WATER SUPPLY OR EASTERN AND SOUTHERN EEORIDA. 153 
a watch and a gallon measure, or a keg or a barrel of known 
capacity, but for wells flowing over twenty or thirty gallons a 
minute, it is not so easy to determine with accuracy. 
“If the well is large it may be measured with a weir, but that 
is constructed only with considerable trouble. If the water runs 
in a sluice or ditch of uniform width, its cross section may be 
estimated and its velocity taken. This method, however, is not 
very accurate. The following are methods which give fairly 
accurate results with little trouble and in short time. All that is 
necessary for the purpose is that the water be discharged through 
a pipe of uniform diameter, a foot rule, still air, and care in taking 
measurements. 
“Two methods are proposed, one for pipes discharging 
vertically, which is particularly applicable before the well is 
permanently finished, and one for horizontal discharge, which is 
the most frequent way of finishing a well. For the measuring a 
vertical flow we have extended a method which wa's first used 
by Mr. P. E. Manchester, C. E., of Chamberlain, who published 
a table adapted to large wells, in the Chamberlain Register, 
December, 1895. 
“The table below is adapted to wells of moderate size as well 
as to larger. In case a well is found of other diameter than that 
given in the table, its discharge may be obtained without much 
difficulty from the table by remembering that other things being 
equal the discharge varies as the square of the diameter of the 
pipe. If, for example, the pipe is one-half inch in diameter its 
discharge will be one-fourth of that of a pipe one inch in diameter, 
whose stream reaches the same height, so also a pipe eight inches 
in diameter may be obtained by multiplying that of the four-inch 
pipe by four. 
“In the first case the inside diameter of the pipe may be 
measured, then the distance from the end of the pipe to the 
highest point of the dome of water above, in a strictly vertical 
direction —a to b in the diagram. Then these distances may be 
found in the table and the corresponding figure will give the num¬ 
ber of gallons discharged per minute. The blowing of the wind 
