CONDUCTORS, in electricity, are long metal rods, whose points are raised so high as may be convenient, above houses, &c. for the purpose of attracting or re ceiving the electric fluid, and of conduct ing it into the earth, or into water, thereby to prevent the building from being struck by lightning. To effect this, the rod should he detached, and its point should be sharp ; by which mean the electric fluid will be silently discharged. If the conductor is allowed to lay along the wall of the house, or that it is blunt, instead of being pointed, at its summit, it will attract the lightning, which in such case will do more or less damage to the building. Thus the rod should be kept from the walls, &c. by pieces of wel•seasoned wood, coated with resin, or of lead, which, as well as glass, sealing wax, sulphur, bees'-wax, oil-water, &c. are all non-conductors while cold . though, when heated to a great degree, they be come conductors. The rod should pass freely from the top of the building to the ground, without the line of its continuity being any where broken. It is found that black lead is an excellent aid, both to affix as a sharp point to the apex, and to be laid at a few feet deep in the earth, where it is moist and surrounded by a bed of charcoal. The rod should pass
into the mass of black lead, which will cause the electric fluid to be extinguish ed. Where buildings are extensive, and especially where there are many high chimneys, turrets, &c. two or more con ductors should be used, else the electric fluid, in its passage from a charged cloud, may be intercepted by such heights, and do considerable injury. Trees standing single on plains are very dangerous con ductors, as are those lofty trees that rear their heads conspicuously in large woods. Hence we so often see them rent to pieces by lightning, and such cattle as take re fuge under their inviting shelter destroy ed. Walls are conductors when light ning has entered a room ; therefore all persons should avoid sitting near them during thunder storms ; and in countries where lightning is frequent, care should be taken to remove iron bars, &c. For the various amusing and interesting mat ters relating to ELECTRICITY, we must refer the reader to that article, and to GALVANISK.