s are, doesn't it? No offence meant, of
course. As for you, Mr. Narkom--or Mr. Gregory Lake, as I must remember
to call you for the good of the cause--I'm ashamed of you, I am indeed!
You ought to know better, a man of your years!"

"But the flames, Cleek, the flames!" There was a tension in Merriton's
voice that spoke of nerves near to the breaking point. Instantly Cleek
was serious. He reached out a hand and laid it upon the young man's
shoulder. Merriton was trembling, but he steadied under the grip, just
as it was meant that he should.

"See here," Cleek said, bluntly, "you oughtn't to work yourself up into
such a state. It's not good for you; you'll go all to pieces one of these
days. Those flames, eh? Why I thought any one knew enough about natural
phenomena to answer that question. But it seems I'm wrong. Those flames
are nothing more nor less than marsh gas, Sir Nigel, evolved from the
decomposition of vegetation, and therefore only found in swampy regions
such as this. Whew! and to think that here is a community that has been
bowing down to these things as symbols from another world!"

"Marsh gas, Mr.--"

"Headland, please. It is wiser, and will help better to remember when the
necessity arises," returned Cleek, with a smile. "Yes, that is all they
are--the outcome of marsh gas."

"But what _is_ marsh gas, Mr.--Headland?" Merriton's voice was still
strained.

Cleek motioned to a chair.

"Better sit down to it, my young friend," he said, gently. "Because, to
one who isn't interested, it is an extremely dull subject. However, it is
better that you should know--as you don't seem to have learnt it at
school. Here goes: marsh gas, or methane as it is sometimes called, is
the first of the group of hydrocarbons known as paraffins. Whether that
conveys anything to you I don't know. But you've asked for knowledge and
I mean you to have it." He smiled again, and Merriton gravely shook his
head, while Mr. Narkom, dropping for the time being his air of pompous
boredom, became the interested listener in every line of his ample
proportions.

"Go on, old chap," he said eagerly.

"Methane," said Cleek, serenely, "is a colourless, absolutely
odourless gas, slightly soluble in water. It burns with a yellowish
flame--which golden tinge you have no doubt noticed in these famous
flames of yours--with the production of carbonic acid and water. In the
neighbourhood of oil wells in America, and also in the Caucasus, if my