The passion for exploration and discovery, the hunger to learn all things about all aspects of the physical world, the great and preposterous optimism that held that such truths were in fact discoverable, its dazzling sophistication and its occasional startling innocence; an age in which geographical and scientific discoveries surpassed anything previously dreamt of, and yet an age in which it was still, just barely, possible to believe in mermaids and unicorns - these remarkable traits so characterized the British 18th century