Lovering and Bond on Magnetic Observations at Cambridge. 51 
September 21-2. The sweep during this day was 45’.5. The 
disturbances on the days observed in this month have been already 
discussed at length. They were distinguished more by number 
than extent of arc. 
October. The October curves were not entirely free from dis- 
turbances though they are all comprehended, in their widest excur- 
sions, in a zone of 22’ in breadth. 
November. The three days of this month have some perturba- 
tions, but none deserving especial notice. 
December. Two of the curves observed in this month were dis- 
turbed considerably ; yet, the whole range does not surpass 28'.5. 
1841. 
January. The curves observed in this month were generally 
regular. On the 26th of January, between 4" and 5" A. M. Gott. 
M. T., a small disturbance was felt amounting to 17’. 
February. General perturbations spread over the three days of 
this month, particularly observed at night. Those of greatest extent 
occurred on the Term-day, February 26-7, amounting in one case 
to 16’ of arc in 15 minutes of time. In addition to these extracts 
from the records of the different months, Table II. contains a column 
showing the extremes of the Magnetometer every day when com- 
plete observations were made. 
The theory of the Aurora Borealis which has of late years found 
most favor with men of science supposes it to have some connex- 
ion with Electricity and Magnetism. It is important to investigate 
this subject further and see whether there be any and what relation 
between this brilliant appearance of the heavens and the derange- 
ments of the magnetic declination. For this purpose a careful 
record has been kept of all the Auroral appearances that have been 
