Falling images

9. As a silver mirror, made from a thin plate, reflects the image confusedly and weakly, whilst from a thick solid plate it takes a high polish, and reflects the image brilliantly and strongly; so plastering, when thin in substance, not only cracks, but soon decays. On the contrary, that which is well covered with plaster and stucco, and closely laid on, when well polished, not only shines, but reflects to the spectators the images falling on it.

Vitruvius


The coat of Carthaginian wax thus put on is so strong that it neither suffers the moon by night, nor the sun-beams by day, to destroy the colour

Philosophical Transactions of the Royal Society Vol. 51 Dec 1759