MARINE BLOWING STONE.
It was in the course of my enquiries for words of the Guanche language that I accidentally heard yesterday, from an old inhabitant, of the existence of a cave in the rocks, about 3 miles to the north-east of Santa Cruz, which it was impossible to enter, but which, when examined from the sea, could be observed to be full of bones.

This cave, he said, was known to the old inhabitants by the name of La Cueva de los Guanches; and according to traditionary report it had been the burying-place of the original inhabitants of this island.

Several English merchants of whom I made enquiries knew nothing of it, even by report, but the master of the hotel was aware of its existence and promised to procure me guides to it.
Although this day was Sunday, yet, as I was to sail in the afternoon, the inducement was too strong to resist, and I started in a boat at 6 o'clock with Mr.Walker our surgeon, taking my geological hammer as I intended to return overland.
When we had proceeded about a mile and a half from Santa Cruz I was astonished to hear, from the rocks on the shore, a loud roaring noise, and to see large clouds apparently of ascending smoke.

I landed to ascertain the cause of this, and found it arose from one of those hollow rocks which are sometimes seen on our own coast and are known by various names, such as blowing stones, boiling kettles, etc.etc.I had however never seen one at all to be compared to this in size.

It was formed by a hole in the rocks through which the water is first poured as the waves rush in; and then is partly driven out with a loud noise through a hole far up, and partly returns, in the form of spray, by the opening through which it was at first impelled.