THERE is perhaps no branch of natural science which has been cultivated with less ardour and success than that of Meteorology. The imperfect nature of the instruments employed to measure the variation in the gravity, temperature, and dryness of the air, and the inattention of observers to many of the more important, though perhaps the less obvious phenomena of the atmosphere, are two of the leading causes of the slow progress of Meteorological Science. The observations on the barometer, thermometer, and hygrometer, at stated times of the day, are by no means fitted to exhibit the changes which are so frequently going on in the atmosphere, and therefore afford us a very trifling assistance in discovering their cause. The most correct meteorological journals indeed do not even contain data for determining the mean state of the atmosphere; nor could we place any confidence in the average results, though the observations were greatly multiplied, and repeated after the shortest intervals. Hence it is an important desideratum in meteorology to have an instrument which shall record, as it were, at every instant, the changes in the atmosphere; and point out, at the end of any required period, the sum of all the changes, or the mean VOL. II. PART. II.

state of the air, during the period which is fixed for this purpose. We expected to have had it in our power to lay before our readers an instrument of this kind, but as it has not yet obtained the sanction of experi ence, we must reserve the description of it for our next volume.

In measuring the quantity of rain which falls upon the earth, no attention has yet been paid to the different heights above the level of the sea at which the guage is placed, though it is a curious fact, that the higher we ascend, the quantity of rain diminishes. A great degree of attention should likewise be paid to the size of the drops at different altitudes;-to the angle at which they fall;-to the force and direction of the wind at different heights in the atmosphere;-to the nature and the certainty of mists and fogs, one species of which obstructs the passage of the most refrangible rays, while another transmits the light in its natu ral state;-to the transparency of the atmosphere, and to the undulations and changes in its refractive power, which often produce optical illusions of the most singular kind. The height and the nature of the clouds

when the moon is surrounded with halos and luminous rings, ought also to be carefully marked, together with

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the height of meteors and the state of the atmosphere when such phenomena

are seen.

Though accurate and multiplied observations on the various subjects which we have mentioned are absolutely necessary to the formation of a theory that pretends to account for the numerous phenomena of the atmosphere, yet we can scarcely hope to find any private individual who has both time and abilities to execute such a task; and if such a plan is ever carried into effect, it must be done in some national establishment, furnished with the most delicate instruments, and conducted by the most able ob

servers.

In the following Meteorological Tables we have endeavoured to present our readers with an accurate account of the changes in the atmos

phere at Edinburgh and London during the year 1809.

The Meteorological Journal for Edinburgh, which is the most valua ble and correct that has yet been made in Scotland, was kept in the house and under the superintendance of a philosopher of distinguished eminence, to whom the writer of the present article is indebted for the liberty of making it public. It contains the height of the barometer to the thou sandth part of an inch at 9 o'clock in the morning ;-the state of the thermometer attached to the barome ter at the same instant ;-the height of the mercury in the thermometer at 8 o'clock in the morning, 12 o'clock noon, and 10 o'clock in the evening;

the force and the direction of the wind; and the state of the weather, both in the forenoon and in the evening of each day.