MAGNETIC OBSERVATIONS. 3 



The reductions and discussions in this report have been made by me, so that 

 I am personally responsible, not only for the general plan of the work, but for every 

 figure contained in it. All the results have been very carefully checked, and it is 

 hoped no material error will be found in them; still, absolute accuracy is scarcely 

 to be expected in any work involving so many figures, the more especially as 

 much of it has been done during moments snatched from other and more pressing 

 professional duties. 



The observations naturally divide themselves into three classes: 1st. Those 

 relating to astronomy. 2d. Those relating to terrestrial magnetism. 3d. Those 

 relating to the magnetism of the ship. As that is the order in which they must 

 necessarily be reduced, they will be so treated of in the subsequent sections of this 

 report. 



