IO RESEARCH IN CHINA. 
The projections upon the sheets are controlled by azimuths, seven in 
all, observed by theodolite on Polaris at points along the line, namely; 
at Pau-ting-fu, which controlled the eastern end of the stadia traverse; 
at T’ang-hién, for the western end and the first of the triangulation points; 
at Li-ytian-p’u, Liu-yiian, Wu-t’ai-shan, and Han-yang, for intermediate 
points; and at T’ai-yuan-fu, for the southern end of the route. 
The determinations of elevation by triangulation and vertical angle 
checked out satisfactorily. The altitude of each station was determined 
a number of times by observations of vertical angle from as many other 
stations. The figures for the more important points are given in Table I, 
Appendix I. 
From Pau-ting-fu to Wu-t’ai-shan we passed from an elevation of about 
18 meters above sea to that of 3,050 meters, and thence descended to an alti- 
tude of about 825 meters at T’ai-yiian-fu. We believe these elevations to 
be within an error of 6 meters at Wu-t’ai-shan and of 15 meters at 
T’ai-yuan-fu, as compared with the railroad at Pau-ting-fu. The elevation 
of the railroad, which we necessarily took as the datum and which was given 
by the Belgian authorities at Peking as 18 meters, is not connected by a 
line of levels with mean tide, there being a break between the English 
road at Peking and the Belgian road at the same place, which has not been 
bridged by leveling. 
In addition to the graphic triangulation, which was executed between 
T’ang-hién and T’ai-ytan-fu, a continuous traverse of the road which we 
followed was run from T’ang-hién to Shi-tsui, a distance of about 145 kilo- 
meters. An attempt was made to do this by means of a specially built 
wheelbarrow and odometer, but in the mountainous country this was found 
impracticable, and the stadia method was substituted. From Shi-tsui to 
T’ai-yuan-fu the trail and road were sketched as accurately as possible 
between numerous points along the route which were located by triangu- 
lation. 
STATISTICS OF THE SURVEY. 
From ‘f’ang-hién to T’ai-yiian-fu the graphic triangulation and accom- 
panying route surveys were executed between the dates of January 9 and 
March 8,1904. Fifty and a half days were spent in actual fieldwork. The 
scale of the field map was 1:90000. ‘The detailed topographic work cov- 
ered an area from 8 to 4o kilometers in width and about 362 kilometers 
in length, comprising 7,000 square kilometers. Eighty-nine stations were 
occupied by plane-table and 1,783 points were intersected, an average 
of one point to every 4 square kilometers. The elevations of about 
1,500 points were ascertained. Azimuths were observed at seven places, 
including Pau-ting-fu, T’ang-hién, and ‘T’ai-ytian-fu. 
