Meteorological Observations for December 1827. 159 



has been rather low, there is a great probability, from the sea air being 

 warmer than the land air, that the maximum temperature will happen in 

 the night instead of in the day. 



Long solar lights and shades were very conspicuous half an hour before 

 sunset on the 30th, and moved round the sun, in a westerly direction, like 

 the spokes of a large wheel in slow motion. This singular appearance was 

 no doubt caused by a brisk wind blowing against the eastern side of a 

 hemispherical cumulus cloud (on whose dense surface the sun's horizontal 

 rays had previously impinged and were reflected) so as to give it a revolving 

 motion. 



These reflected rays repeatedly varied in length, perhaps from the un- 

 even surface of the cloud. A short time before they disappeared, they 

 were nearly equidistant, their angular distance from each other in at least 

 a semicircle, was about twelve degrees ; and each of the horizontal rays 

 reflected to a distance of nearly sixty degrees. The sun being near the 

 horizon, the lower rays could scarcely be traced: but the phenomenon 

 certainly exhibited a grand and gratifying appearance. 



The mean temperature of the external air this month, is h\ degrees 

 higher than the mean of December for the last twelve years, and is also for 

 that period unprecedented. 



The atmospheric and meteoric phenomena that have come within our 

 observations this month, are one parhelion, one large lunar halo in the 

 night of the 26th, which set with the moon ; four meteors, one rainbow ; 

 lightning and thunder in the night of the 20th ; and fourteen gales of wind, 

 or days on which they have prevailed ; namely, one from the East, three 

 from the South, seven from South-west, and three from the West. 



REMARKS. 



London.— Dec. 1. Cloudy. 2. Drizzly. 3. Fine. 4. Cloudy: drizzly. 

 5. Cloudy. 6. Fine. 7. Stormy night. 8, 9. Fine. 10. Rain : drizzly. 

 1 1. Foggy morning : rainy night. 12. Cloudy : rain at night. 13. Cloudy : 

 foggy morning. 14. Rainy. 1 5. Cloudy : rainy night. 16. Fine morning : 

 heavy shower at 3 p.m. 1 7. Cloudy. 1 8. Rain : boisterous night. 1 9. Rainy. 

 20. Fine. 21, 22. Cloudy. 23. Fine. 24. Rain. 25 — 27. Fine. 28. Fine 

 day : foggy night. 29. Gloomy : dense fog all day. 30. Fine. 31. Fine : 

 rain at night. 



Penzance.— Dec. 1, 2. Showers. 3. Fair. 4, 5. Misty. 6. Clear. 7. Clear, 

 fair : rain at night. 8. Clear. 9. Misty : rain. 10. Rain. 1 1, 12. Rain : 

 fair. 13. Clear. 14. Rain: fair. 15. Rain. 16. Clear : hail-showers. 

 1 7. Fair : rain. 18, l9.Rain. 20. Hail-showers. 2l,22.Rain. 23. Fine: 

 rain. 24. Rain : fair. 25. Clear. 26. Fair. 27. Clear. 28. Fair. 29 — 

 31. Clear. — Rain-gauge ground level. 



Boston. — Dec. 1. Cloudy : rain early a.m. 2. Rain. 3. Cloudy. 4. Cloudy : 

 rain early a.m. 5. Fine. 6. Stormy. 7— 9. Fine. 10. Cloudy. 11. Fine: 

 rain p.m. 1 2. Misty : rain at night. 13. Cloudy: rain early a.m. 14. Rain: 

 rain early a.m. 15—17. Fine. 18. Cloudy: rain p.m. 19. Cloudy. 

 20— 21. Fine. 22. Fine : rain p.m. 23. Fine. 24. Cloudy. 25. Fine: 

 rain a.m. 26. Cloudy. 27— 29. Fine. 30. Cloudy. 31. Fine. 



RESULTS. 



Winds, NE. 1 : SE. 4: SW. 14 : W. 3 : NW. 9. 



London. — Barometer: Mean height for the month S0'0S8inch. 



Thermometer : Mean height for the month 44«274 



Rain 3-60 



Evaporation , 1*24 inch. 



Meteoro- 



