Meteorological Observations. 159 



deficient of the rays of greatest refrangibility, or rather from the 

 singular crimson character of the portion occupied by the red ray, 

 it appeared as if the spectrum was doubled on itself, and the violet 

 mingled with the less refracted rays. The very remarkable appear- 

 ance and situation of the bow necessarily attracted the attention of 

 many persons, and some who saw it from Falmouth harbour, de- 

 scribed it to me as being nearly in a line with the sun. 



It is necessary to notice, that no rain was falling : the day was 

 unusually fine for the season ; and the temperature, which had 

 during the day been above the freezing point, was then certainly 

 below it. Over the hill on which this phsenomenon appeared, was 

 slowly spreading the lightest possible veil of vapour, so thin that 

 a casual observer would have stated that the rays were painted on 

 the most transparent air. It has been suggested, that the pheeno- 

 menon was produced by an image of the sun reflected from some 

 of the clouds behind the orb itself, and it certainly appears to me 

 highly probable that such was the case ; and from its similarity to 

 some of the phsenomena I have observed in my experiments on 

 polarized light, I am almost inclined to look upon it as an instance 

 of atmospheric polarization. 



I expect the frost bows, of which some accounts have recently 

 been given, are of analogous character to the bow I have described. 

 I remain. Gentlemen, yours, &c. 



Robert Hunt, 

 Falmouth, Jan. 2, 1841. Secretary Royal Corn. Polytechnic Society. 



METEOROLOGICAL OBSERVATIONS FOR DEC. 1840. 



Chiswick. — Dec. 1. Hazy: overcast and mild. 2. Very fine. 3. Frosty: fine. 

 4. Sharp frost : overcast. 5, 6. Hazy. 7. Overcast. 8. Rain. 9. Frosty : 

 clear. 10. Thawing: hazy. 11. Hazy. 12, 13. Overcast and cold. 14. Sharji 

 frost. 15. Dry frosty air. 16. Overcast: snowing. 17. Snowing: cloudy: 

 severe frost at night. 18. Frosty: overcast and cold. 19. Hazy : rain. 20,21. 

 Overcast and cold. 22—24. Severe frost. 25. Intense frost : Dense fog. 26.' 

 Thick hoar frost. 27—29. Foggy. 30. Clear : cloudy : rain at night. 31 " 

 Cloudy : clear and fine. 



The mean temperature of this month was lower than that of any December 

 within at least the last forty years. 



Boston. — Dec. 1. Cloudy: rain early a.m. 2 — 4. Fine. 5 — 7. Cloudy. 8. 

 Rain: rain early a.m. 9. Fine. 10—13. Cloudy. 14. Cloudy: snow p.m. 

 15. Cloudy: snow A.M. 16. Snow. 17, 18, Cloudy. 19. Rain. 20 21 

 Cloudy. 22—24. Fine.. 25—29. Cloudy. 30. Fine: rain p.m. 31. Fine. 



This is the coldest December since 1829. 



Applegartk Manse, Dumfries-shire.— T>ec. 1. Raw but fair. 2,3. Fine and 

 fair. 4. Slight showers. 5, 6. Drizzling. 7. Wet and stormy. 8. Fair, but 

 cloudy. 9,10. Fair, but wet preceding night. 11 — 13. Fair throughout. 

 14—16. Hard frost. 17. Thaw, with slight drizzle. 18. Frost again. 19. 

 Slight frost A.M. : drizzle. 20. Frost: Aurora Borealis. 21-24. Frost. 25. 

 Frost A.M. : thaw p.m. 26. Frost again, but cloudy. 27. Thaw a.m. : cloudy 

 and dark. 28. Frost but slight. 29. Frost— moderate. 30. Thaw and snow. 

 31. Raw and drizzly. 



Sun shone out 21 days. Rain fell 9 days. Snow 1 day. Frost 14 days. 



Wind north 1 day. North-north-east 1 day. North-east 7^ days. East-north- 

 east 1 day. East 4 days. East-south-cast 3 days. South-cast 3 days. South- 

 soutli-east 1 day. .South 1 day. South-west 3* days. West-south-west 1 day. 

 West 2 days. North-west 2 days. 



Calm 12 days. Moderate 8 days. Brisk C days. Strong breeze I day. 

 Boisterous 4 days. 



