A coconut shell. A pincushion. A shipwreck survivor. A Royal Navy expedition. A Captain Cook monument. And a journey of thousands of miles. Some museum objects announce their importance immediately. They are large, beautiful, rare or obviously historic. Others are rather more deceptive. Our Object of the Month is one of the latter. At first glance, it looks like a rather attractive piece of old coconut shell, polished to a warm brown, with the inside adapted to make a pincush