170 



Periodic Meteors, or supposed Asteroids 



To sum up, I shall say that the barometer, whose progress was gra- 

 dually ascending, rose in the space of twelve hours of observation 

 4mm. 22; that the thermometer, whose minimum had been -f 5o-2, vari- 

 ed in the same space of time only 2o-6 ; and that the hygrometer pro- 

 ceeded llo towards humidity. As to the ethrioscope, it did not give 

 (as might be anticipated, with a tranquil and regularly clouded sky) any 

 sign of radiation of heat across the atmosphere. The pitli-ball electro- 

 meters, placed in the open air, remained motionless ; lastly, the mag- 

 netic needle presented, at eleven minutes past nine, a slight deviation 

 of 0o-5 to the east in declination ; a deviation which remained the 

 same till a quarter of an hour after midnight, after which it varied, 

 always in the same direction, and till the morning, between Qo-l and 

 Go. 7. 



Assisted by three amateurs who vrished to join me, a continued look- 

 out was kept, not only towards the region of the east, but in every 

 quarter of the heavens; the terrace of the Observatory commanding 

 the entire horizon. 



From seven to ten o'clock in the evening a light breeze prevailed, 

 hardly perceptible, which blew from the north-east; and from ten in 

 the evening till seven in the morning the air remained perfectly calm, 

 excepting at three periods, namely, at two, at forty-five minutes past 

 three, and at fifteen minutes past four, when a light breeze was again 

 perceived, and lasted each time ten minutes. 



At forty-five minutes past eight in the evening, and from the south- 

 south-east, a feeble white light illuminated the upper part of the 

 clouds for from three to four seconds. At fifty-one minutes past nine 

 a reddish light, resembling lightning, streaked the upper part of the 

 clouds for nearly three seconds, in the east. At forty minutes after 

 eleven there were white glimmerings, very feeble, which streaked the 

 clouds betvreen the north-east and the south-east ; they had a kind of 

 intermitting, and they lasted about six seconds. At thirty-five minutes 

 past one, and directly in the east, there w^ere, in the upper region of the 

 clouds, some lights, in general very feeble, which continued during ten 

 seconds. Lastly, at three minutes past four a wiiite light, less pale, 

 shone for two or three seconds in the elevated stratum of the clouds, in 

 the south-east. But during the whole night, not a single luminous 

 meteor, no shooting star, no aerolite or visible asteroid pierced the 

 clouds to fall in the circle of our horizon. Nevertheless, it is probable 

 that if the sky had not been clouded we should here have very well 

 ^<een the shooting stars which were observed at the same date in our 



