f. 253 } 
VI. An Account of the Effetis of Lightning on a large Rock 
- i Gloucefter, In a Letter from the Rev. Ext FORBES, £o 
to the Rev. Manassexn CUTLER, F. 4. A. 
Gloucefter, Jub 39 RE 
REVEREND: ‘SIR, 
CY. the 18th of March; 1965; we hád a moft fevere clap 
of thunder, and its effeéts were moft furprifing. A large 
rock, of the contents of near ten feet fquare above ground, re- 
ceived the full weight of its thock. It ftruck the rock near 
the top, and made an impreffion like that of a cannon-ball. It 
broke off near twenty pounds of the folid ftone, and cracked 
the remaining body in feveral directions, though not very deep. 
Then it ran down on thé weftern fide of the rock in three direc- 
tions, or main branches,—each branch smarking its path with 
a chalky colour, tinged: with blue.- The lightning fo pene- 
trated: the {old ftone,-as to alter the texture of its parts, and 
change its colour an inch deep ; which ftill remains on a large 
piece of the rock now by me. When thefe three branches 
reached: the ground, they took different routs.———One, that 
feemed to contain the greateft quantity of the fluid, took its 
courfe northward, rending the ground, and throwing up cart- 
loads of earth when it met with large rocks. Some large rocks, 
whofe furfaces were nearly on a plain with the earth, it paffed 
_over, with only marking its path, about an inch and an half 
wide, with the fame colour as on the rock it ftruck firft : then 
it entered the ground, and tore up the turf about an inch deep. 
At a rock in its way, which rofe fome inches above-ground, it 
divided itíelf into two equal branches, turning up the turf from 
