Miltown; Thursday.—We walked to-day to view a singular piece of sea-engineering, a regular canal—once probably a cavern worn by the sea, the roof of which had fallen in. It is about a mile from the hotel, near the headland of a small bay. The opposite headland is Spanish point, where two of the Armada were wrecked in 1688. Its creamy appearance shows how likely a spot it was for such a catastrophe to take place at.

The weather is so stormy and unpropitious, that we have been obliged to give up the great object of our coming here—a visit to the cliffs of Moher, and the tomb of Conan, on Mount Callan, where there is a stone inscribed with Ogham characters.

We ventured, however, to-day, as far as the Phoul-a-kirché; and were tempted by the report of some boys, to try a visit to the puffing-hole, represented by them as a mile off; but which turned out to be nearly three.

The puffing-hole is a cavity in the rocks, near the shore, through which the sea is forced up, so as to form a splendid jet-d'eau, which sometimes rises to a considerable height. This singular effect is caused by the compression of air in the cavern to which the puffing-hole is the mouth. As the wave retires, the air forces it out of the cavern with great violence, producing a roar like thunder; but this takes place only at a certain period of the tide, when the two great contending powers are nearly balanced as to force.