IV.

_SCIENTIFIC DOMESTIC VENTILATION._

An open fireplace secures due ventilation--Evils of substituting air-tight stoves and furnace heating--Tendency of warm air to rise and of cool air to sink--Ventilation of mines--Ignorance of architects--Poor ventilation in most houses--Mode of ventilating laboratories--Creation of a current of warm air in a flue open at top and bottom of the room--Flue to be built into chimney: method of utilizing it.

V. STOVES, FURNACES, AND CHIMNEYS.

The general properties of heat, conduction, convection, radiation, reflection--Cooking done by radiation the simplest but most wasteful mode: by convection (as in stoves and furnaces) the cheapest--The range--The model cooking-stove--Interior arrangements and principles--Contrivances for economizing heat, labor, time, fuel, trouble, and expense--Its durability, simplicity, etc.--Chimneys: why they smoke and how to cure them--Furnaces: the dryness of their heat--Necessity of moisture in warm air--How to obtain and regulate it.