Casgliadau Arlein
Amgueddfa Cymru
Chwilio Uwch
Helland-Hansen's Photometer, lantern slide
On the left, as it is sent down; in the middle, open for exposure; on the right, closed and ready for hauling up.
Nid yw sylwadau ar gael ar hyn o bryd. Ymddiheuriadau am yr anghyfleustra.