VOL. LXXIV.J PHILOSOPHICAL TRANSACTIONS. 481 



air stirring. Towards Q at night it was so dark, that I could scarcely discern the 

 hedges, road, or even the horses heads. As we proceeded, I observed to my 

 attendants, that there was something singularly striking in the appearance of 

 the night, not merely from its stillness and darkness, but from the sulphureous 

 vapours which seemed to surround us on every side. In the midst of this gloom, 

 and on an instant, a brilliant tremulous light appeared to the n. w. by n. At 

 first it seemed stationary; but in a short time it burst from its position, and 

 took its course to the s. e. by e. It passed directly over our heads with a buz- 

 zing noise, seemingly at the height of 60 yards. Its tail, as far as the eye could 

 form any judgment, was about 8 or 10 yards in length. At last, this wonderful 

 meteor divided into several glowing parts or balls of fire, the chief part still re- 

 maining in its full splendour. Soon after this I heard two great explosions, each 

 equal to the report of a cannon carrying a 9 lb. ball. During its progress, the 

 whole of the atmosphere, as far as I could discern, was perfectly illuminated 

 with the most beautifully vivid light I ever remember to have seen. The horses 

 on which we rode shrunk with fear; and some people whom we met on the road 

 declared their consternation in the most expressive terms. 



XII. On the Meteor of Jug. 18, 1783. By R. L. Edgeworth, Esq., F. R. S. 



p. 118. 



This observation was made near Mullinger, in Ireland. At half past 9 in the 

 evening Mr. E. saw the meteor. Its size appeared to be about one-third of the 

 moon's diameter; and it moved from the north with an equable velocity, at an 

 elevation of 10 or 12 degrees, and in a line parallel to the horizon. It was visible 

 during 10 or 15 seconds, and seemed to be of a parabolic figure, with a lumi- 

 nous tail, 20 or 25 of its diameters in length. It exhibited the most vivid co- 

 lours; the foremost part being of the brightest blue, followed by different shades 

 of red. Twice during its flight it was eclipsed or extinguished, not gradually, 

 but at once, immerging and emerging with undiminished lustre. 



XIII. Experiments on Air. By H. Cavendish, Esq., F. R. S., & S. A. p. 119. 

 The following experiments, says Mr. C, were made principally with a view to 



find out the cause of the diminution which common air is well known to suffer 

 by all the various ways in which it is phlogisticated, and to discover what becomes 

 of the air thus lost or condensed; and as they seem not only to determine this 

 point, but also to throw great light on the constitution and manner of production 

 of dephlogisticated air, I hope they may be not unworthy the acceptance of this 

 society. 



Many gentlemen have supposed that fixed air is either generated or separated 

 from atmospheric air by phlogistication, and that the observed diminution is 



vol xv. 3 Q 



