ClipArt ETC
A problem exercise to creating a star using series of triangles and squares. The image is divided by the dotted line to scale images to appropriate size.

Star Construction Using Triangles and Squares

A problem exercise to creating a star using series of triangles and squares. The image is divided by…

A diagonal line pattern drawing exercise in for T square and triangle. The image is constructed by dividing the paper into squares with the T square, and the diagonal lines are drawn using a 45 degree triangle.

Drawing Exercise for Drawing Diagonal Line Pattern using T Square and Triangle

A diagonal line pattern drawing exercise in for T square and triangle. The image is constructed by dividing…

The construction of a star with square overlapping each other using a triangle and T square. This image is drawn by dividing the paper with dashed lines using T square. Using the 45 degree triangle, draw diagonal lines to create the star and the star.

Constructing Star and Box Overlap Pattern using T Square and Triangle

The construction of a star with square overlapping each other using a triangle and T square. This image…

A problem exercise to construct a star overlapping square using a triangle and T square. The image is drawn by dividing the paper with dashed lines using T square. Using the 45 degree triangle, draw diagonal lines to create the star and the star.

Constructing 4 Point Star Overlapping Box Pattern using T Square and Triangle

A problem exercise to construct a star overlapping square using a triangle and T square. The image is…

A mechanical drawing exercise of a circle with curved wavy lines. The image is drawn by dividing horizontal lines into half inches, and draw smaller half circles within the large circle.

Mechanical Drawing Exercise Circle with Wavy Curved Lines Inside

A mechanical drawing exercise of a circle with curved wavy lines. The image is drawn by dividing horizontal…

A mechanical drawing exercise of drawing a curved line with circle in the middle. The image is drawn by drawing a small circle in the middle. The curved lines around the circle is drawn by using the ticked line as the radius.

Curved Line with Circle Mechanical Drawing Exercise

A mechanical drawing exercise of drawing a curved line with circle in the middle. The image is drawn…

A mechanical drawing practice problem of shading the sides of the inscribed circles. The darker area shows where the light is not hitting the image making the 2D image look 3D. These shadings are done in pen.

Mechanical Drawing Exercise Shading Sides of Inscribed Circle with Ink

A mechanical drawing practice problem of shading the sides of the inscribed circles. The darker area…

Mechanical drawing exercise of shading squares and circle in ink. The squares are first drawn with the right angles, then rounded off with a compass. Using a pen, the sides of the shapes are darkened to show points where no light is hitting the image.

Mechanical Drawing Exercise Shading Sides of Inscribed Squares and Circle with Ink

Mechanical drawing exercise of shading squares and circle in ink. The squares are first drawn with the…

An apparatus used to photograph images in a light microscope. The long camera is connected to the eye piece while the microscope uses a mirror to light the specimen. The image is captured on the photographic plate.

Micrographic Apparatus with Camera and Microscope

An apparatus used to photograph images in a light microscope. The long camera is connected to the eye…

The illustration is showing both inside and outside view of the tadpole. The left inside view shows the tadpole with two front legs, heart, intestines, and gills. The right image shows the tadpole with frog like features with forelegs, back legs, and a tail.

Inside and Outside View of Tadpole During Metamorphosis

The illustration is showing both inside and outside view of the tadpole. The left inside view shows…

A Hartmann Spectrocomparator device to measure accurate displacement of the star by measuring the relative star motion to the observer. The object is first photographed, then the image is attached to the device measuring the distance.

Hartmann Spectrocomparator

A Hartmann Spectrocomparator device to measure accurate displacement of the star by measuring the relative…

An illustration of the position and the size of the image viewed by the eye. The eye approximates the the height of the image. The image's height is the hypotenuse of the triangle, creating an angle with the eye. This image is then reflected upside down in the eye.

Position and Size of Image for Eye Optics

An illustration of the position and the size of the image viewed by the eye. The eye approximates the…

"If y be the object the image appears to a normal eye situated behind the system L with passive accommodation at a very great distance under the angle w'. Since H' P= F O, = y, from the focal length of the simple microscope is the image side focal length." —Encyclopaedia Britannica, 1910

Optical Position and Size of Image Through Magnifying Glasses

"If y be the object the image appears to a normal eye situated behind the system L with passive accommodation…

The illustration of putting lenses in front of the eye. The focal point of the image is reflected into the eye. The focal point in the lens will end past the eye, creating a blurry image.

Optical Position and Size of Image Through Lens in Front of Eye

The illustration of putting lenses in front of the eye. The focal point of the image is reflected into…

"The intersection of the principal rays in this case lies in the middle of the entrance pupil or of the exit pupil. By head and eye motion the various parts of the whole field can be viewed one after another." —Encyclopaedia Britannica, 1910

Optical Position of Diaphragms using Lens

"The intersection of the principal rays in this case lies in the middle of the entrance pupil or of…

"The image produced by a microscope formed of two positive systems is inverted, the objective L1 tracing from the object OO1 a real inverted image O'O'1, and the eyepiece L2L2 maintaining this arrangement." —Encyclopaedia Britannica, 1910

Ray Transmission in Compound Microscope with a Positive Ocular

"The image produced by a microscope formed of two positive systems is inverted, the objective L1 tracing…

An illustration of a compound microscope that produces upright image using negative eyepiece. The image is focused onto a concave lens, instead of convex lens, to diverging light.

Ray Transmission in Compound Microscope with a Negative Eyepiece

An illustration of a compound microscope that produces upright image using negative eyepiece. The image…

"The lens is spherically corrected for OO', but the sinecondition is not fulfilled. Hens the different magnifications of a point O1 beyond the axis." —Encyclopaedia Britannica, 1910

Magnification of Image Beyond Axis with Lens

"The lens is spherically corrected for OO', but the sinecondition is not fulfilled. Hens the different…

"O' is the virtual image of O formed at a spherical surface of centre C and radius CS." —Encyclopaedia Britannica, 1910

Virtual Image Formed on Spherical Surface

"O' is the virtual image of O formed at a spherical surface of centre C and radius CS." —Encyclopaedia…

"Showing a system with chromatic difference of spherical aberration. O" ₌ image of O for red light; O'" for blue. The system is under—corrected for red, and over—corrected for blue rays." —Encyclopaedia Britannica, 1910

Light Correction of Blue and Red Lights using Spherical Lens

"Showing a system with chromatic difference of spherical aberration. O" ₌ image of O for red light;…

"If the real image produced by the objective coincides with the collective lens, only the inclination of the principal rays is altered. The lens nearer to the eye is distant from it about its focal length. The eye—lens converts diverging pencils into parallels. Both lenses together form the exit pupil of the objective behind the eye—lens." —Encyclopaedia Britannica, 1910

Ramsden Eyepiece Lens Refraction Diagram

"If the real image produced by the objective coincides with the collective lens, only the inclination…

"They have also a shorter focus for red, and a longer one for blue, and thus magnify the red image more than the blue; and as the objective gives a large blue and small red image, the two cancel one another and a colourless image is produced." —Encyclopaedia Britannica, 1910

Huyegenian Eyepiece Diagram Showing Lens Refraction

"They have also a shorter focus for red, and a longer one for blue, and thus magnify the red image more…

Device used for contact printing that holds a negative against the photographic paper. The paper is exposed by light from an external light

Printing Frame

Device used for contact printing that holds a negative against the photographic paper. The paper is…

A column depicting carvings and images of life in Thebes.

Column from Thebes

A column depicting carvings and images of life in Thebes.

An image of an important commercial junction at the Tigris river.

The Tigris at Nineveh

An image of an important commercial junction at the Tigris river.

An image depicting the ruins of the ancient city of Susa, in modern-day Iran.

Ruins of Susa

An image depicting the ruins of the ancient city of Susa, in modern-day Iran.

An image of the divinity whom the Phoenicians worshipped as Astarte, or the goddess associated with fertility, sexuality, and war.

Nana, The Phoenician Astarte

An image of the divinity whom the Phoenicians worshipped as Astarte, or the goddess associated with…

The animal life of Assyria was extremely varied. This image depicts a mule from this area.

Assyrian Mule

The animal life of Assyria was extremely varied. This image depicts a mule from this area.

The Canaanite fertility goddess and accompaniment of Baal.

Image of Ashtaroth

The Canaanite fertility goddess and accompaniment of Baal.

Literally means 'Lord of the Flies.' In Christian and Biblical texts, he is associated with a demon.

Image of Beelzebub, the Fly God

Literally means 'Lord of the Flies.' In Christian and Biblical texts, he is associated with a demon.

An image depicting an ancient city of the Persian, Parthian, and Elamite empires of Iran.

Ancient Susa

An image depicting an ancient city of the Persian, Parthian, and Elamite empires of Iran.

Image depicting a mythical moral anecdote, consisting of two morals. The first that regardless of who wears the crown, they are bound to have threats sent their way. The second is that the threat of terrorism is much greater than the act itself.

Banquet of Damocles

Image depicting a mythical moral anecdote, consisting of two morals. The first that regardless of who…

An image depicting the city of ancient Corinth.

Ancient Corinth

An image depicting the city of ancient Corinth.

An image depicting Alexander visiting the Temple of Amun.

Alexander at the Temple of Amun

An image depicting Alexander visiting the Temple of Amun.

An image depicting Julius Caesar, a Roman general and statesman. He was a key component to the shift of the Roman Republic into the Roman Empire. He emerged as the unrivaled leader of the Roman world in 49 BC.

Julius Caesar

An image depicting Julius Caesar, a Roman general and statesman. He was a key component to the shift…

An image of two Gaulish warriors participating in a series of military campaigns against Julius Caesar.

Gaulish Warriors

An image of two Gaulish warriors participating in a series of military campaigns against Julius Caesar.

An image of Julius Caesar and his army crossing the Rubicon River, which is located in northeastern Italy. The idiom "Crossing the Rubicon" refers to Julius Caesar passing this river in 49 BC, and means to pass a point of no return.

Caesar Crossing the Rubicon

An image of Julius Caesar and his army crossing the Rubicon River, which is located in northeastern…

An image of a bald cypress, in pyramidal cultivated form. It is otherwise known as taxodium distichum, and is native to the southeastern United States.

Bald Cypress in Cultivated Form

An image of a bald cypress, in pyramidal cultivated form. It is otherwise known as taxodium distichum,…

An image of a bald cypress in swamp form, with aerating roots, or knees. It is otherwise known as taxodium distichum, and is native to the southeastern United States.

Bald Cypress in Swamp Form

An image of a bald cypress in swamp form, with aerating roots, or knees. It is otherwise known as taxodium…

An image of laguncularia racemosa, or white mangrove. They grow in coastal areas of bays, lagoons, and tidal creeks. This white mangrove has aerating roots, or roots that rdide above the ground.

Aerating Roots of Swamp Mangrove

An image of laguncularia racemosa, or white mangrove. They grow in coastal areas of bays, lagoons, and…

Also known as taraxacum officinale. Part A of the image shows the common form, grown in plains region at low altitude. Part B of the image is the alpine form.

Common Dandelion

Also known as taraxacum officinale. Part A of the image shows the common form, grown in plains region…

Known to attack hickory. This image depicts the ambrosia of the Xyleborus celsus.

Xyleborus Celsus

Known to attack hickory. This image depicts the ambrosia of the Xyleborus celsus.

A species of bark beetle. This image depicts a male and a female.

Xyleborus Xylographus

A species of bark beetle. This image depicts a male and a female.

This image depicts a female spotted Java chicken.

Mottled Java Hen

This image depicts a female spotted Java chicken.

"When a grapevine is first set in a vineyard, it closely resembles the plant shown in [the image]. Such a rooted cutting may be one or two years old, the former being preferable in the majority of cases. The cane is cut back to two buds, and during the first season its shoots are allowed to lie prone upon the surface of the soil."—Government Printing Office, 1897

Rooted Grape Cutting

"When a grapevine is first set in a vineyard, it closely resembles the plant shown in [the image]. Such…

"The cross-wire system is another method of training which appears to be confined in this country to the Hudson River Valley, and even there it is used only to a limited extent. But at Juraçon, Bassess-Pyrénées, France, this system is regularly followed. Poles are used in place of the wires, however. [The image] represents vines trained in this manner."—Government Printing Office, 1897

Cross-Wire System of Grape Training

"The cross-wire system is another method of training which appears to be confined in this country to…

A diagram depicting an unpruned vine trained according to the umbrella system. This image shows stem renewal. This system is also known as the two-cane Kniffin system.

Unpruned Vine According to the Umbrella System

A diagram depicting an unpruned vine trained according to the umbrella system. This image shows stem…

An image depicting a pruned vine that was trained according to the umbrella system. This system is also called the two-cane Kniffin.

Pruned System According to the Umbrella System

An image depicting a pruned vine that was trained according to the umbrella system. This system is also…

Also known as Pinus sabiniana and Digger Pine. This image depicts the cone of the tree, which is generally flaccid, slightly twisted, and rounded on the outer side with a prominent rib on the inner side.

Gray Pine

Also known as Pinus sabiniana and Digger Pine. This image depicts the cone of the tree, which is generally…

Also known as Pinus sylvestris. This image depicts the branchlet and cones of the Scots Pine.

Scots Pine

Also known as Pinus sylvestris. This image depicts the branchlet and cones of the Scots Pine.

The image depicts the flower and portion of a leaf of the Pitcairnia andreana. The petals are yellow at the tip with red at the bottom.

Pitcairnia Andreana

The image depicts the flower and portion of a leaf of the Pitcairnia andreana. The petals are yellow…

An image depicting Pleospora herbarum in perfect stage, with asci.

Pleospora Herbarum in Perfect Stage

An image depicting Pleospora herbarum in perfect stage, with asci.

An image depicting a Pleospora herbarum in macrospore stage. A, Conidium on Stalk; b, Conidium after falling from Stalk; c, Another Form of Conidium, more typical of Sarcinula stage.

Pleospora Herbarum

An image depicting a Pleospora herbarum in macrospore stage. A, Conidium on Stalk; b, Conidium after…

An image of a fruiting plum branch.

Fruiting Branch of Plum

An image of a fruiting plum branch.

An image of a strawberry plant in flower. There are numerous short Stamens that are readily accessible to insects.

Strawberry Plant

An image of a strawberry plant in flower. There are numerous short Stamens that are readily accessible…

Also known as Kalmia latifolia. It is a flowering plant in the blueberry family. This image shows four different parts of the plant.

Spoonwood

Also known as Kalmia latifolia. It is a flowering plant in the blueberry family. This image shows four…

Also known as Puccinia graminis. This fungus is a significant detriment to cereal crops. It is currently spreading across Africa, Asia, and the Middle East. This image depicts a a spore of the fungus germinating and producing Sporidia on the tips of small stalks.

Stem Rust

Also known as Puccinia graminis. This fungus is a significant detriment to cereal crops. It is currently…

Also known as Pieris brassicae. An image of the larva and pupa of the large white cabbage butterfly.

Larva and Pupa of a Large White Cabbage Butterfly

Also known as Pieris brassicae. An image of the larva and pupa of the large white cabbage butterfly.

A medal with Adam Smith's profile image. He is cited as the father of modern economics and capitalism.

Adam Smith

A medal with Adam Smith's profile image. He is cited as the father of modern economics and capitalism.

A capital letter W with the image of a sailing ship in the background.

Pictorial Letter W

A capital letter W with the image of a sailing ship in the background.