law to carry equipment that might be needed to save cargo and ships. Such equipment included heavy anchors for kedging (hauling) ships off reefs, heavy hawsers and chain, fenders and blocks and tackle. Wreckers also had to be prepared to make emergency repairs to ships to refloat them or keep them afloat while they were sailed or towed back to Key West. By the middle of the 19th century, windmill-powered pumps, and later a steam-powered pump, were kept in Key West. If the wreckers were not able to pump out a ship fast enough to float it using the ship's own pumps, they could rent one of the large pumps from Key West. As the wrecking vessels could not always directly approach wrecked ships, they had to carry sturdy boats. Cargoes saved by wreckers varied tremendously. Cotton was perhaps the most valuable bulk cargo. A bale of cotton might be worth US$50 or $60 in Charleston, South Carolina, but a bale pulled from a flooded hold would be saturated with water, and weigh as much as half a ton. Unusual cargoes salvaged by wreckers included the fossilized "Hydrarchos" skeleton collected in Alabama by Albert Koch, and a locomotive. In 1827, Guerrero, a Spanish slave-runner carrying 500 African captives, and the Royal Navy warship HMS Nimble ran onto the Florida Reef during a running gun battle. Wreckers went to the aid of both ships. After most of the Africans and the Spanish crewmen had been transferred to wrecker vessels, the Spanish crewmen commandeered two of the ships and sailed to Cuba with most of the Africans. The remaining 120 Africans were taken to Key West, and then to St. Augustine. After Congress passed a special law the next year, 96 surviving Africans were sent to Liberia. Decline In an effort to reduce the number of wrecks along the Florida Reef, the United States government funded the construction of lighthouses. Lighthouses were built in the 1820s at Cape Florida, Key West (both on the island itself and on nearby Sand Key), and on Garden Key in the Dry Tortugas. A lightship was stationed at Carysfort Reef. Mariners complained that the lights were not visible enough. There were also long interruptions. The Cape Florida lighthouse was burned by Seminoles in 1836 and remained dark for ten years. It was also dark while the tower was made higher in 1855. It was put out