VOL, XXXVII.] PHILOSOPHICAL TRANSACTIONS. 455 



continued right line ; the method of doing which was as follows : that end of 

 the line, where the attraction was to be made, was suspended on a silk line, 

 fixed across the garret-window on the north side of the house, which was about 

 40 feet high : at about 100 feet from hence two rods or poles, of about 10 feet 

 in length, and at 2 feet distance from each other, were driven into the ground, 

 in such a manner as that they stood nearly perpendicular. These were in the 

 large garden, beyond these in the large field, that is separated from the garden 

 by a deep foss : about the same distance from the first were fixed another pair 

 of poles ; then 4 others at a like distance. On the ends of these poles were tied 

 the cross lines of silk, to support the line of communication ; which being laid 

 on the silk lines, the ivory ball hanging in the garret window ; and the other 

 end of the line being hung by a loop on the tube, the leaf-brass was held under 

 the ball ; and after the tube had been rubbed for some time, they called to 

 Mr. Gray to let him know, that there was an attraction of the leaf-brass : this 

 was several times repeated with success. Then Mr. Wheler came into the field, 

 and rubbed the tube himself, that Mr. Gray might see there was an attraction ; 

 which he did, though he perceived it not to be so strong, as when the attrac- 

 tion was conveyed by a longer line by returning it, as in the experiments above- 

 mentioned. Tile length of the line was 630 feet. This was several times re- 

 peated ; but the experiment being made in the evening, at length the dew be- 

 gan to fall. They began about 7 o'clock, or some little time after ; but before 

 8 o'clock the attraction ceased : but whether this was caused by the dew falling, 

 or by Mr. Gray's being very hot, could not positively be said. This experi- 

 ment was made July 14, 1729. 



Some days after, this experiment was repeated from the turret closet window, 

 when the line was 765 feet ; and the attraction was no less perceivable than in 

 the experiment abovementioned. 



The following experiments, made at Mr. Wheler's, show that large surfaces 

 may be impregnated with electric effluvia. 



A large map of the world, containing 27 square feet, as also a table cloth, 

 containing 59 square feet, being suspended on the tube by packthreads, be- 

 came electrical : an umbrella suspended by a packthread, tied to its handle, be- 

 came strongly electrical. 



An experiment to see whether the electric virtue would be any way hindered 

 by the magnetical effluvia of a loadstone. The loadstone had a small key sus- 

 pended by one of its arming irons, and both of them were suspended on the 

 tube by a packthread ; then the tube being rubbed, both the key and stone at- 

 tracted the leaf-brass ; the attraction being the same as that of other bodies. 



An experiment made to show tliat the electric virtue is carried several ways at 



