MAGNETIC DECLINATION AT KEW AND NEKTSCHINSK. 
231 
has its counterpart in the correspondence shown by the term-observations at the different 
stations in Europe, is not found to prevail in anything like the same degree between the 
curves of the two continents when they are exhibited in comparison. Nevertheless indi- 
cations are not wanting of participation in disturbances having a common cause The 
character of the term-day, in respect to the degree of disturbance by which the mag- 
netometers are affected, may always be derived alike, whether we view the European or 
the American curves; and instances are not infrequent of individual perturbations 
common to both continents, having their culminating points at the same individual 
instant. There are sometimes disturbances in the same direction in both continents and 
sometimes in opposite directions. On the other hand, there are perturbations, and 
occasionally of considerable magnitude, on the one continent, of which no trace is 
visible in the observations on the other.” 
These facts were in full accordance with the conclusions which had been derived by 
the eminent geometrician of Gottingen from the observations of the Association formed 
under his auspices. They were further confirmed by a still more extensive and search- 
ing comparison, the means for which were furnished by a practice adopted at the British 
Colonial Magnetic Observatories shortly after their operations had commenced, of sum- 
moning the whole observing staff of the Observatory whenever in the course of the 
hourly observations of the magnetometers (maintained without intermission except on 
Sundays) they were perceived to be under the influence of an unusual disturbance ; and 
thus the movements of each of the magnetometers were recorded at as short intervals as 
circumstances would permit, until the disturbance appeared to have subsided. These 
records were received at the Headquarter Office at Woolwich from Toronto, St. Helena, 
the Cape of Good Hope, and Van Diemen Island, as well as from the Expedition 
employed under Sir James Boss in the Magnetic Survey of the Antarctic regions, when- 
ever the ships were sufficiently long in port to admit of the magnetometers being esta- 
blished and observed. The comparison of the records showed that magnetic disturb- 
ances prevailed, almost invariably, on the same days and at the same hours, in all these 
very various parts of the globe. The observations themselves were subsequently 
published in two parts; Part I. in 1843, containing the observations in 1840 and 1841, 
and Part II. in 1851, containing those in 1842, 1843, and 1844; together with the 
corresponding values of the declination and of the horizontal force in Part I., and of the 
declination, horizontal and vertical forces, and of their theoretical equivalents, the 
Inclination and the Total Force, in Part II. ; accompanied by the normal values of the 
elements at the different stations in the months in which the disturbances occurred, and 
their absolute values at each of the stations. Abundant evidence is to be found in these 
publications that fluctuations of the most marked character are strictly synchronous in 
the northern and southern hemispheres, as well as in Europe and America ; whilst at 
stations remote from each other the disturbance of the one element may differ widely 
in amount, and occasionally may be even reversed in direction. Not unfrequently also 
a disturbance showing itself at the same instant at distant stations is found to affect one 
