Plano-convex ingot problematic in the case of the stamped examples as this would require the furnace to be dismantled or else have a short shaft to allow access for stamping (Merkel 1986, Tylecote 1986, 22.) As a solution the furnace could have been tapped into a mould at the completion of smelting. It is possible that both methods were used as several of the ingots seem to have had additional metal poured onto the top in order to allow stamping (Tylecote 1986, 23-4.) Plano-convex ingot Plano-convex ingots are lumps of metal with a flat or slightly concave top and a convex base.
Cylindrical lens Cylindrical lens A cylindrical lens is a lens which focuses light into a line instead of a point, as a spherical lens would. The curved face or faces of a cylindrical lens are sections of a cylinder, and focus the image passing through it into a line parallel to the intersection of the surface of the lens and a plane tangent to it. The lens compresses the image in the direction perpendicular to this line, and leaves it unaltered in the direction parallel to it (in the tangent plane). In a light sheet microscope, a cylindrical lens is placed in