"What is it in the thermometer that shines so, mother?"

"Oh, that is quicksilver, Ethel. See the line of silver run up the tube while I hold it in my hand."

"Quicksilver? I should think it was quick! See it run back, now the tube is cool. But father called it something else the other night. What was it?"

"Oh, yes; he called it mercury, my dear. It is named after one of the gods the Greeks used to worship, their swift wind-god, Mercury. We read of him in many old stories. He was so quick that he became a messenger boy for the other gods."

"Oh, I like those old myths. Tell me about Mercury. I am going to name my dove after him, for it takes messages for me. Tell me a long one, please."

"Well, my dear, Mercury is also the name of the planet that will soon be our evening star. And, Ethel, if I tell you this story now, you must tell it to me sometime when we watch his beautiful namesake in the sky. Will you try to remember it?"

"Oh, yes, indeed, I'll remember. I love the stories about the stars. It makes them seem so real. I know Venus and Jupiter, and Mars with his red eye, and now I am going to have another friend among them. Oh, I am glad I asked about that quicksilver," and Ethel settled down on a footstool at her mother's feet.

This is the story Mrs. Brown told Ethel:

"In the days when the earth was young, a little baby lay alone in its cradle in a beautiful cave in a mountain side. This baby was Mercury. His mother had left him because someone had called her away for a moment, but for some reason she stayed an hour.

"As soon as she had gone, this wee baby turned over, lifted his head, and, seeing the door of the cave ajar, put out his hand. Touching the sides of the cradle, he sprang out like a boy ten years old. Slipping through the doorway, Mercury ran quickly down to the river bank near his home. A river tortoise was in his way. His tiny toes tripped over it and he fell. Vexed to be stopped by such a slow, clumsy creature, Mercury dashed it on a rock and killed it. Then he threw it into the river and watched the fish feed on its flesh. It seemed but a minute before the empty shell drifted to his feet. Mercury picked it up and felt sorry for what he had done.

"'I will make this shell live forever,' he said. 'I do not mean to be cruel to earth's creatures.'

"Quick as a thought he bored nine holes in each side, and taking the lacings from his tiny sandals, he split them and strung them into the holes in the shell.

"Drawing his little hand across the strings, there came the sweetest sounds, and the first harp on earth was made. He was so pleased that he hid it under his white dress until he came to some thick reeds by the river, and there he laid it safely away.

"Running swiftly homeward, he came softly through the narrow opening, back into his own room, and, creeping into his cradle, he cuddled down and went to sleep."

"Why, mother, he was so little! Only a baby; how could he?"

"The old myth says he was only three days old when he did this, but remember, this is like a fairy story, and Mercury was the son of the great Jupiter. But let me tell the rest. When his mother came back, she was frightened to think he had been alone an hour, but he was sleeping so sweetly when she looked at him that she felt he had not been harmed. The mother never dreamed when she saw the open sandals that he had been away."

"But the harp, mother; didn't she ever find that?"

"No, you know the little rogue had hidden the harp in the reeds by the river. Another day he ran away and got into worse trouble than he expected, for he dared to steal some of Apollo's cattle. They were beautiful snow-white creatures, feeding in the violet meadows of the sky. As he saw them drifting slowly toward him, the mischief in him made him drive these gentle creatures into the sea, and, being tired and hungry, he tore the last one to pieces and fed on it.

"Though this mischief-maker walked backward to his home, trying to deceive any who would hunt for him, Apollo found him out. When the sun-god saw him lying there, a helpless baby in a cradle, Mercury almost made him think that he had not done the wrong. But at last even Mercury's mother believed him guilty, for the proofs brought were many, and Apollo came to take him away. Then the little wind-god took from under his cradle-clothes the harp which he had hidden there, and breathed upon it. Apollo was charmed by the melody and could only say:

"'Give me that, and I will not ask for my stolen cattle.'

MERCURY. From a statue in Florence, Italy.

"That was just what Mercury wished. He quickly handed him the tortoise shell. In Apollo's hands it made still sweeter music, for everything Apollo did was best.

"So nimble Mercury was free. When the child was a few months older, Apollo chose him for his messenger. He gave him a cap with wings at either side, and winged sandals. In his hands he always carried a winged wand with two serpents crossed and recrossed upon it. You have surely seen his picture, Ethel?"

"Oh, yes. Down at the art store there is a little statue of him. I can remember, this story always."