VOL. XLVIII.] I'HILOSOPHICAL TRANSACTIONS. 527 



tion he found the electricity from the atmosphere more vehement than it was 

 without it. This he first observed on May 31, 1753, when the electrical fire 

 exploded with such a force, that it might be heard at the distance of 3 rooms 

 from the apparatus. On the left hand of the bottle was placed a 2d electrical 

 gnomon. When this was made use of, the wire of metal bo, and the wire hl, 

 were connected with mbl, a prime conductor from an apparatus for artificial 

 electricity, viz. a glass globe, &c. At the same time also, from the chain ab 

 was fastened a piece of wire bk, in contact with the vessel ik. By these means, 

 when the electrical machine was put in motion, both the electrical gnomons were 

 electrized: but this went off^ in a great measure, as soon as the motion of the 

 machine ceased. By this whole apparatus taken together, Professor Richman 

 observed a kind of reciprocation in the effects of electricity ; for at first, when 

 the electrical machine was put in motion, both the linen threads cg and cg arose 

 with the degrees of their respective quadrants. If then the wire bc of the right 

 gnomon was touched, the thread cg collapsed to the rod cd; but the thread on 

 the left side continued diverging as before the touch. Also, if the wire bc of 

 the left gnomon was touched, then in its turn the thread cg at the rod cd of the 

 right gnomon collapsed, and the thread of the right gnomon ascended again. 

 This reciprocation of the ascending and descending of the thread, might be 

 repeated 3 or 4 times without exciting the machine anew. 



The ingenious and industrious Professor Richman lost his life on the 6th of 

 August 1753, as he was observing, with Mr. Sokolow, engraver to the Royal 

 Academy at Petersburg, the effects of electricity on his gnomon, during 3 

 thunder storm. As soon as his death was publicly known, it was imagined that 

 the lightning was more particularly directed into his room by the means of his 

 before-mentioned apparatus. And when this affair was more inquired into, this 

 opinion appeared to be not ill-founded; for Mr. Sokolow saw that a globe of 

 blue fire, as large as his fist, jumped from the rod of the right gnomon cd, to- 

 wards the forehead of Professor Richman, who at that instant was at about a 

 foot distance from the rod, observing the electrical index. This globe of firej 

 which struck Professor Richman, was attended with a report as loud as that of 

 a pistol. The metal wire bc was broken in pieces, and its fragments thrown on 

 Mr. Sokolow's clothes, from their heat burnt marks of their dimensions on 

 them. Half of the glass vessel e was broken off, and the filings of metal in it 

 were thrown about the room. Hence it is plain, that the force of the lightning 

 was collected on the right rod cd, which touched the filings of metal in the glass 

 vessel E. On examining the effects of lightning in the Professor's chamber, they 

 found the door-case split half through, and the door torn off, and thrown into 

 the chamber. The lightning therefore seems to have continual its course along 

 the chain, conducted under the ceiling of the room ; but tliat it came from the 



