MATERIALS EXISTING IN WATER. 39 



try has become proverbial, and exercises considerable influence 

 upon its agricultural character. From the observations which 

 have already been made, it appears, as might be expected, that 

 the quantity of rain that annually falls in this country on the 

 west and south-west coast, considerably exceeds that which 

 has been observed at Dublin, Belfast, and several places on 

 the eastern shores. It has been estimated that the total 

 amount of rain which falls over the entire surface of the island 

 would, if collected, cover it to the depth of 36 inches ; and 

 that, of this water, not more than 12 inches annually reach 

 the sea. The number of days upon which rain falls in 

 Ireland is greater than in England or on the continent; 

 thus, it is stated that on an average we have only 150 

 days yearly on which no rain falls. The constant evapora- 

 tion of so large an amount of water from the surface of the 

 island must exercise an unfavourable influence upon its tem- 

 perature; for, to convert water into steam, to make it eva- 

 porate, a certain amount of heat is consumed. When we dip 

 our hands in water on a hot day, and wave them through 

 the ah-, they are rendered cool by the ' loss of the heat 

 required to convert the water into vapour. Upon the same 

 principle, the surgeon directs the patient to cover an inflamed 

 part with pieces of linen dipped in water, or in mixtures 

 which evaporate with gi-eater rapidity. It is in the same 

 way that our undrained fields are rendered cold, and the har- 

 vests in several districts delayed by the excessive moisture 

 of the soil ; the rays of the sun which should ripen the crop 

 being expended in converting the surface water into vapour.* 

 The thermometer, or measurer of heat, employed by the 

 chemist shows a difierence of several degrees between the 



• The difficulty of drying agricultural produce was noticed a good 

 many years ago by the celebrated Arthur Young. Fanners, however, 

 in England have but little idea how much farm-work is influenced by 

 our humid and variable climate. As an instance of tliis, we find it 

 stated in the Farmer's Gazette, that while on the east coast of Ireland, 

 in the neighbourhood of Dublin, the dew has dried up so that the hay- 

 maker can commence his work in the morning at seven or eight o'clock, 

 and keep the hay opened out witliout danger of injury from the even*;^ 

 ing's dew till six in the evening; on the west coast washed by the' 

 Atlantic ocean, in Kerry and Cork, he considers himself fortunate 

 if he can commence work in the hay-making season at nine A.iM. and is 

 obliged to gather the hay at four in the afternoon to protect it from the 

 heavy dews or " sea -fogs." 



