Britons reach N. Pole but it's not all downhill yet

Two British daredevils attempting to make the first trip around the world through both poles planted a frozen Union Jack on the North Pole Sunday and sent off a triumphant Easter telegram to Prince Charles, a sponsor of the expedition.

Sir Ranulph Fiennes and Charles Burton took a well-deserved rest at the top of the world after completing the most hazardous portion of their 52,000-mile trip, described by other Arctic experts as the ''toughest journey on Earth.'' Their adventure is far from over, however. The Transglobe Expedition team still must return to Greenwich, England, where they set out in September 1979. They hope to arrive in July.