Crossword Genius

Joseph Bazalgette used this design to map sewer (5,5)

Ross

I believe the answer is:

steam power

I'm a little stuck... Click here to teach me more about this clue!

'joseph bazalgette used this design' is the definition.
I know nothing about this answer so I can't tell whether it can be defined by this definition.

'map sewer' is the wordplay.
I cannot quite see how this works, but
an anagram of 'map' is 'amp' which is within the answer.
This explanation may well be incorrect...

'to' acts as a link.

Can you help me to learn more?

I've seen this clue in The Telegraph.
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