minimum was 43"o° F. on the 13th. This temperature, it will be noted, 

 occurred on the night after the highest barometrical reading, 25'o6 inches was 

 taken. The lowest barometrical reading occurred on the 28th, between the 

 two maximum temperatures for the month. This seems to bear out the rule 

 regarding the inverse relationship between the thermometer and barometer. 



The average maximum and minimum readings were 8i*i° F., and 57*9° F. 

 respectively, whilst the average barometrical reading was z^'Sy inches. 



The psychrometer showed differences between the two bulbs of io'o° or 

 more, more frequently than not ; but only once on the 25th, did the difference 

 reach i5'o°. This was followed on the 26th by absolute saturation in the air, no 

 difference between the bulbs being discernible. The rainfall on the 26th, as 

 already stated, was "72 of an inch. 



July, 1909. Lan-chou Fu. Alt. 5106 ft. 



Observations were made at Lan-chou Fu from the ist to the 15th of this 

 month, when the expedition left the district. 



During these fifteen days the average temperatures were slightly higher 

 than those of June. The barometer remained correspondingly low, never 

 once reaching 25*00 inches. The humidity of the air varied from saturation 

 to a dryness showing a difference between the bulbs of ig'5°. 



Rain fell on six of the fifteen days, making a total fall of i'2g inches, 

 considerably more than that of the previous month. 



The direction from which the rain came was not properly recorded this 

 month, but the last wind recorded before each period of rain was from the 

 north-east. 



Wind was of less frequent occurence than during the preceding months, 

 calm being recorded on seven days, whilst no reference whatever was made to 

 the subject on three others. What wind there was came usually from the 

 north-east. 



Cumulus and stratus clouds were prevalent till the 15th, when cirrus 

 clouds were recorded. Nimbus clouds appeared on the 2nd. 



The maximum temperature for the fifteen days occurred on the gth when 

 87-8° F. was registered. The minimum was 53"o° F. on the 2nd. The 

 highest barometer reading occurred on the ist close to the date on which the 

 minimum temperature was recorded, whilst the lowest barometrical readings 

 occurred on the same date as the maximum temperature for the month. 



The highest and lowest barometrical readings were 24*98 inches, 2470 



150 



