264 SIEGE OF THE SOUTH POLE 
portant problem of deep-sea sounding was approaching 
a successful solution though it did not reach it on this 
voyage. Ross had a sounding-line 3600 fathoms in 
length prepared on board, strong enough to stand a lead 
weighing 76 pounds, and fitted with swivels to prevent 
the strands untwisting in the water. With this he got 
a sounding in 2425 fathoms on January 3rd, though the 
line parted in heaving in. 
On January 31st, 1840, the two ships anchored in 
St. Helena Roads, having had a hard time of it beat- 
ing up to the island against the trade-wind. Steps were 
immediately taken to select a site for the magnetic 
observatory, and Lieutenant Lefroy, the young artillery 
officer who was sent out to take charge of it, landed 
with his assistants. The ships sailed again on Feb- 
ruary 9th and made their way leisurely to the Cape of 
Good Hope, occasionally stopping to sound when the 
sea was calm and boats could be used, and always mak- 
ing magnetic observations for the purpose of deter- 
mining the line of least intensity, to the exact position 
of which Sabine attached much importance. On March 
17th anchor was cast in Simon’s Bay and the magnetic 
instruments were at once landed in order to secure 
comparisons that would enable the Antarctic observa- 
tions to be properly interpreted. The fixed observatory 
was set up close to the Astronomical Observatory and 
Lieutenant Eardley Wilmot of the Royal Artillery with 
three assistants who had come out with the Erebus 
were landed to take charge of it. 
Light baffling winds made it a difficult matter to get 
away from Simon’s Bay when the ships set out on April 
6th, 1840, but at night a succession of violent squalls 
with thunder and lightning separated the two vessels and 
