Celestial globe by Giovanni Antonio Vanosino in1567, showing the main Ptolemaic constellations in convex representation, is exhibited on October 13,...
Celestial globe by Giovanni Antonio Vanosino in1567, showing the main Ptolemaic constellations in convex representation, is exhibited on October 13,...
The opticians at �The Sign of Isaac Newton and Two Pair of Golden Spectacles� sold a range of optical toys and instruments, barometers, thermometers...
The convex lower surface of the upturned dish has been made to resemble an oxyrhynchus fish. The ancient Egyptians were very conscious of their...
Steel dentist�s tool with slightly ornamental shaft, plain circular bolster, single claw position and convex claw margin with two notches and inner...
These small, coloured convex glasses were used by landscape painters as visual aids. They are named after the highly infuential French landscape...
These small convex mirrors were used by landscape painters as visual aids. They were named after the highly infuential French landscape painter...
Heat is produced as sunlight is focused by a large convex lens, such as this example which is mounted on a brass pivot on a wooden stand. Heat can...
If a convex lens is held near an object, the object looks bigger because the lens bends the rays of light inwards. The eyes trace the light rays back...
These small, coloured convex glasses were used by landscape painters as visual aids. They are named after the highly infuential French landscape...
