PART I.--HEAT.

I.--The SUN a source of heat

II.--ELECTRICITY a source of heat Thunder and lightning

III.--CHEMICAL ACTION a source of heat III.--Combustion IV.--Smoke and smoky chimneys V.--Lamps and candles VI.--Animal heat

VII.--MECHANICAL ACTION a source of heat VII.--Percussion VIII.--Friction VIII.--Compression

IX.--EFFECTS OF HEAT X.--Expansion XI.--Liquefaction XI.--Vaporization (clouds) XII.--Evaporation

XIII.--COMMUNICATION OF HEAT XIII.--Conduction XIV.--Absorption XV.--Reflection XVI.--Radiation (dew) XVII.--Convection (boiling)