The night of the party the whole Fairfield house was so transformed that it must scarcely have recognised itself.

The large front drawing-room represented the arctic regions in the vicinity of the North Pole.  Frames had been erected which, when covered with sheets, simulated peaks of snowy mountains and snow-covered icebergs.  Here and there signs, apparently left by explorers, told the latitude and longitude, and a flag marked the explorations Farthest North.  Over these snow peaks scrambled white polar bears in most realistic fashion, and in one corner an Esquimau hut was built.

The ceiling represented a clear blue sky, and the floor the blue water of the open polar sea.

By a clever arrangement of electric lights through colored shades a fair representation of the Aurora Borealis was made to appear at intervals.

The library, which was back of the drawing-room, had been transformed into an aquarium.  All round the walls, waves of blue-green gauze simulated water, in which papier-mache fish were gliding and swimming.  The illusion was heightened by other fishes, which, being suspended from the ceiling by invisible threads, seemed to be swimming through the air.

Altogether the effect, if not entirely realistic, was picturesque and amusing, and coral reefs and rocky cliffs covered with seaweed gave aquatic impressions, even if not entirely logical.

But Nan’s pride was what she chose to call the Upper Deck.  This was a room on the second floor, a large front room, which had been made to represent the upper deck of a handsome yacht.  Sail-cloth draped and held up by poles formed the roof and sides, and a realistic railing surrounded it.  A dozen or more steamer chairs stood in line, strewn with rugs, pillows and paper-backed novels.  Coils of rope, lanterns, life-preservers, and other paraphernalia added to the realism of the scene, and at one side a carefully constructed window opened into the steward’s cabin.  The steward himself, white-duck-suited and white-capped, was prepared to serve light refreshments exactly after the fashion of a correct yachting party.

When the guests began to arrive and were dressed in various costumes, each representing some type or phase of water pleasures, the scene took on a gay and festive air.

Patty’s kelpie costume was a great success, and the girl never looked prettier than as she stood receiving her guests in the pretty green silk gown, trailing with seaweed and shimmering with silver dust.  Her curly golden hair was wreathed with soft green water-grasses, and her rosy cheeks and dancing eyes made her look like a mischievous water sprite.

Nan’s own costume was that of a fish-wife, and though very different from Patty’s, it had all the picturesqueness of the quaint costume of the Breton fisher-folk.  A basket slung over her shoulder held realistic-looking fishes, and Nan looked quite as if she might have stepped out of the frame of a picture in the French Academy.