The defeated fleet sought refuge in the small harbour of Tchesmé, where it was blockaded by Admiral Elphinstone. The British officers devised a scheme for destroying the Turkish fleet. Lieutenant Dugdale volunteered to pilot a fire-ship against them. Before coming to close quarters the Russian sailors deserted the vessel, and Dugdale alone remained on board. He steered the vessel against a Turkish ship and set fire to it. The fire spread to the other vessels, closely packed in the harbour, and the whole of the Ottoman fleet was burnt and destroyed with the exception of a single frigate. A more gallant and successful attack has never been recorded in the annals of naval warfare. Elphinstone, who had fortunately escaped death—as did also Hassan the Algerian, when their warships were blown up in the recent naval battle—then advised that the Russian fleet should sail without delay to the Dardanelles and force its way through the Straits to the Sea of Marmora and Constantinople. But Orloff hesitated and delayed, with the result that the Turks, getting wind of the intention, hastily erected four batteries at the Dardanelles, two on either side of it, crossing their fire. These were sufficient to make it impossible for the Russian fleet to force its way through the Straits. Orloff and the Russian fleet then proceeded to the island of Lemnos, where it landed troops and besieged the chief fortress. It was evidently hoped to secure a base for the fleet in the Ægean Sea. After sixty days of siege the garrison gave in, and terms of capitulation were agreed upon with Orloff. In the meantime, however, Hassan had persuaded the Porte to allow him to make a desperate effort to save Lemnos. He enlisted four thousand ruffians at Constantinople for this purpose. When it was pointed out what a hazardous enterprise it was, the reply was that it mattered little whether it was successful or not. If successful, Lemnos would be saved; if unsuccessful, Constantinople would be rid for ever of four thousand of its greatest blackguards. Hassan landed unexpectedly in Lemnos, and, declining to recognize the capitulation, attacked the Russians and defeated them, and compelled them to take to their ships again.