BOOK III. CHAP. Vir. 643 



Many of the houfes in Janjaica are conflruded with hip roofs. A 

 perpendicular piece of wood, or a fmall mart, might be ereded againft 

 the wall, at one or both ends of fuch houfes, at fuch an elevation as 

 to fupport a copper rod rifing about three feet above the ridge. If an 

 iron or fleel rod is made ufe of, it ought to be frequently painted, to 

 hinder the air from corroding it. 



Buildings made of fir entirely, having no metal for the faftenings, 

 ornaments, or conveniencies, are the lead liable to be attacked by 

 lightning. Houfes therefore covered with pitch-pine fliinglcs are in 

 fome degree fecurer than others, fo long as their turpentine or rcfin 

 remains unexhaufted. 



Sulphureous and inflammable vapours arifii-g from the earth are 

 eafily kindled by lightning. So alfo the vapours fent out by ftacks of 

 moift hay, corn, or other vegetables, which heat and reek. Wood 

 rotting in old trees, or buildings, fuffer the like effe(3:. Such are there- 

 fore eafily and often fired. Thatch appears therefore to be an improper 

 covering for building. And it may be owing to this, that old thatched 

 barns are fo frequently fired in England by lightning. 



For fecuring magazines of powder Mr. Franklin propofes the eredl- 

 ing a maft not far from them, which may rife fome feet higher than 

 the top of them, with a thick iron rod (e. g. four inches fquare) 

 in one piece, faftened to it, and reaching down through the earth till 

 it comes to water, which lies not far from the furface in the places 

 where fuch buildings are commonly fituated. Iron is a cheap metal ; 

 but if it were dearer, the expence is infignificant, confidering the im- 

 portant fervice to which it is applied. The rod is advifed to be of 

 this thicknefs, to allow for its wafting by ruft ; which however might 

 be retarded by painting with common white lead and linfeed oil ; it 

 will probably laft as long as the maft, and may be renewed with it. 



A perfon apprehenfive of danger from lightning, happening during 

 the time of thunder to be in a houfe not fecured by a rod, will do 

 well to avoid fitting near a chimney, a looking-glafs, any gilding on. 

 pidtures or wainfcot. The fafeft place is the middle of the room (fo 

 it be not under a metal luftre fupported by a chain) fitting in one 

 chair and laying the feet up in another. It is ftill fafer to bring two 

 or three mattrafles, or beds, into the middle of the room, and, folding 

 them up double, place the chair upon them ; for they being not fo 

 good condudtors as the walls, the lightning will not chufe an interrupted 

 courfe through the air of the room and the bedding, when it can go 

 through a continued and better condu<ftor, the wall. But, where it 

 can be had, a hammock, or fwinging bed, fufpended by filk cords, 



4 N 3 equally 



