Conversation so far:
What is dirt research?
gathering masses of firsthand information and accumulating what he called "dirt" experience.
What kind of information was he gathering?
archival documents to understand the history of the fur trade.
When did he start?
Innis travelled extensively beginning in the summer of 1924.
Where did he travel?
he and a friend paddled an 18-foot (5.5 m) canvas-covered canoe hundreds of miles down the Peace River to Lake Athabasca.
Was his research successful?
CANNOTANSWER.
How long did he travel?
He travelled so extensively that by the early 1940s, he had visited every part of Canada.

Question: How did he gather research?
Self-contained rewrite: How did Harold Innis gather research?