Meteorological Observations for December 1831. 159 



Scale of the prevailing Winds. 



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

 2 3J 1^4 12i 2J 5 31 



General Observations. — This month was very wet and boisterous till the 

 winter solstice, then dry and fine to the end. Such a long continuance 

 of gales from the South and South-west in December we have not expe- 

 rienced for many years ; and they were found very strong in the Atlantic 

 Ocean and in the British Channel, where they did some damage. On the 

 12th, after several days of heavy rain, a strong gale blew from the South 

 in the day, and from the South-west in the evening, accompanied with 

 vivid lightning from 6 P.M. till 4 o'clock the next morning, when it ter- 

 minated in a thunder-storm, with heavy hail. The lightning in the first 

 part of the evening was unusually strong at this season of the year, and 

 most of the vivid flashes seemed to be generated by the inosculation of the 

 passing clouds, which often collapsed from the suddenness of the squalls. 

 So mild has been the autumn in comparison of the two preceding ones, 

 that we have not yet had any snow here, and but little frosty weather; but 

 as the sun is now returning to the equinoctial, with a daily augmentation 

 in his diurnal arch, we may soon expect cold weather to set in, especially 

 as nearly a foot in depth of rain has fallen during the last three months. 



The mean temperature of the external air this month is two degrees 

 and a half higher than the mean of December for many years past. 



The atmospheric and meteoric phaenomena that have come within our 

 observations this month, are, one lunar halo, one meteor, lightning and 

 thunder on the 12th, and fourteen gales of wind, or days on which they 

 have prevailed, namely, five from the South, and nine from the South- 

 west. 



REMARKS. 



London. — December 1 — 4. Fogg)'. 5. Clear : hazy. 6. Fine: cloudy. 

 7. Boisterous wind, with rain. Barometer very low. 8. Heavy rain. 



9. Cloudy. 10. Rain: fine. 1 1. Cloudy : stormy, with rain. 12. Rain: 

 stormy, with heavy thunder showers at night. 1:3. Fine. 14, 15. Clear. 

 16,17. Fine: rain at nights. 18. Heavy rain early a.m.: very clear. 



19. Clear and fine. 20. Foggy : rain at night. 21. Foggy. 22. Hazy: 

 rain. 23. Hazy: clear and frosty. 24. Extremely thick fog at night. 



25, 26. Foggy. 27. Drizzly : very dense fog, even at noon. 28. Drizzly : 

 fine. 29, 30. Damp in the mornings : fine. 31. Clear and frosty. 



Penzance. — December 1, 2. Fair. 3. Fair: misty rain. 4. Misty rain. 

 5, G. Fair: rain. 7, 8. Rain. 9. Fair: rain at night. 10. Fair: rain. 

 11,12. Rain. 13. Fair: showers. 14. Showers. 15. Fair: showers. 

 JC, 17. Fair : rain. 18. Fair : showers, hail and rain. 19.Fair: showers. 



20. Rain. 21. Fair : showers. 22.Rain. 2:i. Showers. 24, 25. Fair. 

 2C. Rain : fair. 27. Fair. 28. Clear : fair. 29, 30. Fair. 31. Clear. 



Jionlon. — December 1. Cloudy. 2. Cloudy : rain p.m. 3, 4. Cloudy. 

 5. Fine. 6 — 8. Cloudy. 9. Fine: heavy rain early a.m. 10. Cloudy. 

 1 1 . Cloudy: rain early a.m., and p.m. 1 2. Cloudy : i ain p.m. 1 3 — 15. Fine. 

 16. Fine: rain at night. 17. Fine. 18. Cloudy: wind and rain early a.m. 

 I'j. Fine. 20.Cloudy: rain at night. 21. Fine. 22. Cloudy. 23— 25. Fine. 



26. Cloudy: rain at night. 27. Cloudy. 28. Cloudy : rain p.m. 29. Fine : 

 rain P.M. 30. Cloudy. 31. Foggy. 



Meteor 0- 



