MAKING OUR EASTING DOWN 35 
they are usually too strong for comfort was explained by 
Pennell by a theory that we were travelling in an anti- 
cyclone, which itself was travelling in front of a cyclone 
behind us. We were probably moving under steam about 
the same pace as the disturbance, which would average 
some 150 miles a day. 
From this may be explained many of the reports of con- 
tinual bad weather met by sailing ships and steamers in 
these latitudes. If we had been a sailing ship without 
auxiliary steam the cyclone would have caught us up, and 
we should have been travelling with it, and consequently in 
continual bad weather. On the other hand, a steamer pure 
and simple would have steamed through good and bad 
alike. But we, with our auxiliary steam, only made much 
the same headway as the disturbance travelling in our 
wake, and so remained in the anticyclone. 
Physical observations were made on the outward voyage 
by Simpson and Wright 4 into the atmospheric electricity 
over the ocean, one set of which consisted of an inquiry 
into the potential gradient, and observations were under- 
taken at Melbourne for the determination of the absolute 
value of the potential gradient over the sea.2, Numerous 
observations were also made on the radium content of the 
atmosphere over the ocean, to be compared afterwards with 
observations in the Antarctic air. The variations in radium 
content were not large. Results were also obtained on the 
voyage of the Terra Nova to New Zealand upon the subject 
of natural ionization in closed vessels. 
In addition to the work of the ship and the physical 
work above mentioned, work in vertebrate zoology, marine 
biology and magnetism, together with four-hourly observa- 
tions of the salinity and temperature of the sea, was carried 
out during the whole voyage. 
In vertebrate zoology Wilson kept an accurate record 
of birds, and he and Lillie another record of whales and 
dolphins. All the birds which could be caught, both at sea 
1 Vide Scozt’s Last Expedition, vol. ii. pp. 454-456. 
2 “ Atmospheric Electricity over the Ocean,” by G. C. Simpson and C. S. Wright, 
Pro. Roy. Soc. A, vol. 85, 1911. 
