John sits on a rock on the left with a white bird at his feet observing the vision of seven angels in the clouds above. They are about to receive the vials with the seven last plagues to befall on the inhabitants of the earth. A group of men are standing on a green “sea of glass” mingled with tongues of fire; they are holding harps and singing the canticle of Moses. The poses and groupings of John and all the other figures are almost identical to that in the English Lambeth Apocalypse, even down to minor iconographic details like the bird at John's feet, which of course receives no mention in the biblical text and whose inclusion has to be explained as merely a feature of the landscape as conceived by the artist. The scene is set against a dull-green diaper ground, and a border bar links the initials of the texts below, with an owl perched on the top foliage spray and two hybrids on the bottom spray.
“And I saw another sign in heaven, great and wonderful: seven angels having the seven last plagues. For in them is filled up the wrath of God. And I saw as it were a sea of glass mingled with fire, and them that had overcome the beast and his image and the number of his name standing on the sea of glass, having the harps of God, and singing the canticle of Moses, the servant of God, and the canticle of the Lamb, saying, "Great and wonderful are thy works, O Lord God Almighty! Just and true are thy ways, O King of ages! Who shall not fear thee, O Lord, and magnify thy name? For thou only art holy, for all nations shall come and shall adore in thy sight, because thy judgements are manifest.” (Apoc. 15: 1-4)
