133 
the quality of the enquiries made in meteorological establish- 
ments. 
Mr. Baxendell stated in reference to Dr. Joule’s observa- 
tion, that on the same evening he had observed a very fine 
auroral arch, which at 8h. 20m., G. M. T., passed over e 
Bootis, a Ursse majoris, Capella, and a point midway 
between the Pleiades and e Tauri. There was at the same 
time a considerable segment of bright auroral light in the 
northern part of the heavens. No streamers were visible. 
About twenty minutes later it was noticed that the position 
of the arch had changed, the western portion having moved 
very sensibly in a southerly and the eastern portion in a 
northerly direction. This change of position was probably 
connected with the remarkable disturbance of the magnetic 
needle noticed by. Dr. Joule. The western portion of the 
arch was brighter than the eastern, and was estimated to be 
from ten to twelve times brighter than the milky way in 
Cepheus and Cassiopeia. 
Mr. Baxendell also stated that the Society had in its 
possession a thermometer constructed by the late Dr. Dalton, 
and which, it is believed, was used by him in many of his 
meteorological observations. The scale has the initials J.D. 
and the year 1823 engraved upon it ; and the freezing and 
boiling points of water are indicated on the stem by fine file 
marks. As it is known that the zero points of thermometers 
sometimes change to the extent of one or even two degrees in 
the course of several years, it occurred to Mr. Baxendell 
that it would be interesting to ascertain whether any change 
had taken place in this thermometer, and he had therefore 
lately tested very carefully the position of the freezing point, 
but found that no sensible alteration had taken place ; and 
he believed therefore that great confidence might be placed 
in the observations which Dalton had made with this instru- 
ment. 
