THE experience of more than a century has eminently proved the advantages of such works as exhibit, under an alphabetical arrangement, the complete circle of human knowledge. Dictionaries of language, of general terms, and of particular branches of science and art, have been multiplied by the labours of men fully qualified to display the subjects they have undertaken to discuss; and the first characters in the various nations of Europe have been proud to rank their names and unite their exertions in the production of immense works, containing every subject which can engage the intellectual research or active occupation of man. The order of the alphabet has been so skilfully combined with that order which is indicated by the natural relations of the materials, that works of this description have been received with the most striking approbation; and, notwithstanding the great labour and expense required to keep pace with the rapid improvements and discoveries of modern times, the number of Dictionaries of all descriptions have been so great, that it would be difficult, and perhaps useless, even to name them, and point out their respective merits.

From the great Encyclopedias, each of which may be said to constitute an entire library, to those smaller compositions intended for mere reference :-from the hurried compilations of book-makers to those elaborate and luminous works, in which men of the highest reputation

have recorded their comprehensive views, and their most striking discoveries, it is not difficult to observe and deduce the distinct and separate utilities of each, and the duties to be expected from the editors and proprietors of such undertakings. Among the most obvious of these, it is indispensable that a new work should be called for, by circumstances which point out advantages of size, plan, and materials, not before adopted, and that the means to be employed, in the actual performance, should be such as must determine its worth and authority with every description of readers.

We are already in possession of the large Cyclopedia of Dr. REES, which has advanced to its twelfth volume, by a progress that insures its regular completion, and in a style of execution which is truly honourable to the skill and diligence of those who have undertaken it; to the activity and enterprise of the proprietors, and to a nation which has ever taken the lead in 'science and the arts. On the smaller dictionaries it is needless to enlarge. After various deliberate consultations between the Proprietors, the Editor, and the principal gentlemen engaged in the different departments, it was concluded, that a new Dictionary, appropriated exclusively to the Arts and Sciences, and containing a dense, accurate and ample exhibition of our whole knowledge respecting them, might with the greatest advantage be comprehended in the limits of six large octavo volumes. It was accordingly decided, that the undertaking should be entered upon with vigour and activity, it the same time that the utmost attention should be paid to the means by which alone it was possible to insure the alue of the in