Proceedings of the British Association. 289 



ously the effects of disturbing causes, that the localities in which they 

 originate may be determined : these are very remarkable conclusions, 

 and well calculated to show the advantages of combined observa- 

 tions ; for such inquiries, observations in a single and independent 

 locality, however carefully they may be made, are absolutely value- 

 less. 



The meteorological observations are made, in all these observato- 

 ries, on the same system, and with equal care with those of magnet- 

 ism ; they embrace the mean quantities, diurnal and annual variations 

 of the temperature, pressure of the atmosphere, tension of the aque- 

 ous vapour, the direction and force of the wind, with every extraor- 

 dinary departure from the normal condition of these elements, as 

 well as auroral and other phenomena. It would be premature to 

 speak of the conclusions which are likely to be deduced from these 

 observations, inasmuch as the reduction and comparison of them 

 have hitherto made little progress, but they cannot fail to be highly 

 important ; for it is by the comparison of observations such as these, 

 made with reference to a definite system, with instruments construct- 

 ed upon a common principle, and carefully compared with each 

 other, and by such means alone, that the science of meteorology can 

 be not only advanced but founded. Our philosophical records have 

 for the last century been deluged with meteorological observations ; 

 but they have been made with instruments adapted to no common 

 principle, compared with no common standard, having reference to 

 no station but their own, and even, with respect to it, possessing no 

 sufficient continuity and system ; they have been for the most part 

 desultory, independent, and consequently worthless. It would be 

 unjust to the merits of one of the most assiduous and useful of our 

 members, Mr. Snow Harris, if I did not call your attention, in con- 

 nexion with this subject, to his Reports, included in the reports of 

 our twelfth meeting, [Athen. No. 769, see also No. 827,] on the 

 meteorological observations at Plymouth, made by him or under his 

 superintendence, with the aid of a very moderate expenditure of the 

 funds of the Association. They comprehend observations of the 

 thermometer, at every hour of the day and night, during ten years, 

 and of the barometer and anemometer, during five years, carefully 

 reduced and tabulated, and their mean results cynographed or pro- 



