<P> It has been demonstrated that manned hot air balloons can be built using ancient materials . While there is no direct documentary or archaeological evidence that any manned or unmanned flights prior to those discussed below occurred using these methods, Ege notes an indirect report of evidence that the Chinese "solved the problem of aerial navigation" using balloons, hundreds of years before the 18th century . The Mongolian army studied Kongming lanterns from China and used them in the Battle of Legnica during the Mongol invasion of Poland . This is the first time ballooning was known in the western world . </P> <P> The first documented balloon flight in Europe was by the Brazilian - Portuguese priest Bartolomeu de Gusmão . On August 8, 1709, in Lisbon, Bartolomeu de Gusmão managed to lift a small balloon made of paper full of hot air about four meters in front of king John V and the Portuguese court . According to the Portuguese speaking community, this was the "earliest recorded model balloon flight". </P> <P> Following Robert Boyle's Boyle's Law which had been published in 1662, and Henry Cavendish's 1766 work on hydrogen, Joseph Black proposed that if the gaseous element filled a balloon, the inflated object could rise up into the air . Jacques Charles, whose study of gases led to his namesake law of volumes, had studied the works of Cavendish, Black, and Tiberius Cavallo, and also thought that hydrogen could lift a balloon . </P> <P> Jacques Charles designed the balloon, and the Robert brothers constructed a lightweight, airtight gas bag . Barthélémy Faujas de Saint - Fond organized a crowd - funded subscription to finance the brothers' project . The Roberts dissolved rubber in a solution of turpentine, with which they varnished stitched - together sheets of silk, to make the main envelope . They used alternating strips of red and white silk, but the rubberising varnish yellowed the white silk . </P>

Who pioneered a method of using hydrogen in balloons to produce lift
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