below it. 



The second table gives similar date for the minimum temperature 

 of the same 16 stations for the same period. 



The third table gives the daily difference of the maximum tempera- 

 tures for each, of eight pairs of stations consisting of a hill station 

 and adjacent plain station. lu every case the maximum temperature 

 at the plain stations exceeds that at the neighbouring hill station. 



The fourth table gives the difference between the minimum tem- 

 perature registered at each of the eight selected hill stations and the 

 neighbouring plain stations. In the majority of cases the minimum 

 temperatures at the plain stations exceed those at the plain stations in 

 which case no sign is prefixed to the number. In a few cases the latter 

 temperatures are the greater and this is indicated by the minus sign pre- 

 fixed to the number. 



