17 6 Lieut. Foster’s observations on the diurnal changes 
the existence of that phenomenon, in the atmosphere, de- 
tected by the electrometer. 
Towards the end of May, however, I commenced another 
set of observations (at S. 85° W.), but the needle never be- 
came stationary throughout their continuance ; its north end 
sometimes proceeding towards the north, at others towards 
the south, during the time of westerly daily variation, and 
that occasionally the needle was observed to vibrate in small 
arcs, as already noticed at its other azimuthal positions. 
It will also be seen, on looking over the preceding obser- 
vations, that the times of maximum westerly, and easterly 
daily variation, by this needle, differ on many occasions very 
considerably from those by the suspended needle : this dif- 
ference it may be observed, arises from the circumstance of 
the observations on each needle not being made simultane- 
ously, as well as from the minuteness of some of the pheno- 
mena escaping observation by the suspended needle ; but 
which were elicited by this needle, proportionally to its re- 
duced directive force. Besides these observations on the 
daily changes of the horizontal needle, I also attempted a 
similar set on the dipping needle, but the difficulty of ad- 
justing the magnets was such, as to prevent me from obtain- 
ing any satisfactory results. 
Port Bowen, July 1st, 1825. 
from about N. E. to N.W. at an elevation of from 10 to zo degrees, with streamers 
sometimes shooting towards the zenith. At times when it was brightest, although 
not very brilliant during any part of the winter, I have frequently watched this 
needle, without ever being able to detect a change, that could be ascribed to its 
influence. 
