SANITARY SURVEY OF DRAINAGE BASIN OF POTOMAC RIVER. 249 
in Frederick every year. During 1906, to July 22, there were two 
deaths recorded from this disease. 
About 10 miles below the Monocac}^, Goose Creek joins the Potomac 
from the south. Goose Creek drains an area of 80 square miles with 
a population of 13,577 in 1900. This population is pretty generally 
scattered. Leesburg is the only town of any size within this area. 
Leesburg is on Tuscarora Creek, a tributary of Goose Creek, 19 
miles above Great Falls. The water supply of the town is from a 
spring on its western edge and from wells. There is no sewerage 
system, but there is a drain which discharges its sewage into the 
creek. The town creek is also polluted by a few overhanging privies. 
Some cases of typhoid occur here and in the surrounding country 
every year. 
Passing the mouth of Goose Creek, the Potomac receives Broad 
Run, Sugarland Run, Seneca Creek, Muddy Branch, and Watts 
Branch before it reaches the Washington dam at Great Falls. The 
area drained by these small, almost insignificant streams, with about 
10,000 population, is given over to farming. The pollution which 
they get is indirect. 
Cases of typhoid occur in and near the small towns along the line 
of the Baltimore and Ohio Railroad which traverses the northern 
part of this area, from east to west. 
The railroads which traverse the watershed are vehicles of pollu- 
tion the amount of which it is difficult to estimate. They carry 
. thousands of passengers annually whose excretions are scattered 
along the lines, which here and there, sometimes for miles, skirt 
the Potomac and some of its tributaries. 
As a general thing the solid excretions do not get into the stream 
until they are washed there by a rain, so that they are exposed 
during a variable interval to the influence of light and temperature. 
This interval may obviously be very short. It is a little different 
with urine, as some of this may flow in directly and immediately. 
PREVALENCE OF TYPHOID FEVER. 
In general it may be stated that typhoid occurs from time to time 
in every part of the watershed. The data available for a study of 
the degree of its prevalence, however, are extremely unsatisfactory. 
In West Virginia the records of vital statistics are very incomplete 
and defective, while in Virginia there are none at all. Such data as 
are available have been given above in connection with the locality 
to which they relate. 
Some idea of its seasonal prevalence may, however, be formed 
from the following table, showing the monthly deaths for 1905 ® 
O' Obtained in correspondence from Dr. John S. Fulton, secretary State board of 
health of Maryland. 
