No. 5 is a meniscus lens, having one of its sides concave and the othor side convex, gradually ncaring each other, until they meet at tha edge. No. 6 is a concavo-convex, having surfaces like a ...

The direction in which this tail points depends upon the side of the lens which is presented to the light. With a concavo-convex lens the convex surface gives an inward pointing coma, and the ...

The highly elongated necks, and often tails, of sauropod dinosaurs were composed of concavo-convex vertebrae that provided stability without compromising mobility. Polarities of these concavo-convex ...