The boys' book of engine-building;
A. Frederick Collins's 1918 how-to manual from Small, Maynard and Company in Boston, teaching American boys to build working model steam and gas engines at the home workbench. Line drawings show cylinders, flywheels, boilers, cranks and bases in plain outline with light hatching, isolated on blank ground, giving designers clean mechanical silhouettes and repeatable spoke and piston shapes.
