94 Proceedings of the British Association, 



department. Under the head of occasional phenomena, storms, 

 magnetic disturbances, auroras, extraordinary tides, earthquake move- 

 ments, meteors, &c, would supply an ample field of observation — 

 while among the secular changes, indications of the varying level of 

 land and sea, would necessitate the establishment of permanent marks, 

 and the reference to them of the actual mean sea level which would 

 emerge from a series of tidal observations, carried round a complete 

 period of the moon's nodes with a certainty capable of detecting the 

 smallest changes. 



The abridgment of the merely mechanical work of such observa- 

 tories by self-registering apparatus, is a subject which cannot be 

 too strongly insisted on. Neither has the invention of instruments 

 for superseding the necessity of much arithmetical calculation by the 

 direct registry of total effects, received anything like the attention it 

 deserves. Considering the perfection to which mechanism has arriv- 

 ed in all its departments, these contrivances promise to become of 

 immense utility. The more the merely mechanical part of the 

 observer's duty can be alleviated, the more will he be enabled to 

 apply himself to the theory of his subject, and to perform what 

 I conceive ought to be regarded as the most important of all his 

 duties, and which in time will come to be universally so considered-^ 

 I mean the systematic deduction from the registered observations of 

 the mean values and local co-efficients of diurnal, menstrual, and 

 annual change. These deductions, in the case of permanent insti- 

 tutions, ought not, if possible, to be thrown upon the public, and their 

 effective execution would be the best and most honourable test of the 

 zeal and ability of their directors. 



Nothing damps the ardour of an observer like the absence of an 

 object appreciable and attainable by himself. One of my predecessors 

 in this chair has well remarked, that a man may as well keep a 

 register of his dreams as of the weather, or any other set of daily 

 phenomena, if the spirit of grouping, combining, and eliciting results 

 be absent. It can hardly be expected indeed, that, observers of facts 

 of this nature should themselves reason from them up to the highest 

 theories. For that their position unfits them, as they see but locally 

 and partially. But no other class of persons stands in anything like 

 so favourable a position for working out the first elementary laws of 



