338 
Mr. Christie's theory of the 
recorded after this hour until i h P. M. : for March, the first 
observation is at 9 h A. M. Even with instruments best 
adapted for the purpose, the time of maximum cannot be 
determined with great precision ; and although Lieutenant 
Hood possessed the requisites of zeal and ability, yet the in- 
struments that were made use of were not such as would 
have been employed, had not the nature of the expedition in 
which Captain Franklin was engaged, restricted him to 
carrying only those most essential. Much latitude, with 
respect to the time of maximum, must therefore, under 
these circumstances, be allowed ; and I think the time by 
experiment, io h A. M., is probably not far from the truth. 
The time of minimum east or maximum west appears by the 
table to be between 5 h P. M. and 6 h P. M. Lieutenant Hood 
states it at 3 h or 4 h P. M. ; but the mean of his observations 
certainly indicates that the time was later than 5 h P. M. 
Observations in London , variation 19 0 IV. The mean of 
Canton's observations for the months nearest the equinoxes, 
February, March, April, August, September, October, gives 
8 h 40™ P. M. as the time of minimum west in the evening : 
the experimental result is about n h P. M., making the dif- 
ference in the times considerable. In both cases, however, 
the course of the deviation is the same ; the needle deviating 
slightly towards the west during the night and early part of 
the morning ; then proceeding towards the east, and attaining 
the maximum east, or minimum west, at almost precisely the 
same time in the two cases : namely, 9 h A. M. in the one, 
and 8 h 53™ A. M. in the other. Canton’s observations give 
11' as the mean difference for these equinoctial months, be- 
tween the maximum west and morning minimum west, and 
