4. Yen-an Fu, Latitude 36°35'331 N., Longitude 108°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 103°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. Ta-yiian Fu, Shansi (Altitude 2600 ft.) and 
neighbourhood. 
As already stated, observations were commenced on May 16th, 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 3Ist, when 
the thermometer stood at 470° 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 81°2° F., average 
minimum, 565° 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 192° F. on the 21st. Towards the end of the month rain and 
thunder were noted. 
June, 1908. T ai-yiian 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 roth, 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 go’o° 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 
137 
