518 EFFECTS or LIGHTNING, 



Specimens of polish by moulding itself on the glass into which it had been 

 e?pose?to°*^'^^P^^s^'^^- This result seems to bear some analogy to the sub* 

 strong heat stance called resinasphaltum, described by Mr. Hatchett. 

 siou^bv^Sir^^' Number 30, is a piece of wood, partially converted into coal 

 James Hall. by heat and compression. In some parts, the substance 

 entirely resembles pitch, being full of large and shining air holes ; 

 in others, the fibres of the wood are still distinctly visible. The 

 whole is jet-black, and burns with a bright flame. 



Number 31, is a specimen of (he substance like wool, formecl 

 in several of these experiments by the exudation of the fusible 

 metal through the barrel of iron, the metal in a liquid state 

 spouting to a considerable distance, and depositing this sub"* 

 stance upon any obstacle opposed to the stream. 



IV, 



J^nnmeration of several Cases of Ships which have been struck by 

 Lightning ; the destructive Effects having acted in a vertical' 

 Direction towards the Centre of the Earth, and never horizon'* 

 tall^. In a Letter from James Korsburgii, Esq^ 



To Mr. NICHOLSON, ■ 



I 



SIR, Walworth, July 2, 1805. 



Introductory J[ HAVE taken the liberty to enclose some remarks on a few- 

 letter. 



ships that have been struck by lightning. I was induced to do 



so, because it has never come within the reach of my knowledge, 



that the yards of any vessel have' been injured by lightning. 



It may be probable, that the electric matter never acts in a 



horisontal direction, destructively. But I must own that I have 



little knowledge of the subject here mentioned, And it is 



principally to point out, how seldom the yards of ships are 



injured by lightning, that I have taken this liberty.* If you 



* Authentic facts seldom fail to afford instructions to those sci- 

 ences which arc grounded immediately on experiment. That the 

 yards of ships are seldom or never injured by lightning, appears to 

 arise not from their horizontal position, but from their lying out of 

 the circuit or immediate path of the lightning from the clouds to the 

 earth.— -W. N. 



think 



