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.