22 THE ANTARCTIC MANUAL. 
observed by both the Unifilar Magnetometers and both Barrow’s Dip 
Circles ; firstly to connect Kew and Melbourne magnetically ; secondly 
to obtain fresh values of Constant A for the Dip Circles with the 
weights used at Simon’s Bay, and then with heavier weights suitable 
for measuring the largely increased forces predominant in the 
Southern regions after leaving Melbourne. (See Chart of Total Force 
supplied to the Expedition.) The value of the observations of 
Intensity in Antarctic regions with Lloyd’s needles is dependent upon 
the accuracy with which these base observations are made. 
Observations at the Antarctic Land Station. 
As soon as the Antarctic land station is selected and circum- 
stances permit, the Variometers should be mounted and brought into 
action and kept so during the sojourn of the landing party. 
It is expedient that the absolute determinations for zeros and 
scales values should be made once a week during the first month of 
the installation of the Variometers. 
Hourly observations of the three elements are required to be 
made on the following term days agreeably with international 
urangement, Greenwich mean time being adopted throughout. 
Commencing with 1st February, 1902, on the 15th February, and 
then on the 1st and 15th of every succeeding month ending on 15th 
February, 1903. Also observations for every 20 seconds from 10 a.m. 
to 11 a.m. G.M.T. on each of the above term days. Forms are sup- 
plied for registering the observations. 
The series of observations made at Melbourne should be repeated 
at this Antarctic station. Values of the Total Force with the 
Barrow’s Circle are expected to yield more reliable results here than 
those by the Unifilar magnetometer, owing to the low horizontal 
force prevailing and the liability of the horizontal needle to frequent 
and large disturbances. 
As complete a magnetic survey of the neighbourhood of this 
Southern base as possible should be made, and the magnetic ele- 
ments observed by sledging parties with the Fox circles and small 
azimuth compasses. 
Observations of the Absolute Horizontal Force, Absolute Dip, 
Total Force by Lloyd’s needles, and Absolute Declination should be 
made here once a month. Quiet days are recommended for this work. 
Observations on Board the Ship. 
Observation shows that a large-number of land stations are 
affected by local magnetic disturbance, and normal values are only 
