Alexander Gill the elder (1565-1635) was Milton's Headmaster at St Paul's School. The Logonomia Anglica, first published in 1619, is a grammar of English, but its closing chapters deal specifically with poetics. See also No. 147.
From Logonomia Anglica (1621), pp. 124-5; repr. edition of O.L. Jiriczek (Strasburg, 1903), pp. 129-30:
Now you will admit that nothing in the way of ornamented speech is beyond our poets, for our Homer is not alone in this kind. I have spoken triflingly-our Spenser, for he is more correct in beautifying his language, and as he is more fertile of neatly expressed general truths, so he is more serious, and as he is richer in the variety of his invention, so he is the more useful in his conception of any topic. This is obvious in as much as he has appropriately and fully described, by means of the loveliest poetical fictions, the moral virtues in all their circumstances. 1
1Iam fateris ad sermonis ornatum nihil a nostris praetermissum. Neque enim solus est in hoc genere Homerus noster; exiguum dixi, Spenserus noster: nam & sermonis cultu accuratior est; & sententiis vt crebrior, ita grauior; & inuentionis varietate locupletior; & materiae cognitione multo vtilior; vtpote qui morales virtutes, secundum omnes suas circumstantias, aptissime & copiosissime, iucundissimis figmentis poeticis descripsit.