Account of a Thunderstorm in Scotland. V39 
fituation reprefen ted in the figure; the earth at L muff, of 
courfe, become fuperinduced by the elaftic electrical preflure of 
the electrical atmolphere of the thunder-cloud ; which fuper- 
induced elaftic electrical preflure muft gradually have increafed 
as the cloud came clofer to the earth, and approached nearer 
to the limit of the finking diftance. 
§ 17. Confequently, if any conducting body (not having 
any prominent conducting points) were to be placed at L, 
upon the furface of the earth, and to be there electrically in - 
fulated\ then fuch conducting body, by the laws of eleCtri- 
city, muft, at its upper extremity (namely, the part neareft to 
the poftive cloud) become negative ; at its lower extremity, it 
muft become poftive ; and, at a certain intermediate point, it 
will be neither plus nor minus. 
So that this infulated conducting body, thus fituated, will 
be in three oppofite dates at one and the fame time ; that is 
to fay, that it will be, at the fame inftant, pofitively eleCtrifled, 
negatively eleClrified, and not eleCtrified at all. 
This propofition 1 have rigoroufly demonflrated in rov 
Treatife * on Electricity. 
§ 18. But if this conducting body, on the furface of the 
earth, be not infulated -j~, or be but imperfeCtly infulated, then 
the whole of fuch body (from its being immerged in the elec- 
trical atmofphere of the poftive cloud) will become negative ; 
becaufe part of the eleCtricity of this conducting body will, 
in this cafe, pals into the earth. And this conducting body 
will become the more negative , as it becomes the more deeply 
immerged into the denle part of the elaftic eleCtrical atmo- 
fphere of the approaching thunder-cloud. 
* See Principles of Electricity, from § 55 to § 74, inclufively. 
t See Principles of EleCtricity, § 182 and § 183* 
T 2 § 19- 
