6 Beppicker—On the Influence of Magnetism on the Rate of a Chronometer. 
No. 1. No. 2. No. 3. Observations. 
me 48-5 a 0:9 
5-1 aay a) OP ateiasg At the Royal 
-4:4 -0°9 -3°9 Observatory, 
-4°1 -1-4 = ahoil 
J 
. ) 
-1-4 +2°6 -6:1 
Elsewhere, 
-1-4 +2°8 -6°6 
immediately after 
= 0:9 + 3:0 -7°6 
removal, 
-0°9 +3.1 — 
J 
which, certainly, show a marked and considerable difference. In Robert Fitz Roy’s 
narrative (No. 20) I find the remark that five of the chronometers of H. M.S. 
‘* Adventure” accelerated, and the other four retarded, upon being brought on 
board. Captain King adds—‘ It would be difficult to assign any other reason for 
this change than the effect of the ship’s local attraction.” FitzRoy, however, 
considers the temperature the chief, if not, ‘‘ generally speaking,” the only reason 
for ‘‘marked” changes of rate. ‘It often happens,” he says (p. 326), ‘ that the 
air in port or near land is at a temperature very different from that over the 
open sea in the vicinity, and hence the difference sometimes found between 
harbour and. sea-rates. The changes so frequently noticed to take place in the 
rates of chronometers moved from the shore to the ship, and the reverse, are well 
known to be caused partly by change of temperature and partly by change of 
situation.” To this we give his annotation + ‘‘This may be connected with 
magnetism.” 
Finally, there remains a pamphlet of M. Lesquen de la Ménardais, which, 
however, I know only from the criticism of it by E. Mouchez (No. 24) and Ansart- 
Deusy (No. 25). Lesquen thinks he is able to base upon his observations made 
at the Toulon observatory the following law:—‘‘ Les montres marines en marche 
retardent par un mouvement de translation ou tout autre equivalent, tandis le repos 
prolongé leur donne une tendence 4 l’avance d’autant plus marquée que ce retard 
a été plus fort.” The facts from which this law is deduced are obtained by seven 
years’ observations, which show, (1) that some hundreds of chronometers, when 
transported from Paris to Toulon (and the reverse), neither advanced nor retarded ; 
(2) that some hundreds, when transported from Toulon on board the ships, lost, on 
the average, 0°:5 daily ; (3) that some hundreds, transported from the ships to the 
Observatory, gained, on the average, 0°°5 daily. Mouchez considers it too early 
