However, from the peculiar mode in which they travel there is often a way of preventing this, and on one occasion it was resorted to, and the town of Catania thereby saved. A current of lava from Mount Etna was making its way straight towards the town, but a body of fifty bold strong fellows went out to meet it, armed with crow bars; with these they broke great holes in the crust at the side, and thus the stream was turned into another course, and pursued its way on one side of the town.
Throughout an eruption, a great quantity of dust is produced by the rubbing of the stones against each other which are thrown out from the crater, and often fall back and are thrown up again several times.
This dust is driven over a great extent of country, and a gentleman whom I visited, who lived about fourteen miles from Mount Vesuvius, told me that during the great eruption of 1822, his garden was covered with them, to the depth of full six inches.
But in more violent eruptions they are carried much further than this. In an eruption of a Volcano in Sumbawa, an island which lies some miles to the East of Java, the ashes were carried to a distance of 270 miles in such quantities as to darken the air, and in another direction they were found 300 miles off. They fell so heavily 40 miles away from the Volcano that they broke into many houses, and rendered them uninhabitable.
Quantities of liquid lava are thrown upwards, and shape themselves into nearly the forms of fish by their passage through the air. These are called bombs by the inhabitants, and the fall of them is very justly dreaded, as they come with great violence.
The size of the largest of those from which the following picture was taken, was six inches long, two inches and a quarter wide, and one inch and three quarters thick; but there are much larger sometimes.
If you should have a chance of examining any of these, you may observe how wisely the living principle, which gives the figure to fish, has been ordained by their Creator to provide the best form to assist their motions, in a medium in which they are suspended, and do not move on ground as the beasts do; seeing that it is precisely the same sort of figure as the laws of inanimate matter impress upon it, when in a yielding state, and being impelled to move under similar circumstances.
I must give you a notion of the quantity of lava sometimes sent out in a single eruption.