EffeBs of Lightning m a Grove of Tftes. j^^ 



I happened to be in Kenfington Gardens, in every part of which extenfive piece of ground 

 the lightning had left fome marks of its agency, chiefly by difcoloration of the grafs in 

 zigzag ftreaks, fome of which were fifty or fixty yards in length. Inftances of this fupcr-' 

 ficial courfe of the lightning along the ground before it enters the earth are fufficienfly 

 frequent. _ But the circumftance which attradled my attention the mod was feen in a fmall 

 grove of trees at the angular point of one of the walks. Plate XXII. figure 3- exhibits a 

 (ketch of part of the gardens, in which the angular point is denoted by the letter A. 

 Figure 4. reprefents the pofition of the trees. The numbers exprefs the diftances be- 

 tween the trees in feet. 



Clofe to the ftem of the tree A was a hole in the ground four inches long and two wide, 

 proceeding to the fouthward ; and at two feet further to the fouth was another fimilar hole. 

 Between thefe two holes the ground \vas torn away. This appearance is reprefented iu 

 figure 3, in which the letter A reprefents the trunk of tlie tree. The grafs was very much 

 fcorched to the diRance of about three feet in every diredion from the trunk, and in this 

 burned fpacc there were fi?Veral other fmaller holes. 



Clofe to the trunk of B, on the fouth fide, there was a hole in the ground. 



Near the tree C there was alfo a hole in the ground, and it was furrounded with a faint ' 

 ring of burnt grafs at a little diftance ; but as the grafs was grown again, it feemed pro- 

 bable, that the ring was occaGoned by fome earlier ftroke than that on Tuefday. 



The tree D was furrounded by a ring of 6 feet radius, and 18 inches broad. Within 

 the ring the grafs was freJh ; but on the furface of the ring the grafs and the ground were' 

 much burned. To the eaftward of the tree upon the ring itfelf were two holes, in which ' 

 the ground had the appearance of afhes. The tree E had half a faint ring to the weft- 

 ward. 



The tree F was furrounded by a faint ring of twoy ards radius. Within the ring the 

 jrafs was unhurt. To the weftward, at about three feet dillance from the inner ring, was 

 part of another fimilar ring, of much the fame appearance ; the verdure being unhurt in 

 the interval between the rings. 



I imagined the leaves of the trees were a little curled, but could obferve no blafted boughs; 

 a circumftance which, together with the other fafts, appears to indicate that thefc appear- 

 ances were produced by the recent ftorm of the 19th. 



VII, 



E^xperimental Reftttrchts to af certain the Nature of the Prtcefs by -which the Eye adap's il7!f 

 io produce diJiiiiB fifiori. 



[ConcludcJ from page .|79.] 



JIN the eel there is a tranfparcnt horny convex covering at fome diftance before the ivc, to 

 defend it from external accidents. This covering to an eye futed to fee in air, would en-' 

 ♦ irely take off the efFeds arifing from change of figure in the cornea ; but in water, whci'd 

 no fuch change coukl be attended with advantage, fuch a covering is employed as .m ex- 

 ternal defence. ' * 

 ' • "•* 4 A 2 111' 



