brilliancy and beauty of flame. What diamond can shine like flame? It owes
its lustre at night-time to the very flame shining upon it. The flame
shines in darkness, but the light which the diamond has is as nothing
until the flame shine upon it, when it is brilliant again. The candle
alone shines by itself, and for itself, or for those who have arranged the
materials. Now, let us look a little at the form of the flame as you see
it under the glass shade. It is steady and equal; and its general form is
that which is represented in the diagram, varying with atmospheric
disturbances, and also varying according to the size of the candle. It is
a bright oblong--brighter at the top than towards the bottom--with the
wick in the middle, and besides the wick in the middle, certain darker
parts towards the bottom, where the ignition is not so perfect as in the
part above.

[Illustration: Fig. 3.]

I have a drawing here, sketched many years ago by Hooker, when he made his
investigations. It is the drawing of the flame of a lamp, but it will
apply to the flame of a candle. The cup of the candle is the vessel or
lamp, the melted spermaceti is the oil, and the wick is common to both.
Upon that he sets this little flame, and then he represents what is
true--a certain quantity of matter rising about it which you do not see,
and which, if you have not been here before, or are not familiar with the
subject, you will not know of. He has here represented the parts of the
surrounding atmosphere that are very essential to the flame, and that are
always present with it. There is a current formed, which draws the flame
out--for the flame which you see is really drawn out by the current, and
drawn upward to a great height--just as Hooker has here shewn you by that
prolongation of the current in the diagram. You may see this by taking a
lighted candle, and putting it in the sun so as to get its shadow thrown