TOPOGRAPHIC SURVEYS. 13 
SHI-TS’UAN-HIEN TO HING-AN-FU. 
Boat Traverse of the Han River.—From Shi-ts’iian-hién we proceeded to 
Hing-an-fu via the Han river, by means of a houseboat. The distance of 
169 kilometers was traversed in about two and one-half days, from May 12 to 
May 14, the boat being laid up over night. We floated with the current, 
which varied greatly, there being long reaches interspersed with shorter 
rapids. 
The conditions did not permit us to stop frequently, as would have 
been necessary for any method of accurate measurement of distance, and 
we were therefore obliged to restrict the topographic work to a simple 
traverse, the courses being noted by compass and the distance being 
determined by time observations and estimates of the rate at which we 
were moving during each interval. When platted, thesurvey was adjusted 
to the latitude observations obtained at its two ends, Shi-ts’tian-hién and 
Hing-an-fu, and was found to be one-fourth of a minute out, north and 
south. The east and west distance was made to conform to the longitudes 
of the two ends, and this section of reconnaissance was thus inserted 
between the two more accurately surveyed sections, which it connects. As 
we had no means of noting the special topographic features of the magnifi- 
cent canyon of the Han river, we have not attempted to contour the 
mountains, but have indicated the steep slopes by the conventional symbol 
of hachures. 
HING-AN-FU TO WU-SHAN-HIEN. 
Stadia Traverse.—From Hing-an-fu to the Yang-tzi river our route lay 
through a very mountainous country with luxuriant vegetation. The 
greater part of the way was made on foot, as indeed was commonly the 
case elsewhere. On reaching the Ta-ning-ho, a tributary of the Yang-tzi, 
we again took boats and ran the swift stream to Wu-shan. A stadia 
traverse was carried by plane-table, with orientation by compass and 
elevations by vertical angles, precisely as had been done between 
Won-kung-miau and Shi-ts’tian-hién. The direction was nearly north 
and south, and the distance was checked by latitude observations at 
Shuang-ho-k’6u, Ts’ong-kia-pa, Ta-miau-ssi, Ta-ning-hién, and one point 
on the Ta-ning-ho about 16 kilometers from the Yang-tzi. To these obser- 
vations the maps are adjusted. For longitude, that of Wu-shan-hién, as 
given on the German Plankammer map on the scale of 1:1000000, was 
accepted (109° 55’). It was afterwards found that Le Chevalier had 
determined it as 109° 50’. 
