BappickER— On the Influence of Magnetism on the Rate of a Chronometer. 25 
chronometer A, and two box-chronometers, B and C. The rates of these time-pieces 
were observed in four different positions, which are represented in figures 1 to 4, 
Plate I. His description of these positions is :— 
Fig. 1. Main-spring (S) nearly in contact with the magnet and the attractive 
power transmitted through its centre. 
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 (B) and 
its spring. Balance at the least distance from the pole. 
Fig. 3. Centre of the main-spring 180° from its first situation, and the magnetic 
power transmitted through its centre. 
Fig. 4. As under fig. 2, balance at the greatest distance from the pole. 
Chronometer A was thus exposed to the north pole only, while B and C were 
also brought under the influence of the south-pole. This was so arranged, that 
while B was exposed to the south pole, C stood at the same time before the north 
pole of the same magnet. Besides these experiments, A was observed also in the 
positions figs. 5 to 8, where the balance (instead of the main-spring) is brought into 
four different positions relative to the magnet. The time of exposure was four 
days in each situation. I reproduce the observed changes of rate as briefly as 
possible. 
Situation of A. Rate. | Situation of A. Rate. 
| 
Detached. + 204 Detached. + 20°1 
Big. 1* + 68:9 Fig. 5.* + 50°8 
shee — 23 -2 EG: + 29+1 
ot ios + 43°4 rs + 383°7 
Bau ike -— 26 a th + 18°5 
* The values under figs. 1 and 5 are means of two observations, made respectively before and after 
figs. 2 and 4 and figs. 6 and 8, namely— 
+ 68-9 = 4 (+ 65:1 +727) fig. 1. 
+ 50°8 = 4 (+ 52:3 + 49°8) fig. 5. 
(There is on page 5 the misprint 52°3, instead of the second number 49:3.) 
TRANS. ROY. DUB. 8OC., N.S. VOL. III. E 
