426 



The Rev. H. Llotd on the Meteorology of Ireland. 



arithmetical means of the latitudes and longitudes of the stations of observa- 

 tion. The resulting equations are thus reduced to the following: — 



nT='S,{t), 

 6'2 (a--) + FS (xy) = 2 (xt), 

 U^{xy)+Vli{y-) =^{yt). 



For the reason already stated, I shall employ in this calculation only the 

 results obtained at the coast stations. These are, in the order of latitude, 

 Portrush, Buncrana, Donaghadee, Killybegs, Killough, Westport, Dublin, 

 Courtown, Kih'ush,Dunmore, Cahirciveen, Castletownsend. Tlie mean latitude 

 and longitude of these stations are 53°29', and 7"39' respectively. And we find 



2 {x"") = 39094, 2 {xy) = - 22569, 2 (/) = 65811. 



Substituting and eliminating between the second and third equations, we 

 obtain — 



U = '0000319 2 (,rt) + ^0000109 2 (yt) ; 



F= -0000109 2 (xt) + ■0000189 2 (yf). 



By these formulis the values of T, U, and T^, for each month are calculated. 

 They are given in the following Table : — 



Table VI. Elements of Monthly Isothermal Lines. 



