80 THE EFFECTS OF A FLASH OF LIGHTNING. 



facts to which you have now been kind enough to listen to the 

 detail of. 



In the discussion which followed the reading of the paper and the ex- 

 hibition of the sketches it was suggested that the eight trees, or at any 

 rate some of them, were not struck at the top by strokes from the thunder 

 cloud downwards, but by discharges from the earth upwards, the cloud and 

 the earth being the one in a positive, the other in a negative, state of 

 electricity ; that this alone would account for the overturning (but not 

 shattering or detaching) of clods of turf at the bases of the trees, and the 

 upturning of the soil between them without any connection with the trees 

 themselves, as detailed by the Rev. 0. P. Cambridge ; and that this would 

 accord with the known laws of electricity, as well as account for so many 

 objects being struck over an extensive area, accompanied by only one flash 

 and a single thunder-clap. 



DESCRIPTION OF PLATES III., IV., V., VI. 



PLATE III. 



General sketch of the whole group of trees struck. The trees 

 struck are numbered i to 8 ; and the same order is followed in 

 each of the other plates. 



PLATE IV. 



Ground plan laid down to scale of the positions of the trees 

 struck, and of some others close by, but untouched. If this plan 

 be compared with the sketch of the trees themselves (PI. III.), 

 remembering that the sketch gives an oblique and perspective 

 view, it will be easy to understand the nature and wide area of 

 the stroke. 



a. A curious irregular ploughing up of the soil close to trees 4, 

 5, and 6. 



PLATE V. 



This and the following plate represent some of the trunks and 

 other parts of the trees struck, to show the direction and course 

 of the stroke, which are coloured red. 



