but it can never be higher than the temperature of the air: when the latter falls (supposing them at the same point) the former must fall also the superfluous moisture (i. e., some portion of the invisible vapour) being condensed either into dew, fog, clouds, or perhaps rain. In autumn, when the temperature of the air is advancing during the day, it often happens that the dew point advances as much, and in the evening, when the air is again cooling, the dew point must fall; its subsidence being accompanied by a copious deposition of dew, and where the lower strata of the atmosphere are chilled by radiation, by the appearance of mist or fog. The form in which moisture under these circumstances is deposited upon the ground, is much modified by the state of the air: if the wind blows strongly, surfaces become moist and perhaps wet; it is only when the air is calm, that those minute drops, standing at the very tips of the blades of grass and upon every, the minutest fibre, constituting dew properly so called, can be seen.

Air of the same temperature affects our sensations differently; the impression is greatly modified by the force of the wind and the state of the dew point. When the atmosphere is calm, the temperature moderate, and the dew point very high, it seems close, warm, and oppressive-sensations much diminished by a light breeze; on the other hand, when the temperature is moderate, the air calm, and the dew point very low, the feeling is cool, bracing, and pleasant; but if the wind blows fresh, we then feel it cold, harsh, and disagreeable; this last condition is very apt to induce catarrh, sorethroat, and rheumatism in those disposed to these affections. It is when the dew point is high that ladies' hair falls out of curl, a ringlet is an elegant and delicate hygroscope. Every one must have observed, occasionally, the visible condensation of the breath; this is a tolerable indication of the state of the vapour of the atmosphere, such an appearance shewing that the temperature of the air and dew point are quite, or very nearly, the same: it may sometimes be remarked in the open air, before, almost always during, or just after, continued heavy rain.

During the winter season, (and the remark will apply generally to the autumn and spring), a rise in the thermometer and dew point at the same time, is a sure indication of clouds and rain.

It often happens on a clear sunny day after rain, when evapora➡ tion is going on with the utmost rapidity, that the dew point does not rise, or, in other words, that the quantity of vapour in the lower regions of the atmosphere does not increase, nor do clouds form in the higher; the vapour, therefore, must be drawn off to distant regions.

Sometimes when the weather is very foggy in the morning, the hygrometer exposed to it will not be dewed or moistened until the temperature of the dark bulb be reduced two, three, or four degrees. When this occurs, the fog is usually succeeded by a clear and fine day.

The following Table of the wind is arranged in accordance with the remarks made in the second volume of The Analyst, p. 221; and it appears that those to the south of the east and west points of the compass, in comparison with those to the north of these points, were, in the former year, as 15 to 10 at Malvern, and in the latter as 18 to 10; and they bore very nearly the same relation to each other in London-the numbers being, for the first year, 15 and a fraction to 10, in the last 19 to 10.

TABLE IV. Of the Wind at Malvern and London for the Seasons of 1834-5 and 1835-6.

Two or more different currents of wind may be frequently detected by observing the clouds. Sometimes the higher ones may be seen nearly stationary, the lower moving rapidly, either at various angles to the slow-moving higher ones, or now and then in an opposite direction. The primary indication of a change in the direction of the wind may be detected sometimes by noticing the appearance of clouds, even before they are influenced in their movements by the ærial current. They display a great variety of circular segments or curls, in a plane apparently parallel to the horizon -the convex face of the curl when below the zenith being turned downwards towards the horizon, whereas the convex arch of the cumulus is turned upward towards the zenith. The appearance

here spoken of may be difficult to describe, but it is very characteristic. The convexity of the curl is generally in the direction of the approaching current.

When the air is calm, evaporation is proportionate to the interval between the dew point and the temperature of the air; it is ac

celerated by the slightest current, and enormously increased by a brisk or high wind.

In calm weather, if there is no interval between the dew point and the temperature of the air, there is no evaporation; if the lat ter rises evaporation commences, but if it falls precipitation begins. If when the dew point and the temperature of the air are the same the wind blows strong, there is then some degree of evaporation, and the air appears to carry with it particles of nascent vapour, something in the same way that it blows up the dust in our roads, the particles of vapour remaining visible, and rendering the air misty or, as it is termed, thick and hazy.

TABLE V. The number of days on which Rain or Snow fell during each Season in 1834, 1835, and 1836,

In taking notice of rain and rainy days with reference to season and climate, the length of time during which it is falling is quite as worthy of regard as the quantity. As much rain may fall during a heavy shower in an hour or two as in a whole day's mizzling rain; and yet the former may be a fine, sunny, and beautiful day; the latter, a wet and miserable one.

The temperature of rain as it descends is, doubtless, very various ; it is generally of the same temperature as the dew point. Whatever the temperature of rain may be when it descends for an hour or two, the air and constituent temperature of the vapour will be equalized.

The following remarks, taken from the meteorological journal to which we are indebted for the preceding tables and observations, may not be unacceptable to our readers.

Jan. 23rd, 1834. Notwithstanding the extreme mildness of this winter, and the great quantities of rain which have fallen during the last thirty days, it has not been by any means sickly—all accounts seem agreed in this particular— though coughs, colds, and rheumatic attacks of a minor character, were observed in the early part of the autumn of

1833. Whether the salubrity of the season is at all attributable to the very boisterous winds of November and December, we cannot venture to determine.

March, 1834. A remarkably dry month, with cold N. E. winds. Epidemic catarrh very prevalent.

The spring and early period of the summer of 1834 very dry. Rain fell on the 4th of June very seasonably for all kinds of vegetation: the rest of the month was showery.— the early part of July was hot, with genial showers; towards the middle of the month, heavy continued rain and floods. August was generally wet, with a marked and continued decline of temperature towards the end. September was remarkably fine, October seasonable, and November mild and dry.

1835. On the 16th and 17th of April, after mild seasonable weather, the thermometer fell, at night, to 28°, or four degrees below freezing. Snow fell in London, and ice was seen in many places half an inch thick. This thermometric depression seems to have been very general, not only in this country, but in France, and other places. At Bourdeaux, the mercury fell, during the night of the 16th, to 25.5, having been for many days previously at 72" or 75." An account of the sudden increase and subsequent rapid decrease of temperature which occurred in the month of June, 1835, will be found in our 3rd volume, p. 175.

July and August, 1835, were hot and dry. Rain fell in quantity for the first time for some weeks on the 24th of the latter month this was followed by a considerable decline of temperature. The last few days of August and the first week in September were again hot and fine. On the 8th of the latter month heavy rain fell; the remainder of the month was wet, and the temperature rather low.

October was cold, cloudy, and, for the most part, wet, with some heavy rain towards the latter end of the month. The early part of November was cold, with heavy rain; the middle mild, with showers, and fresh S. W. breezes. During the last two days of the month the rain was incessant. The first few days in December were mild. Frost set in severely on the night of the 19th, with snow, which continued, with fog and a beautiful hoar-frost, till the 28th.

January and February, 1836, were characterised by great alternations of temperature, with much snow and rain. For several interesting remarks upon the spring of 1836, we must refer to our 3rd volume, p. 348.

W. A.

ON THE RARITY OF CERTAIN BIRDS IN DERBY.

SHIRE,

ABUNDANT IN OTHER PARTS OF BRITAIN.

BY NEVILLE WOOD, ESQ.

FEw features are more remarkable in the ornithology of the flat portions of this district, than the scarcity or the non-appearance of several birds which abound in almost every other part of the kingdom. As the ornithologist cannot fail being interested in the circumstance, I propose, in this paper, to give an account of such species, and to attempt to assign some reason for so extraordinary

an occurrence.

The Corn Bunting (Emberiza miliaria), according to every British author who has written on the subject, is common in every part of the kingdom, and as abundant in the Orkneys as elsewhere. Here, however, in the plain portion of Derbyshire, the species is rarely met with. I have seen it only in two or three instances in these parts; and every one with whom I have conversed on the subject appears perfectly ignorant of the existence of the "Common Bunting." Near Tutbury, on the borders of Staffordshire, three miles from the spot where I formerly resided, it is seldom met with, and the nest, when found in that neighbourhood, is considered a rarity. But about a mile beyond Tutbury, and indeed in almost every part of Staffordshire which I have explored, it is as common as I have found it to be in other districts both to the north and south of this county. During the number of years which I have passed in Derbyshire, the species under consideration has always appeared to me in the light of a rare bird, and were it not for its abundance in the adjoining counties, my knowledge of its habits would be very deficient. Its manners, or at least its general economy, are so familiar to almost every one, that they need not be detailed in this communication, especially as I have elsewhere enlarged upon them at some length.*

The south west portion of Derbyshire is extremely fertile and well cultivated, and the corn fields, which everywhere abound, present as inviting an aspect as those of any other county; and yet the Corn Bunting never makes its appearance, although it usually

*In the British Song Birds.