Mr. W. Walker, M.R.C.S. read a paper on the “Physical Characters of Water”.

The point (32 deg. Fahr.) at which water assumes a solid condition is below the ordinary temperature of the earth. Ice occupies more space than water from which it is formed, and it is this expansion of water in freezing that causes the breaking of our pipes & water jugs.

The force thus developed is very great, iron cannons half in inch thick having been easily cracked by it. This expansion also renders Ice lighter than water & causes it to float on the surface, were it not so, ice when formed, would be deposited at the bottom of our lakes & rivers which would gradually become a solid mass involving the destruction of nearly all life in them.

The freezing point of water is lowered by pressure and on this fact are based certain theories respecting the cause of motion of glaciers, which are vast fields of ice produced by the partial melting and refreezing of snow. Snow is congealed vapour, each flake being composed of numbers of lovely crystals grouped together. The variety of forms is very considerable, as many as 96 having been counted.

Sleet consists of small icy needles, due to the freezing of cloud drops in an agitated atmosphere. Hail is a variety of snow & sleet, which has suffered many congelations from passing through various temperatures. Its formation is supposed to be in some way dependent upon electrical influences, as it invariably precedes a thunderstorm.