Does the "one by one" refer to him finding the artifacts one by one, or putting them under the scope one by one?

Question

Each artifact

One by one he finds

He puts under

The scope and then knows

why.

Answer 1

This is a Yoda phrasing.

The meaning is

One by one he finds each artifact.

Answer 2

After each artifact that he finds he puts it under the scope.

He finds an artifact, he puts under the scope. He finds another and puts that one under the scope, and so on.