398 Meteorological Observations for September 1831. 



Scale of the prevailing Winds, 



N. N.E. E. S.E. S. S.W. W. N.W. Days, 

 3 i U 5 3i 8 2 6| 30 



General Observations. — The weather this month has been alternately 

 wet and dry, and the nights were generally warm. 



The 1st was a colil day, with a gale from the North, and heavy rain 

 nearly an inch in depth, which considerably lessened the temperature of 

 the ground. Distant thunder occurred in the afternoon of the 2nd; but 

 the night being clear, with a North-west wind, the first hoar frost ap- 

 peared in the grass fields early in the morning of the 3r(l. On the 7th 

 and 8th, distant thunder occurred, and the lightning was vivid at mid- 

 night of the latter day. In the evening of the 12th a faint aurora borealis 

 appeared from half-past 8 till 10 P.M. Early in the morning of the 19th 

 a great number of swallows assembled, and suddenly departed for a warmer 

 climate : they remained iiere this year only twenty-two weeks. 



There were a few flashes of sheet lightning in the evening of the 2Gth. 

 It lightened in the night of the 27th from 7 P.M. till midnight, when a 

 change of wind to the North-east brought on a thunder-shower. Heavy 

 showers of rain and hail in the afternoon of the 28th were succeeded by 

 vivid lightning, from 5 till 10 P.M. Strong forked lightning, with thunder 

 and rain, also occurred in the evening of the 30th from 6 till 9 P.M. 



The mean temperature of this month is nearly a degree lower than 

 the mean of September for many years past. 



The atmospheric and meteoric phaenomena that have come within our 

 observations this month, are, eleven meteors, one rainbow, one aurora 

 borealis, lightning and thunder on five days ; and two gales of wind, namely, 

 one from the North, the other from the South-east. 



REMARKS, 



London. — Sept. 1. Very heavy rain. 2. Fine, with showers. 3, 4. Fine. 

 5. Rain in the morning: cloudy. 6. Rain : clear at night. 7. Fine: heavy 

 rain at noon : clear. 8. Fine. 9. Rain. 10. Cloudy; fine. 11,12. Over- 

 cast. 13 — 16. Foggy in the morning: fine. 17. Fine. 18. Slight haze: 

 fine. 19, 20.Fine. 21. Rain: fine. 22. Foggy ; very fine. 23, 24. Fine, 

 25. Cloudy: rain at night. 26. Rain. 27, Hazy and drizzly: fine. 



28. Slight fog : heavy rain and thunder at night. 29. Fine. 30. Cloudy 

 and warm : at night much thunder and lightning, with heavy rain. 



Penzance. — Sept, 1. Rain, 2, Showers : clear, S.Clear, 4, Rain, 

 5. Fair: rain. 6. Fair: showers. 7, 8. Showers. 9, 10. Clear. 1 1. Fair: 

 rain. 12. Misty: fair. 1 3. Fair : misty. 14. Misty : fair. 15. Clear. 

 le.Fair. 17. Clear. 18. Clear: fair. 19.Showers. 20.Rain. 21. Clear: 

 a shower, 22, 23. Clear. 24. Fair. 25. Misty rain, 26, 27, Misty. 

 28. Fair. 29. Fair: showers, 30. Rain. 



Boston. — Sept. 1. Cloudy : rain a.m. and p.m. 2. Cloudy. 3, 4. Fine. 

 5. Cloudy: rain P.M. 6. Rain. 7,8. Fine: rain p.m. 9. Cloudy: rain a.m. 

 10. Fine. 11. Cloudy: rain early a.m. 12 — 17. Fine. 18. Foggy, 

 19. Cloudy, 20. Fine. 21. Cloudy. 22. Fine. 23. Fine : rain at night, 

 24. Fine. 25. Fine : rain at night. 26. Fine. 27. Cloudy: lightning at 

 night, 28. Cloudy: rain, with thunder and lightning r.M, 29, Rain. 

 .'JO. Cloudy. 



Mcltoro- 



