The Causes and Phenomena of Earthquakes. 17 



ruary " three loud explosions " from below were heard along the 

 coast of Naples, during a most violent earthquake, Vesuvius only 

 smoking, the sea calm, and great damage done. 



At Ancona, in the Papal States, on 22nd March, 1829, " noise 

 like the firing of artillery " was heard during two severe shocks. 



Similar explosions, seemingly high in the air to the south, quite 

 unlike thunder, are recorded of the severe shock felt at La 

 Eochelle, in France, on 27th November, 1829. " Dull explosions 

 were heard in the air," and terrible portents are mentioned of 

 the earthquake in China on 26th June, 1830. " A loud explosion, 

 as a fire of heavy ordnance," followed a shock at Coblentz, on 

 the Rhine, on 28th December that year ; and " an explosion like 

 that of a cannon " followed the destructive earthquake in Cala- 

 bria on 8th March, 1832. At Katmandu, in Nepaul on 26th 

 July, 1833, a frightful earthquake was " attended by a noise 

 compared to that of a hundred pieces of artillery." " Loud ex- 

 plosive noises were heard at Volterra, in Tuscany, 15th to 17th 

 April, 1834. At Chichester, on 27th August, 1834, during a 

 shock (which I well remember to have occurred), a man on the 

 shore heard a loud report of a great gun, and immediately felt 

 the ground shaking under his feet." Explosions or detonations 

 also accompanied shocks at Keni, in Bessarabia, on 6th May, 

 1834 ; and at Porsgrund, in Norway, 3rd September, 1834 ; at 

 Borgataro, in Tuscany, on 8th March, 20th April, and 25th April, 

 1835 ; at Palma, in Majorca, 16th and 17th June, 1835 ; at 

 Simegh, in Hungary, 9th February, 1836 ; at Yenice, 21st June, 

 1863 ; at Nismes, 16th September, 1836 ; and at Vizille, in 

 Prance, on 29th January, 1837, a violent explosion like the 

 simultaneous discharge of several pieces of artillery preceded 

 some considerable shocks. A noise like the report of a cannon 

 accompanied two slight shocks at Meleda, in the Adriatic, on 7th 

 June, 1838 ; and singularly enough in the same place, on 7th 

 June, 1839 ; the former coming from "W. to E., and the latter 

 from S. to N. 



On the 10th September, 1839, a loud explosion followed a 

 severe shock in Monmouthshire ; and on 21st October, 1839, the 

 noise was compared to that of artillery, and other similar sounds, 

 when two-thirds of Scotland were shaken. During the Comrie 

 shocks of that time the noise was heard in the air, while the 

 earth was not sensibly in motion. Mr. Stewart says the noise 

 heard by him on the 23rd October of that year, at Ardvoirlich, 

 seven miles west of Comrie, could be compared to " nothing more 

 nearly than the report of one of the heavy guns of Edinburgh 

 Castle, as heard in the New Town when fired on the south side 

 of the Castle." He says the " sound proceeded from the atmos- 

 phere, and not from the ground." At Hamilton, in Upper 

 Canada, on 10th September, 1840, loud subterraneous explosions ; 



