BOOK in. CH A P. VII. ti<) 



I — Its nppeaiMncc, as it changed its direflion downwards, nnd to the 

 E. S. E. It now began to lofe its luilre, and aflumed the com- 

 plexion of a red-hot coal of tire, having fome parts brighter than- 

 others, as it were in concentric circles. 

 J — Its phnfis «i~5 it defcendcd with a faintly-luminous, reddifli tail, 

 tranrverfely interrupted with dark or dulky portions, before the 

 whole entirely difappeared. 

 About 14 or 15 minutes after it ceafed to be vifible, there was heard 

 a very full and loud report, like the explofion of a powder magazine^ 

 which gradually declined into a found relcmbHng dlfiant thunder, or 

 ih" diftant rumblin? of feveral coaches over IIciks. It uas f^cn with 



O 



the fur.e appearances at Luidas, Port- McTant; and many other parts of 

 the ifland. 



Whether the explofion, that was heard, happened on its attaining the 

 meridian, or at the time of its vanifliing, is uncertain; but, in either 

 cafe, the diflance rauft have been alniofi: incredibly great. Sound is 

 fuppofed to move 1000 feet in a lecond of time. \n the firfl cafe, it 

 mull have been diflant from the obfervers about 214 miles; and, va 

 the fecond cafe, about 18 i|, allowing the interval at the lowclt com- 

 putation, or 14 minutes; conltquentlv, in the former cafe, it mull 

 have been very far indeed above our atmofphere, at the height com- 

 monly fuppofed of 45 to 50 miles: and its velocity muft have been 

 immenle; lince, taking' the Icnpth of the ifland for the chord of the arcli 

 apparently defcribcd (equal to about 150 miles), it traverfed over it in 

 fo f}\ort a fpaec of time as that of 5, or, at moli, 6 minutes. If, there- 

 fore, it could admit of menluration, the feries would turn out ama- 

 zingly great. 



Whether it portended a change of weather feems not to be very 

 certain; but in May following, the heavielt rains fell after the long 

 drought, that had been known for the time of year. But to return: 



The means whereby the mifchief of lightning is vv^arded off from 

 m:ns habitations, is one of the greateft and moit ufeful difcoveries that, 

 the prefent age has afforded. 



Experiments in eleflricity fliewed, that the dangerous effe61s of this 

 SEtherial fire might be obviated, by attracting it upon iron rods ercfted 

 to the height of fome feet above the roofs of building*, and carried on 

 to the earth below, to the depth of two or three feet in a direction, di- 

 verging from the foundation ; or into a well, or piece of water. 



The ingenious Mr. Franklin, whom 1 have often quoted, was the 



firfl- who introduced this invention into prac^tice. He ereded feveral 



of thele apparatus on different buildings in Philadelphia; experience 



L^upht him how to improve them flill further ; and at lenpth that e!e- 



2 ment. 



