4. Yen-an Fu, Latitude 36°35'33« N., Longitude io8"^26'49" E., 

 altitude 2769 ft., in north central Shensi, from December 

 19th, 1908, to January 30th, 1909. 

 6. Lan-chou Fu, Latitude 36°3'6" N., Longitude I03°40'54" E., 

 altitude 5106 ft., in western Kansu, from April 5th to July 

 15th, 1909. 

 In this chapter an endeavour will be made to deal with the meteorological 

 observations month by month as they come ; but at the same time stress is 

 laid upon the periods enumerated above, when sets were taken during lengthy 

 stays at various places. 



May, 1908. Tai-yUan Fu, Shansi (Altitude 2600 ft.) and 

 neighbourhood. 



As already stated, observations were commenced on May i6th, from which 

 date to the end of the month daily maximum and minimum temperatures were 

 recorded, besides somewhat erratic observations for the pressure and humidity 

 of the atmosphere. The maximum temperature noted was on the 27th, 98'2° 

 F. being recorded. The minimum temperature occurred on the 31st, when 

 the thermometer stood at 47*0° F. Both these records were taken at Chao- 

 chuang, a small village on the plain some fifteen miles north-west of T'ai-yiian 

 Fu. The average maximum temperature for the period is 8i"2° F., average 

 minimum, 56'5° F. The lowest barometrical observation, 26-84 inches, was 

 made on the 26th, at T'ai-yiian Fu, the highest, 27*05 inches on the 23rd, and 

 again on the 30th, both at T'ai-yiian Fu. 



The first part of the second half of the month was marked with consider- 

 able dryness, the difference between the wet and dry bulb readings being as 

 much as i9'2° F. on the 21st. Towards the end of the month rain and 

 thunder were noted. 



June, 1908. Tai-yikm Fu (Altitude 2600 ft.) and neighbourhood. 



Throughout June, the members of the expedition were encamped at 

 Chao-chuang, where daily observations were made. From time to time the 

 mercurial barometer, which was left in T'ai-yiian Fu, was read. Much hotter 

 weather was experienced than in May. The maximum temperature, 98*0° F. 

 was recorded on the loth, and the minimum, 42-9° F. on the 7th. The 

 average maximum temperature for the month, excluding the last four days 

 which were spent in the hills west of T'ai-yiian Fu, was 90'0° F., the average 

 minimum was 58.4° F. The barometer was at its lowest on the 24th, the 

 reading being 26"67 inches, whilst the highest reading 27*08 inches occurred 



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