altar, the range of gas lamps in our streets, all have their stories to
tell. All, if they could speak (and, after their own manner, they can),
might warm our hearts in telling, how they have ministered to man s
comfort, love of home, toil, and devotion.
Surely, among the millions of fire-worshippers and fire-users who have
passed away in earlier ages, _some_ have pondered over the mystery of
fire; perhaps some clear minds have guessed shrewdly near the truth. Think
of the time man has lived in hopeless ignorance: think that only during a
period which might be spanned by the life of one man, has the truth been
known.
Atom by atom, link by link, has the reasoning chain been forged. Some
links, too quickly and too slightly made, have given way, and been
replaced by better work; but now the great phenomena are known the
outline is correctly and firmly drawn cunning artists are filling in the
rest, and the child who masters these Lectures knows more of fire than
Aristotle did.
The candle itself is now made to light up the dark places of nature; the
blowpipe and the prism are adding to our knowledge of the earth s crust;
but the torch must come first.
Among the readers of this book some few may devote themselves to
increasing the stores of knowledge: the Lamp of Science _must_ burn.
_Alere flammam._
W. CROOKES.
CONTENTS.
LECTURE I.
A CANDLE: THE FLAME ITS SOURCES STRUCTURE MOBILITY BRIGHTNESS
2