134 TERRESTRIAL MAGNETISM. 



of hourly observation in the first-named portion of the year, 

 viz. from May to September, while the Sun is in the northern 

 signs, being the winter of the southern hemisphere, the 

 declination- needle points at 19h. furthest to the east of its 

 mean direction, and from that hour moves as it does in the 

 middle latitudes of Europe and North America towards the 

 west until 22h., and remains nearly stationary until 2h. 

 On the other hand, in the opposite portion of the year, from 

 October to February, the summer of the southern hemisphere, 

 when the Sun is in the southern signs, and theEarth is nearest 

 to the Sun, the needle points at 20h. most to the west, and 

 its movement from thence to noon is to the east, pre- 

 cisely in accordance with the type of Hobarton (in 42 53' 

 S. lat.) and other places in the middle latitudes of the 

 southern hemisphere. At the time of the equinoxes, or soon 

 after, in March and April, and in the latter portion of Sep- 

 tember, the march of the needle fluctuates on different days, 

 forming periods of transition from the type of the southern 

 to tliat of the northern, and from that of the northern to 

 that of the southern hemisphere. ( 165 ) 



Singapore is situated a little to the north of the geogra- 

 phical equator, between it and the magnetic equator, which 

 in this part of the earth is almost coincident, according to 

 Elliot, with the line of least force. According to the ob- 

 servations made every two hours at Singapore for the years 

 1841 and 1842, Sabine finds there the same opposite types 

 in the diurnal march of the needle from May to August, and 

 from November to February, as at St. Helena; and so also 

 at the Cape of Good Hope, although the latter station is 34 

 from the geographical equator, and doubtless still further 

 from the magnetical one (the magnetic dip at the Cape 



