of theory and deduction, in which considerable progress is already made. Until the results can be laid before the public, what is now produced may serve the purpose of reference, and occasional information on various points of the history of our climate, for the series of years comprehended in the tables. Persons moderately conversant with natural philosophy, will know how to make use of them in this way: still more, they who have been accustomed to make similar observations for themselves. There are indeed but few at present who can be said to study the subject, compared with the number of amateurs in chemistry, in astronomy, in electricity, &c. Yet it is one with which gentlemen possessing the requisite information, together with domestic habits, might very agreeably fill up a portion of their daily leisure. There is nothing splendid or amusing to be met with in the outset of such a course: but, I believe, that even in more attractive pursuits, the pleasure of study resolves itself sooner or later into the feeling of the gradual acquisition of knowledge, the perception of the relations, agreements, and differences of facts, and their orderly arrangement in the mind. Now, in no one department of natural knowledge is the field less trodden, or the opportunity for a successful exertion of the judgment in establishing general principles greater, than in meteorology in its present state. There is no subject on which the learned and the unlearned are more ready to converse, and to hazard an opinion, than on the weather-and none on which they are more frequently mistaken! This alone may serve to show that we are in want of more data, of a greater store of facts, on which to found a theory that might guide us to more certain conclusions; and facts will certainly multiply together with observers. He who wishes to study astronomy (the most perfect, perhaps, because

the most ancient of the sciences), must begin, I imagine, where the Chaldeans began, though with so much better means before him:-he must remark for himself in the heavens, the actual courses of the planets, and the most obvious points in the construction of our own system. So, to become qualified to reason on the variations of our own climate, we should begin by making ourselves familiar with their extent and progress, as marked by the common instruments, and the common natural indications: for which purpose such a model as the present volume may be found very serviceable. A moderate knowledge of the phenomena acquired in this way, will naturally excite a desire to become acquainted also with their causes, and eventually, with the principles of the science. These have been ably investigated in parts by several writers: in our own language, by Franklin, Cavallo, Kirwan, Dalton, Marshall, Wells : in French, by Saussure, De Luc, Cotte, Bertholon: a work by Beccaria is extant in an English translation; and there are many detached extracts of the opinions of foreign authors, as well as essays of minor bulk, dispersed in the Philosophical Transactions, and other periodical publications. Dr. Thomson has given a good summary of meteorological facts in the former editions of his System of Chemistry; and Dr. Robertson has done the same in a separate work. But we are not as yet possessed of a general elementary treatise, displaying in a sufficiently familiar manner the present extent of the science; which from this cause appears more confined and imperfect than it really is. In the early part of this introduction, I made mention of some lectures on meteorology, which I had a view of publishing. These are necessarily a more remote object than the completion of the present work. I must, therefore, entreat the patience of my friends in regard to

these for while I have long owed such a work to the public, the materials have been accumulating, and the labour of selecting and arranging in a small compass, what may be deemed fittest for the purpose, is likely to be yet considerable.

ERRATA ET CORRIGENDA.

Table 1. line 15-Barometer 39·83 read 29-83.

11. in the references-e read c.

23, 24. The lunar phasis omitted: which, with several inaccuracies discovered in the placing of these, will be rectified by a table of them all.

25. line 24 in the reference bread l.

50. omitted November 18, SW-29.25—29·17-51°-45°.

51. line 14-The maximum and minimum of pressure appear to be reversed.

52. at bottom; minimum of temperature 53° read 33o.

58. in the notes, fourth page, line 6 from bottom; burnt read burst.

64. in the notes, fifth page, line 10; No. 1, read No. 2.

102. in the notes, second page, line 6 from bottom: burn read burnt.