114 Mr. J. Y. Buchanan. On Rapid Variations of [May 31, 



stances where the hot puffs are observed. Unfortunately, owing to 

 an accident to the thermometer, very little use could be made of 

 them. Where the rate of change of temperature of the thermo- 

 meter is used to determine the temperature of the air, the movement 

 of the air must be measured or estimated. The observations made on 

 the 19th and 21st August are given in Table I. 



Table I. Temperature Observations at Equal Altitudes on the 

 Morteratsch Glacier, and on the Mountain west of it. 



For comparison with the temperatures on the ice on the 19th, the 

 mean of the observations on the land station at 2.45 and 4.35 P.M. is 

 taken, and on the ice the mean of the observations at 3.20 and 3.55 

 P.M. The altitudes of the two stations were as nearly as possible 

 identical, and they were not more than 1 kilometre distant from each 



