and form for a compass needle. 
121 
Experiment 24. 
Directive 
force. 
Small parallelogram 
Large parallelogram 
655 
6 7i 
The needles were again magnetized in the same manner 
as before, excepting that the magnets were separated at the 
top by a piece of wood of the same thickness as that at the 
bottom. 
Experiment 25. 
Directive 
force. 
Small parallelogram 
Large parallelogram - 
595 
58° 
The magnets were placed perpendicularly together on the 
centre of the needle, and then their lower extremities separated 
by a piece of wood to the distance of half the length of the 
needle, the upper extremities remaining in contact. They 
were then slid on the needle backwards and forwards from 
end to end, as before. 
Experiment 2 6. 
Directive 
force. 
Small parallelogram 
Large parallelogram 
760 
780 
mdcccxxi. 
R 
