Proceedings of the British Association. 95 



phenomena, and referring them to their immediate points of depen- 

 dence. Those who witness their daily progress, with that interest 

 which a direct object in view inspires, have in .this respect an infinite 

 advantage over those who have to go over the same ground in the form 

 of a mass of dry figures. A thousand suggestions arise, a thousand 

 improvements occur — a spirit of interchange of ideas is generated, the 

 surrounding district is laid under contribution for the elucidation of 

 innumerable points, where a chain of corresponding observation is de- 

 sirable ; and what would otherwise be a scene of irksome routine, 

 becomes a school of physical science. It is needless to say how much 

 such a spirit must be excited by the institution of provincial and colonial 

 scientific societies, like that which I have just had occasion to mention. 

 Sea as well as land observations are, however, equally required for the 

 effectual working out of these great physical problems. A ship is 

 an itinerant observatory ; and, in spite of its instability, one which 

 enjoys several eminent advantages — in the uniform level and nature 

 of the surface, which eliminate a multitude of causes of disturbance 

 and uncertainty, to which land observations are liable. The exceeding 

 precision with which magnetic observations can be made at sea, has 

 been abundantly proved in the Antarctic Voyage of Sir James Ross, 

 by which an invaluable mass of data has been thus secured to science. 

 That voyage has also conferred another and most important accession 

 to our knowledge, in the striking discovery of a permanently low 

 barometric pressure in high south latitudes over the whole Antarctic 

 ocean — a pressure actually inferior by considerably more than an inch 

 of mercury, to what is found between the Tropics. A fact so novel 

 and remarkable will, of course, give rise to a variety of speculations as 

 to its cause ; and I anticipate one of the most interesting discussions 

 which have ever taken place in our Physical Section, should that great 

 circumnavigator favour us, I hope he will, with a viva voce account 

 of it. The voyage now happily commenced under the most favourable 

 auspicies for the further prosecution of our Arctic discoveries under Sir 

 John Franklin, will bring to the test of direct experiment a mode of 

 accounting for this extraordinary phenomenon thrown out by Colonel 

 Sabine, which, if realized, will necessitate a complete revision of our 

 whole system of barometric observation in high latitudes, and a total 

 reconstruction of all our knowledge of the laws of pressure in regions 



