MISCELLANEOUS. SUBMARINE TUNNEL TO THE ISLE OF WIGHT. Works are now in progress under the direction of MR. VIGNOLES, the well-known engineer, with a view to ascertaining the practicability of a submarine tunnel to connect the Isle of Wight with the mainland. The spot selected is the narrow part of the Solent just to the westward of Cowes, the actual width of the sea here not being more than one mile and three-quarters, though the tunnel would have to be nearly three miles long. The greatest depth of the channel at low water spring tides is twelve fathoms, or seventy-two feet, and this depth occurs nearly on the Isle of Wight shore, the water on the mainland side being comparatively shallow. Experiments are now being carried on by MR. PRICHARD, the contractor, to ascertain the nature of the soil through which the tunnel would have to run, and up to the present time the results have been eminently satisfactory. A depth of 150 feet has been reached through good stiff clay, and if the same kind of soil continues there would be but little danger of the water finding its way into the works; but in order to prevent the possibility of its doing so, it is proposed to form an iron casing, inside of which the ordinary brickwork would be turned.