328 PHILOSOPHICAL TBANSACTIONS. [aNNO 1706. 



Stars observable in a good telescope in the via lactea; and the whole was attended 

 with such a whiteness, by the small light proceeding from them, as is seen to 

 that part of the hemisphere with the naked eye. 



After that I tried whether the addition of heat, by placing a red-hot iron just 

 under the moving glass, would advance any thing the appearance of light, 

 which I found without the attrition of my hand would do nothing, and with it 

 no more, that I could discover, than if it had been absent; both, with the glass 

 exhausted of its air and without. 



Having always observed that light bodies approached near any part of the 

 fricated cylinder, would seemingly be equally attracted or gravitate; so that I 

 contrived a semicircle of wire, which I could fasten at a constant distance, en- 

 vironing the upper surface of the glass at 4 or 5 inches from it. This wire had 

 twisted round it some pack-thread, by which I could with ease hang the threads 

 at pretty nearly equal distances; the lower ends of which reaching within less 

 than an inch of the glass, when directed towards the centre, but when at liberty 

 they appeared as in fig. 14, pi. 9. And when the cylinder was turned round 

 pretty swiftly, those threads would appear by the agitated air as in fig. 15. But 

 when on the lower part of the glass a hand was applied, the threads would then 

 represent a form like fig. 16; and from all parts seem to gravitate, or were 

 attracted in a direct line to the centre of the moving body, suffering no incon- 

 venience or disorder of posture by the wind occasioned by the rapidity of the 

 motion; and by shifting the attrition, 1 could draw them in a line towards either 

 end of the cylinder; yet still pointing to its axis. And when the wire with the 

 threads is reversed, that is, encompassing the under part of the cylinder, as 

 before the upper, it answered exactly the same, all the threads pointing towards 

 the axis, as in fig. 17. I have likewise given a motion to the same glass in a 

 perpendicular position, by which means I had the opportunity of placing a hoop- 

 wire horizontally, with threads as before, and left only one smaFl part exposed 

 for the touch of my fingers between them, yet the threads, upon the motion 

 and attrition given the cylinder, elevated themselves from their hanging posi- 

 tion, making an horizontal plane all round, and directing their loose ends to 

 the axis as before. But how far this experiment may serve to explain the nature 

 of electricity, magnetism, or gravitation of bodies, I leave to others to deter- 

 mine. 



A Findicaiion of Mr. James Gregory against the Misrepresentations of the Abbot 

 Galloise, in the History of the Academy of Sciences for the Year 1703. By 

 Dr. David Gregory. N° 308, p. 2336. Translated from the Latin. 

 Twelve years ago* I undertook the defence of my learned uncle, Mr. James 



'AUii (iifojit t^ * Philos. Trans. N° 214. Abridgment, Vol. III. p. 673. 



