Raffles Lighthouse (Chinese: ; ; ) is a lighthouse located on Pulau Satumu in the Singapore Strait, about south of the main island of Singapore. History The Raffles Lighthouse was first mooted in 1833, but the foundation stone was only laid in 1854 when William John Butterworth was the Governor of the Straits Settlements from 1843 to 1855. The stones on which Raffles Lighthouse stands come from the granite quarries on Pulau Ubin. The lighthouse was named after Sir Stamford Raffles, who founded modern Singapore in 1819. The lighthouse was erected on a rocky island called Pulau Satumu, the southernmost island off the main island of Singapore. Pulau Satumu means "one tree island" – sa refers to satu ("one") and tumu is the Malay name for the large mangrove tree, Bruguiera confugata. The light source was a wick burner which was replaced in 1905 by a pressurised vapour kerosene mantle burner to increase the light intensity for a greater visible range. A 2nd Order optic was mounted on a roller carriage to allow for smooth rotation. (The Order is a system of classifying the type of lenses used based on the focal length of the lens). This roller carriage was a weight-driven machine which had to be rewound manually to lift the weight whenever it reached the base. The rewinding was done hourly. A crew of seven men was required to man the lighthouse. In 1968, the installation of a 4th Order electrically operated revolving optic replaced the original 2nd Order optic with a pressurised vapour kerosene "Hood" mantle burner. The light source was changed to a 100-volt/1,000-watt incandescent bulb producing 350,000 candelas of light intensity with a visibility range of . The power supply came from one of the three generators installed in a generator room built close to the keeper's room. As the rotation was electrically driven by motors, the crew was reduced to four men. In 1988 the 4th Order optic was replaced by a rotating beacon. This comprised an array of quartz halogen lamps in aluminium parabolic reflectors mounted on a gearless revolving pedestal. The lamps require only one-fifth of the energy required to produce the same intensity as incandescent lamps. These low-power lamps therefore allow solar power to be used in place of generators. In addition, the operation of the light is controlled by a photocell. The manning of the lighthouse was further reduced to