The path of prayer Thyself hast trod:
Lord! teach us how to pray!
Like as a father pitieth his children, so the Lord pitieth them that fear Him.—Psalm CIII.
LXVII.—THE THERMOMETER.
All substances produce in us, when we touch them, the sensation of heat or of cold. The degree of heat of any substance is called its temperature; and the temperature varies from time to time, according to circumstances. Boiling water, for example, contains so much heat that it scalds the skin; but, when removed from the fire, the water gradually becomes less and less warm, until at last it contains so little heat that it cools the hand instead of scalding it.
Our feelings do not always give us true information about the temperature of the bodies by which we are surrounded. A person comes into a warm room from the open air on a cold day, and exclaims, “How warm it is here!” Another person enters the same room from one still warmer, and cries, “How cold it is here!” The first person gains heat, and therefore calls the room warm; the second loses heat, and calls it cold; while, in reality, the air of the room, all the while, is at the same degree of temperature.
A nurse prepares water for a child’s bath, and measures the heat by the feeling of her hand; but she learns from the quick and sudden cry of the child, when placed in the bath, that what seemed warm to her is cold to the child.