Few remember Sir George Cayley. Sir George designed the first successful man-carrying glider, but being a knight of cautious disposition, he ordered his coachman, John Appleby, to take the machine aloft.
It was the latter, therefore, who ought to have flown into history by remaining airborne for 500 yards across a Yorkshire valley in the summer of 1853. But history remained aloof; Appleby proved to be no more memorable than Sir George.
Three decades later, Otto Lilienthal transformed this eccentricity into a scientific discipline, and laid the foundations for the sport of gliding. Lilienthal was born in 1848 in the Prussian town of Anklam. Throughout his childhood and early adult years, he would gaze for hours at storks and other birds, noting, as the poet William Cowper put it, that "the bird that flutters least is longest on the wing".
He trained to be an engineer, and it was his engineering knowledge applied to ornithology that led him to develop successful designs for heavier than air machines.
It is to Lilienthal that we owe the first appreciation of the importance of rising currents of air in the atmosphere to sustained unpowered flight. In a static atmosphere, a glider inevitably drifts slowly back to earth; Lilienthal realised if the aircraft is to gain height, it is necessary for the pilot to find areas of the sky where the lift provided by the air is greater than this tendency to sink earthwards - areas with "thermals", or where the air ascends to clear a ridge of elevated ground.
In 1891, he put his ideas into practice when he built his first man-carrying glider. It consisted of two curved fabric wings to which Lilienthal attached himself by his outstretched arms, and when in the air he used the shifting weight of his body to control the craft.
It was a technique more akin to hang-gliding than to the more sophisticated gliding aircraft of today. It was the first of many he built, and using such machines, Lilienthal clocked up more than 2,000 flights throughout his life.
For most of us, like Horace, scire nefas, quem finem di dederint; we do not know what end the gods may have in store for us. Some, on the other hand, like Yeats's airman, engage in a tumult in the clouds despite a premonition of their fate. Whether or not Otto Lilienthal had any inkling we shall never know; in any event, he died tragically when his latest glider caught a sudden gust of wind and crashed, near Rhinow, in his native Germany, 105 years ago today on August 10th, 1896.