“Guess I did,” said Billy, giving the fire an extra poke, “only I didn’t stop to think. But I don’t believe I know just exactly what makes them after all.” “In the case of coal--pressure,” said Somebody. “This old world of ours has been a long time in the making; at some time in its history dense forests, which had been centuries in growing, were crushed and buried by some disturbance of the earth and under the mountains of earth and rocks were pressed into a rock-like substance composed of carbon, oxygen, nitrogen, and hydrogen, with sulphur and silica added. The carbon and gases burn up, and what is left is what you take away in the form of ashes before you go to school mornings, like the good boy that you are.” “Is coal everywhere under us then?” asked the boy named Billy. “Probably not,” answered Somebody. “It is usually found in streaks, very likely because there was much open country where no forests grew. Then, too, the moving glacier or flood or whatever it was that destroyed the forests may have taken them a long way from home before it buried them.” “The coal we burn in the furnace is not like the sort that you burn in your grate,” said the boy named Billy. “The Anthracite, or hard coal which is used in furnaces,” said Somebody, “is the kind that has been under most pressure and is found at a greater depth than the Bituminous or soft coal which is found nearer the surface.” “Who was the first to find out that coal would burn?” asked Billy. “Nobody knows,” said Somebody. “Perhaps some little mother whose babies were cold and chilly found some black rocks and used them for a fireplace to hold the little sticks which she was burning to cook breakfast over, and found that the stones also burned.” “I’ll bet that’s right,” said Billy. “I can just see the picture. What kind of mother would she have been?” “Anglo-Saxon,” said Somebody, “as they were the first to use it as a fuel. They have been known to have used coal since 842 A. D.” “As useful as coal itself is, its derivatives are more so,” went on Somebody. “From coal tar is made so many articles of daily use that it would be impossible to tell you about them all.” “Old King Coal,” sang Billy. “Thanks, Somebody--I’m off for a swift skate on the ice this morning!” [Illustration: “A true Star has but five Points”] Flag Day [Illustration: REVOLUTIONARY FLAGS USED BEFORE THE ADOPTION OF THE STARS AND STRIPES] “I can’t seem to make this flag-staff do what I want it to,” said the boy named Billy. “Let me help you,” said Somebody; “I’ll hold it while you clamp it to the window-sill.” “Just when did we begin to have Flag Day, please?”