ON MAGNETIC DISTURBANCES AT TORONTO. 161 
VIII., page 14 of vol. 3rd, Toronto Observations, we find that the 
ratios at 9 a. m. and 10 a, m. are 0°94 -and’ 1°46, so that the discre- 
pancy amounts simply to a transfer of the passage through unity from 
about 9 a. m. to 8 a. m. : 
In table II., giving the annual distribution of the disturbances, 
while there is a general resemblance in the ratios of the two series, the 
maxima and minima, in the more recent series, are less distinctly de- 
veloped, owing in some measure to the fact that they embrace only 
the disturbances at six hours, instead of at each of the twenty four 
hours, and are therefore differently affected by the disturbance diur- 
nal variation. 
Other points of difference in the two series are the following: 
(1,) In five instances the September maximum is transferred to 
October. 
(2,) In nearly every case the April maximum occurs in March, 
and in the general disturbances of declination, and in those of westerly 
disturbance the ratio is less than unity. 
(3) In every case there is an abrupt decrease in the Novem- 
ber disturbances with a subsequent increase in December. 
_ The generality of these points of difference, as far as they extend, 
will be better seen by comparing the means of the ratios, for the decli- 
nation, horizontal force and vertical force, as given in the following 
table. 
—— 
Seule ( 5 : 
b| oR BT ey pas deel ae 
Sle Wel at | ee es a/e|2/8)8 
Se eee eagle | Sees i iieanmD 
Sle lela /aealinA tal atanlojljasa 
1844—1848 Geer leuceidl alga lta ulaicnglomaelo re otoaltieal Geen nee ane 
1856—1862 Med TNR ec aE ey 
In the following table is shewn the comparative prevalence of 
easterly and westerly disturbances of declination in the different months, 
The ratios indicating the preponderance of easterly and westerly dis- 
turbances reach a maximum in June, a minimum in December, a 
second maximum in March, with a secoad minimum in April. 
Vou. VIII. N 
