### Trigonometric Angles and Quadrants

Axes showing trigonometric angles, and quadrants.

### Antipathes Dichotoma

"A, portion of a colony of Antipathes dichotoma. B, single zooid and axis of the same magnified. m,…

### Appalachian Mountains

This illustration shows the Appalachian Mountains, a region of numerous flexures on a grand scale, as…

### The Axis (2nd Cervical Vertebra)

The axis, which is the second cervical vertebra. Labels: D, odontoid process of axis; Fas, facet on…

### Axis

Second cervical vertebra, or axis.

### Axis from Above

The axis from behind and above.

### Axis from Side

The axis from left side.

### Axis from the Side

The axis from the side.

### Front View of Axis

The axis from in front.

### Symmetry axis

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

### The First and Second Cervical Vertebrae

B, the first cervical vertebra, the atlas. A, the atlas, and the second cervical vertebra, the axis;…

### Chalcocite

"Orthorhombic. Usually in small tabular crystals with hexagonal outline. Striated parallel to the brachy-axis."…

### Invariable Cone

Possible forms of the invariable cone by means of the intersections with a concentric spherical surface.

### Conic Sections 2D

Two dimensional view of the cuts required to create the conic sections hyperbola, parabola, ellipse,…

### Conic Sections 3D

Three dimensional representation of the intersecting planes required to create the conic sections hyperbola,…

### Cube

"Science has succeeded in classifying the thousands of known crystals in six systems, to each of which…

### Earth Axis

"Now it is the inclination of the Earth's axis, as above described, which causes the lengths of the…

### Earth Axis

"Now it is the inclination of the Earth's axis, as above described, which causes the lengths of the…

### Earth's Axis Perpendicular to Plane of Orbit

"The earth shown as it would be if its axis were perpendicular to the plane of the orbit." -Wiswell,…

### Inclination of Earth's Axis

"A quadrant, or one fourth of a circle. The oblique lines indicate various angles with the base. The…

### Eccentric Angle

"In geometry, an angle connected with an ellipse and defined as ... angle BCL, reckoned from one determinate…

### Electrical Machine

"The electrical machine most usually employed consists of a large circular plate of glass, mounted upon…

### Electrical Machine

"A form of an electrical machine. S being the glass cylinder turning on an axis, Y the conductor, F…

### Ellipse Second Method

Draftsman's second method for drawing an ellipse

### Construction Of Ellipse

Illustration used to show how to draw an ellipse when given the diameters.

### Construction Of Ellipse

Illustration used to show how to draw an ellipse by circular arcs.

### Spring Equinox and Autumn Equinox

"Relative positions of the earth and the sun on March 21 (spring equinox) and September 21 (autumn equinox)…

### Pyramid of the first order

"This form consists of twelve isoceles triangular faces, each of which intersects two of the horizontal…

### First Right Square Octahedron

"Science has succeeded in classifying the thousands of known crystals in six systems, to each of which…

### First Right Square Prism

"Science has succeeded in classifying the thousands of known crystals in six systems, to each of which…

### Flexures

This illustration shows a rock formation with folds or flexures in strata. a x represents the axis or…

### Heliometer

"The type of instrument which resulted from Russian labors. The brass tube, strengthened at the bearing…

### Magnetic Curves

An illustration of magnetic curves, "the name given to those curves in which an infinite number of very…

### Micrometer

"The horizontal section in the direction of the axis of the telescope. The eye-piece ab consists of…

### Micrometer

"The vertical section in the direction of the axis of the telescope. The eye-piece ab consists of two…

### Micrometer

"a is the sphere, placed in half-holes on the axis bb, so that when its principal axis is parallel to…

### Micrometer

"a is the sphere, placed in half-holes on the axis bb, so that when its principal axis is parallel to…

### Nerves

"a, axis cylinder; b, inner border of white substance; c, c, outer border of same; d, d, tubular membrane;…

### Ligaments of the Occipital Bone

Dissection from behind the ligaments connecting the occipital bone, the atlas, and the axis with each…

### Construction Of Oval

Illustration used to show how to draw an egg-shaped oval when given the diameters.

### Pole Depression

"Two hoops of thin iron are placed upon an axis which passes through their poles. The two ends of each…

### Pulley

"[The pulley] consists of a wheel with a grooved circumference, over which a rope passes, and an axis…

A point lies in the first quadrant if the plan lies below, the elevation above the axis; in the second…

### Regular Octahedron

"Science has succeeded in classifying the thousands of known crystals in six systems, to each of which…

### Regular Tetrahedron

"Science has succeeded in classifying the thousands of known crystals in six systems, to each of which…

### Retina

"Diagrammatic section through the eyeball. xx, optic axis; k, nodal point." —Martin, 1917

### Retina

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

### Rhombic Dodecahedron

"Science has succeeded in classifying the thousands of known crystals in six systems, to each of which…

### Rose

"Proliferous or monstrous Rose, showing the prolongation of the axis beyond the flower. C, calyx transformed…

### Hindley's Screw

"A screw cut on a solid, of such form that if any plane be taken through its longitudinal axis, the…

### Second Right Square Octahedron

"Science has succeeded in classifying the thousands of known crystals in six systems, to each of which…

### Second Right Square Prism

"Science has succeeded in classifying the thousands of known crystals in six systems, to each of which…

### Shoe Block

"Nautically, a block with two sheaves, whose axes are at right angles to each other, used for the buntlines…

### Axial Skeleton

"Fig 56 - Axial skeleton, minus the skull, of an owl, Asio wilsonianus, life size; from nature by Dr.…

### Sliding Contact

These are skew bevel wheels, made of a hyperboloid of revolution around an axis.

### Lateral Sliding Contact

The lines of contact are equal, but the axes are neither parallel to each other, or the line of contact.

### Solenoid

"Coil some No. 12 copper wire throuh holes in a board, as shown, and pass a strong current through it.…

### Summer Solstice

"Relative positions of the earth and the sun on June 21, the summer solstice. Summer and long days north…

### Winter Solstice

"Relative positions of the earth and the sun on December 21, the winter solstice. Winter and short days…

### Sphere Made by Revolution of Semicircle

Illustration of a sphere generated by the revolution of a semicircle ACB about its diameter AB as an…