118 



actually fallen from the sky. Further, he sought to show that 

 the fall of a heavy body from the sky was the direct cause 

 of the luminous phenomenon known as a fire-ball. 



About seven o'clock on the evening of June 16, 1794, as 

 if to direct attention to Chladni's theory, there fell quite a 

 shower of stones at Siena, in Tuscany (148 R). The 

 event is described in the following letter to the Earl of Bristol, 

 written from Siena on July 12, 1794, by Sir William Hamil- 

 ton, K.B., F.R.S., at that time British Envoy-Extraordinary 

 and Plenipotentiary at the Court of Naples : — 



" In the midst of a most violent thunderstorm, about a 

 dozen stones of various weights and dimensions fell 

 at the feet of different persons, men, women, and 

 children. The stones are of a quality not found in 

 any part of the Siennese territory : they fell about 

 18 hours after the enormous eruption of Mount 

 Vesuvius: which circumstance leaves a choice of diffi- 

 culties in the solution of this extraordinary phenome- 

 non. Either these stones have been generated in this 

 igneous mass of clouds which produced such unusual 

 thunder, or, which is equally incredible, they were 

 thrown from Vesuvius, at a distance of at least 250 

 miles: judge, then, of its parabola. The philosophers 

 here incline to the first solution. I wish much, Sir ? 

 to know your sentiments. My first objection was to 

 the fact itself, but of this there are so many eyewit- 

 ^ nesses it seems impossible to withstand their evi- 

 dence." 



Soon after there fell a stone in England itself. About three 

 o'clock in the afternoon of December 13, 1795, a labourer 

 working near Wold Cottage, Thwing, Yorkshire (149 Z), 

 was terrified to see a stone fall about ten yards from where he 

 was standing. The stone, weighing 5 6 lbs., was found to 

 have gone through 12 inches of soil and 6 inches of solid 

 chalk rock. No thunder, lightning, or luminous meteor 

 accompanied the fall ; but in the adjacent villages there 

 was heard an explosion likened by the inhabitants to the 

 firing of guns at sea, while in two of them the sounds were 



