ON THE METEOROLOGY OF IRELAND. 319 



phenomena of temperature, requisite for the determination of the 

 possible geographical limits of a single species of plants, is by no 

 means inconsiderable ;* and when to this we add the consideration 

 of the various other agencies which are at work in the atmosphere, all 

 influencing vegetable life, it is plain that we are not in a condition to 

 deduce any useful result connected with the distribution of species, 

 until we have mastered a much larger amount of theoretical know- 

 ledge than is usually brought to bear in such deductions. 



It would seem, therefore, to be the duty of the Government of 

 every civilized state to provide the statistical data which have so 

 many important bearings upon the material welfare of the people, 

 and in the form best fitted for their discussion and examination. 

 And to the lover of truth itself, for its own sake, the fulfilment of 

 this duty would, fortunately, supply the wants of science in the 

 most complete and satisfactory manner. 



In many countries, accordingly, provision has been made by 

 their respective Governments for the collection and discussion of 

 meteorological data upon a uniform and well-digested plan. The 

 Government of Prussia appears to have taken the lead in this im- 

 portant labour. Its example has been followed by those of Russia, 

 Austria, Bavaria, and Belgium ; and the names of Dove, Kupffer, 

 Kreil, Lamont, and Quetelet, to whom the superintendence of these 

 observations has been intrusted, afford the surest warrant of their 

 successful prosecution. f But perhaps the most important under- 

 taking of this nature is the recent organization of a system of 

 meteorological observations at sea by the Government of the 

 United States. There are, at the present time, nearly 1000 

 masters of ships, belonging to the navy and merchant services of 



* For each plant there is a lower limit of temperature, helow which it will cease to 

 vegetate; while, in order that it may blossom and bear fruit, it must receive, botwtvn 

 the two seasons of this minimum temperature, a certain amount of heat beyond this 

 limit which is constant for each species. It is upon this integral of effective heat, as has 

 been shown by De Candolle, that the existence of the species depends. For informa- 

 tion on this and other subjects connected with the applications of meteorology, see tin- 

 interesting introduction, by M. Martins, to the Annuaire Meteorologiqtie de la Frann: 



t The results of many of these series have been already published. Professor Dove 

 has published the results of the observations made in Prussia in the years 1848 ami 

 1849. The observations made at the Hn-<ian }>-> Tviitorirs h;iv- b.M-n pultlishrd from 

 time to time by M. Kupffer, in the Recuril <l> -K (t/wn-Hfinimfnit,;* il<, - 

 The results of the Bavarian observations have hrcu j, p ivm by Mr. L-miniit. in t!, 

 tnitt-n <t,'r Metcorofagir ; and those cf the IScl-ian s\ Mnn, in tlu- adiniial.lc .-rricsof papery 

 drawn up by M. Quctelct, Stir le Climat de Jicfy 



