The Ottoman administration brought a significant improvement to Cyprus in terms of water supply. The most notable example of this is the Bekir Pasha Aqueduct, built under the auspices of Ebubekir Pasha between 1746 and 1748. This aqueduct supplied fresh water to Larnaca and prior to its construction, local residents had to carry water on their backs for two hours. Silihtar aqueduct, built between 1801 and 1803, and the Arab Ahmet aqueduct supplied water to Nicosia. The authorities also encouraged the construction and improvement of artificial channels for water supply and irrigation, which greatly increased crop yield and allowed large-scale fruit production. Among villages described as prosperous due to artificial irrigation upon the British takeover of the island are Morphou, Lapithos, Polis, Lefka, Avdimou and Kolossi. Samuel Baker, who visited Cyprus in 1879, noted "mills turned by water" and "narrow lanes streaming with water" in Lefka. He also wrote that "every garden and farm was irrigated by water conducted from the mountains in artificial channels" in the northern slopes of the Kyrenia Mountains extending to the Karpas Peninsula. In Karavas, streams were diverted into artificial channels to supply water to the village. In the 19th century, a major effort was undertaken by a series of Ottoman governors to straighten and regulate the course of the Pedieos. Edhem Pasha, who served as governor in the 1840s, completed the construction of the Larnaca-Nicosia road and several bridges. Governor Mehmet Halet in the 1850s further improved the road network and harbour of Larnaca and established a grain store and market in Nicosia to encourage cattle breeding.. How many years did the construction of the Silihtar aqueduct take?