earths and minerals. After studying Vesuvius he visited Etna. In February 1783 he journeyed in Calabria to observe the effects of the recent earthquakes. Hamilton, who was elected a fellow of the Royal Society in 1766, published his observations on volcanoes in the 'Philosophical Transactions,' 1766–80. His chief work on the volcanoes of the Two Sicilies was 'Campi Phlegræi' (text in English and French), with fifty-four plates, 2 vols. Naples, 1776, fol.; also a Supplement (English and French), Naples, 1779, fol. He also published 'Observations on Mount Vesuvius,' &c. (letters to the Royal Society, with additional notes), London, 1772, 8vo; other editions, 1773, 8vo, 1774; and 'An Account of the Earthquakes in Calabria, Sicily,' &c., Colchester , 8vo; an Italian translation, Florence, 1783, 4to.
Hamilton was a fellow of the Society of Antiquaries, and became a member of the Society of Dilettanti in 1777. He was a patron (about 1769) of Morghen the engraver, and at Naples was intimate with Charles Townley and R. Payne Knight. In 1799 he gave valuable advice to Lord Elgin. He tried to interest the Neapolitan court in the Pompeian discoveries, of which he published an 'Account' in vol. iv. of the 'Archæologia' of the Society of Antiquaries (reprinted London, 1777, 4to). He gave Father Antonio Piaggi, a monk engaged in unrolling the Herculaneum papyri, about 100l. a year (till 1798), to supply him with weekly reports, and procured him the same sum as a pension from the Prince of Wales. Piaggi left Hamilton all his manuscripts and papers. Hamilton purchased at Naples, in 1766, a collection of Greek vases belonging to the Porcinari family, and gradually formed a museum which at the beginning of 1772 included 730 vases, 175 terracottas, about 300 specimens of ancient glass, 627 bronzes (about half, arms and armour), 150 ivories, about 150 gems, 143 gold ornaments, more than 6,000 coins, including specimens from Magna Græcia, miscellaneous objects, and a few marbles. This collection he sold in 1772 to the trustees of the British Museum; it was purchased with a parliamentary grant of 8,400l. It formed the groundwork of the present department of Greek and Roman antiquities. In the library of that department is a manuscript inventory (a transcript from the original by Dr. Noehden) of the contents of the XIIth or 'Hamilton' Room in the British Museum as it was in 1824, also a manuscript inventory of the Hamilton gems (cp. 'An Abstract of Sir W. Hamilton's Collection of Antiquities' [London, 1772 (?)], fol., Brit. Mus. Cat.). The Hamilton Collection has now been incorporated with the other antiquities in the Museum. In 1766 and 1767 'D'Hancarville' (P. F. Hugues) had written and published an account of Hamilton's collection at that period, 'Antiquités etrusques, grecques et romaines' (text in French and English), 4 vols. Naples, 1766–7, fol.; 2nd edit. 4 vols. Florence, 1801–8. The cost of printing and illustrating the first edition, 6,000l., was borne by Hamilton, who was a patron of D'Hancarville and a believer in his fanciful theories. Hamilton liberally circulated proof-plates of the work, and those representing vases exercised much influence on Josiah Wedgwood, who said that in two years he had himself brought into England, by the sale of Wedgwood imitations of the Hamilton vases, three times as much as the 8,400l. paid for the antiquities by parliament. Hamilton was one of the first Englishmen who collected and appreciated Greek vases. He valued them chiefly as good models for modern artists, and is said to have ridiculed antiquarians by training (1780) his monkey to hold a coin-collector's magnifying glass. Hamilton renounced collecting after 1772, but the passion revived, and in 1787 Goethe (Italienische Reise, 27 May 1787) found his private art-vaults at Naples full of busts, torsos, vases, and bronzes. Tischbein once saw Hamilton at Naples in full court dress helping a ragged lazarone to carry a basketful of vases. Hamilton now formed a collection of Greek vases finer than the first, the specimens being chiefly discovered, in 1789 and 1790, in tombs in the Two Sicilies, especially the neighbourhood of Naples. This collection he tried to sell (3 May 1796) for 7,000l. to the king of Prussia, through the Countess of Lichtenau (Edwards, Founders of British Museum, p. 357). In 1798 he sent it for sale to England in the Colossus, which was wrecked off the Scilly Isles. Eight cases of the vases were lost, but sixteen cases were rescued and were purchased for 4,500 guineas in 1801 by Thomas Hope, of whose collection at Deepdene they formed an important section. W. Tischbein had published the whole of Hamilton's second vase collection in his 'Collection of Engravings from Greek Vases ... in the possession of Sir W. Hamilton' (text, in English and French, by Hamilton and others), Naples, 1791, &c. Only vols. i–iii. are generally to be found, but a copy in the library of the department of antiquities in the British Museum has the additional volumes iv. and v. (supplement), consisting of illustrations without text. A second edition appeared as 'Pitture de' Vasi antiche' (Italian and French text), 240 plates, 4 vols. fol., Florence 1800–3; another edit.,