In Tahiti in the morning of 2 May 1769 Captain James Cook and astronomer Charles Green discovered that the large quadrant that they had brought from the Endeavour to Fort Venus was missing. They peered into every corner of the fort and on board the Endeavour. Without the quadrant, the expedition would be worthless. Green would not be able to measure the altitude of the sun, which was needed to set the clock (and to calculate the longitude). He would also not be able to take the altitude of planets, moons and satellites necessary to determine their latitude. The observation of the transit of Venus was only useful in combination with the exact geographical position of the observer – the quadrant was essential to the success of the voyage.
The twelve-inch portable astronomical quadrant (made by London instrument-maker John Bird) that was taken by Cook to Tahiti
One of the Tahitians must have taken it. It was not the first time that they had stolen. They took ‘every thing that was loose about the ship’, from knives, snuff boxes to even the glass panes from the portholes. Cook had not sailed across the globe through storms and dangerous seas to fail now. He ordered that some of the ‘Principle people’ be locked up until the precious instrument was found. As Cook began to question his prisoners, Green together with botanist Joseph Banks and the midshipman scoured the island. They rushed from one hut to another, questioning and cajoling. By late afternoon and seven miles from the fort, they finally discovered the person who had taken their quadrant.
After some discussion (and a display of the pistols that they had brought), Banks and Green persuaded the Tahitians to return the stolen goods. Green watched in horror as they brought out one part after another: the islanders had dismantled the delicate instrument to divide it between them. But after examining the pieces, Green was relieved to see that there seemed to be only minor damage. They packed the quadrant in a box and padded it with grass before beginning their long walk home. By the time they returned to Fort Venus it was dark. It had been a long, hot and tiring day – they were exhausted but triumphant. Everything they needed for the transit observations was in place. They had only to guard their instruments carefully for another month.
