### Cylinder

A cylinder is a body of uniform diameter throughout its entire length, whose ends are equal parallel…

### Sphere

A sphere is a solid bounded by a uniformly curved surface, every point of which is equally distant from…

### Conic Sections

Conic sections, cones divided by a plane.

### Crystals, Forms of

Forms of crystals.

### Accidental Point

"That point in which a right line drawn from the eye parallel to another given right line cuts the picture…

### Metacenter

"The Metacenter is the point of intersection of the vertical line passing through the center of gravity…

### Contours of a cone

The contours of a cone are circles of different sizes, one within another, and the same distance apart,…

### Contours of a half sphere

"The contours of a half sphere are a series of circles, far apart near the center (top) and near together…

### Contours of a concave cone

"The contours of a concave (hollowed out) cone are close together at the center (top), and far apart…

### Cube

A regular solid body, with six equal square sides.

### Prism

A transparent body, with usually three sides and two equal and parallel triangular ends or bases.

### Cylinder

A body of roller-like form, of which the longitudinal section is oblong, and the cross-section is circular.

### Hand and pyramid

A hand holding a square pyramid, suspended by a string.

### Parallelogram

"In the diagram, let AB and AC represent two forces acting upon the point, A. Draw the two dotted lines…

### Circles

A line of interlocking circles.

### Symmetry plane

"A crystal has a center of symmetry if an imaginary line is passed from some point on its surface through…

### Symmetry axis

"A crystal has a center of symmetry if an imaginary line is passed from some point on its surface through…

### Symmetry center

"A crystal has a center of symmetry if an imaginary line is passed from some point on its surface through…

### Orthorhombie pyramid

"Crystal faces are described according to their relations to the crystallographic axes. A series of…

### Orthohombie prism

"Crystal faces are described according to their relations to the crystallographic axes. A series of…

### Sulphur crystal

"The forms present upon it are two pyramids of different slope but each intersecting all three of the…

### Crystal of the monoclinic system

"A crystal form does not necessarily make a solid figure. One such an example is this, of the Monoclinic…

A cube.

An octohedron.

### Cube trunctuated by octahedron

"When a corner or an edge of one form is replaced by a face of another form, the first is said to be…

### Octahedron trunctuated by cube

"When a corner or an edge of one form is replaced by a face of another form, the first is said to be…

### Distorted octahedron

A distorted octahedron.

Dodecahedron.

### Distorted dodecahedron

A distorted dodecahedron

### Twinned cubes

"A penetration twin, since the two individuals interpenetrate each other." — Ford, 1912

### Twinned octahedron

"A contact twin, since the two individuals lie simply in contact with each other upon a certain plane."…

### Cube and dodecahedron

"A combination of dodecahedron and cube." — Ford, 1912

### Octahedron and dodecahedron

A combination of octahedron and dodecahedron.

### Dodecahedron and octahedron

A dodecahedron and octahedron

### Cube, octahedron and dodecahedron

A cube, octahedron, and dodecahedron.

### Tetrahexahedron

"The tetrahexahedron is a form composed of twenty-four isoceles triangular faces, each of which intersects…

### Cube and tetrahexahedron

"A cube with its edges beveled by the faces of a tetrahexahedron." — Ford, 1912

### Trapezohedron

"The trapezohedron is a form composed of twenty-four trapezium-shaped faces, each of which intersects…

### Dodecahedron and trapezohedron

A dodecahedron and trapezohedron.

### Dodecahedron and trapezohedron

A dodecahedron and trapezohedron

### Cube and trapezohedron

"A combination of cube and trapezohedron." — Ford, 1912

### Trisoctahedron

"The trisoctahedron is a form composed of twenty-four isosceles triangular faces, each of which intersects…

### Octahedron and trisoctahedron

"A combination of a trisoctahedron and an octahedron. It will be noted that the faces of the trisoctahedron…

### Hexoctahedron

"The hexoctahedron is a form composed of forty-eight triangular faces, each of which cuts differently…

### Cube and hexoctahedron

"A combination of cube and hexoctahedron." — Ford, 1912

### Dodecahedron and hexoctahedron

"A combination of dodecahedron and hexoctahedron." — Ford, 1912

### Dodecahedron, trapezohedron and hexoctahedron

"A combination of of dodecahedron, trapezohedron, and hexoctahedron." — Ford, 1912

### Symmetry of pyritohedral class

"The symmetry of the Pyritohedral class is as follows: The three crystal axes of binary symmetry; the…

### Pyritohedron

"This form consists of twelve pentagonal-shaped faces, each of which intersects one crystallographic…

### Diploid

"The diploid is a rare form found only in this class. It is composed of twenty-four faces which correspond…

### Cube and pyritohedron

"A combination of cube and pyritohedron, in which it will be noted that the faces of the pyritohedron…

### Octahedron and pyritohedron

"Combiantion of pyritohedron and octahedron." — Ford, 1912

### Octahedron and pyritohedron

"A combination of pyritohedron and octahedron." — Ford, 1912

### Pyritohedron and octahedron

"A combination of pyritohedron and octahedron." — Ford, 1912

### Pyritohedron, cube, and octahedron

"A cube trunctuated with pyritohedron and octahedron." — Ford, 1912

### Diploid and cube

"A combination of cube and diploid." — Ford, 1912

### Symmetry of tetrahedral class

"The symmetry of this class is as follows: The three crystallographic axes are axes of binary symmetry;…

### Positive tetrahedron

"The tetrahedron is a form composed of four equilateral triangular faces, each of which intersects all…

### Negative tetrahedron

"The tetrahedron is a form composed of four equilateral triangular faces, each of which intersects all…

### Positive and negative tetrahedrons

"If a positive and negative tetrahedron occured together with equal development, the resulting crystal…