ABSTRACT
PEALS of thunder and the strokes and flashes of lightning have a frightening energy and effect in northern lands, especially in parts lying towards the noonday sun, 1 on account of the dense vapour exhaled from fertile areas; 2 for when this rises up moist to a cold region, 36in this case to the middle of the air, parts of it thicken and coalesce with various results, producing rain, hail, snow, and fog, according to the degree of their condensation by the cold. 2 When however its warmth is restrained and, because of the cold, prevented from issuing from the sides of the clouds, it forcibly bursts the cloud apart and causes a furious clap of thunder. 3 Thunder comes also from the quenching of fire in the belly of a cloud. 4 But the brilliance is a part of the air, which gleams through the violent impulse of the fire thus discharged. The lightning flash and thunderbolt are the strokes of a heavenly dart, being derived from ferire, ‘strike’, according to the pronouncement of Isidore, and also in the opinion of Virgil, who writes in his Georgics: The cloud-father’s self, at midnight, right-handed Wields glittering lightnings. 5
Effect of thunder
Brilliance of lightning Lightning flash
