218 I'HILOSOPHICAL TRANSACTIONS. [aNNO 1787. 



where the shock of the returning stroke happens, shall receive no detriment 

 whatever." ' 



But, before speaking of the accident of Lauder, which appears to have been 

 occasioned by a returning stroke, proceeding from an assemblage of clouds, I 

 will say a few words on one or two other facts, mentioned in Mr. Brydone's ac- 

 count. Mr. Brydone informs us, that " the shepherd belonging to the farm of 

 Lennel-hill was in a neighbouring field, when he observed a lamb, only a few 

 yards from him, drop down, though the lightning and claps of thunder were 

 then at a great distance from him. He ran up immediately, but found the lamb 

 quite dead; nor did he perceive the least convulsive motion, or symptom of life 

 remaining, though the moment before it appeared to be in perfect health." This 

 effect is so precisely similar to those explained in my Principles of Electricity, 

 and particularly to that mentioned in section 328, that it is quite unnecessary to 

 enlarge on it. I shall only observe, that such an electrical returning stroke as 

 that by which this lamb was destroyed, namely, a returning stroke which hap- 

 pens at a place where there is neither lightning nor thunder near, belongs to the 

 most simple class of returning strokes; and that it may be produced by the sudden 

 removal of the elastic electrical pressure of the electrical atmosphere of a single 

 main cloud, as well as by that of an assemblage of clouds. It appears by Mr. » 

 Brydone's account, that the shepherd, who saw the lamb fall, was near enough 

 to it to feel, in a small degree, the electrical returning stroke at the same time 

 that the lamb dropped down. 



Mr. Brydone further relates, that " a woman making hay near the banks of 

 the river fell suddenly to the ground ; and called out to her companions, that she 

 had received a violent blow on the foot, and could not imagine from whence it 

 came." This blow was, unquestionably, the electrical returning stroke. When 

 a person, walking or standing out of doors, is knocked down or killed by the 

 returning stroke, the electrical fire must rush in, or rush out, as the case may 

 be, through that person's feet, and through them only ; which would not be the 

 case, were the person to be knocked down or killed by any main stroke of ex- 

 plosion, either positive or negative. 



Lord S. then proceeds to explain, froni the returning stroke, described in his 

 Principles of Electricity, how the chief eflfects mentioned in Mr. Brydone's ac- 

 count may probably have been produced ; viz. the death of the man and horses, 

 with the dispersion of parts of the cart, and the marks on the wheels, &c. 



XVIIL Concerning the Latitude and Longitude of the Royal Observatory at 

 'Greenwich; with Remarks on a Memorial of the late M. Cassini de Thury. By 

 the Rev. Nevil Mashelyne, D.D., F.R.S., &c. p. 151. 



Memoire sur la jonction de Douvres k Lohdres. Par M-. Cassini de Thury, 

 Directeur de I'Observatoire Royal ; de la Societe Koyale de Londres, &c. 



