INTRODUCTION. vii 



The granitic and metamorphio rocks are all of enormous antiquity, 



Nauru r> 135 ^°^^ later than the Cambrian formation. The 



whole of the Secondary and Tertiary series are 



entirely unrepresented. A few remains of animals haye been 



found in the quaternary deposits, but fossils can hardly be said 



Nour 4 ^° exist. On the other hand, to the mineralogist 



"L'lle de Jersey ofEre dans le voisinage immediat 



du Ootentin un massif &uptif du plus haut interet et riche en types 



vraiement exceptionels." 



II. The climate of Jersey is mild and equable. Summer merges 

 almost imperceptibly into autumn, and autumn into mnter, and 

 cold weather is rare before the New Year. Severe frosts are very 

 unusual, and snow seldom lies long upon the ground. The coldest 

 months are January and February, the warmest July and August. 

 The number of hours of bright sunshine is large,* but the air is 

 always laden with moisture and often feels more chilly than the 

 thermometer readings would seem to indicate. 



Since 1894 meteorological observations have been regularly and 

 scientifically made at the Observatory connected with the Maison 

 St. Louis by Father M. Deohevrens, S.J. (see next page). These 

 may be regarded as absolutely reliable, but eight years is a short 

 period to take as a basis for meteorological means, and the amount 

 of rainfall in the appended table is certainly too low, for 1899 

 and 1901 were exceptionally dry years. 



These figures are taken from the yearly resume published in the 

 Bulletins Annuels of the Societe Jersiaise. A paper on the cUmate 

 of Jersey by the Eev. H. W. Yorke was printed in the Quarterly 

 Journal of the Royal Meteorological Society (vol. xxv. No. Ill) 

 in 1899. His conclusions were based on data derived from several 

 different sources, covering a far larger space of time (1844 to 1898), 

 and may usefully be compared with the table already given. He 

 gives the following yearly means : — 



Barometer... 29-977 inches Sunshine 1930 hours 



Shade Temperature ... 52° Eainfall 34 inches 



Coldest month (Jan.)... 42° Rainy days 190 



Warmest month (Aug.) 63° Hail or snow 30 



Frost (in air) 13 days Humidity 82 



Frost on grass 49 days Temperature of sea 54° 



* 1930 on an average of 15 years. (Eev. H. W. Yorke, Quarterly Journal 

 of Meteorological Society, July, 1899.) 



