"Our lessons on coal-tar and naphtha, Fred, like a good many others, have led us farther than I thought they would," said Willie. "Who would have thought now that they had anything to do with paraffin oil?""Does paraffin oil come from coal-tar and naphtha then?"" asked Norah.
"No," said Fred, "not exactly. But teacher has been showing us today that there are a great many inflammable liquids very much like the coal-naphtha in their properties. Some of them are prepared by man, but most of them are got direct from the ground.
"Petroleum or rock-oil is the commonest of these. It is obtained from springs in many parts of the world, but chiefly in America and Russia.
"Teacher says that these oil springs in some places rise to the surface of the ground, but as a rule deep wells are sunk, and the oil is pumped up from them.
"The petroleum as it comes from the earth is of a dirty greenish-yellow color and very thick and oily. In this state it is unfit for use. It is pumped from the wells into great tanks, whence it is sent along iron pipes to the refining factories to be purified.
"A coarse rough oil very like this is obtained from peat, from various kinds of coal, and, as we have seen, from coal-tar.
