C 22 5 1 
XI. A Meteorological Journal, principally relating to Atmo- 
spherical Electricity ; kept at Knightsbridge, from the gth of 
May, 1790, to the 8th of May, 1791. By Mr. John Read; 
communicated by Richard Henry Alex. Bennet, Esq. F. R. S. 
Read April 2 6, 1792. 
A description of the instruments for collecting atmospheri- 
cal electricity, used in the following journal. 
Fig. 1 and 2 (Tab. IV.) represent the apparatus. A A fig. 1, 
is a round deal rod, 20 feet long, two inches diameter at the 
lower, and one inch at the upper end : into the lower end of 
it is cemented a solid glass pillar B, 22 inches long ; the lower 
end of this glass stands in a socket of wood C, which is screwed 
on the garret floor D, and supports the whole. About seven 
feet above the floor, is firmly fixed to the wall a strong arm 
of wood E, which holds perpendicularly a strong glass tube 
F, through which the rod is slided gently upwards, till the 
glass pillar B may be lowered into the socket C. It is thus 
fixed, and stands 12 inches from the wall. The tube F is of 
sufficient width to admit a case of cork, which is fastened in 
the inside of it, at the part where the tube is sustained by the 
arm of wood E, so that the rod, when bent by the wind, can- 
not touch the tube or break it. The upper extremity of the 
rod is terminated by several sharp-pointed wires G ; two of 
them are of copper, each one-eighth of an inch thick ; and, in 
order to stiffen the rod, as well as conduct more readily the 
