4 
Transactions Texas Academy of Science. 
[36] 
directly interested. It was our intention to have the observations made 
at the site of the dam, about forty miles above Wichita Falls, but the 
inaccessibility of the place made it necessary to have them made at the 
town of Wichita Falls. . A few samples were also taken with the sampler 
from the Pecos river and from the Rio Grande river, at FI Paso, besides 
a number that were taken higher up the river with the collecting cans 
and examined by Professor Goss. While in El Paso I secured a number 
of samples that were collected in 1897 and 1898 by the International 
(Water) Boundary Commission and arranged with the Consulting 
Engineer of the Commission to have other samples taken from time to 
time. In Arizona Professor Forbes had charge of observations, and in 
Wyoming Professor Slosson was in charge. 
From the Brazos river thirty or forty sets of samples have been col- 
lected and the results of the determinations of the sets of four and three 
samples each are given below: 
Four sets of four samples each were taken with the water sampler and 
yielded the following average percentages: 
From top 1.078 per cent. 
From one-third depth 1.088 per cent. 
From two-thirds depth 1.173 per cent. 
From bottom 1.210 per cent. 
Mean 1.137 per cent. 
The average results for twenty-one sets of four samples each, including 
the above four sets and seventeen others taken with the collecting cans; 
were as follows: 
From top 1.008 per cent. 
From one-third depth 1.043 per cent. 
From two-thirds depth 1.085 per cent. 
From bottom 1.028 per cent. 
Mean 1.041 per cent. 
This would seem to indicate that the mean percentage of silt is carried 
at about the one-third depth, though if only the samples taken with the 
water sampler be considered the mean percentage would seem to fall a 
little lower in the section. However, the samples taken with the sampler 
were too few in number to base any general conclusions on the results, 
and in all cases the individual variations are very marked. 
The average results for five sets of three each are as follows : 
From top 1.032 per cent. 
From mid-depth 1.008 per cent. 
From bottom ...0.990 per cent. 
Mean. 
1.010 per cent. 
