4 Mr Harvey on the Influeiuie qf Magnetism 
mean of four observations. In the following Table, they are 
more conveniently arranged for inspection : 
Situation or Chronometer (B). 
Daily Rates 
of first set of 
Experiments. 
Daily Rates of 
second set of 
Experiments. 
Detached, 
— . 2".0 
Fig. 1. Main-spring nearly in contact with 
the magnet, and the attractive power trans- 
mitted nearly through its centre, 
-h lO'^O 
+ 1FM 
Fig. 2. Centre of the main-spring removed 
90° from the preceding position, and the 
magnetic power transmitted nearly through 
the centre of the balance and its spring. 
+ 3M 
+ 3".4 
Fig. 3. Centre of the main-spring 180° from 
its first situation, and the magnetic power 
transmitted through its centre. 
+ 5" 0 
+ 7".0 
Fig. 4. Centre of the main-spring 90° from 
its first situation, and the magnetic power 
transmitted nearly through the centre of 
the balance and its spring. 
— I'M 
+ 1".4 
From the preceding observations, it may be inferred, that 
the rate of a chronometer receives a considerable acceleration, 
when the centre of the main-spring is in the axis of the magnet 
produced ; and that this acceleration attains a maximum, when 
the centre of the spring is at the least possible distance from the 
pole of the magnet, as denoted by Fig. 1. ; and the next infe- 
rior degree of acceleration, when the same point is again found 
in the direction of the magnetic axis, after turning the chrono- 
meter through an arc of 180 degrees, as in Fig. 8. The maxi- 
mum declension of rate was also observed to take place, when 
the radial line passing through the centre of the spring was at 
right angles to the magnetic axis, as in Fig. 2. ; the balance be- 
ing in this situation at its least distance from the pole, and the 
attractive power transmitted nearly through its centre. The 
minimum declension was likewise observed when the spring was 
placed as in Fig. 4., but the balance at its greatest distance from 
the same attractive pole, the magnetic power being directed 
nearly through its centre. An increase of rate resulted.^ there- 
fore^ from the direct transmission qf the magnetic infuence 
through the centre of the main spring ; and a diminution the re- 
