The inscription is an excerpt from a poem by the 11th century Arab poet, Ibn Mucana, who lived on the Iberian Peninsula in the Alcabideche area (in present day Cascais, Portugal). The excerpt translates as, "If you are a determined man, you need a mill that works with the clouds without depending on the streams". Ibn Mucana is thought to be the first writer on the Iberian Peninsula to expressly mention the existence of windmills in the area.
Wailes, Reginald (1901-1986), engineer, known as Rex
"With the complements of HA". Stamped Hallam Ashley FRPS "for Rex Wailes". Rex Wailes' note reads, "Langley Marsh. The [?]shaft of brakewheel of Langley Marsh drainage mill during demolition. The author if taking measurements".