weaker > too-weak; or: weaker (than his father's hand) rein > (Or reign; a typically Spenserian pun)

5 Proud of such glory and advancement vain, 6 While flashing beams do daze his feeble eyes, 7 He leaves the welkin way most beaten plain,

welkin > {Sky, skyey, heavenly; welkin way: the sun's path through the sky}

8 And, rapt with whirling wheels, inflames the skies

rapt > carried away, enraptured

9 With fire not made to burn, but fairly to shine.

fairly > gently, entirely, properly

104.10

So proud she shyned in her Princely state,
2 Looking to heauen; for earth she did disdayne,
And sitting high; for lowly she did hate:
4 Lo vnderneath her scornefull feete, was layne
A dreadfull Dragon with an hideous trayne,
6 And in her hand she held a mirrhour bright,
Wherein her face she often vewed fayne,
8 And in her selfe-lou'd semblance tooke delight;
For she was wondrous faire, as any liuing wight.

1 So proud she shone in her princely state,