ClipArt ETC
"a, prism; b, plane glass; c, spherical lens; d, double-convex; e, plano-convex, f, double-concave; g, plano-concave; h, meniscus; i, concavo-convex lenses." -Comstock 1850

Lenses of Various Forms

"a, prism; b, plane glass; c, spherical lens; d, double-convex; e, plano-convex, f, double-concave;…