A MR. CHUBB has published in London, in a small volume, a paper which he read before the Institution of Civil Engineers, on the construction of locks and keys. It embraces a history of the lock and key from the earliest ages, illustrated profusely with wood cuts. It forms an instructive and entertaining essay; but we think Mr. Chubb might have learned something more of the subject in the lock factories of Newark and this city. * * * * * MR. TICKNOR'S History of Spanish Literature has been translated into German, and is announced for publication by Brockhaus. * * * * * MR. DICKEN'S "David Copperfield" is at length completed, and Mr. Wiley has published it in two handsome volumes, profusely illustrated. There is a variety of opinions among the critics as to its rank among the works of "Boz"; but it is not contended by any that it evinces a decay of his extraordinary and peculiar genius. We copy a paragraph which strikes us as just, from the _Spectator_: "This story has less of London life and town-bred character than most of its predecessors; but what may thus be gained in variety is lost in raciness, breadth, and effect. The peculiar classes forced into existence by the hotbed of a great city, and owing a part of their gusto to town usage, may be narrow enough if compared with general nature, but they are broader than the singularities whom Mr. Dickens copies or invents as representatives of genteel country life, or human nature in general. In the mere style there is frequently an improvement--less effort and greater ease, with occasional touches of the felicity of Goldsmith; but we should have thought the work was likely to be less popular than many of the previous tales of Mr. Dickens, as well as rather more open to unfavorable criticism. Any prose fiction that is to take rank in the first class, must have what in epic poetry is called a fable,--some lesson of life embodied in a story that combines the utile and the dulce. This fable should not only please the reader by its succession of coherent events, and by the variety of its persons and fortunes, but should touch by appeals to the common kinship of humanity, and teach worldly conduct of ethical lessons by particular incidents, as well as by the general development. And when this end is attained, whether by design or instinct, technical rules are readily forgotten; even the great rule of unity of action can be dispensed with. It does not appear that Mr. Dickens has the critical training necessary to feel the importance of this principle, or a knowledge of life sufficiently deep and extensive to enable him to embody it unconsciously, as a well-chosen story will always compel an author to do. So far as _David Copperfield_ appears