Page:The Worst Journey in the World volume 1.djvu/116

Rh they are usually too strong for comfort was explained by Pennell by a theory that we were travelling in an anticyclone, 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 continual 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 into the atmospheric electricity over the ocean, one set of which consisted of an inquiry into the potential gradient, and observations were undertaken at Melbourne for the determination of the absolute value of the potential gradient over the sea. 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 observations 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