Sea of Glory

optical device that projected the virtual image of an object onto a piece of paper for tracing. In the months ahead, the two artists, as well as the naturalist Titian Peale, would use the camera lucida to create images of hundreds of specimens and artifacts, as well as portraits of the many different peoples they encountered. They also created drawings and paintings depicting important scenes and events during the voyage, often basing their work on sketches provided by the squadron’s officers.
    On the afternoon of November 23, under full sail, the Vincennes stood in for Rio. Soon she had entered a circular bay almost one hundred miles in circumference surrounded by the spurs of a low mountain range. Ships from all over the world were anchored in groups around the bay. As the Vincennes sailed up the harbor, she passed the USS Independence, the flagship of the Brazil squadron, and Commodore John Nicholson’s band struck up “Hail Columbia.” Under normal circumstances, naval ceremony required that Wilkes fire a salute in recognition of his superior officer, but because of the delicacy of the chronometers aboard the Vincennes, Wilkes decided to forgo this custom. He sent an officer to the Independence to explain the reason behind the apparent slight, but Nicholson “appeared somewhat put out,” Wilkes remembered, “and it was industriously circulated that I had intentionally treated him with disrespect.”
    The Peacock had preceded the Vincennes by three days and was already undergoing repairs, but the Relief, which had been sent ahead soon after leaving Norfolk, was nowhere to be seen. Not until four days later, one hundred days after leaving Norfolk, did the storeship arrive, making it one of the longest passages to Rio on record. Instead of following the prevailing breezes east before heading south and west for South America, Lieutenant Long had sailed a more direct, but very slow course. Wilkes already had little confidence in Long (he had been, after all, one of the officers he had inherited from Jones’s original expedition), and he took the opportunity to berate him in the presence of the Peacock ’s Captain Hudson.
    Wilkes planned to stay in Rio for at least a month. While the squadron underwent repairs, he would conduct his initial gravity and magnetic experiments. He made arrangements with the Brazilian authorities to create a base at an old convent on Enxadas Island at the mouth of Gunabara Bay facing Rio. Here Wilkes created the same hive of activity that had existed at his Capitol Hill home the previous summer. “[T]he tents are spread,” Reynolds recorded, “and the portable houses for the Instruments are put up, and the Instruments are fixed in their stands . . . , and there is a hum and a life and a stirring spirit pervading the usually quiet island.”
    In addition to supervising his own experiments, Wilkes was responsible for coordinating the scientists’ journeys into the Brazilian interior, where they would collect no less than five thousand specimens for shipment back to the United States. Wilkes also supervised the repair of the Peacock and the fumigation of the Porpoise, and he quickly found himself spread too thin. “I have too much anxiety or rather too many persons depending upon me,” he wrote Jane. He knew that his own observations must meet exacting standards since they were to be later integrated with observations being made by Lieutenant Gilliss at the Depot and Professor William Bond at Harvard.
    Particularly torturous were the pendulum experiments. Wilkes had procured a sixty-eight-inch-long nonadjustable, or “invariable,” free-swinging pendulum from Francis Baily. After suspending the pendulum from an iron tripod, he set up a pendulum clock behind the tripod. Both the clock and the invariable pendulum were swung, and since the two pendulums were different lengths, they swung at different rates. Every so often, however, they would coincide. Observing the two pendulums through a telescope set up on the opposite side of the room, he would record the exact time of the coincidence, repeating the observation over and over again for days on end. Eventually, enough data was accumulated to determine the precise duration of a single swing of the pendulum. With this time and the length of the pendulum, it was then possible to calculate the force of gravity.
    As the experiments wore on, Wilkes started to experience terrible headaches. He demanded complete quiet, and when a man