Meteorological Observations for May 1829. 79 



but upon the whole, more genial weather for the formation and rapid growth 

 of the fruits and vegetation in general, which have still a promising appear- 

 ance, has not occurred since May 1822. The grasses generally, which 

 looked so well at the beginning of the month, shot up suddenly, and were 

 in seed too prematurely from the want of moisture ; consequently the hay, 

 the making of which has partially commenced in this neighbourhood, will 

 not perhaps amount to an average crop. 



Two parhelia appeared from 4 till 6 P.M. on the 4th instant; their co- 

 lours were peculiarly bright, and each exhibited a white train from the 

 sun about 15 degrees long, which terminated evanescently : they appeared 

 to be formed in an almost imperceptible vapour that preceded the coming 

 up of clouds from the S.W. Two other parhelia of a similar appearance, 

 and distant from each other 45^ degrees, were observed from 4 P.M. till 

 sunset on the 20th. 



In the evening of the 14th a large lunar halo appeared, whose vaporous 

 edge was full three degrees broad, and tolerably well defined for nearly an 

 hour, when it began to wane. Several flashes of lightning emanated from 

 the clouds in the northern horizon in the evening of the loth, after a warm 

 sunny day: and an unusually thick fog came on at 5 P.M. on the 16th, 

 and continued throughout the night with a strong gaseous smell. 



On the 24th a moist S.W. wind was crossed at noon by a cold brisk gale 

 from the North, and their union immediately produced a desirable shower 

 of rain, after a dry period of seventeen days. This change was succeeded 

 by a very dry gale from the North-east till the 30th ; and although the 

 27th and 28th were very fine sunny days, with but few clouds, yet the sun- 

 shine was remarkably turbid in colour, which may have been caused by 

 small dust raised by the powerful land gale, and mixing with the vapour 

 arising from the earth. The aridity of the air near the earth was re- 

 markable for absorbing aqueous vapour from the 24th to the 30th ; as 

 during the six days, under somewhat more than a mean pressure of the 

 atmosphere, with a mean temperature of 63° where tiie water was exposed, 

 the mean dew-point about 53", and strong gales from the N. and N.E., 

 the quantity that actually evaporated from a cubic foot of water (allowing 

 it to contain 437,2/2 grains] was one-eighth part of the whole, or 6'3 grains 

 per minute from its surface, which is one-seventh more than calculations 

 on the theory of evaporation afford under similar circumstances, taking 

 into consideration tiie form of the area, and the greatest force of the gales. 



The atmospheric and meteoric pliienomcna that have come within our 

 observ;.tions this month, are five parhelia, four solar and three lunar halos, 

 lightning once, and seven gales of wind, or days on which they have pre- 

 vailed J namely, two from the North, and five from the North-east. 



London.— ^lay \ — 4. Very fine. 5. Fine morning: cloudy. G. Drizzly: 

 very fine. 7. Fine. 8 — 13. Very fine. 14. Ilazy morning: fine. 15. Very 

 fine: sligiit rain at night. 16. Cloudy: very fine. 17 — 23. Very fine. 

 24. Very fine : heavy rain in the afternoon. 25. Cloudy, with strong gale 

 at night. 26—28. V^ery fine. 29, 30. Cloudy. 3 1 . Very fine. 



Penzance. — May 1 — 3. Fair. 4. Fair : rain. 5. Jiuin : liiir. 6. Clear. 

 7, 8. Fair. 9, 10. Clear. 11. Fair. 12. Clear : rain at night. 13, 14. Fair. 

 15 — 22. Clear, 23. Fair: a shower at night. 24, 25. Clear. 26. Fair. 

 27, 28. Clear. 29. Fair. 30, 31. Clear. 



Jiuston. — May 1. Cloudy. 2. Cloudy: showery during the day. 3, 4. Fine. 

 S. Cloudy. 6. Fine: showery early a.m. 7 — 22. (Jloudy. 23. Fine. 

 24. Cloudy. 25. Fine. 26. Cloudy. 27, 28. Fine. 29— 31. Cloudy. 



Meteoro- 



