Reflection in water and air; concave mirrors
Optical notes on mirroring surfaces, with a personal reminder
On these facing pages Leonardo studies reflection and mirrors. He states that all incident rays pass first through the centre of concave mirrors before reaching their surface, and that every smooth transparent surface mirrors the objects it faces, so that whatever lies under water is mirrored in the surface of the air, and whatever is in the air is mirrored in the surface of the water. A marginal note adds that the further a larger body withdraws from a smaller one, the less of it is seen. Among the optical remarks he jots a private reminder to make 'the mace that breaks in the water of the trough' on Sunday morning and begins, but leaves unfinished, a reflection on how he has spent his time.
On this page
Rays and the centre of concave mirrors
Leonardo states that all incident rays pass first through the centre of concave mirrors before reaching their surface. The remark opens a short group of notes on reflection.
Mirroring at the boundary of water and air
Every smooth, transparent surface mirrors the objects that face it. Hence whatever lies under water is mirrored in the surface of the air bordering the water, and whatever is in the air is mirrored in the surface of the water bordering that air.
A larger body seen less as it withdraws
A marginal note observes that the more a larger body moves away from a smaller one, the less of it the smaller can see.
A reminder for Sunday morning
Amid the optical notes Leonardo jots a private memorandum to make 'the mace that breaks in the water of the trough' on Sunday morning, and begins an unfinished reflection on how he has spent his time, followed by the fragment 'if you are under water...'.