122 
Captain Kater on the best kind of steel 
The magnets joined, placed perpendicularly on the centre 
of the needle, as before, then moved in opposite directions 
from the centre to the extremities, keeping each magnet 
perpendicular to the needle ; afterwards joined at a dis- 
tance from the needle, placed again on its centre, and the 
operation thus continued. 
Experiment 27 . 
Directive 
force. 
Small parallelogram 
Large parallelogram 
993 
1155 
Remarking that the surface of the small parallelogram 
was unequal, so as to be touched by the magnet in very few 
places, I filed it flat, and having reduced the large parallelo- 
gram to the same weight, they were magnetized by joining 
the magnets, placing them perpendicularly on the centre of 
the needle, separating their lower extremities, and carrying 
them to each end of the needle, the upper ends remaining in 
contact. 
Experiment 28 . 
Directive 
force. 
Small parallelogram 
Large parallelogram - 
1025 
1 150 
The needles were next magnetized according to the me- 
thod of Du Hamel, the magnets being inclined at an angle 
