His preparation for the Ecole Polytechnique assured him a brilliant superiority in his present surroundings. He could explain the laws of mechanics, and tell his wonderstruck comrades what is meant by the resultant of several forces and the equilibrium of forces, giving them unexpected notions about kinematics and dynamics.[13] From the laboratory or industrial experiments then being made, he acquired, on his part, a knowledge of the resisting power of the materials used in aviation: wood, steel, steel wires, aluminum and its composites, copper, copper alloys and tissues. He saw things made--those famous wings that were one day to carry him up into the blue--with their longitudinal spars of ash or hickory, their ribs of light wood, their interior bracing of piano wire, their other bracing wires, and their wing covering. He saw the workmen prepare all the material for mortise and tenon work, saw them attach the tension wires, fit in the ends of poles, and finally connect together all the parts of an airplane,--wings, rudders, motor, landing frame, body. As a painter grinds his colors before making use of them, so Guynemer's prelude to his future flights was to touch with his hands--those long white hands of the rich student, now tanned and callous, often coated with soot or grease, and worthy to be the hands of a laborer--every piece, every bolt and screw of these machines which were to release him from his voluntary servitude. [Footnote 13: See _Etude raisonnee de l'aeroplane_, by Jules Bordeaux, formerly student at Ecole Polytechnique (Gauthier-Billars, edition 1912).] One of his future comrades, _sous-lieutenant_ Marcel Viallet (who one day had the honor of bringing down two German airplanes in ten minutes with seven bullets), thus describes him at the Pau school: "I had already had my attention drawn to this 'little girl' dressed in a private's uniform whom one met in the camp, his hands covered with castor oil, his face all stains, his clothes torn. I do not know what he did in the workshop, but he certainly did not add to its brilliance by his appearance. We saw him all the time hanging around the 'zincs.' His highly interested little face amused us. When we landed, he watched us with such admiration and envy! He asked us endless questions and constantly wanted explanations. Without seeming to do so, he was learning. For a reply to some question about the art of flying, he would have run to the other end of the camp to get us a few drops of gasoline for our tanks...."[14] [Footnote 14: _Le Petit Parisien_, September 27, 1917.]