4 BULLETIN 659, U. S. DEPARTMENT OF AGRICULTURE. 
8 per cent. This income is a measure of efficiency of farming. In 
general it varies with the size of the farm. 
Percentage returns on the investment. — This term is used to desig- 
nate the percentage income that the invested capital makes after de- 
ducting all expenses. It is determined as follows: The estimated 
value of the operator's labor is deducted from the farm income and 
this result is divided by the amount of the capital invested. It was 
found that on account of the wide variation in price of land between 
farms of approximately the same value it was necessary to equalize 
the land values in determining a measure of efficiency which elimi- 
nates size of business. Since the variation in price of land has 
scarcely any relation to the efficiency of farm operation, an average 
land value of $139 per acre was assumed for the purpose of deter- 
mining the per cent return on the investment where this measure 
is used as a standard of efficiency. 
AREA SURVEYED. 
Ellis County is located in the northeastern part of Texas near the 
line between what are locally known as Central and North Texas 
(fig. 1). Waxahachie, the county seat, is approximately 30 miles 
south of Dallas. The area surveyed extends from north to south 
through the center of the county and also east from the center 
toward Ennis. 
This area was chosen for several reasons: It was possible to find 
a large number of farms on the same soil type, i. e., the Houston 
black clay (fig. 2), thus making it possible to compare farms of 
similar practice, which is not possible on soils of widely different 
character; a comparison of census data for the pricipal "black- 
land " counties shows this to be one of the leading cotton-producing 
sections of the State ; it is one of the oldest agricultural sections 
of the State, so that quite definite systems of farming have been 
established in local practice ; and, finally, the farms of all of practi- 
cally the same type. Since these conditions exist, the comparative 
study of farm organization, costs, efficiency, etc., is made possible. 
TOPOGRAPHY. 
The general surface of Ellis County is undulating to rolling, being 
cut by numerous small streams. The area occupied by the Houston 
black clay soil is generally more level than other parts of the county. 
The elevation varies from about 450 feet to 750 feet above sea level/ 
Waxahachie being 551 feet. 
Practically all of the drainage of the country is toward the south 
or southeast, through small streams to the Trinity Kiver. Small 
