the flanges of the beam to the desired form. Kroehl secured the patent as #12,133 on January 2, 1855. Mount Morris Fire Watchtower The City of New York, in order to improve safety during its growth, laid out a series of fire watch towers. James Bogardus, an innovator of cast iron houses, introduced the first of these towers. One was needed in the Harlem district, which would be situated on an outcropping of rock. On January 14, 1856, the Commissioner of Repairs and Supplies received two bids. Bogardus submitted his usual design at a bid of $5,750, but Kroehl and his partner Peter V. Husted (H&K) won the contract with a lower bid of $2,300; H&K pointed out that the tower need not be as tall, thus saving material and labor. This tower still stands in what is now Marcus Garvey Memorial Park. Comparing the structure and techniques of this tower with those designed and constructed by Bogardus show many similarities, especially in the method of bolting joints together. In April 1857, Bogardus sued the Mayor, Aldermen and Commonalty of the City of New York, claiming a patent infringement (#7,337). He cited that he was entitled to a royalty payment of $289, plus actual damages of $20,000. The jury agreed that he was entitled to the royalty payment, but not to the damages. Bogardus appealed the ruling to the U.S. Supreme Court, but Supreme Court Chief Justice Roger B. Taney upheld the ruling on appeal. Vanderbilt Rock On 21 May 1853, Cornelius Vanderbilt's yacht, the North Star, ran aground on Corlear's Hook and had to go back to dry dock for repairs, though no material damage was sustained. The area was then called "Vanderbilt Rock" with the expectation that City and State officials would arrange its removal as a hazard to navigation. For over a year, no action was taken. Later, H&K received a contract and they promptly removed the obstruction. Diamond Reef The maritime hazard of Diamond Reef lies at the entrance to the East River between Governor's Island and Lower Manhattan. Benjamin Maillefert was favored to win the contract based on his experience with underwater demolition and salvage. He attempted in 1851 to reduce this underwater obstacle by blasting. This effort was accomplished by lowering a canister of powder onto the rock at flood tide, then backing away a safe distance, detonating it with a galvanic battery. However,