1. Lyman Duff later took courses at Osgoode Hall Law School and was called to the Ontario Bar in 1893.

1. Lyman Duff later took courses at Osgoode Hall Law School and was called to the Ontario Bar in 1893.
Lyman Duff practised as a lawyer in Fergus, Ontario, after being called to the bar.
In 1895, Lyman Duff moved to Victoria, British Columbia, and he continued his career there.
In 1923, Mount Lyman Duff, known as Boundary Peak 174, was named after him.
Lyman Duff was the first and only Puisne Justice of the Supreme Court of Canada to be appointed to the Imperial Privy Council.
Lyman Duff took on the position, as the Chief Justice was unavailable.
In 1933, Lyman Duff was appointed as Chief Justice of Canada, succeeding Chief Justice Anglin.
Lyman Duff was made a Knight Grand Cross of the Order of St Michael and St George the following year as a result of Prime Minister Richard Bennett's temporary suspension of the Nickle Resolution.
When Governor General Lord Tweedsmuir died in office on February 11,1940, Chief Justice Lyman Duff became the Administrator of the Government for the second time.
Lyman Duff held the office for nearly four months, until King George VI appointed Alexander Cambridge, 1st Earl of Athlone as Governor General on June 21,1940.
Lyman Duff was the first Canadian to hold the position, even in the interim.
Lyman Duff heard more than eighty appeals on the Judicial Committee of the Privy Council, mostly Canadian appeals; however, he never heard Privy Council appeals from the Supreme Court of Canada while he served on the latter, otherwise, it would have been seen as a conflict of interest.
The last Privy Council appeal heard by Lyman Duff was the 1946 Reference Re Persons of Japanese Race.
In 1942, Lyman Duff served as the sole member of a Royal Commission constituted to examine the Liberal government's conduct in relation to the defence of Hong Kong.