An elementary treatise on coordinate geometry of three dimensions
A university-level textbook on analytic geometry of three dimensions, written by Robert J. T. Bell and published by Macmillan in London in 1912 for mathematics students. The line diagrams plot surfaces and curves against labelled x, y, z axes — cylinders, cones, helices, dashed hidden edges, angle marks and small captions — giving designers clean technical linework and axonometric scaffolding.
