### Clue: Perhaps Galileo's maestro or Newton, possibly (10)
### Answer: ASTRONOMER 
 ### Explanation: Definition: Perhaps Galileo
 **Anagram of**(…, possibly) [MAESTRO OR + N(abbrev. for "Newton", symbol in physics for a unit of force) ].
Defn: Of which Galileo Galilei is an example/perhaps.
The man's instrument: