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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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