WHEN a former shopkeeper's apprentice set sail on the second of his three great voyages of discovery, he circumnavigated Antarctica without ever sighting land. Disappointed though Capt Cook was, he did help to solve two riddles on his second trip: scurvy and longitude.
His ship's diet of sauerkraut tackled the former, and his experimentation with a sea clock the latter. "Our trusty friend, the Watch" was how he referred to the invention of an Englishman, John Harrison, in his log in 1775.
As US science journalist Dava Sobel records now in her current best seller, Longitude, global ignorance of the meridian "wreaked havoc on the grandest scale", and efforts by monarchs to resolve it involved much calumny and intrigue.
Until Harrison came up with an answer, oceangoing vessels were restricted to a few narrow shipping lanes that guaranteed safe passage. There were disasters and near misses, and many vessels just got lost.
One poor skipper got caught in a storm rounding Cape Horn in 1741. After two months at sea, he sighted land, only to find it was Tierra del Fuego again. He hadn't made any, progress. In fact, he had been sailing in reverse!
It's a predicament that would gain a lot of sympathy from the crew of the Tom Crean, as the five members continue on their harsh sea passage in Antarctic, latitudes this week, with 500 miles now between them and their destination, South Georgia.
"Cold, finding it hard to keep dry, but in good spirits," was how the Irish Antarctic Expedition's manager, John Bourke, summed up the mood yesterday, speaking from their rescue yacht, Pelagic, to this reporter on the Professor Molchanov.
Rough seas with 30 knot northerly winds over the last two days had made life difficult in the 23 foot wooden craft, which cannot heat up into the wind. The wind chill factor set the average temperature at about -8 Celsius on the helm.
A switch to westerlies at about 6 a.m. Irish time yesterday lifted the mood during the VHF radio call between the two vessels.
Sailing on an easterly bearing, co skipper Frank Nugent reported a lat/log of 59 degrees 55 minutes South, 47 degrees 22 minutes West, and said that they, had been "bouncing".
Every 30th wave hits the deck, the cabin is getting damper, and it is becoming something of a challenge to stay warm. "We keep our hats and gloves on down below for at least half an hour after coming off watch," he said. "But we're eating away, grubbing up as best we can."
If the Tom Crean, packed with Ambrosia Creamed Rice, has a diet a little more varied than seal blubber, it also has the benefit of satellite navigation by GPS. The skipper on the original Shackleton rescue voyage, Frank Worsley, had to get two men to hold him up while he took sun sights on his sextant.
Worsley only saw the sun four times on that voyage, in the winter of 1916, and his fingers were often so cold that he couldn't interpret the details taken down. "Navigation is an art, but words fail to give my efforts a correct name," he wrote afterwards, while acknowledging that Harrison's chronometer, first used by Capt Cook, helped to save their lives.
