Fog, examples of great fog-belts. CHAPTER III NARRATIVE OF WEATHER OBSERVATIONS FROM AN AIRPLANE In order to qualify as meteorologist competent to confer with aviators, it seemed desirable to become personally acquainted with some of the conditions that confronted them. As a matter of professional acquirement therefore, I was glad to accept an invitation to go aloft after the necessary official arrangements had been made with Washington. This trip was in line with the previous endeavors of applying practical meteorology to the science of flight and appropriately extended the work which was begun in San Diego with Chanute and the sea-gulls fifteen years before. _Object of Flight._--I wished to put myself in the student’s place and learn at first hand the practical facts he demanded from weather observations and to acquaint myself with everything possible that might be of value to an aviator. There were two definite things of which I desired knowledge: first, to determine the height of the upward trend of the sea-breeze over Point Loma which causes the mysterious “woolly” of a score of years’ acquaintance from a yachting standpoint; second, to observe the extent, form, and composition of the velo cloud which is the characteristic sun-cover of California. _Preparations for the Ascent._--Aviator Instructor Oscar Brindley (the 1915 winner of the Curtiss trophy), in military tractor No. 50, was assigned as pilot. It may be stated here that the accepted definition of aviator is a pilot of a flying-machine heavier than air. The airplane used in my first flight (see Fig. 13) was made in Los Angeles and is the present standard army model. This tractor has an 80-horsepower engine and 8-foot propeller. It is 21 feet long, has a wing-spread of 38 feet, supporting area 364 square feet, and a flying radius, with two persons, of 300 miles. The maximum altitude attained with this model at San Diego was 13,000 feet. Before being placed in service the machines are thoroughly gone over at the repair shop (see Fig. 22), and the motors are run at full speed for twenty-four hours, after which they are taken down and subjected to scrutiny for possible defects. All of the struts, guys, and wires are closely examined; the boltheads are all drilled, wired, and soldered so that no amount of vibration will loosen them. Regardless of the length of the flight, each machine, before going up again, is given a rigid inspection and not until the mechanicians have tested every part is it pronounced ready. Not being prepared with a regulation aviation suit, I was loaned a leather jacket by one officer, face-goggles and safety helmet by others. I then took my place in the observer’s seat forward and was strapped into it with the safety belt (see Fig. 12). I was cautioned to let my body give way as the waist-controls were moved from side to side and not pay any attention to the steering rudder wheel which had a way of mysteriously revolving, advancing and receding.