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 as to retain the earth far more firmly than those of any
grass or grain. Although the double poppy is an annual, it sows itself
after the first year.
A Cheap Concrete.--A kind of concrete made without cement is composed
of 8 parts of sand, gravel and pebbles, 1 part of burnt and powdered
common earth, 1 part of pulverized clinkers and cinders, and 1-1/2
parts of unslacked hydraulic lime.
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