393 
During the last ten years there have been only twenty-three days on 
which the rain-fall has exceeded one inch, and only thirty-three days on 
which it has exceeded seven-tenths of an inch. The heaviest rain-fall, 
amounting to 1°78 inch, occurred on the 1st of April, 1853. The two 
wettest consecutive days were 27th and 28th of September, 1856, on 
which 2°72 inches of rain fell; 1°31 inches on the 27th; and 1°41 inches 
on the 28th. 
‘ Plate I. represents the rain-fall for twenty years, from 1841-1860; 
the ordinates which represent the depths of rain are drawn to a scale of 
one-tenth. : 
Plate IL. represents Kirwan’s observations on the rain-fallin Dublin, 
as observed at his house in Cavendish-row, from 1792-1808. These 
observations are to be found in volumes v., Vi., Vii., Viii., and x. of the 
Transactions of the Academy. There seems to be no record of the year 
1793. 
The rain-gauge of the Magnetic Observatory is circular, having an 
orifice of 12 inches, and is placed on the flat roof of the Observatory, 
which is 17 feet above the level of the ground. 
Tass I. 
Rain-fall for ten years, 1851-1860. 
- 
Years.| Jan. | Feb. | Mar.| Apr. | May. |June.| July.) Aug. | Sepf.| Oct. | Nov.| Dec.| Total. 
1851 |5°28| 0°49 |2°38|1°77/ 1°31] 2°71| 3:48] 2-01/1°81/3°27| 1°01) 0°88} 26°40 
1852 |3°20] 2°72 10°61] 1:28] 2°35! 7:09 |1°96|3'27 | 2°69 | 3:46] 7°43 /4°10| 40°16 
1853 |2°75|2°16/1°63 | 3°81] 1°04) 1°91] 2°73] 1-93 | 2°39 | 4°32/1°69 | 2°60) 28°96 
1854 |3-83| 0:75 10°67] 0-40 | 2°43|3-93|2:29| 1°24] 0°91) 1-64| 3-15 | 2-60| 23°84 
1855 | 1:24] 2°83}1°50)0°59/|1°74|1:92| 3-68) 2°74) 1°34/ 4°83) 1°41)1°65} 25°47 
1856 |2°64] 1:93 |0°77| 1°58 | 5-49 | 2-40) 1°41 | 2-60/3°88/2°03| 0°65) 2°55] 27:93 
1857 |2°66] 1°30 /3°13| 3-96 | 1°48]3-28) 1-65) 1°20/1°57/2°65| 1:79 | 0°44] 25°11 
1858 | 1-04] 1°03 /1-14| 5°08 | 1:°64]1°37)| 3°34| 1-66 |3:02|3-°31|1°38/3-06| 27:07 
1859 | 1-43] 1:00}2°59| 3-99 | 0-68) 1:24)1°35) 1°92|3°01/1°62|3:24)3-21) 25°28 
1860 | 4-15] 0°84|2°57| 2°62 |3°12|4°59/ 2°43) 4°75 | 2°65|2:27|2°90/3'17| 36:06 
Mean |2°82] 1°50) 1-70) 2°5i | 2°13) 3-04 | 2°43 | 2:33 | 2°33) 2°94|2°46/2-43/ 28°63 
TaBLeE II. 
Monthly rain-falis from 1841-1850, compared with those from 1851-1860. 
Mean Value. | Jan.| Feb. | Mar.} Apr. | May. une July.| Aug. | Sept.| Oct. | Nov.] Dec.| Total 
1841-1850 |2°64| 1°86} 1°90) 2°58|2°11/2°16)] 2°34) 2°74 | 2°33 | 3°35 |3°03/2°38| 29°42 
1851-1860 |2°82/1°50)1°70)2°51)2°13|3°04| 2°43 | 2°33 |2°33|2-94 | 2°46/ 2-43] 28-62 
1841-1860 | 2°73) 1°68) 1°80 | 2°54) 2°12 |2°60/2°39 2°54|2°32/3°15|2°7512-40| 29-02 
Mean rain-fall for twenty years (1841-1860) = 29°02 inches. 
R. I. A. PROC.—YVOL. VII. 3K 
