VOL. XLVIIl 



,] VHILOSOPHICAL TRANSACTIONS. . 335 



either F. Frisi, or any geometrician who thinks the question worth his exa- 

 mination, to take the trouble of reviewing my calculations, and to believe me 

 ready to acknowledge my error, when shown to me by a candid and impartial 

 examiner. 



Of a Storm of Thunder and Lightning, near Ludgvan in Cornwall. By the 

 Rev. Mr. fVvi. Borlase, M.A., F.R.S. Dated Ludgvan, Feb. 1, 1753. 

 p. 86. 



This storm was on Dec. 20 preceding. The first traces in the parish of Mad- 

 dern, were an incision, or scratch, made in the turf, about 3 inches wide, and 

 2 deep, where the lightning coming up from the south-west, passing through 

 the bank, and issuing out from the bank in 3 streams, which united again, and 

 turned away to the north. About 10 paces to the north of these breaches, there 

 are more marks of the same kind, but not in the same direction ; for the light- 

 ning here came from the north-west, and, passing upwards, the furrow, which 

 it had made, grew wider, and somewhat deeper, as it gained on the hill, espe- 

 cially where it met with bank or stone; and some banks were 5 feet wide, which 

 had their tops untouched, but were pierced through as with a bullet. This se- 

 cond furrow was (as all the rest) not in a straight line, but in a vermicular direc- 

 tion, and with its turnings led to a karn, or ledge of flat rocks, striking off many 

 splinters from it, and in some places making a perforation through it. There 

 were made also furrows 1 inches wide, and a foot deep ; besides which, were 

 several places in the hill which had holes about a foot wide, and 6 or 8 inches 

 deep, and several clods cut thin and clear off from the ground : which shows, 

 that as this lightning went like darts through banks and stones, and tore up the 

 ground in many places like a ploughshare, so in other places it spread into a 

 horizontal thin edge, which scooped up and carried ofi" the little unevennesses of 

 the turfy ground. The whole workings of this lightning were in length about a 

 furlong from west to east. 



The first thunder-clap was succeeded, in less than a quarter of an hour, by^ 

 another, which broke at a village, in the parish of Gullval, called Trythal, about 

 a mile and half to the south-west of Moelfra hill, and was attended with the fol- 

 lowing melancholy accidents : 



Thomas Olivey, a respectable farmer, had returned from the field, about a 

 quarter before 12 o'clock, and had all his family round him in the kitchen, ex- 

 cept his daughter, who was in the hall. There was a pan over the fire in the 

 kitchen-chimney, full of boiling water. The farmer was sitting by the fire, and 

 his wife on a bench before it : their only son, 23 years of age, was standing at 

 the window, when it lightned much, and the first clap of thunder followed. 

 This was so violent that the back door of the kitchen, which opened to the 



