One man tells us they were beacons; but, first, what an enormous one is here, one hundred and twenty-four feet by sixty of blazing wood, timber being scarce too! next, they sometimes occur in low situations from which a flame could scarcely be seen; thirdly, common wood fire will not melt granite.

Another pundit says they are volcanic.

O wondrous volcano to spout oblong concentric areas of stone walls! Perhaps the best explanation is that the Celts cemented these hilltops of strongholds by means of coarse glass, a sort of red-hot mortar, using sea-sand and seaweed as a flux.

This is Professor Whewell's idea, and with him we had some interesting conversation on that and other subjects." Of this Scotch tour, full of interest, thus very curtly.

Turn we now to Ireland in 1835.