Allagorical depiction of refraction

This is a photo (not mine) of one of the freizes on the side of the new statue of Clark Maxwell in Edinbrough.

http://www.flickr.com/photos/56701337@N00/3063598901/

It is an allagorical depiction of refraction (whihc, by the way is an awesome thing to be able to type). Can anyone help me identify all of the symbology?

Apollo is on the far left, and rosy-fingered dawn on the far right. The prisms and the pin hole in the middle are (I think) for refracting one into the other.
I don't get why the sage on the left (possibly Newton, who's corpuscular theory of light Maxwell built on (or over)) has a block of stone to sit on and the guy on the right (unidentified) gets a chair.
I also don't get chair guy's "holy crap your knee!" pointing.

That underpayed students unable to afford rags do all the experimental work is obvious, although they may an identity and meaning beyond this that I do not recognise :)

I can't find any equivilent photos of the other side, which explains relativity in similar terms :)