From Coleridge's The Rime of the Ancient Mariner. An old mariner tells his tales to a young man who…

Bone points and bone needles. Crafted during the Reindeer age.

"The part of the body in which the centre of gravity is situated, may be found, in some cases, by balancing…

Circle modeling the earth. O is the center of the earth, r the radius of the earth, and h the height…

Illustration of a circle which illustrates that the tangents to a circle drawn from an external point…

Illustration used to construct a circle when given two points that it passes through and a radius.

Illustration of the construction of a perpendicular to a line when given a point O on the straight line.

Illustration of the construction of a perpendicular to a line when given a point B on the straight line.

Coordinate axis with angle XOP equal to theta, Θ, and angle XOQ=180 - Θ. From any point in the terminal…

Angle XOP=Θ and angle XOQ=- Θ. From a point in the terminal side of each a perpendicular line is drawn…

Angle XOP=Θ and angle XOQ=90+Θ. From a point in the terminal side of each a perpendicular line is…

Illustration of blueprint used by highway engineers to widen the pavement on the inside of the curve…

The Double Arrow sign may be used to advise road users that traffic is permitted to pass on either side…

The Double Arrow sign may be used to advise road users that traffic is permitted to pass on either side…

The Double Arrow sign may be used to advise road users that traffic is permitted to pass on either side…

Illustration of half of an ellipse. The square of the ordinate of a point in an ellipse is to the product…

Illustration of a hyperbola and its auxiliary circle. "Any ordinate of a hyperbola is to the tangent…

Illustration of a hyperbola with distances to foci drawn. "The difference of the distances of any point…

Illustration of a hyperbola with a line bisecting the focal radii. "If through a point P of an hyperbola…

Illustration of a point on a hyperbola. "If d denotes the abscissa (x-coordinate) of a point of an hyperbola,…

Illustration showing how to draw a tangent to an hyperbola from a given point P on the convex side of…

"Sectional compartment of the Nave of Lincoln Cathedral." — Encyclopedia Britanica, 1893

"Sectional compartment of the Choir of Lincoln Cathedral." — Encyclopedia Britanica, 1893

To find the projections of a line which joins two points, A, B given by their projections.

An illustration of a straight line with 5 points dividing it into 4 equal parts. Multiple of a given…

Illustration of two lines intersecting at a point. This can be used to show vertical angles.

Illustration showing two straight lines drawn from the same point in a perpendicular to a given line,…

Illustration of two straight lines drawn from a point in a perpendicular to a given line, cutting off…

An illustration of a man sitting on the shore of a lake and a child standing behind him pointing into…

Illustration of a parabola showing point P is equidistant to the focus and the directrix.

Illustration of a parabola. "If a line PT is drawn from any point P of the curve, bisecting the angle…

Two planes lie perpendicular to one another. A line perpendicular to plane 1 and a line perpendicular…

"Diagram illustrating the points at which incident rays meet the retina. xx, optic axis; k, first nodal…

"Potent counter-potent, sometimes called varry cuppy, differs from potent in that the potents of the…

Skadi is a giantess and daughter of Thiassi who was killed while chasing Loki because of a trick. Skadi…

"Lightly touch the wire at its middle point with the tip of the finger or the beard of a quill; the…