630 



posed originating locality, modified (it may be) by a more or less 

 rapid transmission of the disturbance. It will be understood, that 

 in this hypothetical suggestion, the purpose in view is to aid the 

 imagination, if it may be so, in apprehending the ensemble of the 

 phenomena as far as they are yet known to us, rather than to ad- 

 vance a theoretical explanation, when we have not yet sufficient facts 

 before us by which it may be judged ; it may be remarked, however, 

 that the conception of a double locality of origination of the disturb- 

 ances (easterly and westerly) in the one hemisphere will present no 

 especial difficulty to those who are conversant with the general facts 

 of terrestrial magnetism. 



If our attention be limited to the consideration of the facts observed 

 at a single station, unaccompanied by a view of corresponding pheno- 

 mena elsewhere, we might be in danger of regarding some of the 

 features, particularly perhaps those which are not the most pro- 

 minent, as having an accidental rather than a systematic origin ; 

 and we might thus lose a portion of the instruction which they 

 may otherwise convey. On this account it has appeared desirable 

 to exhibit the phenomena as observed at a second station, in com- 

 parison with those at Kew ; and I have selected for this purpose the 

 results of a similar investigation to the present at Hobarton in 

 Tasmania ; not only because the facts have been remarkably well 

 determined there, but also because, though it is a very distant station, 

 differing widely in geographical latitude and longitude, and situated 

 indeed in a different hemisphere, there is a striking resemblance 

 in the laws of the magnetic storms experienced at both. This resem- 

 blance, which is not only general, but extends to very minute par- 

 ticulars, is such that it seems impossible to resist the impression that 

 the accordance cannot be accidental ; and that the methods of obser- 

 vation and of analysis which have been pursued, have proved themselves 

 well adapted to open to us the knowledge of the existence of system- 

 atic laws, pervading and regulating the action of the forces which 

 are in daily operation around us, and are at least co-extensive with 

 the limits of our globe ; and thus to lead us ultimately to the correct 

 theory of these forces. I have placed therefore beside each other in 

 the next Table the Ratios of Disturbance at the different hours of local 

 solar time at each of the two stations, separating them as before 

 into westerly and easterly deflections, and placing the westerly deflec- 



