One bright morning in August little Mary Louise put on her hat and went trudging across the meadow to the beach.
It was the first time she had been trusted out alone since the family had moved to the seashore for the summer; for Mary Louise was a little girl, nothing about her was large, except her round gray eyes.
There was a pale mist on the far-off sea, and up around the sun were white clouds edged with the hues of pinks and violets. The tide was coming in, and the waves, little at first, but growing larger every moment, were crowding up, along the sand and pebbles, laughing, winking and whispering, as they tumbled over each other, like thousands of children hurrying home from school.
Who was down there under the blue water, with the hoarse, hollow voice, urging and pushing them across the beach to her feet? And what was there beneath the sea, and beyond the sea, so deep, so broad and so dim, away off where the white ships, that looked smaller than seabirds, were gliding out and in?
But while Mary Louise stood still and wondered, there came a low rippling laugh to her ear.
A little distance down the beach a girl, somewhat older than herself, rested on the beach. She evidently was tired from swimming, for she lay half in the water and half on the warm sand, her face resting on her upturned palms, looking at Mary Louise with a smile, which seemed to say: "Why don't you come over and comb my hair?"
Indeed, this must have been exactly what she meant, for she held out a pretty pearl comb until Mary Louise could resist no longer.
Little Mary Louise had never before seen such beautiful long hair. It spread like a scarf from the girl's shoulders down upon the sand.
Mary Louise had forgotten that there were mermaids, and that mermaids always had most beautiful hair, and that they always combed it with pearly combs!
"Have you been swimming?" asked Mary Louise.
"Yes, a long swim," answered the little mermaid, and she gave a sudden kick in the water with her little feet, or, should I say, with her small fin-tail, which sent the spray flying.
"Oh, you're a mermaid!" exclaimed Mary Louise, surprised and delighted at her unexpected discovery. "I saw your finny tail. Do you like tails better than feet?"
"I never had feet," said the little mermaid, "so I can't say, but I should think they'd be very nice to walk on."
"Yes, if you go to the mountains, as we did last summer," answered Mary Louise, "but you don't have to climb hills in the ocean."
"Perhaps you don't know there are mountains in the sea," said the little mermaid. "Of course, you have seen nothing but their tops. What is that little rocky ledge over yonder, where the white lighthouse stands, but the stony top of a hill rising from the bottom of the sea? And what are those pretty green islands, with their clusters of trees and grassy slopes, but the summits of hills lifted out of the water?"
"Oh!" said Mary Louise, with a gasp. "You do know geography, don't you? Is it pretty, away down there under the waves?" she added wistfully.
The mermaid smiled very sweetly as she answered, "Yes, it is. There are many wonderful things to see, and many strange beautiful things to hear under the sea! I will comb your hair with my magic comb," and she ran the pearly comb gently through Mary Louise's hair.
"Over the sea the white ships sail,
Out through the mist and the rollicking gale,
While deep below the mermaids swim
With their finny tails so neat and trim.
So please, little magic comb, don't fail
To give Mary Louise a mermaid tail."
And the more she combed the longer grew the pretty curls, until, to the astonishment of Mary Louise, she found her hair trailing down to her very feet. The breeze suddenly blew it to one side, and there on the sand, instead of her two little shoes, was a mermaid's tail, with a flippy-floppy fin on the end!
"Come with me," said the mermaid, and without a moment's hesitation Mary Louise followed her into the water and out beyond the breakers, swimming as easily as if she had always been a little mermaid, instead of a girl who wore tan shoes.
"Where are we going?" asked Mary Louise, as the dim line of the shore disappeared and there was nothing in sight but the great, restless ocean.
The mermaid did not answer, but looked about intently, as if trying to find something.
"What are you looking for?" asked Mary Louise, for she was a curious little girl, and forgot one question as soon as she asked another.
"Oh, there it is!" exclaimed the mermaid. "Come with me. Hold your hands out before you like this and dive down!"
"But where are we going?" again asked Mary Louise as they sank lower and lower in the sea.
"Oh, I forgot," answered the mermaid, turning with a smile to her little companion; "I was so busy looking for the subway entrance that I forgot your question."
"Goodness!" cried Mary Louise. "I didn't know there was a subway in the sea!"
"To be sure," answered the mermaid. "The track lies along the bottom of the ocean. It's not a railroad train we're going to take, but a water train that comes all the way from the Northern seas, sweeping on like a river in the sea. Wait till we get down there. You'll see how fast it goes."
Mary Louise was too astonished to speak.
"The Pullman cars," continued the mermaid, "are icebergs. They come from the North every summer to take a trip South."
"Whew!" shivered Mary Louise. "I think we ar near one now, for I feel quite cold."
Sure enough, she was right, for there close at hand was a great white object.
"All aboard!" shouted a big polar bear. "Watch your step!"
The mermaid helped Mary Louise to slide on a projecting ledge, and off they went.
"Now we can enjoy the scenery," laughed the mermaid, as she arranged her tail in an artistic curve and brushed back her hair, which had been swept over her eyes by the swift action of the water.
"The train never stops, you know, until it reaches its destination, but that need not interfere with our getting off any time we please should you wish to visit any pretty spot we pass on our journey."
Just at that moment there was a tremendous crash and Mary Louise found herself thrown off into the water, while a muffled roar rolled through the depths of the ocean.