Delaware state flag
Historical flag of Georgia, a state in the southern United States of America, from 2001 to 2003.
Historical flag of Georgia, a state in the southern United States of America, from July 1, 1956, to January 31, 2001.
Maine state flag
Illinois state flag
Florida state flag
Idaho state flag
Kentucky state flag
Flag of the state of Georgia
California state flag
Kansas state flag
Wisconsin state flag
Wyoming state flag
Historical flag of the United States of America
Oregon state flag
Maryland state flag
Alabama state flag
Rhode Island state flag
Flag of Indiana
Colorado state flag
Hawaii state flag
Flag of Finland
New Mexico state flag
New Hampshire state flag
Early 19th-century whaleboat
Vermont state flag
Connecticut state flag
Missouri state flag
Iowa state flag
North Carolina state flag
Oklahoma state flag
South Dakota state flag
Nebraska state flag
Virginia state flag
Man and penny-farthing, 19th century illustration
Paraguay locals, 19th C illustration
19th Century Indian people, illustration
19th Century King of Siam, illustration
19th Century South American Mayoruna man, illustration
19th Century South American Ticuna man, illustration
19th Century South American Juri man, illustration
19th Century South American Marahua man, illustration
19th Century Timor couple, illustration
19th Abyssinian warrior, illustration
Dakota Native American man, 19th century illustration
Icon Honduran flag on white circle with a long shadow
John Scott Haldane, caricature
Arkansas state flag
Montana state flag
Mississippi state flag
Ohio state flag
Utah state flag
Flag of Nova Scotia, a Canadian province located on the eastern seaboard of North America.
Flag of Dominica
Flag of Egypt
19th Century Mandinka women, illustration
19th Century Norwegian women, illustration
19th Century Chinese hairstyles, illustration
Lallement's velocipede, 19th century illustration
North American indian, illustration
17th century Madagascan men, 19th Century illustration
19th Abyssinian men, illustration
Louisiana state flag
Minnesota state flag
New Jersey state flag
16th Century Tupinamba men, illustration
Michigan state flag
Robert Bulwer-Lytton, British statesman
paper cutting
Crawford Long, US surgeon
Carbon microphone, 19th century illustration
Watt's steam engine, historical artwork
19th Century internal combustion engine
Tabarin character, 19th Century illustration
The flower girl and the undertaker, 19th C illustration
New Zealand man, 19th Century illustration
Ancient Assyrian bas relief, illustration
Henrik Ibsen, Norwegian playwright
Flag of the Dominican Republic
silhouette of the smith on white background
William Cullen, Scottish physician
Brian Cox, caricature
Flag of the Yukon Territory
Icon America flag on white circle with a long shadow
Star of David
Filipino man wearing salakot, 19th century illustration
Direct steerer tricycle, 19th century illustration
19th Century Sardinian women, illustration
Celeripede bicycle, 19th century illustration
Draisine, 19th century illustration
Pedestrian curricle, 19th century illustration
Dalzell's rear drive, 19th century illustration
Man riding penny-farthing, 19th century illustration
Chief Badumbe of Ancient Sudan, illustration
19th Century Java tribal Chief, illustration
Arizona state flag
South Carolina state flag
Tennessee state flag
Alaska state flag
Washington state flag
backpack icon on white circle with a long shadow
19th Century parallel-flow turbine
Apollo mission profile for a lunar landing and return, outlining the various stages along the mission.
Spanish spider torture device, 19th century illustration
Flag of Cape Verde
Martian canals, historical artwork
Horace by Rotrou, 19th Century illustration
Albrecht Durer, German artist
Gods on Mount Olympus, 19th Century illustration
Victor Hugo, French Author, illustration
Michelangelo, Italian artist, 19th Century illustration
Michelangelo, Italian artist, 19th century illustration
August Kekule, German chemist
Georg Riemann, German mathematician
Arthur Cayley, caricature
Augustin Cauchy, caricature
Charles Babbage, caricature
David Hilbert, caricature
Ernst Kummer, caricature
James Watt, caricature
Joseph Priestley, caricature
Henri Poincare, caricature
Karl Friedrich Gauss, caricature
Lord Kelvin, caricature
Nikola Tesla, caricature
Dmitri Mendeleev, caricature
Joseph Lagrange, caricature
Flag of Equatorial Guinea
Flag of Fiji
Newton's telescope, historical artwork
19th Century amphibious vehicle, artwork
19th Century safety lamps, artwork
Nasmyth's steam hammer, artwork
B. F. Skinner, caricature
John Maynard Smith, caricature
Cicero, Roman philosopher
Jeremy Bentham, British philosopher
Sallust, Roman historian
Agrippa, Roman general
Seneca the Elder, Roman orator
Persius, Roman poet
Edward Kelley, English astrologer
Charles Darwin, caricature
Joseph Lister, British surgeon
vector silhouette of the smith on white background
A vector illustration of shield icon sets
Flag of Ecuador
19th Century Russian bath house, illustration
fortress icon
Duplex bicycle penny-farthing, 19th century illustration
Diamond frame safety bicycle, 19th century illustration
Coventry chair tricycle, 19th century illustration
Elliott quadricycle, 19th century illustration
Union spring frame safety bicycle, 19th century illustration
Velox spring frame safety bicycle, 19th century illustration
19th Century Javanese dancer, illustration
Johnson's pedestrian curricle, 19th century illustration
The three families of conic sections (ellipse, parabola, and hyperbola) result from intersecting a plane with a double cone.
Representation of an ellipsoid, a closed surface such that its intersection with any plane will produce an ellipse or a circle.
15th century courtesan house, 19th century illustration
17th century German cabaret, 19th century illustration
Cabaret, 19th century illustration
Felix Faure, President of France
George IV, British monarch
Napoleon III, Emperor of France, 19th Century illustration
19th Century Sardinian men, illustration
19th Century washing machine, artwork
Old Babylon jew, 19th C illustration
15th C English clothing, 19th C illustration
Flowers and butterfly
Flowers and butterflies
Lucky clouds and butterflies
Signs of the Zodiac, historical artwork
palette and paintbrush on white circle with a long shadow
Hammer and sickle on a white background vector illustration
Brahmin wedding, India, 19th century illustration
Salisbury cathedral
的
Phrenology head, illustration
Pennsylvania state flag
Compound pier
Basic features of a modern road bicycle.
Glycolysis, the dissolution of sugar, is carried out in the cytoplasm of cells.
Electrostatic precipitator, a common particle collection device at fossil-fuel power-generating stations.
A saddlepoint, or entry, in a payoff matrix at which the expected gain of each participant has the highest guaranteed payoff.
In variable-sum games each payoff depends on both players' actions, so each matrix entry lists two payoffs, one for each player.
The second reduction for an n-person voting game theory, illustrating the strategies least suitable for each participant.
The normal, or perpendicular, at each point of a surface defines the corresponding tangent plane, and vice versa.
Each point on the Riemann sphere corresponds to a point on the plane. The ray tangent to the north pole corresponds to infinity.
Operating principle of a parallel-flow heat exchanger.
Schematic diagram of a fluidized-bed combustion boiler.