Port Weller became a major shipping town in the beginning of the 20th century. John Laing Weller, nicknamed ,“The Man who does things," was a visionary when it came to the construction of the Fourth Welland Canal. There were technological difficulties with the harbour at Port Dalhousie. For instance, the harbour at Port Dalhousie was at a different altitude of water. The old Canals were thus limited to ships that had a particular draft. Despite Port Dalhousie losing its trade, Port Weller became the new entrance to Lake Ontario in 1913. In addition, construction began on the Fourth Welland Canal in 1913 and it did not open until 1932. The Fourth Welland Canal had been constructed of concrete whereas the previous three canals were made of stone. However, after many decades, the stone has held up nicely more than the concrete. The artefact below is a picture of the construction of the Fourth Welland Canal. The huge locks that can be seen were invented by John Laing Weller. Originally, the lock gates were less secure, and would threaten to break when masses of water would break through. Weller created a mechanism by which the hinges would snap the gates back, thus averting danger.