One of the first requisites of a ball-room is thorough ventilation, especially if there is a prospect of a large number of guests. One of the most desirable points in a ball is to have a beautifully arranged room. The floor must be well waxed, and perfectly even, and it is well to draw a cord across two-thirds of it, not admitting more than can dance inside the space so cut off at once. The French make their ball-rooms perfect flower-gardens. Every comer has its immense bouquet; the walls are gracefully wreathed; bouquets, baskets, and exquisitely decorated pots of growing plants are placed in every available place. The staircases, landings, and supper-room are all filled with floral treasures, harmonizing with fine effect with the brilliant lights and gay the dresses of the ladies. It adds to the effect to conceal the musicians behind a screen of evergreen and flowers. The dressing-rooms should be provided with two servants apiece, and small cards, with the names of the invited guests upon them, should be in readiness to pin to the wraps of each one. In each dressing-room, have plenty of water, soap, and towels upon the washstand, several brushes and combs, small hand-mirrors, pin- cushions well filled, and stick pomade upon the bureau. The ladies' room should also have hair-pins, a work-box in readiness to repair any accidental rip or tear; cologne, hartshorn, and salts, in case of faintness. The gentlemen's room should be provided with a boot-jack, a whisk, and a clothes-brush. No one should accept an invitation to a ball who cannot or who will not dance. They are mere encumbrances. Nothing is more trying to the feelings of a hostess than to see a number of wallflowers ornamenting (?) her ball-room. The hour at which one may go to a ball varies from ten o'clock in the evening until daybreak. Any one who attends several balls in one evening will, of course, find it impossible to appear at an early hour at each one.