The last volume we have had from the hand of Dr. Mayo is, _Romance Dust from the Historic Placer_, a collection of shorter stories chiefly founded on historical incidents. In these he exhibits the fresh feeling, occasionally the humor, and always the bold drawing and effective coloring which distinguish his more ambitious performances. The volume contains also a poem, but not one of such striking qualities as to induce regret that the author has commonly chosen to write in prose. The style of his novels, especially in the narrative parts, is uncommonly good, but with its many excellencies it does not seem to us that it possesses a poetical element. Dr. Mayo has commenced a brilliant course, in which we trust we shall have occasions to record still greater triumphs than those by which he has won a place in the first rank of the young writers of English. The portrait at the beginning of this article is very truthful; it is from a recent daguerreotype by Brady. [Illustration: THE CRYSTAL PALACE.] _Original Correspondence._ LONDON, _May 23, 1851._ Historical Sketch--Why England was the most appropriate location for Exhibition--First impressions--Contrast between barbaric and civilized industry--Use and beauty--Moral and social influences. The Great Exhibition constitutes the one absorbing topic in which, for the time being, all other topics are merged. Go where you will, nothing else is thought of, talked of, or heard of, from one end of London to the other--this magnificent display of the achievements of art and industry forms the sole theme of conversation, calling forth the most animated descriptions, the most energetic discussions, the warmest and most enthusiastic praise. Nor is this interest confined to London alone; the whole kingdom shares in the excitement, and seems to be only waiting for warmer weather, and the approaching reduction of the entrance fee, to march upon the metropolis, and satiate its curiosity within the walls of the Crystal Palace. As the season advances, and the brilliant success of the enterprise becomes known, foreign nations, who have contributed so largely to the splendor of the show, will send over hosts of friendly visitants; and the World's Fair, so veritably cosmopolitan in design and execution, will become equally so in its social character and results.