--------+------------+------------+---------------+------------ Feet | Aviator | Aëroplane | Place | Date --------+------------+------------+---------------+------------ 3,445 | Latham | Antoinette | Betheny Plain | January 7 4,165 | Paulhan | Farman | Los Angeles | January 12 4,541 | Latham | Antoinette | Rheims | July 7 6,175 | Brookins | Wright | Atlantic City | July 9 6,604 | Drexel | Blériot | Lanark, Sc. | August 11 8,271 | Morane | Blériot | Havre, France | September 3 8,406 | Chavez | Blériot | Issy | September 8 9,104 | Wijnmalen | Farman | Mourmelon | October 1 9,714 | Johnstone | Wright | Belmont Park | October 31 10,499 | Leganeaux | Blériot | Pau | December 9 11,474 | [54]Hoxsey | Wright | Los Angeles | December 26 --------+------------+------------+---------------+------------ Such lofty flights have proved a severe test of both the aëroplane and the pilot. In the lighter atmosphere the engine must turn the propeller at higher speed to secure the same thrust, and the aëroplane must sail faster to support the same weight as at the lower levels. Thus more power is required on high, though the explosive medium, being less dense, is less capable of exerting power. The driver has, therefore, to jockey his machine with assiduous care and alertness, at a time when he is least fitted for exertion, owing to fatigue, cold, and it may be, physical discomfort due to the great change of atmospheric pressure. But still, both aëroplane and pilot are capable of ascending well above any levels thus far attained. After the triumphant altitude flights of 1910 the aëronautical skeptics could no longer contend that the aëroplane was useless in transportation and warfare, because of its inability to fly above high land or the usual range of the guns of battleships and coast fortifications. Most of the important mountain passes lie below 10,000 feet. The safe elevation for motor balloons menaced by terrene guns is taken to be much less than two miles, and in military practice they usually operate below the one-mile level. The aëroplanes, therefore, may not only cross mountain ranges, but may also scrutinize, or grievously molest, land forces, marine squadrons and perhaps even the great gaseous cruisers of the atmosphere, which they can far outspeed, and may even destroy.