92 REPORT—1846. 
On the Calculation of the Gaussian Constants for 1829. By A. ERMAN. 
As purely theoretical speculations on natural phenomena remain highly 
unsatisfactory until they can be founded on a sufficient number of observa- 
tions, in the same manner collections of the most careful observations must 
be almost useless before they are thoroughly elaborated according to a given 
theory. Nay, the accumulation of observed numbers, notwithstanding the 
value they possess when viewed by themselves, may even become injurious 
to science, by retarding its progress. Indeed the aspect of progressively in- 
creasing, but not duly elaborated, materials, must at last give rise to the ap- 
prehension, both on the part of those engaged in furnishing them, and of 
every one interested in the results to be gathered from them, that the means 
may be wanting to bring such a stock of matter to bear for their proper 
purpose. The loss of the whole, that is to say, of data which have not been 
acquired without the exertion of considerable scientific labour, and which 
seemed pregnant with beautiful germs, would then be a most discouraging 
consequence. 
The British Association for the Advancement of Science has many times 
proved itself convinced of the truth of this principle. A resolution adopted by 
the Association in 1833, during its first meeting at Cambridge, warded off the 
peril just mentioned, even from a department of science whose long-established 
rate of progress had not been able to protect it sufficiently against such a 
risk. The reduction of the Greenwich observations of planets, undertaken in 
consequence of this resolution, and now published by order of the Lords 
Commissioners of the Admiralty, has been fully appreciated by all astrono- 
mers, and particularly by the late M. Bessél, who in the last moments of his 
life welcomed it as the beginning of a new period in astronomy. Moreover, 
the condition that a uniform progress of observation and calculation is equally 
indispensable in less-developed or only nascent branches of physical science, 
has been expressed by the British Association at its second meeting at 
Cambridge in 1845; first, by several of the members being inclined to 
raise the question, whether the continuation of magnetic and meteorological 
observations were desirable, as long as a great part of the materials collected 
by them are still waiting their first employment ; and, secondly, by including 
the calculation of the Gaussian constants of terrestrial magnetism for 1829 
within the sphere of their own operations, being pleased at the same time to 
entrust me with the superintendence of the same, and to place at my disposal 
the sum of £50, granted for this purpose for the year 1845 to 1846. I shall 
endeavour to point out in a few words the fruits this arrangement seems to 
promise, and the results it has already obtained. 
I think we are authorised to suppose that all those phenomena which we 
have learned to express by numbers, with the help of remarkably accurate 
instruments, will at length lead us to a theory of the forces which produce 
them ; and that, in consequence, the intriusic value of observations on such 
phenomena—a value which hitherto could not be demonstrated—will then 
at once become most evident. It was this expectation alone which often 
encouraged observers to persevere in labours apparently rather tedious, and 
the zeal with which the meteorological and part of the magnetic variations 
are pursued by your members in British and colonial observatories, is, I think, 
attributable to the same cause. In the branches of physics which they cul- 
tivate, these observers, it is true, have still to look to futurity for both kinds 
of progress, viz. the discovery of an abstract theory, and the true establishment 
of the same by means of observed numbers. As to the first and most import- 
