"That night which I lay there, it rained ashes all over the city, and ten miles at sea it troubled my eyes. This fire in its progress met with a lake of four miles in compass; and it was not only satisfied to fill it up, though it was four fathom deep, but hath made of it a mountain."
[21] I have heard since, from some of our countrymen who have measured this tree, that its dimensions are actually as abovementioned, but that they could perceive some signs of four stems having grown together, and formed one tree.
[22] No great stress should be laid upon these observations, as the many inconveniences we laboured under, and the little practice we had in such nice operations, must necessarily have rendered them very inaccurate. The Canon Recupero, who was our guide, attended Mess. Glover, Fullerton, and Brydone, up Mount Etna in June 1770. The latter is a very ingenious and accurate observer, and has taken the height of many of the highest mountains in the Alps. His observations, as the Canon informed me, were as follows: At the top of the mountain the quicksilver in the thermometer was 9 degrees below freezing point, when at the foot of the mountain it rose to 76. At the foot of the little mountain that crowns the Volcano the barometer stood at 20° 42/3', half way up this little mountain it was at 19° 6'; but the wind was too violent for them to attempt any more observations. The barometer and thermometer were of Fahrenheit's. Mr. Brydone remarked, as he went up in the night, that he could distinguish the stars in the milky way with wonderful clearness, and that the cold was much more intense than he had ever felt upon the highest mountains of the Alps.
[23] This passage, in Cornelius Severus's poem upon Etna, seems to confirm my opinion:
"Placantesque etiam cælestia numina thure
"Summo cerne jugo, vel quâ liberrimus Ætna
"Improspectus hiat; tantarum semina rerum
"Si nihil irritet flammas, stupeatque profundum."
[24] A better account of the formation of tufa will be seen in my next [letter].
[25] The dates of the eruptions of Mount Etna, recorded by history, are as follows: Before the Christian æra four, in the years 3525. 3538. 3554. 3843. After Christ, twenty-seven have been recorded, 1175. 1285. 1321. 1323. 1329. 1408. 1530. 1536. 1537. 1540. 1545. 1554. 1556. 1566. 1579. 1614. 1634. 1636. 1643. 1669. 1682. 1689. 1692. 1702. 1747. 1755. 1766.
The dates of the eruptions of Vesuvius are as follows: After Christ—79. 203. 472. 512. 685. 993. 1036. 1043. 1048. 1136. 1506. [1538, the eruption at Puzzole.] 1631. 1660. 1682. 1694. 1701. 1704. 1712. 1717. 1730. 1737. 1751. 1754. 1760. 1766. 1767. 1770. 1771.
[26] Pliny, in his account of these islands, in the ix chapter of the third book of his Natural History, seems to confirm this opinion.
"Lipara cum civium Romanorum oppido, dicta à Liparo rege, qui successit Æolo, antea Melogonis vel Meliganis vocitata, abest xii millia pass. ab Italia, ipsa circuitu paulo minori. Inter hanc et Siciliam altera, antea Therasia appellata, nunc Hiera; qui sacra Vulcano est, colle in ea nocturnas evomente flammas. Tertia Strongyle, a Lipara millia passuum ad exortum solis vergens, in qua regnavit Æolus, quæ à Lipara liquidiore flamma tantum differt: e cujus fumo equinam flaturi sint venti, in triduum prædicere incolæ traduntur; unde ventos Æolo paruisse existimatum. Quarta Didyme, minor quam Lipara. Quinta Ericusa; sexta Phœnicusa; pabulo proximarum relicta. Novissima, eademque Minima, Evonymos."