A.M. It appeared at B in 22 min., and at E in 3 hours and 52 min.

The red was started at 8.45 A.M. It reached B in 21-1/2 min., but it was so faded that the time of its appearance at E could not be noted exactly.

The bran was started at 9.00 A.M. It reached B in 22 min., and appeared at E in 3 hours and 51 min.

From the average of these figures, the velocities were:

and the discharges were:

The application of the equation for equalized relative velocities, as in the first test, gives:

These last figures would check exactly, except for dropping figures in the fourth decimal place.

The results of these two tests, considering that 20 days elapsed between them, are in very close agreement, and establish the fact that bran is an accurate medium of measurement.

Test No 3.—The 500 ft. of 10-in. pipe in the 16-in. line near the reservoir (Fig. 2) were replaced by 16-in. pipe in the summer of 1908.

On May 12th, 1909, green aniline was started through the pipe at A at 11.00 A.M., 11.30 A.M., and 12.00 A.M. In each case it appeared at E in 3 hours and 31 min. This time is 20 min. less than that observed in the tests of the previous year, and is due to the removal of the 10-in. pipe from the 16-in. line and to the increasing smoothness of the interior surface of the pipe.

The relative velocities and discharges under the third test, using the nomenclature of the first and correcting the lengths of pipe on account of the removal of the 10-in. pipe near the reservoir, are: