"WINGS INVERTED. When the feathers point downwards." -Hall, 1862

Wings Inverted

"WINGS INVERTED. When the feathers point downwards." -Hall, 1862

"Goad-spur, 13th or 14th century. A spur without a rowel and having a single more or less blunt point. In the early middle ages this was the common form in Europe." -Whitney, 1911

Goad-Spur

"Goad-spur, 13th or 14th century. A spur without a rowel and having a single more or less blunt point.…

"Fig 27. - Bones of the right wing of a duck, Clangula islandica, A, shoulder, omos; B, elbow, ancon; C, wrist, carpus; D, end of principal finger; E, end of hand proper, metacarpus. AB, upper arm, brachium; BC, fore-arm, antibrachium; CD, whole hand or pinion, manus; composed of CE, hand proper or metacarpus, excepting d2; ED, or d2, d3, d4, fingers, digits, digiti, h, humerus; rd, radius; ul, ulna; sc, outer carpal, scapholunare or radiale; cu, inner carpal, cuneiforme or ulnare; these two composing wrist or carpus. mc, the compound hand-bone or metcarpus, composed of three metacarpal bones, bearing as many digits - the outer digit seated upon a protuberance at the head of the metacarpal, the other two situated at the end of the bone. d2, the outer or radial digit, commonly called the thumb or pollex, composed or two phalanges; d3, the middle digit, of two phalanges; d4, the inner or ulnar digit, of one phalanx d2 is the seat of the feathers of the bastard wing or alula. D to C (whole pinion), seat of the flight feathers called primaries; C to B (fore-arm), seat of the secondaries; at B and above it in direction of A, seat of tertiaries proper; below A, in direction of B, seat of scapularies (upon pteryla humeralis), often called tertiaries. The wing shown half-spread: complete extension would bring A B C D into a right line; in complete folding C goes to A, and D to B; all these motions nearly in the plane of the paper. The elbow-joint and wrist are such perfect hinges, that, in opening or closing the wing, C cannot sink below the paper, nor D fly up above the paper, as would otherwise be the effect of the pressure of the air upon the flight-feathers. Observe also rd and ul are two rods connecting B and C; the construction of their joining at B and C, and with each other, is such, that they can slide lengthwise a little upon each other. Now when the point C, revolving about B, approaches A in the arc of a circle, rd pushes on sc, while ul pulls back cu; the motion is transmitted to D, and makes this point approach B. conversely, in opening the wing, rd pulls back sc, and ul pushes on cu, making D recede from B. In other words, the angle A B C cannot be increased or diminished without similarly increasing or diminishing the angle B C D; so that no part of the wing can be opened or shut without automatically opening or shutting the rest..." Elliot Coues, 1884

The Bones of the Right Wing of a Duck

"Fig 27. - Bones of the right wing of a duck, Clangula islandica, A, shoulder, omos; B, elbow, ancon;…

Illustration of a parallelogram with diagonals AC and BD intersecting at point O.

Parallelogram With Diagonals

Illustration of a parallelogram with diagonals AC and BD intersecting at point O.

Illustration used to show "The two perpendiculars to the sides of an angle from any point in its bisector are equal."

Perpendiculars To The Sides Of An Angle

Illustration used to show "The two perpendiculars to the sides of an angle from any point in its bisector…

Illustration used to show "The two perpendiculars to the sides of an angle from any point not in its bisector are unequal."

Perpendiculars To The Sides Of An Angle

Illustration used to show "The two perpendiculars to the sides of an angle from any point not in its…

Illustration used to prove "The bisectors of the angles of a triangle are concurrent in a point which is equidistant from the three sides of the triangle."

Angle Bisectors In A Triangle

Illustration used to prove "The bisectors of the angles of a triangle are concurrent in a point which…

Illustration used to prove "The perpendicular bisectors of the sides of a triangle are concurrent in a point which is equidistant from the three vertices of the triangle."

Perpendicular Bisectors In A Triangle

Illustration used to prove "The perpendicular bisectors of the sides of a triangle are concurrent in…

Illustration used to show "Any two medians of a triangle intersect each other in a trisection point of each."

Medians In A Triangle

Illustration used to show "Any two medians of a triangle intersect each other in a trisection point…

This sign is used to indicate that a point of interest is nearby. A point of interest is a location that someone may find useful or interesting.

Point of Interest, Black and White

This sign is used to indicate that a point of interest is nearby. A point of interest is a location…

This sign is used to indicate that a point of interest is nearby. A point of interest is a location that someone may find useful or interesting.

Point of Interest, Color

This sign is used to indicate that a point of interest is nearby. A point of interest is a location…

This sign is used to indicate that a point of interest is nearby. A point of interest is a location that someone may find useful or interesting.

Point of Interest, Outline

This sign is used to indicate that a point of interest is nearby. A point of interest is a location…

This sign is used to indicate that a point of interest is nearby. A point of interest is a location that someone may find useful or interesting.

Point of Interest, Silhouette

This sign is used to indicate that a point of interest is nearby. A point of interest is a location…

"Gyroscope. Gyroscopic top, an instrument consisting of a heavy fly-wheel revolving about an axis one point of which is fixed, but which is otherwise free to move in any way." -Whitney, 1911

Gyroscope

"Gyroscope. Gyroscopic top, an instrument consisting of a heavy fly-wheel revolving about an axis one…

Star pattern.

Star Pattern

Star pattern.

The sculpture of comus depicts comus (God of festivities) with the attending spirit descending on a glancing star.

Sculpture of Comus

The sculpture of comus depicts comus (God of festivities) with the attending spirit descending on a…

The bowie knife is a type of sheath knife with a clip point. This knife has a unique twisted design.

Bowie Knife

The bowie knife is a type of sheath knife with a clip point. This knife has a unique twisted design.

Color flag of Algeria. Two equal vertical bands of green (hoist side) and white; a red, five-pointed star within a red crescent centered over the two-color boundary.

Flag of Algeria, 2009

Color flag of Algeria. Two equal vertical bands of green (hoist side) and white; a red, five-pointed…

Black and white outline flag of Algeria. Two equal vertical bands of green (hoist side) and white; a red, five-pointed star within a red crescent centered over the two-color boundary

Flag of Algeria, 2009

Black and white outline flag of Algeria. Two equal vertical bands of green (hoist side) and white; a…

Color flag of Angola. Two equal horizontal bands of red (top) and black with a centered yellow emblem consisting of a five-pointed star within half a cogwheel crossed by a machete (in the style of a hammer and sickle).

Flag of Angola, 2009

Color flag of Angola. Two equal horizontal bands of red (top) and black with a centered yellow emblem…

Black and white outline flag of Angola. Two equal horizontal bands of red (top) and black with a centered yellow emblem consisting of a five-pointed star within half a cogwheel crossed by a machete (in the style of a hammer and sickle)

Flag of Angola, 2009

Black and white outline flag of Angola. Two equal horizontal bands of red (top) and black with a centered…

Color flag of Aruba. Blue, with two narrow, horizontal, yellow stripes across the lower portion and a red, four-pointed star outlined in white in the upper hoist-side corner.

Flag of Aruba, 2009

Color flag of Aruba. Blue, with two narrow, horizontal, yellow stripes across the lower portion and…

Black and white outline flag of Aruba. Blue, with two narrow, horizontal, yellow stripes across the lower portion and a red, four-pointed star outlined in white in the upper hoist-side corner

Flag of Aruba, 2009

Black and white outline flag of Aruba. Blue, with two narrow, horizontal, yellow stripes across the…

Color flag of Australia. Blue with the flag of the UK in the upper hoist-side quadrant and a large seven-pointed star in the lower hoist-side quadrant known as the Commonwealth or Federation Star, representing the federation of the colonies of Australia in 1901; the star depicts one point for each of the six original states and one representing all of Australia's internal and external territories; on the fly half is a representation of the Southern Cross constellation in white with one small five-pointed star and four larger, seven-pointed stars.

Flag of Australia, 2009

Color flag of Australia. Blue with the flag of the UK in the upper hoist-side quadrant and a large seven-pointed…

Black and white outline flag of Australia. Blue with the flag of the UK in the upper hoist-side quadrant and a large seven-pointed star in the lower hoist-side quadrant known as the Commonwealth or Federation Star, representing the federation of the colonies of Australia in 1901; the star depicts one point for each of the six original states and one representing all of Australia's internal and external territories; on the fly half is a representation of the Southern Cross constellation in white with one small five-pointed star and four larger, seven-pointed stars

Flag of Australia, 2009

Black and white outline flag of Australia. Blue with the flag of the UK in the upper hoist-side quadrant…

Color flag of Azerbaijan. Three equal horizontal bands of blue (top), red, and green; a crescent and eight-pointed star in white are centered in red band.

Flag of Azerbaijan, 2009

Color flag of Azerbaijan. Three equal horizontal bands of blue (top), red, and green; a crescent and…

Black and white outline flag of Azerbaijan. Three equal horizontal bands of blue (top), red, and green; a crescent and eight-pointed star in white are centered in red band

Flag of Azerbaijan, 2009

Black and white outline flag of Azerbaijan. Three equal horizontal bands of blue (top), red, and green;…

Color flag of Burkina Faso. Two equal horizontal bands of red (top) and green with a yellow five-pointed star in the center.

Flag of Burkina Faso, 2009

Color flag of Burkina Faso. Two equal horizontal bands of red (top) and green with a yellow five-pointed…

Black and white outline flag of Burkina Faso. Two equal horizontal bands of red (top) and green with a yellow five-pointed star in the center

Flag of Burkina Faso, 2009

Black and white outline flag of Burkina Faso. Two equal horizontal bands of red (top) and green with…

Color flag of Burundi. Divided by a white diagonal cross into red panels (top and bottom) and green panels (hoist side and fly side) with a white disk superimposed at the center bearing three red six-pointed stars outlined in green arranged in a triangular design (one star above, two stars below).

Flag of Burundi, 2009

Color flag of Burundi. Divided by a white diagonal cross into red panels (top and bottom) and green…

Black and white outline flag of Burundi. Divided by a white diagonal cross into red panels (top and bottom) and green panels (hoist side and fly side) with a white disk superimposed at the center bearing three red six-pointed stars outlined in green arranged in a triangular design (one star above, two stars below)

Flag of Burundi, 2009

Black and white outline flag of Burundi. Divided by a white diagonal cross into red panels (top and…

Color flag of Central African Republic. Four equal horizontal bands of blue (top), white, green, and yellow with a vertical red band in center; a yellow five-pointed star to the hoist side of the blue band.

Flag of Central African Republic, 2009

Color flag of Central African Republic. Four equal horizontal bands of blue (top), white, green, and…

Black and white outline flag of Central African Republic. Four equal horizontal bands of blue (top), white, green, and yellow with a vertical red band in center; a yellow five-pointed star to the hoist side of the blue band

Flag of Central African Republic, 2009

Black and white outline flag of Central African Republic. Four equal horizontal bands of blue (top),…

Color flag of Chile. Two equal horizontal bands of white (top) and red; a blue square the same height as the white band at the hoist-side end of the white band; the square bears a white five-pointed star in the center representing a guide to progress and honor; blue symbolizes the sky, white is for the snow-covered Andes, and red represents the blood spilled to achieve independence.

Flag of Chile, 2009

Color flag of Chile. Two equal horizontal bands of white (top) and red; a blue square the same height…

Black and white outline flag of Chile. Two equal horizontal bands of white (top) and red; a blue square the same height as the white band at the hoist-side end of the white band; the square bears a white five-pointed star in the center representing a guide to progress and honor; blue symbolizes the sky, white is for the snow-covered Andes, and red represents the blood spilled to achieve independence

Flag of Chile, 2009

Black and white outline flag of Chile. Two equal horizontal bands of white (top) and red; a blue square…

Color flag of China. Red with a large yellow five-pointed star and four smaller yellow five-pointed stars (arranged in a vertical arc toward the middle of the flag) in the upper hoist-side corner.

Flag of China, 2009

Color flag of China. Red with a large yellow five-pointed star and four smaller yellow five-pointed…

Black and white outline flag of China. Red with a large yellow five-pointed star and four smaller yellow five-pointed stars (arranged in a vertical arc toward the middle of the flag) in the upper hoist-side corner

Flag of China, 2009

Black and white outline flag of China. Red with a large yellow five-pointed star and four smaller yellow…

Color flag of Congo, Democratic Republic of the. Sky blue field divided diagonally from the lower hoist corner to upper fly corner by a red stripe bordered by two narrow yellow stripes; a yellow, five-pointed star appears in the upper hoist corner.

Flag of Democratic Republic of the Congo, 2009

Color flag of Congo, Democratic Republic of the. Sky blue field divided diagonally from the lower hoist…

Black and white outline flag of Congo, Democratic Republic of the. Sky blue field divided diagonally from the lower hoist corner to upper fly corner by a red stripe bordered by two narrow yellow stripes; a yellow, five-pointed star appears in the upper hoist corner

Flag of Democratic Republic of the Congo, 2009

Black and white outline flag of Congo, Democratic Republic of the. Sky blue field divided diagonally…

Color flag of Djibouti. Two equal horizontal bands of light blue (top) and light green with a white isosceles triangle based on the hoist side bearing a red five-pointed star in the center.

Flag of Djibouti, 2009

Color flag of Djibouti. Two equal horizontal bands of light blue (top) and light green with a white…

Black and white outline flag of Djibouti. Two equal horizontal bands of light blue (top) and light green with a white isosceles triangle based on the hoist side bearing a red five-pointed star in the center

Flag of Djibouti, 2009

Black and white outline flag of Djibouti. Two equal horizontal bands of light blue (top) and light green…

Color flag of Ghana. Three equal horizontal bands of red (top), yellow, and green, with a large black five-pointed star centered in the yellow band; uses the popular pan-African colors of Ethiopia; similar to the flag of Bolivia, which has a coat of arms centered in the yellow band.

Flag of Ghana, 2009

Color flag of Ghana. Three equal horizontal bands of red (top), yellow, and green, with a large black…

Black and white outline flag of Ghana. Three equal horizontal bands of red (top), yellow, and green, with a large black five-pointed star centered in the yellow band; uses the popular pan-African colors of Ethiopia; similar to the flag of Bolivia, which has a coat of arms centered in the yellow band

Flag of Ghana, 2009

Black and white outline flag of Ghana. Three equal horizontal bands of red (top), yellow, and green,…

Color flag of Guinea-Bissau. Two equal horizontal bands of yellow (top) and green with a vertical red band on the hoist side; there is a black five-pointed star centered in the red band; uses the popular pan-African colors of Ethiopia.

Flag of Guinea-Bissau, 2009

Color flag of Guinea-Bissau. Two equal horizontal bands of yellow (top) and green with a vertical red…

Black and white outline flag of Guinea-Bissau. Two equal horizontal bands of yellow (top) and green with a vertical red band on the hoist side; there is a black five-pointed star centered in the red band; uses the popular pan-African colors of Ethiopia

Flag of Guinea-Bissau, 2009

Black and white outline flag of Guinea-Bissau. Two equal horizontal bands of yellow (top) and green…

Color flag of Israel. White with a blue hexagram (six-pointed linear star) known as the Magen David (Shield of David) centered between two equal horizontal blue bands near the top and bottom edges of the flag.

Flag of Israel, 2009

Color flag of Israel. White with a blue hexagram (six-pointed linear star) known as the Magen David…

Black and white outline flag of Israel. White with a blue hexagram (six-pointed linear star) known as the Magen David (Shield of David) centered between two equal horizontal blue bands near the top and bottom edges of the flag

Flag of Israel, 2009

Black and white outline flag of Israel. White with a blue hexagram (six-pointed linear star) known as…

Color flag of Jordan. Three equal horizontal bands of black (top), representing the Abbassid Caliphate, white, representing the Ummayyad Caliphate, and green, representing the Fatimid Caliphate; a red isosceles triangle on the hoist side, representing the Great Arab Revolt of 1916, and bearing a small white seven-pointed star symbolizing the seven verses of the opening Sura (Al-Fatiha) of the Holy Koran; the seven points on the star represent faith in One God, humanity, national spirit, humility, social justice, virtue, and aspirations; design is based on the Arab Revolt flag of World War I.

Flag of Jordan, 2009

Color flag of Jordan. Three equal horizontal bands of black (top), representing the Abbassid Caliphate,…

Black and white outline flag of Jordan. Three equal horizontal bands of black (top), representing the Abbassid Caliphate, white, representing the Ummayyad Caliphate, and green, representing the Fatimid Caliphate; a red isosceles triangle on the hoist side, representing the Great Arab Revolt of 1916, and bearing a small white seven-pointed star symbolizing the seven verses of the opening Sura (Al-Fatiha) of the Holy Koran; the seven points on the star represent faith in One God, humanity, national spirit, humility, social justice, virtue, and aspirations; design is based on the Arab Revolt flag of World War I

Flag of Jordan, 2009

Black and white outline flag of Jordan. Three equal horizontal bands of black (top), representing the…

Color flag of Liberia. 11 equal horizontal stripes of red (top and bottom) alternating with white; there is a white five-pointed star on a blue square in the upper hoist-side corner; the design was based on the US flag.

Flag of Liberia, 2009

Color flag of Liberia. 11 equal horizontal stripes of red (top and bottom) alternating with white; there…

Black and white outline flag of Liberia. 11 equal horizontal stripes of red (top and bottom) alternating with white; there is a white five-pointed star on a blue square in the upper hoist-side corner; the design was based on the US flag

Flag of Liberia, 2009

Black and white outline flag of Liberia. 11 equal horizontal stripes of red (top and bottom) alternating…

Color flag of Malaysia. 14 equal horizontal stripes of red (top) alternating with white (bottom); there is a blue rectangle in the upper hoist-side corner bearing a yellow crescent and a yellow 14-pointed star; the crescent and the star are traditional symbols of Islam; the design was based on the flag of the US.

Flag of Malaysia, 2009

Color flag of Malaysia. 14 equal horizontal stripes of red (top) alternating with white (bottom); there…

Black and white outline flag of Malaysia. 14 equal horizontal stripes of red (top) alternating with white (bottom); there is a blue rectangle in the upper hoist-side corner bearing a yellow crescent and a yellow 14-pointed star; the crescent and the star are traditional symbols of Islam; the design was based on the flag of the US

Flag of Malaysia, 2009

Black and white outline flag of Malaysia. 14 equal horizontal stripes of red (top) alternating with…

Color flag of Marshall Islands. Blue with two stripes radiating from the lower hoist-side corner - orange (top) and white; there is a white star with four large rays and 20 small rays on the hoist side above the two stripes.

Flag of Marshall Islands, 2009

Color flag of Marshall Islands. Blue with two stripes radiating from the lower hoist-side corner - orange…

Black and white outline flag of Marshall Islands. Blue with two stripes radiating from the lower hoist-side corner - orange (top) and white; there is a white star with four large rays and 20 small rays on the hoist side above the two stripes

Flag of Marshall Islands, 2009

Black and white outline flag of Marshall Islands. Blue with two stripes radiating from the lower hoist-side…

Color flag of Mauritania. Green with a yellow five-pointed star above a yellow, horizontal crescent; the closed side of the crescent is down; the crescent, star, and color green are traditional symbols of Islam.

Flag of Mauritania, 2009

Color flag of Mauritania. Green with a yellow five-pointed star above a yellow, horizontal crescent;…

Black and white outline flag of Mauritania. Green with a yellow five-pointed star above a yellow, horizontal crescent; the closed side of the crescent is down; the crescent, star, and color green are traditional symbols of Islam

Flag of Mauritania, 2009

Black and white outline flag of Mauritania. Green with a yellow five-pointed star above a yellow, horizontal…

Color flag of Morocco. Red with a green pentacle (five-pointed, linear star) known as Sulayman's (Solomon's) seal in the center of the flag; red and green are traditional colors in Arab flags, although the use of red is more commonly associated with the Arab states of the Persian gulf; design dates to 1912.

Flag of Morocco, 2009

Color flag of Morocco. Red with a green pentacle (five-pointed, linear star) known as Sulayman's (Solomon's)…

Black and white outline flag of Morocco. Red with a green pentacle (five-pointed, linear star) known as Sulayman's (Solomon's) seal in the center of the flag; red and green are traditional colors in Arab flags, although the use of red is more commonly associated with the Arab states of the Persian gulf; design dates to 1912

Flag of Morocco, 2009

Black and white outline flag of Morocco. Red with a green pentacle (five-pointed, linear star) known…

Color flag of Nauru. Blue with a narrow, horizontal, yellow stripe across the center and a large white 12-pointed star below the stripe on the hoist side; the star indicates the country's location in relation to the Equator (the yellow stripe) and the 12 points symbolize the 12 original tribes of Nauru.

Flag of Nauru, 2009

Color flag of Nauru. Blue with a narrow, horizontal, yellow stripe across the center and a large white…