Ivory sundial and Qibla pointer, made by Bayram b. Ilyas. Turkey, 1582-3 © The Trustees of the British Museum

Ivory sundial and Qibla pointer, made by Bayram b. Ilyas. Turkey, 1582-3 © The Trustees of the British Museum

Ivory sundial and Qibla pointer, made by Bayram b. Ilyas. Turkey, 1582-3 © The Trustees of the British Museum