348 



Anniversary Meeting, 



[Nov. 30, 



to the elucidation of the many unsolved problems which have so long 

 fettered the investigation of the laws of climate. 



It will not be thought out of place here if I add a few remarks on the 

 present state of Meteorology as one of the phj^sical sciences, the progress 

 it has really made, and the direction in which further progTess is attain- 

 able. In this I have been aided by General Strachey, a late member 

 of the Treasury Committee, who, having studied meteorology in India as 

 well as in Europe, has kindly drawn up a statement of our views, and 

 placed it at my service for this Address. 



Without question, the chief point in which meteorology now differs 

 from what it was, is the recognition of the necessity for taking into con- 

 sideration the facts observed at many places simultaneously over a large 

 area, instead of facts observed in succession at a single locality. This 

 great step has been no doubt mainly due to the extension of the electric 

 telegraph, which renders possible the rapid juxtaposition of observations 

 made over a very large area, and the equally rapid dispatch to great dis- 

 tances of the results derived from the consideration of such observa- 

 tions, thus furnishing the means both of acquiring the knowledge and of 

 making it practically useful. A comparison of the first feeble eJfforts to 

 appreciate the nature of the fluctuations of barometric pressure recorded 

 in the Reports of the Eritish Association for the years following 1843, and 

 chiefly due to Mr. Birt, and the beautiful synoptical charts now published 

 in many countries, of which those prepared by Captain Hoffmeyer may 

 be taken as an example, will indicate the great progress made in this 

 direction. Charts such as these convey very complete information as to 

 how the chief variations of weather occur over the greater part of 

 Europe and the United States — though why they occur is yet too little 

 understood. It is, unfortunately, still true that very httle has been 

 done towards tracing out the physical causes of the changes of pressure 

 of the occurrence of which we are thus made aware ; but it is not to be 

 doubted that, the facts being now presented to students in a readily 

 accessible and intelligible shape, no great interval is likely to elapse be- 

 fore the causes that produce them are ascertained, at all events 

 approximately. 



It is practically certain that the changes of atmospheric pressure are 

 immediately dependent on changes of temperature ; but no intelligible 

 relation has yet been established between the two, except in the very 

 vaguest manner. And this indicates the first great want of scientific 

 meteorology — namely, an improved theoretical knowledge of the move- 

 ments of elastic fluids subject to changes of temperature. The difficulties 

 to be surmounted in this branch of mechanics are great ; but probably the 

 means may be attained of subjecting the hypotheses that will eventually 

 form the basis of scientific meteorology to the rigorous test of mathema- 

 tical calculation, though hardly the first step has yet been taken in that 

 direction. 



