Byflow

Runoff measurements tended to be slightly inaccurate due to underflow or byflow of small but rapid streams flowing in solid or pebbly mountainous channels.

The internal overflow steel dam should be used for this purpose to allow byflow. With a closed-type riser it should be possible to couple the suction pipe to the hydrant and, of course, no byflow arrangement is required.

Why not cut St. Leonard's-on-Sea, which is a confounded Hastings circuited by a byflow of parade, and come straight here to Bournemouth — really one of the prettiest of all the English Sea-Sides, with pines growing to the sands.

In other words, in the main flow it is the physical variable itself, the "substance", that matters; in the by-flow it is just information.