.\ ADDRESS. XXXV- 
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 di- 
urnal, menstrual, and annual change. These deductions, in the case of per- 
manent institutions, 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 pheenomena, 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 pheno- 
mena, and referring them to their immediate points of dependence. 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 thou- 
sand suggestions arise, a thousand improvements occur-s-a spirit of inter- 
change of ideas is generated, the surrounding district is laid under contribu- 
tion for the elucidation of innumerable points, where a chain of corre- 
sponding observation is desirable ; 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 men- 
tion. 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 observa- 
tions 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 ac- 
cession 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 cireumnavigator favour us, as I hope he 
will, with a vivdé voce account of it. The voyage now happily commenced 
under the most favourable auspices 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 recon- 
struction of all our knowledge of the laws of pressure in regions where ex- 
cessive cold prevails. This, with the magnetic survey of the Arctic seas, and 
the not improbable solution of the great geographical problem which forms 
the chief: object of the expedition, will furnish a sufficient answer to those, 
ifany there be, who regard such voyages as useless. Let us hope and pray, 
that it may please Providence to shield him and his brave companions from 
