I2 RESEARCH IN CHINA. 
angles. Throughout the greater portion of the distance little could be 
seen away from the immediate line of survey, as the route lay in a deep 
and often wooded valley. The traverse was begun on May 2 and finished 
May 10, and occupied 7 days. It was 99 kilometers long and 252 stations 
were occupied. 
The astronomical control of the survey from Chéu-chi-hién in the Wei 
valley to Shi-ts’iian-hién in the Han valley, was limited by bad weather 
to one observation for azimuth and two for latitude. The observations 
for latitude were made at Liu-ytié-ho, on the northern slope of the Ts’in- 
ling range, and at Shi-ts’tian-hién, the southern end of the traverse. The 
length of the survey was adjusted to the distance between these two points, 
as thus determined by the observed latitudes, there being no other control; 
and it was of course intended that the parallels of latitude should be placed 
in accordance with these observations; but in executing the draughting 
an error of about 20” was made and not discovered until all the maps 
were engraved. It was then too late to change them, and in consequence 
all points between Chéu-chi-hién and Shi-ts’iian-hién are platted 20” south 
of their proper positions. This error also enters into the adjustment of 
the boat traverse of the Han-kiang, but does not extend to Hing-an-fu 
and points south of that city, as they were correctly located in accordance 
with independent observations. 
For longitude, that of Chéu-chi-hién was accepted as measured from 
the German Plankammer map, on a scale of 1:1000000, and was taken 
as 108° 18’. 
With reference to elevation above sea for this survey across the Ts’in- 
ling mountains, we were without an accurate datum. Three aneroid 
barometers had been carried from T’ai-ytian-fu and simultaneously read 
twice a day during the journey to Chdéu-chi-hién. These readings were 
carefully compared and checked by consideration of later readings and 
of the state of barometer at the Jesuit observatory at Shanghai on the 
same dates; and the altitude of Chéu-chi-hién, determined from them 
to be 403 meters above sea, was accepted as the best available datum. 
According to this elevation the summit of the Ts’in-ling mountains at 
Won-kung-miau is 2,340, and that of the city of Shi-ts’tian-hién 366 meters 
above sea. In crossing the range we saw to the southwest a group of 
mountains already described by David and von Richthofen, the Ta-pai- 
shan or Great White Mountains. Their position was determined by 
intersections on the principal summits to be 40 kilometers southwest of 
Won-kung-miau, and their altitudes between 3,500 and 3,750 meters. 
