Arizona republican., 1920-07-12
AVIATORS ENGAGED
 IN MAPPING LANDS
 ARRIVE IN PHOENIX

Lieuts. William C. Glover and Nor man Tilley of the aviation service. who are engaged in pnotographing and mapping a triangular section of the country from a point 30 miles east of Tucson to Yuma and south of the Gila to the Mexican border. arrived in the city yesterday morning. They were met by Dr. Monical. who knew them in the aviation camp at Souther Field, below Americus Ga. during the war. where they had come as cadets, Lieutenant Glover being a Yale man and Lieutenant Tilley a graduate of Cornell.
 The doctor treated the former for e 300-foot fall, and when he had been patched up another cadet asked in a tone of criticism, Why in hell. Bin. since you were only 800 feet up, didn't you step off?" There was a delicate allusion in that query to the rangy build of Lieutenant Glove, who is something over six feet.
 The aviatOrs came here directly from Prescott, where they had been detailed to give exhibition flights. They made the flight from Tucson to Prescott in two hours, but in landing they broke the shock absorber of their big De Haviland. so that though the machine was not apparently injured otherwise. they shipped it back and came by train from the north.
 The part of the country which they are engaged in mapping has never been surveyed, and though their work is necessarily imperfect since the pho tographs do not accurately show the contour of the country it will be help full to the geodetic survey in that i. will disclose the landmarks. the roads. creeks, canyons and wells. In fact, a ] finished survey of the country would not be possible in many parts of the region without such a survey as this. | IT. .Ir kI,s q
 western front and consists of mosaic
 mapsy which will be put together for | the use of the government in effecting | accurate and completed surveys. l The photographing is done from a height of 11.000 fet above the plain | which in some parts of the country
 would carry them at an altitude of 13,00O feet. The perspective as shown | in their photographs and maps varies with the state of the atmosphere. The | highest point of land over which they | have flown in this sector is Babloquiv-
 fri peak, which rises to an altitude of | 7700 feet.
 It is intended to cover all the coun- try along the border as far east as l Brownsville, Texas, at the mouth of l the Rio Grande. In making these sur | veys the country to be mapped is dI- l vided by parallel lines, along which {. the machine flies at q speed of about ! 90 miles an hour. taking one line at a time. The camera contains a film | 400 feet in length and every 30 sec onds the button is pushed. The chief | difficulty is following the parallel line l That is hard enough for an expert | aviator under the most favorable con-
 ditions and is increasingly so when q
 strong side wind is blowing. Then he
 must resort to "crabbing" his ma | chine, heading it constantly toward the ' line.
 The. work is being done by two De 1 Havilands; very good machines, said Lieutenant Glover. with a good range | but it is hoped soon to secure a Capro- nj, which is superior for that kind ot | work.
 Both officers have fallen in love witt Arizona, the ardor of which has not | been checked by the weather of the l last week. Both expect to be dis | charged from the service, when they
 will make this state their home. Lieu 1 tenant Glover coming to Phoenix anC
 Lieutenant Tilley to take up work il | the University of Arizona.
 They expressed regret yesterday
 that Phoenix lacked a good landing | field for powerful machines. The on' 1 at the state fair grounds, they said was excellent except for the shortnes
 of the approach. It was adequate fo
 the smaller machines with a motor O
 90 horse power-say, a Curtiss eight but for a De HaviIand, with it's 400 horse power motor. which must hi
 the ground at terrific speed, an ap
 proach of two miles is almost peces Sary.