Optical Principles and Diagrams

A collection of scientific diagrams illustrating optical principles, including lens behavior, focal points, and light refraction, accompanied by historical context in photography.

Engraving depicting multiple images in inclined mirrors. Dated 19th Century

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Technology in Stockholm 1948-1958. Photographic manual. Nature and Culture. Stockholm. 1942. p. 72.

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Technology in Stockholm 1948-1958.genom the aperture aperture ABCD parallel to the optical axis of incident beam after breaking unit is combined in a point F (focal point), while it with the obliquely incident beam OH parallel beams not have any definite focal point.

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Technology in Stockholm 1948-1958.sprising curves.

Engraving depicting John Dalton's diagram showing the reason for the curved appearance of the aurora due to the curvature of the Earth and it's atmosphere. John Dalton (1766-1844) an English chemist, physicist, and meteorologist. Dated 18th Century

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Technology in Stockholm 1948-1958. Description of the X-ray nature and properties.Bäckström, Helmer. Photographic manual. Other revised edition. Nature and Culture. Stockholm. 1948. p. 1102-1110.

Part of the human body with a deviation ..

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Technology in Stockholm 1948-1958.Tamkelning, Chemistry.

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Technology in Stockholm 1948-1958.The chromatic aberration at a simple lens, an acro and an apochromat. (F) is the filmplanet. For more info see: Bäckström, Helmer. Photographic manual. Nature and Culture. Stockholm. 1942. p. 85.

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Technology in Stockholm 1948-1958.ultraviolet radiation, lighting.

Engraving depicting multiple images in inclined mirrors. Dated 19th Century

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Technology in Stockholm 1948-1958.sprising curves.

A woodcut engraving depicting the method of obtaining height and distance of reservoir at B from the fountain at C and size of fountain. Dated 18th century

An engraving depicting the method of obtaining height and distance of a reservoir B) for the fountain C) and the size of the fountain. Dated 18th century

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Technology in Stockholm 1948-1958.Absorption of X-rays.

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Technology in Stockholm 1948-1958.Additive and subtractive multi-color methods.Bäckström, Helmer. Photographic manual. Other revised edition. Nature and Culture. Stockholm. 1948. p. 975

Labor Inspectorate Photo Collection. 5x5 Various schematic drawings stamping shading. undated

Figure 3-5 for NASA Document TM-X-356

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Technology in Stockholm 1948-1958.Some optical data for a new and an old chromato.

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Technology in Stockholm 1948-1958.International Lighting Commission.

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Technology in Stockholm 1948-1958.Bromstrålningenens and its distribution on different wavelengths for voltages between 20 and 50 kV. The image shows partly the sharp limit against short waves and its displacement with the voltage according to. DUANE-HUNTS LAW, partly how the intensity is growing quickly with the voltage especially for short waves, so that the surface of the radiation "or" effective wavelength "is shifted in the same rich in voltage increase. Bäckström, Helmer. Photographic manual. Other revised edition. Nature and Culture. Stockholm. 1948. p. 1106.

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Technology in Stockholm 1948-1958.spectral sensitivity to an Agj-free AGBR layer. Full drawing line - developed stock, dashed line - directly blackened stock.

Diagram depicting Galileo's experiment to measure the force of a ball rolled down an inclined plane. Galileo Galilei (1564-1642) an Italian polymath. Dated 17th century

Klomp Johannes Franziskus (1865-1946), St. Felizitas (expansion), Lüdinghausen (1904-1906): Floor plan porch and longitudinal ship. Tusche, pencil watercolored on transparent, 60.8 x 100 cm (including scan edges) Klomp Johannes Franziskus (1865-1946): St. Felizitas, Lüdinghausen. Erweiterung

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Technology in Stockholm 1948-1958.These images intends to explain the emergence of the harder gradation at magnification with directed light than with diffuse light. For more info see: Bäckström, Helmer. Photographic manual. Other revised edition. Nature and Culture. Stockholm. 1948. p. 646.

Engraving depicting an experiment involving an inclined plane used to demonstrate the action of gravity on a falling body. Dated 18th Century

leisure, riddle, wood engraving, 1884,

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Technology in Stockholm 1948-1958.Bränvängdens influence on the angle. If the object distance is constant, the image angle increases when the lens with shorter focal length is used. Thus: Shorter focal length - larger image angle, longer focal length - less image angle. For more info see: Bäckström, Helmer. Photographic manual. Nature and Culture. Stockholm. 1942. p. 58.

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Technology in Stockholm 1948-1958.Diagram of extinct values for bluefilter.For more info SE: Sjöstedt 1941?

The divine harmony of the universe, tuned by the hand of God. From Robert Fludd 'Ultriusque cosmi... historia', Oppenheim, 1617-1619. Engraving

Illustration showing FARADAY'S experiment with a solenoid. The movement of the bar magnet (right) in and out of the coil of wire causes an electric current to flow in the wires A and B: this is detected by the magnetic needle (left). From Bence Jones 'The Life and Letters of Faraday', London; 1870

Illustration showing cross section of cables from the Brooklyn Suspension Bridge, New York, designed and built by John Augustus Roebling (1806-1869), and his son Washington Augustus Roebling (1837-1926): opened 1883. Arrangement of 19 Strands, each of. 278 wires, which made up the main cables. 1883

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Technology in Stockholm 1948-1958.Då man considers a "around" objects close by two eyes (V and H), you see a larger part of its circumference (namely AD) than If one looks only with one eye (AC or BD). A camera lens corresponds to an eye. For more info see: Bäckström, Helmer. Photographic manual. Nature and Culture. Stockholm. 1942. p. 166.

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Technology in Stockholm 1948-1958.Diagram of Compton radiation.For more info See: Bäckström, Helmer. Photographic manual. Other revised edition. Nature and Culture. Stockholm. 1948. p. 1108.

Rene Descartes' model of the structure of the Universe, 1668. Artist: Unknown

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Technology in Stockholm 1948-1958.Diagram for the synchronization of flash and shutter on drawer camera. Top image: The time the shutter is fully open. The center image: synchronization with flash when the shutter is about to open. Lower image: The time for how long it takes for the shutter to be opened and closed. For more info see: Bäckström, Helmer. Photographic manual. Other revised edition. Nature and Culture. Stockholm. 1948. p. 776-780.

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Technology in Stockholm 1948-1958.The drawing of what is probably a curtain shutters (left) and a sector closer (right) .Bäckström, Helmer. Photographic manual. Nature and Culture. Stockholm. 1942. p. 220-224.

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Technology in Stockholm 1948-1958.spretty -diapositive, blackening-negative.

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material.

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Institute of Technology in Stockholm 1948-1958. Characteristic curves for X-ray film and paper with and without reinforcement screens.

Plate showing diagram of the optics of a reflecting telescope (Fig 29), 1704. Artist: Unknown

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Technology in Stockholm 1948-1958.vandring of Vagabonding AG + ions to a negatively charged sprout (developer sprouts p.291) in a silver bromide crystal. After n.f. Mott.For more info See: Bäckström, Helmer. Photographic manual. Nature and Culture. Stockholm. 1942. p. 289-294.

A diagram of the Solar system, showing the orbits of some of the minor planets. Dated 19th century

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Technology in Stockholm 1948-1958. The limitation of the effective numerical aperture of the condenser, by the absence of immersion a mounting agent.

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Technology in Stockholm 1948-1958.sprising curves.

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Technology in Stockholm 1948-1958.Offärsensitivity of Agfa infrared plates. For more info see: Agfa VI p. 113

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Technology in Stockholm 1948-1958. The radiation flow + Lamberts Cosinus law for the emulsion.

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Technology in Stockholm 1948-1958.Schematic production of a bromsilverkristalls building. The silver ions are marked with plus, the bromide ions with minus. It within a dashed circle marked the silver ion between the third and fourth ion rows is "vagabond" # its original location has been indicated with an empty circle in the second ion row from the top. For more info see: Bäckström, Helmer. Photographic manual. Nature and Culture. Stockholm. 1942. p. 294.

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Technology in Stockholm 1948-1958.Lamberts Cosinus Law for the lighting and radiance. Photometric foundation.

Descartes' model of the Universe, 1668. Artist: Unknown

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Technology in Stockholm 1948-1958.The temperature dependence on the photoelectric effect. For more info SE: Lange in

Illustration showing The magnetic force of the Earth operating along An infinited of curves starting from every point of the equator that divides the sphere into t'wo parts. From William Gilbert De Magnete London, l600

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Technology in Stockholm 1948-1958.isophotes: a curve in a chart that connects points with the same light intensity from a given source.

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Technology in Stockholm 1948-1958.Léon Gaumont's design device for tri-color memoatography.

Geometric figures, Bernard Picart (workshop or), 1732 print On the left a punctured paper with geometric figures. On the left other geometric figures. Amsterdam paper etching planimetry, geometry

Atoms are like tiny solar systems with electron 'planets' revolving round protons and neutrons. (a) Hydrogen is the simplest with one proton and one electron. (b) Heavy hydrogen or deuterium has a neutron as well. (c) Carbon has 6 electrons, 6 protons and 4 neutrons. 1950

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Technology in Stockholm 1948-1958.färktriangel.

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Technology in Stockholm 1948-1958.Diagram of human eye spectral sensitivity distribution.Kosmos. SWEDISH SCIENCE PRESS. Uppsala. 1945, p. 39.

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Technology in Stockholm 1948-1958.Olika dot bulbs.

Theoretical cycle, Lenoir engine, vintage engraved illustration. Industrial encyclopedia E.-O. Lami - 1875.

Figures 208-212. Original caption: From: Surveying Instruments, Their History and Classroom Use, by Edmund R. Kiely, Bureau of Publications, Teachers College, Columbia University, New York, 1947.

The divine harmony of the universe by Robert Fludd (1574-1637) an English Paracelsian physician with both scientific and occult interests. Dated 17th Century

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Technology in Stockholm 1948-1958.Antrygmatens. For more info see: Bäckström, Helmer. Photographic manual. Nature and Culture. Stockholm. 1942. p. 124-125.

Bliven's airship (blueprint)

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Technology in Stockholm 1948-1958. Distribution of clarity and color strength within the color tone. The solid lines bind colors with the same clarity, the dotted colors with the same color strength. For more info see: Bäckström, Helmer. Photographic manual. Other revised edition. Nature and Culture. Stockholm. 1948. p. 942.

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Technology in Stockholm 1948-1958.fig. 965 Schematic preparation of the repression taking from a high pressure form. T Print form, P paper, D deck. Fig. 966 The staining of the gravure molding form with tampon. Fig. 967 schematic representation of the gravure press. Fig. 968 schematic representation of the plant pressure.

Chart showing the evolution of aircraft engines from 1903 to 1918. The chart includes the horsepower, weight, and power of various engines, including the Liberty engine, from 1911 to 1918. The chart was issued by the National Advisory Committee for Aeronautics in May 1918.

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Technology in Stockholm 1948-1958. Curve for: vertical Lighting of the image, percentage illuminated compared to the lighting in the middle of the image. horizontally the angle of incidence of the main beam.

Saturn, 1659. Artist: Unknown

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Technology in Stockholm 1948-1958.Curvor for spectral sensitivity.

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Technology in Stockholm 1948-1958.Bsortionskurvor for silver bromide.For more info See: Mees, Kenneth C.e. The Theory of the Photographic Process. Macmillian Co. New York. 1942. p. 285

Drawings of Saturn, Jupiter, Mars and Venus as observed through a telescope. Dated 17th century

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Technology in Stockholm 1948-1958. On the curve, the veil 1, the threshold 2, the maximum range 6 and the solarization 7. For more info see: Bäckström, Helmer. Photographic manual. Nature and Culture. Stockholm. 1942. p. 266-272.

An engraving depicting the alphabet of Foy and Breguet's needle-telegraph. Dated 19th century

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Technology in Stockholm 1948-1958.spretty measurement. Incident light / through light - transparency.

Thorax of Hornet

Positions of the planet Uranus, vintage engraved illustration. Magasin Pittoresque (1882).

Tips for the study of the sky in 1877, vintage engraved illustration. Magasin Pittoresque 1876.

Diagram showing how a dust whirlwind rotates and spins. Dated 19th Century

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Technology in Stockholm 1948-1958.Diagram of color filters.

Isaac Newton (1642-1727). English physicist, astronomer and mathematician. 'Opuscula Mathematica, Philosophica et Philologica'. Volume II: Philosophica. Illustrations of optics lessons. Published in Lausanne and Geneva, 1744. Newton's original work dates from 1686.

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Technology in Stockholm 1948-1958. . Ry eye. Figure 7. The impulses in individual synnerves, when retina is illuminated with weak light. For more info see: cosmos. SWEDISH SCIENCE PRESS. Uppsala. 1945, p. 29.

Without Stereoscopic Effect 1 Made 1875-1899 United States. Photolithograph, stereo . Unknown

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Technology in Stockholm 1948-1958. Device to increase the recording speed.

Phases of Saturn

Cross section of an oak trunk presenting many slots due to sunburn, vintage engraved illustration.

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Technology in Stockholm 1948-1958.Rotation deep pressure.

Cross section of an oak trunk presenting many slots due to sunburn, vintage engraving. Cross section of an oak trunk presenting many slots due to sunburn, vintage engraved illustration. Copyright: xZoonar.com/PatrickxGuenettex 10648287

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Technology 1948-58. Motifus depicting "Agfa Brovira, Extrahart" (for more text see picture).

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Technology in Stockholm 1948-1958. Blend, Newton's center of gravity construction of mix.

Engraving depicting a section of the moon in the region of Mare Imbrium with details showing craters Newton and Plato under different lighting conditions. Dated 18th century

With Stereoscopic Effect 2 Made 1875-1899 United States. Photolithograph, stereo . Unknown

Pictorial plaque of the Pioneer F Spacecraft destined for interstellar space. Left diagram indicates the position of the Sun. At bottom are the planets, ranging outward from the Sun, with the spacecraft trajectory arching away from Earth. 1972.

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Technology in Stockholm 1948-1958.Diagram of Fotoström.Lange in

This atlas of the giant asteroid Vesta was created from images taken as NASA's Dawn mission flew around the object, also known as a protoplanet.

Brix & Genzmer, Groß-Berlin 1910 (1908-1910) competition: Matrix of the required construction areas. Ink, ink colored, watercolor on cardboard, 78.6 x 106.6 cm (including scan edges)

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Technology in Stockholm 1948-1958. Description of the silver image is converted in colored ferrocyanide. For more info see: Bäckström, Helmer. Photographic manual. Other revised edition. Nature and Culture. Stockholm. 1948. p. 593.

Skiopticone image. Diagram of different types of peat manure.

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Technology in Stockholm 1948-1958.The mutual placement of projector, screen and spectators when focusing projects and overview projection.

Skiopticon image from the Department of Photography at the Royal Institute of Technology. Use by Professor Helmer Bäckström as lecture material. Bäckström was Sweden's first professor in photography at the Royal Institute of Technology in Stockholm 1948-1958.exampel on two emulsion types. Ilford's Q emulsion as well as normal emulsion.Bäckström, Helmer. Photographic manual. Other revised edition. Nature and Culture. Stockholm. 1948. p. 1088.

A chart illustrates the fall of shots fired by thethe Mark 7 16-inch/50-caliber guns aboard thebattle ship USS IOWA (BB-61), at Vieques Island in July 1984. The chart is overlaid with a diagram of prominent buildings. Country: Unknown

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