In 1866, King Mongkut commissioned Sri Suriyawongse to oversee the construction of a 35-km long canal that connected Tha Chin River and Mae Klong River to facilitate commuting into Western Siam. The construction was finished in 1868 and was named Damnoen Saduak Canal. As Sri Suriyawongse had spent his own wealth on the construction of the canal, King Mongkut allowed the Bunnags to settle along the canal. In August 1868, Sri Suriyawongse organized the royal outing of King Mongkut to Wa Keo, Prachuap Khiri Khan Province with his son Prince Chulalongkorn to observe the Solar eclipse of August 18, 1868 calculated by the king.