_The Thames._--Personified and represented, of a venerable, majestic and gracious aspect, sitting on the waters in a triumphal car, steering himself with one hand, and holding in the other the mariner's compass. The car is borne along by our great navigators, Sir Francis Drake, Sir Walter Raleigh, Sebastian Cabot, and the late Captain Cook. In the front of the car, and apparently in the action of meeting it, are four figures, representing Europe, Asia, Africa, and America, ready to lay their several productions in the lap of the Thames. The supplicating action of the poor negro slave--or, more properly, of enslaved Africa--the cord round his neck, the tear on his cheek, the iron manacles and attached heavy chain on his wrists, with his hands clasped and stretched out for mercy, denote the agonies of his soul, and the feelings of the artist thus expressed, before the abolition of slavery became the subject of public investigation. Overhead is Mercury, the emblem of commerce, summoning the nations all together; and following the car are Nereids carrying several articles of the principal manufactures of Great Britain. In this scene of triumph and joy the artist has introduced music, and, for this reason, placed among the sea-nymphs his friend, Dr Burney. In the distance is a view of the chalky cliffs on the English coast, with ships sailing, highly characteristic of the commerce of this country, which the picture is intended to record. In the end of this picture, next the chimney, there is a naval pillar, mausoleum, observatory, light-house, or all of these, they being all comprehended in the same structure. In this important object, so ingeniously produced by the sea-gods, we have at last obtained the happy concurrence and union of so many important desiderata in that opportunity of convenient inspection of all the sculptured communications, the want of which had been so deeply regretted by all who had seen the Trajan and Antonine columns, and other celebrated remains of antiquity.