n Anthracite Coal.--About 40,000 cubic feet.

SUSTAINING POWER OF ICE.

The sustaining power of ice at various degrees of thickness is given
in the following paragraphs:

At a thickness of two inches, will support a man.

At a thickness of four inches, will support man on horseback.

At a thickness of six inches, will support teams with moderate loads.

At a thickness of eight inches, will support heavy loads.

At a thickness of ten inches, will support 1,000 pounds to the square
foot.

THE EXPANSIVE POWER OF WATER.

It is a well known, but not less remarkable fact, that if the tip of
an exceedingly small tube be dipped into water, the water will rise
spontaneously in the tube throughout its whole length. This may be
shown in a variety of ways; for instance, when a piece of sponge,
or sugar, or cotton is just allowed to touch water, these substances
being all composed of numberless little tubes, draw up the water,
and the whole of the piece becomes wet. It is said to _suck up_ or
_imbibe_ the moisture. We see the same wonderful action going on in
nature in the rising of the sap through the small tubes or pores of
the wood, whereby the leaves and upper portions of the plant derive
nourishment from the ground.

This strange action is called "capillary," from the resemblance the
minute tubes bear to a hair, the Latin of which is _capillus_. It is,
moreover, singular that the absorption of the water takes place with
great force. If a dry sponge be enclosed tightly in a vessel, it will
expand when wetted, with sufficient force to burst it, unless very
strong.

London Water Supply.--The quantity of water consumed in London
amounts to about 145,000,000 gallons a day. If this quantity could be
collected together, it would form a lake 700 yards long, 200 wide, and
with a uniform depth of 20 feet.

A Protection for Embankments.--Engineers often have considerable
trouble with the loose soil of newly-made embankments, so apt to slip
or be washed away before they are covered with vegetation. According
to a French railway engineer, the best plan is to sow the banks with
the double poppy. Several months elapse before grasses and clovers
develop their feeble roots, but the double poppy germinates in a
few days, and in a fortnight has grown sufficiently to afford some
protection to the slope, while at the end of three or four months the
roots, which are ten or twelve inches in length, are found to have
interlaced so