INTROIU'CTION. 



XVII 



autumn coincides most nearly with the mean for tin- y -ar ; in winter it docs not amount to hah' 

 so much, and differs most widely from the annual mean, whilst hoth MI miner and Hiring are in 

 excess in the order in which they are named. 



The following tables exhibit more in detail the facts thus announced : 



TAHLE I, 



Shotting tJte lour* of the day in the several months and seasons at which the declination magnet 



attains its easterly and westerly elongations. 



TABLE II, 



Showing the montJdy and quarterly means of the arc described by the declination magnet t between 



its easterly and westerly elongations. 



One scale division = 1'.00896. 



These results are inferred from the sum of the numbers in columns 4 and 8, less those of column 2. 



