 ### Center of Gravity

"When such a surface is irregular in shape, suspend it at any point, so that it may move freely, and… ### Line of Direction from the Center of Gravity of an Object

"When a line of direction falls within the base, a body stands when not, it falls... On the same principle,… ### Finding the Center of Mass

"Let any irregularly shpaed body, as a stone or chair, be suspended so as to move freely. Drop a plumb… ### Circle With Diameter, Radius, Segment, Line

Illustration showing a circle with a diameter, radius, lines, triangle, and segment drawn. ### Circle Inscribed in a Right Triangle

Illustration showing the diameter of a circle inscribed in a right triangle is equal to the difference… ### Circle with Secant and Point of Tangency

Illustrations of a circle with secant AD and line BC tangent to it. ### Circle With Tangent Line Drawn

Illustration of a circle with a tangent drawn - a straight line perpendicular to a radius at its extremity. ### Circle With Inscribed Triangle and Radii

Illustration showing a circle with an inscribed triangle and radii. ### Circle With Various Chords

Illustration showing a circle with various chords drawn. ### Circle With Various Chords

Illustration showing a circle with various chords drawn. ### Circle With Various Chords And Tangents

Illustration showing a circle with various chords and tangents drawn. ### Circle With Various Chords And Tangents

Illustration showing a circle with various chords and tangents drawn. ### Circle With a Right Triangle

Illustration where one leg of a right triangle is the diameter of a circle. The tangent at the point… ### Circle With a Tangent Line and Chord

Illustration showing that from any point in the circumference of a circle, a chord and a tangent are… ### Intersecting Lines in Circles

Illustration showing various circles and the angles formed by intersecting lines. ### Two Intersecting Circles With Lines

Illustration showing 2 intersecting circles with a line drawn through each point of intersection terminated… ### Two Intersecting Circles With Lines

Illustration showing 2 intersecting circles with a lines drawn that form a triangle. ### Tangent Circles With Chords

Illustration showing 2 circles with that touch each other and two lines drawn through the point of contact… ### Rope Clamp

A device consisting of a pair of clamping jaws carrying a ring and a hook. Used for securing or attaching… ### Hanging Clothes

An illustration of clothes hanging on a clothes line with shoe sand gloves resting beneath. ### Early Use Clothesline

A cord on which clothes are hung to dry ### Conic Involution

The lines which join corresponding points in an involution on a conic all pass through a fixed point;… ### Construction of Bisecting a Given Angle

Illustration of the construction used to bisect a given angle. ### Construction of Bisecting a Given Arc

Illustration of the construction used to bisect a given arc. ### Construction of Bisecting a Given Line

Illustration of the construction used to bisect a given line. ### Construction of Dividing Lines

A line which is divided into seven equal parts, shown by construction. ### Construction of Dividing Lines

A line which is divided into equal parts, shown by construction and square. ### Construction of a Circle Through a Given Point that Cuts Chords of Given Lengths From Parallels

Illustration used to construct a circle that shall pass through a given point and cut chords of a given… ### Construction of Perpendicular Upon a Given Line From an External Point

Illustration to let fall a perpendicular upon a given line from a given external point. ### Construction of Perpendicular From a Given Point on a Straight Line

Illustration of the construction of a perpendicular to a line when given a point O on the straight line. ### Construction of Perpendicular From a Given Point on a Straight Line

Illustration of the construction of a perpendicular to a line when given a point B on the straight line. ### Construction of Tangent Line Through a Given Point to a Given Circle

Illustration of the construction used to draw a tangent to a given circle through a given point. ### Intersecting Lines Corollary

Illustration used to prove the corollary that "Two lines perpendicular respectively to two intersecting… ### Perpendicular to Line Corollary

Illustration used to prove the corollary that "From a point outside a line there exists only one perpendicular… ### Cross Quarterly

"Cross Quarterly is a Cross cut by a partition line, and the tinctures reversed or counter-changed."—Aveling,… ### Curve Inked with Circle Arcs

"Any noncircular curve may be approximated by tangent circle arcs, selecting a center by trial, drawing… ### Drawing Irregular Isometric Curves of Solid

The illustration of an irregular curves for solid. The isometric projection of the curve can be drawn… A round, laterally flattened wooden block, encircled by a rope or an iron band, and pierced with three… A round, laterally flattened wooden block, encircled by a rope or an iron band, and pierced with three… ### Dedekind Property 1

Illustration 1 of the Dedekind axiom. ### Dedekind Property 2

Illustration 2 of the Dedekind axiom. ### Dedekind Property 3

Illustration 3 of the Dedekind axiom. ### Dedekind Property 4

Illustration 4 of the Dedekind axiom. ### Angle of Depression

Illustration showing an angle of depression from a horizontal line to a line of sight. ### Diving Dress

"The diving dress envelops the whole body of the diver, the upper portion a being the "helmet," the… ### Drawing Parallel Lines Exercise

Parallel lines are drawn by using a triangle in combination with a T-square. To draw a line parallel… ### Drawing Parallel Lines Using T-square and Triangle

Parallel lines are drawn by holding the triangle against the T-square at an angle, or another triangle,… ### Drawing Perpendicular Lines Using T-square and Triangle

Perpendicular lines are drawn by fitting the hypothenuse of the triangle to the T-square at an angle,… ### Angle of Elevation

Illustration showing an angle of elevation from a horizontal line to a line of sight. ### Line Divided Into Equal Parts

Illustration used to show how to divide a given straight line into any number of equal parts. ### Polar Equation

Finding the polar equation of a straight line. ### Horizontal Solid and Dashed Line Drawing Exercise

An exercise for mechanical drawing to construct a series of horizontal lines. The solid lines are drawn… ### Horizontal Solid Line Drawing Exercise

An exercise problem drawing a series of horizontal lines using a straight edge or triangle without using…  ### Flashcard of a Line

A flashcard featuring an illustration of a Line ### Flashcard of a Line Segment

A flashcard featuring an illustration of a Line Segment ### Flashcard of a Parallel Lines

A flashcard featuring an illustration of a Parallel Lines ### Flashcard of a Ray

A flashcard featuring an illustration of a Ray ### Flashcard of a Straight angle

A flashcard featuring an illustration of a Straight angle