HERTFORDSHIRE EARTHQUAKES. 165 



Many more earthquakes are recorded as having occurred 

 during the night than during the day, but this may be due, as 

 Dr. John Milne has suggested, to the fact that slight shocks 

 which would pass unnoticed in the daytime would be felt by 

 people in bed. Four in Hertfordshire have been felt between 

 3 and 6 a.m., and five between 9 and noon ; all between 3 a.m. 

 and 2 p.m. That this does not accord with the general rule is 

 probably an accidental circumstance or partly due to the length 

 of time taken in their transmission, a few having occurred at 

 their point of origin long before they were felt in oiu' county. 



A few words should be said about erroneous records, some of 

 which have given me much trouble to unravel. 



Two Herefordshire earthquakes, one in March, 1755, the other 

 on 27th December, 1768, have been attributed to Hertfordshire. 

 The error as to both of these was made by Alexis Perrey in his 

 list of British earthquakes (1850). Foi'timately he gave his 

 authorities — for the first the 'Collection Academique ' (1761), 

 where the following occurs : — " 1755, Mars, les montagnes du 

 Comte de Hereford en Angleterre furent ebrank'es et boule- 

 versees"; for the second the ' Mercure de France' (1760), where, 

 after an account of an earthquake in the coimties of Worcester 

 and Gloucester on 21st December, 1768, is the statement: 

 " Le 27, on a senti une nouvelle secousse dans le comte de 

 Herford," evidently from the context a mistake for Hereford. 

 The first of these ei-rors has been copied by Mallet (1753), 

 O'Reilly (1885 and 1886), and Eoper (1889), in their earth- 

 quake catalogues. The date of the earthquake of 13th December, 

 1250, is given by Holinshed (1577) and Prestwich (1870) as the 

 10th. Lowe (1870) gave two dates for one earthquake. Perrey 

 confused the two earthquakes of 19th and 29th March, 1750, 

 giving Hertfordshire localities for the later one, and the error 

 has been copied by Mallet and Eoper. And Meldola and White, 

 in their account of the great Essex earthquake (1884), attributed 

 one to Hertfordshire on 8th March, 1750, and another on 19th, 

 the former date being the old style of reckoning and the latter 

 the new style for the same day. In the present paper the new 

 style has always been given, except in quotations, when the new 

 style has been added in brackets. 



Three Hertfordshire earthquakes, those on 19th February, 

 1750, 1st November, 1755, and 28tli January, 1878, were caused 

 by pulsations transmitted from abroad ; three, those on 6th 

 October, 1863, 20th January, 1886, and 17th December, 1896, 

 came to us from the west of England ; and three, those on 25th 

 May, 1551, 19th March, 1750, and 22nd April, 1884, originated 

 in the south-east of England, the first in Surrey, the second in 

 London, and the third in Essex. The point of origin of the 

 first one named as being abroad may have been in the 

 English Channel, as it was felt at the same time in London 

 as in Normandy, Picardy, and Brittany. Our county is only 

 responsible for two, the earliest, on 13th December, 1250, and 



