Furthermore, sand and earth in Nature are not constrained by forms and
reinforcing rods.

Mr. Meem's paper is very valuable in that it presents some unusual
phenomena, but many of the conclusions drawn therefrom cannot be
accepted without further demonstration.


FRANCIS W. PERRY, ASSOC. M. AM. SOC. C. E.--Pressure-gauge
observations on a number of pneumatic caissons recently sunk, through
various grades of sand, to rock at depths of from 85 to 105 ft. below
ground-water, invariably showed working-chamber air-pressures equal, as
closely as could be observed, to the hydrostatic pressures computed, for
corresponding depths of cutting-edge, as given in Table 2.

These observations and computations were made by the speaker in
connection with the caisson foundations for the Municipal Building, New
York City.


TABLE 2.--EQUIVALENT FEET OF DEPTH BELOW WATER PER POUND
PRESSURE.

Pressure, |Equivalent |Equivalent |Observed |
in |feet of |elevation |pressure. |
pounds. |depth. |for water | |
| |at--6.85. | |
|___________|_____________| |
| | | |
|M.H.W. |Ground-water.| |