But the season at which these fire-festivals are most generally held all over Europe is the summer solstice, that is, Midsummer Eve (23d June) or Midsummer Day (24th June). According to a mediæval writer the three great features of this festival were the bonfires, the procession with torches round the fields, and the custom of rolling a wheel. The writer adds that the smoke drives away harmful dragons which cause sickness, and he explains the custom of rolling the wheel to mean that the sun has now reached the highest point in the ecliptic, and begins thenceforward to descend.(682) From his description, which is still applicable, we see that the main features of the midsummer fire-festival are identical with those which characterise the spring festivals. In Swabia lads and lasses, hand in hand, leap over the midsummer bonfire, praying that the hemp may grow three ells high, and they set fire to wheels of straw and send them rolling down the hill.(683) In Lechrain bonfires are kindled on the mountains on Midsummer Day; and besides the bonfire a tall beam, thickly wrapt in straw, and surmounted by a cross-piece, is burned in many places. Round this cross, as it burns, the lads dance; and when the flames have subsided, the young people leap over the fire in pairs, a young man and a young woman together. It is believed that the flax will grow that year as high as they leap over the fire; and that if a charred billet be taken from the fire and stuck in a flax field it will promote the growth of the flax.(684) At Deffingen, as they jumped over the midsummer bonfire, they cried out, “Flax, flax! may the flax this year grow seven ells high!”(685) In Bohemia bonfires are kindled on many of the mountains on Midsummer Eve; boys and girls, hand in hand, leap over them; cart-wheels smeared with resin are ignited and sent rolling down the hill; and brooms covered with tar and set on fire are swung about or thrown high into the air. The handles of the brooms or embers from the fire are preserved and stuck in gardens to protect the vegetables from caterpillars and gnats. Sometimes the boys run down the hillside in troops, brandishing the blazing brooms and shouting. The bonfire is sometimes made by stacking wood and branches round the trunk of a tree and setting the whole on fire.(686)