and on the Effects of Lightning on certain Ships. -ilS 



thickness placed in the wake of the gaff. This is conclu- 

 sive of the fallacy of Mr. Sturgeon's assertion, that any con- 

 ductor applied to the mast, would, under the operation of 

 lightning, be " probably peeled from the wood." 



In the case of the Kingsbridge spire, No. 6. The lightning 

 which shivered the tower, fell on a cylindrical iron rod of an 

 inch diameter without producing any effect on it. 



In the case of the Rodney, the flash which set the top on 

 fire and splintered the masts, was conducted by a short cop- 

 per funnel for top-gallant rigging without fusion. 



In the case of the Beagle, No. 7, a shock of lightning 

 passed down the conductors without producing any effect on 

 them. 



No. 10. A house was struck at Tenterden ; the lightning 

 fell on an iron bar three-quarters of an inch square, but pro- 

 duced no effect on it.* 



No. 11. A stroke of lightnino; fell on Mr. West's house 



• • • 1 

 at Philadelphia, having a conductor termmatmg m a brass rod 



ten inches long and a quarter of an inch in diameter ; only a 



few inches of the point were melted, but no damage occurred 



to the buildingf. 



No. 12. On the 19th of April 1827, one of the large New 

 York packets, whilst in the Gulph Stream, was assailed by 

 two most awful strokes of lightning twice in the same day. 

 The first shock was productive of serious and destructive ef- 

 fects. The second shock fell on a pointed conductor subse- 

 quently hoisted to the main-mast head. This conductor con- 

 sisted of an iron chain having links of a quarter of an inch thick 

 and two feet in length and turned into hooks at each end, con- 

 nected by rings of the same thickness, and one inch annular 

 diameter. This conductor was attached to an iron rod placed 

 at the mast head, half an inch thick and four feet long. 

 The explosion fell in a concentrated form, and with an awful 

 crash upon this rod. Although the small chain below was dis- 

 jointed and some of the links fused, yet this pointed iron rod 

 was only fused for a few inches. The ship in the second case 

 escaped danger. 



Now these are authenticated cases, and there are numerous 

 others which I might adduce, to show how perfectly capacious 

 and continuous conductors transmit shocks of liohtninff. 



44. No good instance can be adduced in which conductors of 

 great capacity have been even moderately heated by lightning. 

 1 do not admit Mr. Sturgeon's " on dit " respecting the con- 

 ductor passing through the Nelson Monument in Edin- 

 burgh. It is really no evidence whatever on a scientific ques- 



* Pliilosophical Transactions. f Ibid. 



