The curvilinear tracery – the stonework in the apex above the main part of the window (panes A-G) – contains an image of the Virgin and Child at the top, together with personifications of Peace, crowned and carrying the bread and wine of the Eucharist, and Justice, blindfolded and carrying the Tablets of the Law.
The tracery also includes images of four angels, the lower two of whom (F&G) hold banners bearing two lines in Latin which appear in a number of prayers to the Virgin Mary. The lines usually read:
Ora pro nobis, sancta Dei Genetrix; Ut digni efficiamur promissionibus Christi
(Pray for us, O Holy Mother of God; that we may be made worthy of the promises of Christ)
However, the lines in the West Window are transposed, with the angel on the left bearing the banner with the second line and vice versa, so that the message translates as: That we may be made worthy of the promises of Christ; Pray for us, O Holy Mother of God.
Deacon Bill Burleigh gives an explanation for this transposition in the third volume of his History of St Marie’s Cathedral and Parish (ISBN 978-0-9575781-5-9).
St Marie’s most precious stained glass was removed at the start of the Second World War and stored underground in crates at Nunnery Colliery in Handsworth.
The colliery flooded and, although all but a few fragments of the glass survived the flooding, the sketches and notes on how to reconstruct the windows were lost.
When the glass was replaced after the war, the parish priest at the time, Canon James Bradley, believed two pieces of glass – possibly the angels – were the wrong way round.
However, the expert who had led the re-installation was convinced they were the right way round as all the painted surfaces of the glass in the window faced inwards – as they ought to, in order to preserve the image.
The most likely explanation is that the wrong side of the glass was painted when the two tracery panels were originally made and, therefore, had to be installed with the angel bearing the second line of the prayer to the left instead of the right.
Despite the parish priest pointing out the error, it appears that the panels were originally installed with the painted side of the glass on the inside of the cathedral, just as they are now.