Sight-line holding a stone: wire, stone and cardboard	Horizon: paint, plastic film, and Dutch metal	Desert landscape: ink wash on paper
Perspective model: ink, glass, cardboard and mirror	Parallax viewer: cardboard, glass, plastic and gold leaf	Displaced horizon: graphite and crayon on paper
Displaced mountain: ink on paper	Mirrored alignment device: glass, graphite, cardboard and gold leaf	Horizon and ellipse: graphite on paper
Planar surface with objects: graphite and paint on paper	Landscapes: ink, plastic sheet	Parallax viewer: glass, gold leaf and cardboard
Horizon alignment device: cardboard, wood, and thread	Horizon with object: chalk on paper