In cranking an airplane, a certain formula is always gone through. The mechanician at the propeller calls out, “Close!” The aviator closes the switch and repeats the word. This short-circuits the ignition apparatus so that no spark occurs in the cylinders. The propeller is turned in order to introduce explosive mixtures into the cylinders. When ready to start the mechanician says “Open!” The aviator opens the switch and repeats the word. The charges in the cylinders then fire when the propeller is turned. After the engine starts, the machine is “trimmed” by helpers and jockeyed for a favorable “take-off” into the air. (See Figs. 14, 15.) This model of airplane climbs on a gradient 1 to 7; its minimum speed is 41 miles per hour. In other words, if the speed is less than 41 miles per hour the machine will not fly horizontally. _The Ascent._--The tractor was headed into a 30-mile northwesterly wind so that the “take-off” was quick and easy; there were only a few seconds spent rolling over the field, when the airplane left the ground and I felt the never to be forgotten cushioning feeling of the air. For ten seconds there was experienced a decidedly weakening nervous chill, which occurred to me once before when making a high dive from a spring-board. It was the sort of physiological disturbance that can only be counteracted by immediately pulling one’s self together saying, “_Well, here goes nothing!_” The momentary depression was immediately followed by a corresponding elation of feeling which strange to say did not leave me during the trip and is always associated with thoughts of the journey. There was no dizziness, although I am peculiarly susceptible to the least change in balance. The earth did not recede as we progressed steadily upward; we seemed part of the earth, but not of it. Although the airplane reached an altitude of 3,000 feet in a comparatively few minutes, the barometer falling from 30.0 to 27.0 inches, the decreased bodily pressure was not at all noticeable.[H] [H] Trans-American Climatic Association, 1915, 31:20, Hot Springs, Va. Next to the supporting quality of the atmosphere I had noticed the 70-mile blast of air as the airplane pushed its way steadily onward and upward. Naturally, the exhaust of the motor in addition to the roar of the wind made conversation impossible. Some airplanes have telephone communication between observer and pilot. (See Fig. 9.) During one flight in a machine not so equipped, the passenger noticed the breaking of some apparatus. Knowing that it was impossible to make himself heard he hastily scribbled the word “Accident!” on a bit of card, whereupon the pilot shut off his engine and glided to earth.