"Divide the circumference into a number of equal parts, drawing the radii and numbering the points. Divide the radius No. 1 into the same number of equal parts, numbering from the center. With C as center draw concentric arcs intersecting the radii of corresponding numbers, and draw a smooth curve through these intersections." —French, 1911

Draw Spiral of Archimedes

"Divide the circumference into a number of equal parts, drawing the radii and numbering the points.…

Illustration of 16 concentric congruent ellipses that are rotated about the center at equal intervals of 22.5°. The ellipses are externally tangent to the circle in which they are inscribed.

16 Rotated Concentric Ellipses

Illustration of 16 concentric congruent ellipses that are rotated about the center at equal intervals…

Illustration of 2 concentric congruent ellipses that are rotated about the center at 90°. The ellipses are externally tangent to the circle in which they are inscribed.

2 Rotated Concentric Ellipses

Illustration of 2 concentric congruent ellipses that are rotated about the center at 90°. The ellipses…

Illustration of 4 concentric congruent ellipses that are rotated about the center at equal intervals of 45°. The ellipses are externally tangent to the circle in which they are inscribed.

4 Rotated Concentric Ellipses

Illustration of 4 concentric congruent ellipses that are rotated about the center at equal intervals…

Illustration of 8 concentric congruent ellipses that are rotated about the center at equal intervals of 22.5°. The ellipses are externally tangent to the circle in which they are inscribed.

8 Rotated Concentric Ellipses

Illustration of 8 concentric congruent ellipses that are rotated about the center at equal intervals…

Mexican jar with spiral design sketched in the American Museum of Natural History in New York.

Mexican Jar

Mexican jar with spiral design sketched in the American Museum of Natural History in New York.

Illustration of a spiral curve.

Spiral

Illustration of a spiral curve.

Illustration of a spiral curve.

Spiral

Illustration of a spiral curve.

Illustration showing an Archimedean Spiral.

Archimedean Spiral

Illustration showing an Archimedean Spiral.

An illustration showing how to construct a spiral with compasses and four centers. "Given the pitch of the spiral, construct a square about the center, with the four sides together equal to the pitch. Prolong the sides in one direction as shown by the figure, the corners are the centers for each arc of the external angles."

Construction Of A Spiral

An illustration showing how to construct a spiral with compasses and four centers. "Given the pitch…

An illustration showing how to construct an arithmetic spiral. "Given the pitch p and angle v, divide them into an equal number of equal parts, say 6; make 01 = 01, 02 = 02, 03 = 03, 04 = 04, 05 = 05, and 06 = the pitch p; then join the points 1, 2, 3, 4, 5 and 6, which will form the spiral required."

Construction Of An Arithmetic Spiral

An illustration showing how to construct an arithmetic spiral. "Given the pitch p and angle v, divide…

Illustration of a double spiral with unequally spaced intervals.

Double Spiral

Illustration of a double spiral with unequally spaced intervals.

"If B and C are points in the spiral and the ratio of AC to AB be given, the intermediate point D may be obtained by describing a semicircle on BC as a diameter and erecting a perpendicular at A." —Anthony, 1904

Drawing Equiangular or Logarithmic Spiral

"If B and C are points in the spiral and the ratio of AC to AB be given, the intermediate point D may…

A graph showing a logarithmic or equiangular spiral. The spiral is created in polar coordinates (r,Θ) based on the natural log function.

Equiangular or Logarithmic Spiral

A graph showing a logarithmic or equiangular spiral. The spiral is created in polar coordinates (r,Θ)…

A helix spiral generated by revolving about an axis at an angle less than 90 degrees. This generates a cylindrical or coned shape as the tip meets.

Helix Spiral

A helix spiral generated by revolving about an axis at an angle less than 90 degrees. This generates…

"This class of spirals may be generated by unwinding a perfectly flexible but inextensible chord from a polygon of any number of sides, the names of the involutes being derived from the polygons which determine their form. The curves consist of radii increasing by an amount equal to the length of the sides." —Anthony, 1904

Involute Spiral

"This class of spirals may be generated by unwinding a perfectly flexible but inextensible chord from…

Spiral with lines AB and CD drawn on piece of paper shown flat.

Spiral Drawn on Piece of Paper Shown Flat

Spiral with lines AB and CD drawn on piece of paper shown flat.

Spiral with lines AB and CD drawn on piece of paper and rolled into a cylinder to form spiral running from A to D.

Spiral Drawn on Piece of Paper and Rolled

Spiral with lines AB and CD drawn on piece of paper and rolled into a cylinder to form spiral running…