570 OBSERVATIONS ON THE BAROMETER, 
I have not seen any recent attempts to explain 
the great leading facts of the variation of the 
Barometer. A considerable interest has of late 
been shewn by some Meteorologists, to ascertain . 
the nature and magnitude of certain diurnal vari- 
ations or oscillations of the Barometer. These 
were first observed, and are still most conspicuous 
in the Torrid Zone, but they have been traced 
into the northern and southern parts of the globe, 
only they are less easily perceived, by reason of 
the other greater causes of variation in those 
parts. Mr. James D. Forbes, Professor of Natu- 
ral Philosophy in the University of Edinburgh, 
and Mr. Hudson, Assistant Secretary to the 
Royal Society, have distinguished themselves by 
making horary observations in reference to this 
subject. 
2. Or tHe THERMOMETER. 
Thermometers exposed to the weather are not 
so durable as Barometers, they are also more 
liable to accidents. My Thermometer has been 
renewed two or three times in the last 22 years; 
but care was taken to have it as correct as well 
could be. JI have not used a Thermometer for 
registering the maximum and minimum tempera- 
