Protecting Power of Trees, 277 



struck by lightning much more frequently than is generally ima- 

 gined. When the timber is cut, and converted into planks 

 or boards, it exhibits a number of clefts and fissures which 

 have evidently been originally caused by a stroke of lightning. 

 This observation agrees with a remark which M. De Tristan has 

 deduced from the watching of sixty-four distinct thunder-storms, 

 accompanied with hail, which, in the space of twenty-six years, 

 from 1st January 1811 to 1st January 1837, occasioned great 

 damage in different parts of the department of Loiret, near the 

 forest of Orleans. M. De Tristan has noticed that when a 

 storm passes over a forest it is very decidedly enfeebled. 



According to these observations it appears incontestible, that 

 trees rob thunder clouds of a considerable portion of the fulmi- 

 nating matter with which they are charged. They are, there- 

 fore, to be considered as a means of diminishing the power of 

 the thunder-bolt ; but we go beyond the limits of observation 

 if we endow them with an absolute protecting virtue. The fol- 

 lowing facts will shew how decidedly this is true. On the 2d 

 of September 1816, the lightning fell at Conway, Massachusetts, 

 on Mr John Williams' house, and did much mischief. And 

 this in spite of there being in the immediate neighbourhood a 

 number of Italian poplars of from sixty to seventy feet in height, 

 whose summits overtopped the roof of the mansion by between 

 thirty and forty feet. One of the poplars was only six feet from 

 the spot where the lightning entered the house. Not one of 

 the trees was struck. 



Another proof of the inefficiency of trees as lightning con- 

 ductors, or as a security for the houses they surround, may be 

 found in the details of a storm which proved hurtful on the 

 17th of August 1789, to the mansion of Mr Thomas Leiper, 

 near Chester, United States. I extract the account from a note 

 published in 1790 by the celebrated David Rittenhouse. Mr 

 Leiper's house is built in a steep valley or glen. Towards the 

 west, the surface at the short distance of sixty yards is at the 

 level of the highest parts of the house. On this ground there 

 also exists an alley of large oaks. The storm in question came 

 from the west ; before attaining a perpendicular position over 

 the liouse, it had therefore passed the trees, which were 

 much higher than the roof and chimneys. In this instance they 



