234 
MAJOR-GENERAL SABINE ON THE DISTURBANCES OF THE 
And here it becomes proper to recall the instructions regarding the casual and trans- 
itory variations contained in the Report of the Royal Society referred to in page 230, 
in which we find this conclusion to have been in great measure anticipated, — the 
importance of treating the laws and mutual relations of the disturbances as a distinct 
subject of investigation clearly recognized, — and the probable results of such investi- 
gation not obscurely indicated. In pages 2 and 3 of that Report it is stated that “ the 
investigation of the laws, extent, and mutual relations of the casual and transitory 
variations is become essential to the successful prosecution of magnetic discovery 
because the theory of those transitory changes is in itself one of the most interesting 
and important points to which the attention of magnetic observers can be turned, as 
they are no doubt intimately connected with the general causes of terrestrial magnetism , 
and will probably lead us to a much more perfect knowledge of those causes than we 
now possess” In the opinion thus expressed, being myself one of the Committee by 
whom the Report was drawn up, I fully concurred ; and having been appointed by 
Her Majesty’s Government to superintend the observations made at the British Colo- 
nial Observatories, and to coordinate and publish the results, it is alike my duty and my 
desire to show that the methods pursued have been in strict conformity with the spirit 
of those instructions, whilst the conclusions derived will be seen to be in full accord- 
ance with the anticipations expressed therein*. 
* The importance which M. Gauss attached to the further and full investigation of the magnetic disturb- 
ances was not less than that expressed in the Report of the Royal Society. Having had occasion, at the request 
of the President and Council of the Royal Society, to visit Berlin and Gottingen in conjunction with Dr. Lloyd 
in the autumn of 1839, when the British Colonial Observatories were in contemplation, I transcribe the following 
notice of M. Gauss’s opinions from a copy which I have retained of a letter to Baron Alexandek von Humboldt, 
written from Elberfeld on the 24th of October 1839, since it is more to the purpose than anything which I could 
now write from recollection : — “ The conferences with M. Gauss did not close till late on Monday night : we left 
Gottingen early on Tuesday morning, and this is our first stoppage. "We found M. Gauss’s attention resting prin- 
cipally on that part of our proposed system of observation which is directed to the determination of the laws of 
the periodical fluctuations, and of the mode of action of the causes which produce them. Fully satisfied with the 
hourly observations as an almost certain means of attaining these objects, he was only desirous, for the full solution 
of the problem, that the number of stations should he increased so as to comprise the greatest practicable extent 
of latitude ; care being also taken that there should he one or two parallels in which there should be stations in 
meridians widely apart. The relative importance of different localities in reference to the secular changes does 
not yet appear to have received M. Gauss’s attention. The hearing of the stations on the periodical fluctua- 
tions was the chief and almost the only consideration on which he dwelt. We may hope that, in respect to the 
secular changes, the results obtained at the nineteen contemplated stations, so extensively distributed on the 
surface of the globe, will at least serve to test the validity of physical theories, though they may not include 
those points which a more advanced knowledge might indicate as most suitable for suggesting the true theory. 
Barnaoul and Yakutsk appear well situated to throw light on the easterly progression of the maximum of force 
in the Siberian quarter, which is by some believed to he more rapid than the progression, also easterly, of the 
maximum in the American quarter ; forming in their combined effect a double system of translation in the lines 
to which the changes of Declination and Inclination in the northern hemisphere, ever since they were observed, 
appear to have been conformable. Our solicitude was strongly expressed to learn from M. Gauss if there were 
any stations, exclusive of those chosen for the fixed observatories, at which a new determination of the three 
