January, 1000. Yen-an Fu. Alt. 2769 ft. 



January again was a month of extremely cold, but on the whole fine 

 weather. The proportion of cloudless days was not quite so great as in the 

 last twelve days of December, while light falls of snow, usually following 

 stratus clouds, were recorded on the loth, nth, 12th, 13th, i6th, and 30th, 

 Hoar-frosts were recorded daily from the 23rd to the 27th inclusive. In cloud 

 formations there was a decided predominance of cumulus, or cirro-cumulus 

 clouds, over anything else. Cirrus also occurred with comparative frequency, 

 whilst stratus were also recorded more frequently than usual, being generally 

 followed, as already stated, by snow. Again the light variable wind was the 

 rule, though from time to time it freshened, when its general direction was at 

 once discernible. It was then recorded from the north-west, west, and south. 

 Wind was not once recorded from an easterly direction. 



From the 19th to the 22nd some very low temperatures were experienced. 

 The minimum temperature for the month was — 3*5'^ F. on the 19th, while the 

 average minimum was I2"2° F. 



The maximum reading for the month was 39.0" F., which temperature 

 occurred on the 4th, 5th, and 28th. The average maximum was 32* 1° F. 



The highest, lowest, and average barometrical readings were 2j'i6 inches. 

 26'64 inches, and 26"86 inches respectively. 



Yen-an Fti to Lan-chou Fti. 



On January 30th the expedition left Yen-an Fu for Lan-chou Fu, in 

 Kansu. The journey, including many stoppages, was accomplished in a little 

 over two months. 



Observations were regularly taken at altitudes, ranging from 2769 ft., the 

 altitude of Yen-an Fu to 7468 ft. in the high loess country of Kansu. 



Temperatures remained comparatively low till the commencement of 

 March, when the weather began to get distinctly warmer. On April 3rd, just 

 before Lan-chou Fu was reached, the maximum thermometer registered 

 680^ F., and the minimum 32.0° F., and on the morning of April 5th, the 

 day on which the expedition entered Lan-chou Fu, the minimum temperature 

 was 4i"o^ F. This was the highest minimum temperature recorded since 

 November 4th, 1908. Twice in the early half of February the minimum 

 thermometer registered 2*0° F., but no temperature lower than that was 

 experienced. 



Owing to the various altitudes of which observations were taken, nothing 



K 145 



