1 REPORT—1852. 
lated a mass of observations, which, as the fruit of systematic and concerted 
labour, is, I believe, wholly unprecedented. The labour of digesting, com- 
paring, and coordinating the body of facts thus obtained may certainly be 
stated to be not less than that expended in obtaining them; and as the one 
process must necessarily be in great measure carried out subsequently to the 
other, we are only now beginning to reap the first-fruits of this great co- 
operative undertaking in the bearing of its results upon theory, At the 
Ipswich meeting of the British Association, I was requested by the General 
Committee to draw up a report on the state and progress of the magnetic 
researches consequent on the application of the British Association to Her 
Majesty’s Government in 1838. I regret that, from the other very pressing 
duties above alluded to, I have not been able to complete this report in time 
to present at this meeting, but as I may assume, from the request just made 
to me, that the subject retains with the British Association the interest which 
it there so happily acquired, I may venture to avail myself of this opportunity 
to make a very few remarks on some of its most important results; confining 
myself for the most part to results obtained by persons of our own country 
as the direct and immediate consequences of the recommendation of the 
British Association, leaving to a more fitting occasion a more general and 
comprehensive view. 
We recognise in terrestrial magnetism the existence of a power present 
everywhere at the surface of our globe, and producing everywhere effects 
indicative of a systematic action ; but of the nature of this power, the cha- 
racter of its laws, and its economy in creation, we have as yet scarcely any 
knowledge. The apparent complexity of the phenomena at their first aspect 
may reasonably be ascribed to our ignorance of their laws, which we shall 
doubtless find, as we advance in knowledge, to possess the same remarkable 
character of simplicity which calls forth our admiration in the laws of mole- 
cular attraction. It has been frequently surmised, and the anticipation is I 
believe a strictly philosophical one, that a power which, so far as we have the 
means of judging, prevails everywhere in our own planet, may also prevail 
in other bodies of our system, and might. become sensible to us, in the case 
of the sun and moon particularly, by small perturbing influences mea- 
surable by our instruments, and indicating their respective sources by their 
periods and their epochs, As yet we know of neither argument nor fact to 
invalidate this anticipation; but, on the contrary, much to invest it with 
a high degree of probability. Be this however as it may, we have in our 
own planet an exemplification of the phenomena which magnetism pre- 
sents in one of the bodies of our system, on a scale of sufficient mag- 
nitude, and otherwise convenient for our study. Accordingly the first 
object to which the British Association gave its attention was to ob- 
tain a correct knowledge of the direction and amount of the magnetic 
force generally over the whole surface of the globe corresponding to a 
definite epoch. It has been customary to represent the results of magnetic 

