VOL. LXXIV.] PHILOSOPHICAL TRANSACTIONS. 47Q 



and other particulars relating to this meteor, must be very nearly as expressed in 

 the following list; being calculated with mathematical accuracy, on the preceding 

 particulars ; and on the supposition that sound travels 1 1 50 feet per second. 

 But if the noise we heard was not that of the meteor's explosion, then the fol- 

 lowing calculations must be considered as quite useless. 



Distance of the meteor from Windsor Castle . . 130 mile?. 



Length of the path it described in the heavens 550 miles. 



Diameter of the luminous body when first seen 1070 yards. 



Its height above the surface of the earth 56-i- miles. 



The explosion must have happened perpendicularly over Lincolnshire. 



X. An Account of the Meteors of the \8th of August and 4th of October, 

 1783. By Alex. Aubert, Esq., F.R.S., and S. A. p. 112. 



The 18th of August had been a very sultry day. At the time the meteor 

 made its appearance, though the stars were bright in the upper part of the hea- 

 vens, the horizon was surrounded with a haziness which did not permit any stars 

 to be seen under an altitude of about 8°. Mr. A. was returning to Loampit-hill, 

 near Deptford, in Kent; his face was turned towards the south-west. He was 

 at the foot of Lewisham bridge, when he perceived suddenly a kind of glimmer- 

 ing light, resembling faint but quickly repeated flashes of lightning; soon after 

 which the light increased much towards the north-west; he turned directly to it, 

 and saw it form into a large luminous body like electrical fire, with a tinge of 

 blue round its edges. It rose from the hazy part of the atmosphere, and moved 

 at first almost in a vertical direction, changing its size and figure continually, 

 having all the appearances of successive inflammation, and not of a solid body; 

 it was sometimes round, at others oval and oblong, with its longest diameter in 

 the line of its motion; though it had got high enough to be quite out of the 

 hazy part of the horizon, it was surrounded and accompanied in its whole course 

 with a kind of whitish mist or light vapour. The place from which it rose was 

 about 38° from the north towards the west. After rising a little way perpendicu- 

 larly, it made its progress in a curve, so as to be at the highest when it had 

 reached due east, at an altitude of about 35°; after which, continuing a few de- 

 grees beyond the east, and being about 30° high, it left behind it several glo- 

 bules of various shapes; the first which detached itself being very small, and the 

 others gradually larger and larger, till the last was nearly as large as the remain- 

 ing preceding body ; soon afterwards they all extinguished gradually, like the 

 bright stars of a sky-rocket, with some inclination downwards. The meteor was 

 at the brightest and at the largest just before its separation.; Mr. A. estimated its 

 magnitude or area then to be equivalent to 1 full moons. Its light, during its 

 whole course, was so great, that he could see every object distinctly, and when 



