Conversation so far:
Who was Helen Duncan?
Helen Duncan was a Scottish medium best known as the last person to be imprisoned under the British Witchcraft Act of 1735.
How was Harry Price connected to Helen Duncan?
£50 was paid to the medium Helen Duncan so that she could be examined under scientific conditions. Price was sceptical of Duncan and had her perform test séances.
Did Harry Price investigate other things related to Helen Duncan besides having Helen Duncan perform a number of test séances?
She was suspected of swallowing cheesecloth which was then regurgitated as ectoplasm. Price proved through analysis of a sample of ectoplasm produced by Duncan, that it was made of cheesecloth.
What other involvement did Harry Price have with Helen Duncan besides test séances, and proving through analysis that ectoplasm produced by Helen Duncan was made of cheesecloth?
Price wrote that Duncan gave her fake ectoplasm to her husband to hide. The ectoplasm of Duncan in another test was analysed and reported to be made from egg white.
Did Harry Price write anything else on Helen Duncan besides fake ectoplasm?
Price wrote up the case in Leaves from a Psychist's Case Book (1933) revealing rubber gloves and cut-out heads from magazine covers which she pretended to her audience were spirits.

Question: What places did he travel to?
Self-contained rewrite: What places did Harry Price travel to?