546 MR JOHN ALLAN BROUN ON THE HORIZONTAL FORCE 
the daily mean corresponding (for its middle point) to every hou from near 
noon on Monday till near noon on Saturday. Each week gives in this way 121 
daily means; but as the first observation on Monday morning at Hobarton is 14 
hours earlier than the first observation obtained at Toronto on the same morning, 
the whole 121 means have not simultaneous equivalents at all the stations. 
The daily means thus obtained for Makerstoun, Cape of Good Hope, Trevandrum, 
Singapore, Hobarton, and Toronto were corrected by a quantity depending on the 
differences of the weekly means, February 4-9 and March 3-8, for the secular 
increase or diminution. The corrected values are projected in Plate XXVIII. 
92. In these curves we may study the differences as well as agreements of 
movements. Some differences, it is believed, are due to accidental causes, as in 
the commencement of the week February 194-24°, at Trevandrum, where spiders 
were probably acting on the bifilar wires. In other cases we may suppose the 
differences due to different directions of movement of dip. 
93. In the first week, January 29 to February 3°, we find the apex about 
January 31°, 10°-14°, at all the stations excepting Hobarton, where this apex 
seems cut off. The turning point occurs at the Cape of Good Hope at 117; Tre- 
vandrum, 83"; Singapore, 10"; Toronto, 10°; at Makerstoun it is later, and is — 
followed by a higher point. 
94. In the following week we find the increase of force at Makerstoun at 
64 18" greater than at the other stations; the epochs of maximum and minimum 
are as follow :— 
TABLE XXVIII 

STATION. Maximum. Minimum, 
D HH. D. i. 
Trevandrum, 6 14 8 0 
Makerstoun, 6 18 7 20 
Cape, : “ ‘ : ; 6 20 7 20 
Toronto, 6 20 7 20 
Singapore, . Th 2-10 8 1 
Hobarton, is 2-6 8 3 

The order of succession of the maximum or of the minimum does not seem ~ 
to depend either on the latitude or longitude, though, on the whole, the pee 
farthest east are latest. 
95. In the third and fourth weeks we find the maxima and minima to be as j 
in the following table :— | 

