113. What is the Conduction of heat?
It is the communication of heat from one body to another by contact. If I lay a penny piece upon the hob, it becomes hot by conduction.
114. What is the Radiation of heat?
The transmission of heat by a series of rays. If I hold my hand before the fire, the rays of heat fall upon it, and my hand receives the heat through radiation.
"Sing praises to the Lord, which dwelleth in Zion, declare among the people his doings."—Psalm ix.
115. What is the Reflection of heat?
The reflection of heat is the throwing back of its rays towards the direction whence they came. In a Dutch oven the rays of heat pass from the fire to the oven, and are reflected back again by the bright surface of the tin. There is, therefore, considerable economy of heat in ovens, and other cooking utensils constructed upon this plan.