326 



NOTE. 



The readings of the magnetic instruments where given here, are in scale divisions, the values of one scale division in 

 absolute measure (C.G.S. units) being : — 



H.F. -000019 D. I'-O V.F. -00000574, 



increasing numbers denoting increase of force and of easterly declination. These are easily reduced to absolute values 

 by means of the above scale values, and the tables of hourly magnetic observations. For the values there given 

 correspond, at any hour of local mean time to the reading given here (or when three readings are given, to their mean) 

 and from the nearest hourly observations the value of any intermediate observation can be deduced. 



When three readings of the same instrument are recorded ojiposite any hour, the middle reading was taken at that 

 hour, the others at 2 minutes before and after respectively. 



