You're really caught up on this commoner/non-commoner dynamic (from your other comments). Was it really that important? - many of the well known scientists of that time were 'commoners'.
I'm not, but they were. But it was not discussed openly in print at the time, and so must be inferred.
I just read his Wikipedia and he was sponsored by his uncle Sir Charles Wheatstone of Wheatstone bridge fame and ended up a Fellow of the Royal Society so was not so badly situated.