419
10. With reference to their theory that a drain built so steep meline could retain sand along its allows on bed the following table show. the authority of the Rust, the greatest velocities of the current - close to the bed of a water channel consistent with the stability of various materials:
Jure sand
Coarse sand and gravel as large as peas.
...
50 feet per second
} 70 to 100
100
do
do
2.25 de do
do fravel as large French beaus }
fravel 1 inch in dia.
Fur Beardmor gives the limits of velocity at the bottom of a channel thus :
— Feet,
for second moves coarse sans
do do do price gravel size.
do I nich rounder.
Calculated by the stove formuels, the Belmont drain along its last stiv = portion would have had the water flowing through it at ther rate te of 18- or sufficient to carry feet four. & of 15" "bricks and stores with it. Sand wney porn the above tables could not possibly have been, cause of 1. choking of. tta drain as alleges.
11. In paragraphot the and 4 Cornel Stuart makes a мен point of the fact of a drain having been constructed unindiately