28 



REPORT — 1869. 



The instniments were fixed on a stand attached to the outside ring of the cir- 

 cular car, so that the instruments were out of all influence of persons in the car, 

 and shielded from the sun and radiation in the manner described in the preceding 

 volumes of the British Association. 



The ascents and descents were usually even and moderately slow, the balloon re- 

 maining at its highest point till the temperature and hygrometrical state of the air 

 at that "point were assured. The readings of the several instruments were taken 

 on the ground just before an ascent and again just after its completion ; the mean 

 of these two readings was considered to be the temperature on the groimd; in like 

 manner the readings were taken at every 100 ft., as near as possible, both ascending 

 and descending, and their means taken "to represent the temperatures at these ele- 

 vations. In this way the numbers in the following Table were fonned : — 



(l)The sky was nearly free from cloud; the atmosphere was misty; the wind from 

 E.N.E., and its strength was found to be much greater at the height of 1000 ft. than on the 

 ground. 



(2) The sky was principally cloudy ; the wind was from S. W. 



(3) The sky was cloudy ; the wind from the E. ; the strength of the wind much greater 

 than on the ground. 



