.366 



Scientific Proceedings, Royal Dublin Society. 



inches, including Dublin as a centre, extending north to Malahide, west 

 to Lucan, and taking in a narrow part of the coast about Kingstown, 

 Dalkey, and Killiney. It seems very remarkable that the elevated ground 

 at Dalkey and neiglibourhood should have such a low rainfall; but a 

 careful investigation showed no evidence to doubt the values computed for 

 Belle Yue Park and Gloneevin. The 28-inch line was pushed outside tlie 

 coast immediately south of the city in consideration of the values found 

 for Blackrock, Dundrum, Eathmines, and Terenure. The 30- and 32-inch 

 lines were easily determined by. the numerous records available. The 

 35-inch line presented two branches, one enclosing the high-lying land on 

 the north-west corner of the area ; the other branch encircling the mountain 

 system in the south from Carlow to Wicklow. This 35-inch line was brought 

 outside Bray Head in consideration of the height of the latter and the 

 elevations immediately inland. The 40-inch and 45-inoh lines were decided 

 by the records of Roundwood, Bray (Fassaroe), Enniskerry, and Glenas- 

 mole. The 50- and 60-inch lines were based on the records for Grienasmole 

 and Laragh (Glendalough). 



The following represents the areas included in the several zones of 

 rainfall : — 



square miles. 



Under 28 inches, . . . . . . 62-9 



Between 28 and 30 



Over 60 



151-0 

 530'4 

 876-3 

 431-5 

 342-6 

 143-0 

 97-8 

 144-0 



Total, 2779-5 



The rainfall of the area now treated in detail has been broadly repre- 

 sented in previous rainfall-maps of Ireland, to which reference must be 

 made. In 1868 Symons submitted a rainfall-map of the British Isles in his 

 evidence before the Commission on river-pollution.^ The map was based on 

 the short period, 1860-1865. In 1884,= and later in 1899,' Dr. A. Buchan 

 prepared a rainfall-map of Ireland, the former based on the period 1860- 

 1883, the latter on the period 1866-1890. The latest and most reliable 



' Sixth Eeport of Commission on River Pollution, 1868. 



'-' Joum. Scottish Meteor. Soc, Sri series, vol. vii., 188G, p. 131. 



^ Bartholomew's Physical Atlas, vol. iii.. Meteorology, 1899. 



