Produced by Bryan Ness, Stephen H. Sentoff, Alicia Williams and the Online Distributed Proofreading Team at https://www.pgdp.net (This book was produced from scanned images of public domain material from the Google Print project.) OBSERVATIONS ON MOUNT VESUVIUS, MOUNT ETNA, AND OTHER VOLCANOS: IN A SERIES OF LETTERS, Addressed to THE ROYAL SOCIETY, From the Honourable Sir W. HAMILTON, K.B. F.R.S. His Majesty's Envoy Extraordinary and Plenipotentiary at the Court of NAPLES. To which are added, Explanatory NOTES by the AUTHOR, hitherto unpublished. A NEW EDITION. LONDON, Printed for T. CADELL, in the Strand. M DCC LXXIV. THE EDITOR TO THE PUBLIC. Having mentioned to Sir WILLIAM HAMILTON the general Desire of all Lovers of Natural History, that his Letters upon the Subject of VOLCANOS should be collected together in one Volume, particularly for the Convenience of such as may have an Opportunity of visiting the curious Spots described in them: He was not only pleased to approve of my having undertaken this Publication, but has likewise favoured with the additional explanatory Notes and Drawings, The PUBLIC's most obliged, and devoted humble Servant, T. CADELL. May 30, 1772. OBSERVATIONS ON MOUNT VESUVIUS, &c. LETTER I. To the Right Honourable the Earl of MORTON, President of the Royal Society. Naples, June 10, 1766. My LORD, As I have attended particularly to the various changes of Mount Vesuvius, from the 17th of November 1764, the day of my arrival at this capital; I flatter myself, that my observations will not be unacceptable to your Lordship, especially as this Volcano has lately made a very considerable eruption. I shall confine myself merely to the many extraordinary appearances that have come under my own inspection, and leave their explanation to the more learned in Natural Philosophy. During the first twelvemonth of my being here, I did not perceive any remarkable alteration in the mountain; but I observed, the smoke from the Volcano was much more considerable in bad weather than when it was fair[1]; and I often heard (even at Naples, six miles from Vesuvius) in bad weather, the inward explosions of the mountain. When I have been at the top of Mount Vesuvius in fair weather, I have sometimes found so little smoke, that I have been able to see far down the mouth of the Volcano; the sides of which were incrusted with salts and mineral of various colors, white, green, deep and pale yellow. The smoke that issued from the mouth of the Volcano in bad weather was white, very moist, and not near so offensive as the sulphureous steams from various cracks on the sides of the mountain.