The writer fails to find proof in this paper of the author's statement
that earth pressures on the sides of a structure buried in earth are
greater at the top than at the bottom of a trench. That some banks are
"top-heavy," is, no doubt, a fact, the writer having often heard similar
expressions used by experienced trench foremen, but, in every case
called to his attention, local circumstances have caused the
top-heaviness, either undermining at the bottom of the trench, too much
banked earth on top, or the earth excavated from the trench being too
near the edge of the cut.

For some years the writer has been making extended observations on deep
trenches, and, thus far, has failed to find evidence, except in aqueous
material, of earth pressures which might be expected from the known
natural slope of the material after exposure to the elements; and this
latter feature may explain why sheeted trenches stand so much better
than expected. If air had free access to the material, cohesion would be
destroyed, and theoretical pressures would be more easily developed.
With closely-sheeted trenches, weathering is practically excluded, and
the bracing, which seemingly is far too light, holds up the trench with
scarcely a mark of pressure. As an instance, in 1893, the writer was
successfully digging sewer trenches from 10 to 14 ft. deep, through
gravel, in the central part of Connecticut, without bracing; because of
demands of the work in another part of the city, a length of several
hundred feet of trench was left open for three days, resulting in the
caving-in of the sides. The elements had destroyed the cohesion, and the
sides of the trenches no longer stood vertically.

Recently, in the vicinity of Boston, trenches, 32 ft. wide, and from 25
to 35 ft. deep, with heavy buildings on one side, have been braced with
8 by 10-in. stringers, and bracers at 10-ft. centers longitudinally, and