The following is an annotated version of the fairy tale. I recommend reading the entire story before exploring the annotations, especially if you have not read the tale recently.
FAR out in the ocean, where the water is as blue1 as the prettiest cornflower, and as clear as crystal, it is very, very deep; so deep, indeed, that no cable could fathom it: many church steeples, piled one upon another, would not reach from the ground beneath to the surface of the water above. There dwell the Sea King2 and his subjects. We must not imagine that there is nothing at the bottom of the sea but bare yellow sand. No, indeed; the most singular flowers and plants grow there; the leaves and stems of which are so pliant, that the slightest agitation of the water causes them to stir as if they had life. Fishes, both large and small, glide between the branches, as birds fly among the trees here upon land. In the deepest spot of all, stands the castle of the Sea King. Its walls are built of coral, and the long, gothic windows are of the clearest amber. The roof is formed of shells, that open and close as the water flows over them. Their appearance is very beautiful, for in each lies a glittering pearl, which would be fit for the diadem of a queen.
The Sea King had been a widower for many years, and his aged mother kept house for him. She was a very wise woman, and exceedingly proud of her high birth; on that account she wore twelve oysters on her tail; while others, also of high rank, were only allowed to wear six. She was, however, deserving of very great praise, especially for her care of the little sea-princesses, her grand-daughters. They were six beautiful children; but the youngest3 was the prettiest of them all; her skin was as clear and delicate as a rose-leaf, and her eyes as blue as the deepest sea; but, like all the others, she had no feet, and her body ended in a fish’s tail.4 All day long they played in the great halls of the castle, or among the living flowers that grew out of the walls. The large amber windows were open, and the fish swam in, just as the swallows fly into our houses when we open the windows, excepting that the fishes swam up to the princesses, ate out of their hands, and allowed themselves to be stroked. Outside the castle there was a beautiful garden, in which grew bright red5 and dark blue flowers, and blossoms like flames of fire; the fruit glittered like gold, and the leaves and stems waved to and fro continually. The earth itself was the finest sand, but blue as the flame of burning sulphur. Over everything lay a peculiar blue radiance, as if it were surrounded by the air from above, through which the blue sky shone, instead of the dark depths of the sea. In calm weather the sun6 could be seen, looking like a purple flower, with the light streaming from the calyx. Each of the young princesses had a little plot of ground in the garden, where she might dig and plant as she pleased. One arranged her flower-bed into the form of a whale; another thought it better to make hers like the figure of a little mermaid; but that of the youngest was round like the sun, and contained flowers as red as his rays at sunset. She was a strange child, quiet and thoughtful;7 and while her sisters would be delighted with the wonderful things which they obtained from the wrecks of vessels, she cared for nothing but her pretty red flowers, like the sun, excepting a beautiful marble statue.8 It was the representation of a handsome boy, carved out of pure white stone, which had fallen to the bottom of the sea from a wreck. She planted by the statue a rose-colored weeping willow. It grew splendidly, and very soon hung its fresh branches over the statue, almost down to the blue sands. The shadow had a violet tint, and waved to and fro like the branches; it seemed as if the crown of the tree and the root were at play, and trying to kiss each other. Nothing gave her so much pleasure as to hear about the world above the sea. She made her old grandmother tell her all she knew of the ships and of the towns, the people and the animals. To her it seemed most wonderful and beautiful to hear that the flowers of the land should have fragrance, and not those below the sea; that the trees of the forest should be green; and that the fishes among the trees could sing so sweetly, that it was quite a pleasure to hear them. Her grandmother called the little birds fishes, or she would not have understood her; for she had never seen birds.
“When you have reached your fifteenth year,”9 said the grand-mother, “you will have permission to rise up out of the sea, to sit on the rocks in the moonlight, while the great ships are sailing by; and then you will see both forests and towns.”
In the following year, one of the sisters would be fifteen: but as each was a year younger than the other, the youngest would have to wait five year