The records of all flights are carefully preserved, to be counted against the several important trophies which will be awarded at the end of the season. Any one of the scores of contestants can tell you at any moment how the score stands. During this tuning up process, the galleries have filled and an enthusiastic audience is assured. One of the great beauties of indoor aviation is that it is entirely independent of the weather. The air of the great armory is practically at rest, and the aeroplanes escape the baffling side currents and air gusts. In England, for instance, indoor aviation is practically unknown. A whistle sounds above the hum of many voices, and at the signal everyone scurries to the sides, leaving the broad floor clear. The judge, starter, and measurer take their positions, and the aviators, with their models tuned up to concert pitch, stand ready at the starting line. The starter announces whether the flight is "official" and if it is to be counted in the competition for the trophies, or is merely a practice or exhibition flight. The start is made from the extreme corner diagonally across the armory. Only last year the start was made from a point well out in the middle of the floor, but that was when the flights were much shorter. To-day the boys have actually outgrown the armory, and even by flying from corner to corner there is not enough room. The aeroplanes are no longer launched from the hand or even pushed along the ground. They are required to start without assistance and rise in the air without being touched. "Official flight." Everyone’s attention is attracted by the announcement. Hundreds of boys crowd to the lines. The starter is doubtless known to all, as well as his record and standing in the various competitions. Hundreds of critical eyes are upon the model. It is a thrilling moment. The propellers are released, and the aeroplane starts forward under its own power. Some leap into the air, others take the full twenty feet permitted them in getting off the ground. There are surprisingly few failures. The length of the take-off, the angle at which it rises, the altitude in the first rise, are critically observed by the young experts. To the whir of the propellers, which form two blurred circles in the air, the model quickly climbs upward, rights itself and speeds away on its long flight. The young aviator’s skill is revealed to every eye by the angle of the ascent, the altitude and the ability to gain equilibrium aloft. The more you know about aviation, the more absorbing is your interest in a flight.