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46 Pup.. How am- I to judge ofits distanee? Tut. By the interval between the flash and, the thunder-clap. If that interval is considerable, it is distant, and then not dangerous; but when the clap almost instantly succeeds the flash, it is then near, and consequently the danger is greater. Pup. What is the reason,' since the thunder and lightning both take place together, that hunder is not heard until some time afte: the lightning is seen 2 Tut. Because sound is much longer in reaching our hearing than light our sight. Pup. What is the velocity of sound, in the medium of common air 3 Tut Sound noi interrnpted, travels i, 130 feet in one second ; but light travels 2,00,000 uniles in that period of time. Pup. Have you not told nie it is dangerous logo under trees when it thunders and lightens 2 Tut. Yes, because trees very inuch attract the lightning. It is better to continue in the open field or public road (if no house is near), than to take shelter under trees. Pup. How does it happen, that, .during violent storms of thunder and lightning, men and cattle are killed, and other considerable damage done? Tut. When the inflammable matter, of which the electric clouds consist, is thin and light, it will rise to the upper part of the atmosphere, where it will flash without occasioning any harm ; but if it be dense, it will lie near the surface of the earth, where taking fire, it explodes with a surprising force, rare