Show thunder ww ot of sound while lightning may be seen and iti its illumination of clouds an aal 1 mist may be ullen it ia is even miles distant di stint thunder is rarely audible mora more than tell miles the thunder from very distant storms therefore seldom reaches the ear 1 I he reason of this groat great dainty taint y in the audibility of thunder is iq not difficult to understand it depeu Is not merely on the initial intensity of the crash bot but quite as much on the fur soundings roun dings of the observer os ol server erver even as in the quiet country ono one will e foo ble sounds hat that escape the cir car in a noisy city perhaps the most curious and imbor tant taut condition of audibility is that the thunder wave of sound mound shall not la ro or reflected by the layers of wann warm and cold air beta een the observer and the lightning or by the layers of wind swift above and slow below fco he as entirely to pass over and around the observer sound in its wavelike progress ob liquefy through layers of air of different densities lg is to refraction ai fit d this refraction may occur at any time and place thus at the top tolf mast of a ship frequently hear bear fog whistles that aro are inan lible at sea level those on hilltops hear thun ler that 1111 can call not bo be heard in the valley those alio ie in front of an obstacle bt acle hear licar soun li 14 tu in ti li it blo to those behind it tho tile roiling rolling of thunder like that of a distant c iannou ade may be largely due to special reflections and re fractions of an sox nd iff dustrich and iron |