Julian datum. Counting days commenced. 01.01.1960 had
JD 2 436 935.00 astro. days
Babylonian year of 365 days
Babylonian land title and law suits on clay tablets
Babylonians used analog devices for surveying and map making
Glass in Egypt
Northern cubit a standard of length. Mesopotamia, Egypt, N Africa, India, China
Egyptian river gauge called the Palermo stone.
Egyptian world a rectangular box, Egypt in centre, sky was a flat or domed ceiling supported by columns or high mountains.
Glass in Mesopotamia. A lens from Nineveh in Br. Museum
Pyramids erected first at Gizeh by Cheops et al. Base perimeter = ½ geog. mile
Egyptian standard of length on grey basalt column 53 cm long.
Egyptian foot = ½ northern cubit = 13.2 inch. Egypt and Indus valley.
Gudea, High priest shown on tablet holding a plane table on his knees.
Statue of Gidea in Louvre, shows Sumerian cubit = 30 fingers =
This standard used to set out Tower of Babel (Ziggurat of Ur).
Egyptian papyrus map of Nubian goldmines near Koptos.
Crude lenses in Crete and coast of Asia Minor, made of rock crystal.
Nine Chinese bronze vases depicted nine provinces + mountains, rivers etc
Babylonians used astronomical phenomena for astrological purposes.
Chaldeans divided day and night into 12 hours each.
Predicted eclipses, equator divided to 360º, named 12 signs of
Mathematics for surveyors began with the triangle.
Chinese algebra began
Greeks solved problems by geometrical means.
Babylonians advanced into cubic and biquadratic equations.
Egyptian unequal hour shadow clock.
Egyptian papyrus on geometrical problems.
Babylonian clay tablet on survey problems. Contained threats to those
who might remove boundary stones.
Egypt- much practical geometry used in land surveying .
Babylonia, Egypt. Computing area and volumes requiring fractions and pi.
Egypt, Rhind papyrus describing mensuration, fractions, areas.
Egyptian Royal Cubit of Amenhotep I. Now in Louvre.
to -200. Chinese surveyors had plumbob, gnomon, water level, counting rods, hand computer, magnetic c ompass, square, groma.
to -550. Many relics show Babylonian boundary surveys.
Chinese daycount not dependent on sun or moon. Sexagesimal cycles.
Clepsydra in Babylonia and Egypt.
Text of the time of kurigalzu on ancient boundary stone.
Egyptian tomb with pictures of sounding Nile with lead line.
First record of lunar eclipse in China.
Or -1220. Sacred cubit of Moses = 25 in. = Northern cubit.
28 lunar mansions = moon stations of zodiac in Chinese literature.
Lunation of 29.53 days in China
Ramses II (-1292t o -1225) instructed to erect tomb for a surveying engineer.
First record of solar eclipse in China.
Egypt. Simple and complex geometrical figures on urns etc
Official topographic description of China by Wen-Wang.
Or -600. Chinese jade work associated with circumpolar constellation templets.
Forerunners of the European nocturnal of +1150.
Israel. Solomon built temple using Northern cubit (= 0.64 m)
To -500. Homeric Epics mention constellations Orion, Pleiades, Great Bear.
India. Sulvasutras- had chapter on setting out by ropes and rt. angled triangles.
China. Earthquakes recorded.
Hesiodos of Ascra recorded some astronomy.
Moon eclipse recorded by Babylonians
Hezekiah, 12th King of Judah, had water conduit of 1098 ft built in Jerusalem. Lateral breakthrough 20 ft.
Assyrian cubit on baked clay cylinder used to set out Khorsabad.
Chinese bronze mirrors.
Winter solstice in China- observed sun shadow with gnomon on tower.
Phoenicians used Little Bear for navigation.
Periandros of Greece contemplated canal through Isthmus of Corinth
Theodorus of Samos had right-angle instruments
China had decimal foot rules in bronze. Ten Chinese inches into tens
Yang-Chheng gnomon 6 ft high, extant 1966. Shadow 1.5 ft at summer solstice
Pythagoras and his disciples declared earth as a sphere.
Thales calculated heights of mountains from shadow length.
Thales observed power of the magnet
Glass made locally in China
Pythagoras' theory on rays running from eye to object.
Ezekiel described what he saw from top of a mountain - ie cadastral "map"
Sundials delivered from Babylonians or Chaldeans to Greeks.
Josua spent most of his life on cadastral surveys. Knotted cords
Philolaos discussed rotation of planets including sun around "fire".
Babylonians expressed large numbers in multiples of 60.
Chinese large numbers in multiples of 10.
Romans expressed larger numbers in multiples of 12 or 16.
Democritus - formula for volume of pyramid.
- to + 1300. Development of cosmological theories.
Aristagoras - maps on bronze and iron tablets
Babylonian world map on clay tablet.
Antiphon, calculus to measure magnitudes of exhaustion.
Herodotus attributed beginning of geometry to annual overflow of R Nile.
He described aquaduct / tunnel on Samos.
Greece - 6 mile canal through Mt Athos peninsula.
Parmenides "moon shines with reflected light".
Heracleides - geocentric system of planets. Some round sun, others about earth.
Earth rotated about its own axis.
Eudoxus explained maths of celestial motions. 27 spheres.
First armillary rings in China. 1464 stars in Chinese catalogue.
China. Mohists proposed standardisation of length measure.
Indian method of meridian determination in Surya Siddhanta.
Romans attempted orientation of temples, tombs, cities etc.
Chou Pei Suan Ching publication on maths and astronomy.
Water level to get horz. surface for sun shadow. Meridian from sun rise and set.
Studies on vision. Refraction. Reflection. refractive index etc
Heaven likened to Hen's egg, earth to yolk. Circ. 365¼º
Shih Shen's and other star catalogues including Hipparchos.
China. Heaven has 9 layers. Distance to sky 20000 li = 6000 km
Sun illuminates 167000 li diameter (= 50000 km)
Theophrastus and Eudemos wrote histories on cosmography and early astro.
Dikaearchos (-350--290) idea of reference line to orient maps. Ran W - E
Aristotle increased Eudoxus spheres to 55. Concluded earth a sphere.
Menaechmos, rectangular coord axes. Maybe founder of analytical geometry.
Theoretical geometry applied to physical science by Mohist Canon Mo Ching.
Mention of carpenter's square.
onwards. Romans built Aqua Appia. See quote Werner Calendar p 10
Aristarchos postulated heliocentric system of planets. Defined ecliptic.
Rotation of earth about own axis. Angle between sun and half moon = 87º
really 89º 51'. Distance sun-earth 19 x dist. moon-earth. Should be 389 times
Euclid's 15 vol. on mathematics, especially geometry.
Greeks. Complex analogs of solar system
Start of 500 year domination of Univ. of Alexandria in scientific life.
Indian world map allowed China 1/81 of world surface.
Apollonius used coordinate axes.
Eratosthenes size of earth Alexandria - Syene.
China. Minute appreciation of topographic features.
Ctesibius refined clepsydra with float.
to + 6th C. Chinese cosmology- heavens a spherical dome, earth an upturned
bowl. Distance between domes 80000 li
to -212. Archimedes staff with flat disc held to cover sun.
Archimedes solved problems of calculus, analytical and differential geometry
Eratosthenes suggested coordinate grid over a spherical earth.
Fundamental parallel through Rhodes and meridian thro' Syene, Alexandria etc
Lu Pu-Wei assumed earth as flat disc.
Eudoxus' work made known through Phenomena and Prognostica.
Berossos. Inverted hemisphere known as a scaphe.
Aristarchos. Tangent ratio in right angles.
Time by hour glass
Chinese astronomers and mathematicians defined pi 3.14159
Timosthenes of Rhodes. Sea charts with distances between harbours
Halley's comet of +1682 first recorded in China.
China. Hodometer -drum carriage to count miles.
First record of Chinese silk map carried in a wooden box to hide a dagger.
Chinese relief model of R. Yangtze.
Emperor Chhin Shih Huang-Ti collected Empire maps.
Registration of boundaries of areas travelled by Chinese emperors.
China. 2 ten ft gnomon 1000 li apart N-S. Shadow decreased 1 inch per 1000 li
Four cardinal points fixed. Data determined for a calendar.
Appollonius introduced epicycles.
Chinese used negative numbers
to -125. Hipparchos eccentricty of earth orbit 1/24 RE (really 1/60 RE).
Year as 365d 5h 55m (really 49m). Invented? astrolabe.
Persia. Seleucid Greeks constructed tunnels marked by line of well shafts.
Heron's dioptra for areas, inaccessible heights etc
He described standardisation of measuring ropes. Water level and staff.
Crates. Suggested representing earth as globe divided to 4 equal continents.
Hipparchus used terms mekos and platos - longitude and latitude.
Seleucos studied tides in Persian Gulf.
Hipparchus. Graphical solution of spherical triangles.
Hipparchos introduced term climata for area between parallels.
Chinese gnomon up to 40 ft high.
China. Chuang-Hsiung-Phi built Dragon Head canal with shafts and tunnels.
Used metal sighting tube for distance. Water level. Compass. Plumb line.
Sundials in China with plate inclined in equatorial plane, gnomon pointing at the pole. Some dials with centesimal graduation.
Posidonius distancs sun-earth 13000 RE (actually 23400)
Caesar planned complete survey of empire. Responsible for Roman roads and aquaducts in Italy, France, Germany etc.
Posidonius gave meridian quadrant as 11000 km
Egypt. Edfu temple has erroneous inscription on area of quadrilateral.
Historical record of Chinese astronomy written by Ssuma Chhien.
Nero's engineers began Corinth canal. Abandoned for fear of diff in levels
Chinese permanently fixed equatorial ring on armillary.
Large clepsydra in Tower of Winds, Athens
Calendar troubles. Last year before commencement of Julian calendar
lasted 445 days. Sosigenes prepared new work.
Vitruvius reported on automatic timepiece- Horologium anaphoricum- had astrolabe disc with a net of projected parallels and meridians. Water driven.
Boundary line in Wurttemberg 80 km long.Resurveyed 1911. Out of
alignment by 2 m in 29 km.
China. Chia Liang Hu by Liu Hsin, a model to define standard measures.
Balbus constructed right angle with aid of a semi-circle.
Roman wall map
Relief maps modelled in rice.
Apostle Paul report on sounding lines
Diviner's board with compass indications, symbolic rep. of heaven and earth.
Wang Chhung discussed dependence of sea tides on moon.
China. First self-registering direction finder.
China. Ecliptic armillary ring.
Chia Khuei, precise definition of ecliptic.
Fort Caburn, Sussex set out with Sumerian ft of 20 shusi as standard.
Cinerarium in Vatican Gardens portrayed in relief the Roman ft measure.
Difference between Greek and Chinese mathematics
Geocentric system of planets.
Chang Heng scientific cartography in China used rectangular grid.
Menelaos wrote Spherics containing the sine function.
China. South pointing carriage.
Heron's De Speculis on mirrors and angle of reflection.
Mechanical process of paper making from plant fibres.
South pointers frequently mentioned - lodestone; wet and dry models
Ptolemy insisted maps to be based on astro. obs. Longitude in terms of time coords. and not guesses. Lats by transits of circumpolar stars.
Chinese Pan Ku and Pan Chao used coordinate system
Horizon and meridian rings added to Chinese armilleries.
Chinese star catalogue of 2500 stars + 11250 smaaler ones counted.
Ptolemaic chord tables. First mention of abacus by Hsu Yo.
Gnomon shadow template of jade
China. Calendar reform. Ideas on obliquity similar to Eratosthenes.
Shu Shu Chi-I mention of calendrical astronomy.
Anti-Kythera machine. Anaphoric clocks in Hellene.
China. Hydrographic record. Marine navigation.
China. Cosmology of infinite empty space.
Chao Ta, dial and pointer system for direction finding.
Indirect height measurement.
Chinese text on measuring heights and distances with poles bearing crossbars.
Precession of equinoxes by Yu Hsi (or 320?)
China. Levelling. Measuring curves and straights to reduce for slope.
Diophantus called negative numbers absurd.
Chinese calculus. Roman abacus. Celestial globe.
Ref. to crosswire grid. Length standards for small distances based on
diameter of silk thread = 1 hu.
Pytheus travelled Europe et al reporting on tides and other topics.
Magnetic needles in China
First Chinese star map.
Indians produced modern trigonometry as Paulisa Siddhanta.
Ho Chheng-Thien simultaneous obs. at Hanoi and Hue gave decrease in shadow with latitude of 3.56 in per 1000 li.
Chinese wood relief 10 ft square.
Indeterminate analysis in China.
Pi to 3.1415929203 by Tsu Chhung-Chih. Finite differences in astronomy.
Marcellus and Pliny the Elder reported on repellant force of lodestone.
Li Tau-Nguan commented on hydrography in China in 40 volumes.
Chang Chiu-Chien noted survey problems using right angled triangles.
Varaha-Mihira used sines and c osines.
Aryabhata gave name sinus to that function. Tables x 1 degree
Cassiodoros reported on science of land surveying.
Multiplication tables by Li Nien.
Chinese computations by abacus.
Arabs created terms zenith, nadir, azimuth.
Arabs determined obliquity of the ecliptic.
Seismograph by Lin.
Liu Chhuo selected baselines in flat country along meridian through
Honan and Hopei to determine time by clepsydra and to set gnomons.
Astro. obs. tower in Korea about 30 ft high. Use a pin hole to determine
shadow length to 3 dec. places of a foot.
Arabs observed stars with 20 ft quadrant and 56 ft stone sextant at Abul Welfa.
Some obs. in connection with geodetic baselines.
China. Schools of surveying established.
Japanese emperor pordered production of cadastral maps.
Codex Arcerianus (Irish) described survey practice and legal aspects.
European churches oriented N.
China. Magnetic declination discovered.
Japanese used south indicator.
Balance arm clepsydra at Antioch.
Mechanical clockwork in China.
to 800. Terrestrial civil unit fixed as 1/351 Chinese degree.
Original Arabian foot shown on column. The Nilometer.
Indian sine tables traslated into Chinese
to 725. Eleven Chinese obs. points on line through Hue (not on same meridian)
Hue 17.9ºN Weichow 40ºN. Diff. shadow lengths 4 in/ 1000 li.
Clockwork escapement invented in China.
I-Hsing. Armillary spheres with ecliptically mounted sighting tubes.
Al-Fazari under Al-Masur made first Arabic astrolabe.
Arabian plumb bob recorded at that time.
Arabs used carpenter's s quare (Kunija) larger than a groma.
Significance of metric system recognised in China.
Attempts to define terrestrial units in terms of astro. or geodetic constants.
Windroses developed by Vikings.
Arabian manuscript on astrolabes.
Al-Kwarizmi developed Hindu number system and algebra.
Text on algebra in which the word was invented.
Arabs measured baselines near Baghdad.
Camera obscura in China.
Arabs mechanised papermaking.
Al-Battani added the shadow square to the astrolabe.
Alfred the Great determined inch as 3 grains of barley, dry, round.
Arabs rejected earth rotation about own axis.
Ibn Jabir ibn Sinan al Baltani concept of tan and cotan.
Gerbert conveyed Muslim surveying knowledge to the West.
Abul-Wafa al-Buzjani concept of secant and cosecant.
King Edgar ordained 3 ft = 1 yard.
Decimal system for weight became official in China.
Sighting tube reported in a codex of St Gallen monastery.
Hamid Ibn al Khidr al-Khujandi sextant radius 57 ft.
Chinese maps, reasonably accurate, at 1:31 680
Shen Kua, enguineer and surveyor, determined lengths of arcs and
produced tables on chords and arcs. Arc = chord + S.S/R (S= mid ordinate. He also set out canals, slopes, levelling dams etc by water level.
Su Sung's astronomical clock tower 35 ft high. Powerdriven globe and
armillary sphere. Latter had a sighting tube.
Arabs, decimal fractions from Indians, transmission to Jewish and
Latin scholars in 12th C.
Length of year known to Mayas Incas and Indians as 365.2420
Chinese sighting tube for altitude.
Indian horizontal staff described by Bhaskara. Used by Muslims to measure depth of wells.
Henry I, statute on standard yard. Hexagonal brass yard.
Two Chinese maps carved in stone had grid to scale of 100 li.
Jabir ibn Aflah probable inventor of Torquetum.
Recording of star altitudes by finger width of outstretched arm.
First printed Chinese map
Arab cylindrical sundial
Alexander Neckam described magnetic needle in De naturis rerum.
Chinese Astronomer Royal severely punished for wrongly predicting solar eclipse by ½ day.
China. Timekeeping by metal incense clock, burning point of powder
winding through labyrinth of characters.
Determination of diameter and circumference of a circular walled city from afar.
Venetian glass makers developed art of lens making.
Seven day week introduced in China.
Fibonacci analytical geometry in Europe.
Translation of Arab writings on astronomy.
Floating compass needle used in Persia.
Chinese planisphere engraved in stone.
Alfonsine tables of planets
Nasir al-Din al-Tusi first Director of Observatory at Maragha.
Al-Tusi 12 ft wooden mural quadrant with sights, copper limb to degrees.
Peregrinus described azimuthal dial with alidade and compass.
Zero number in Chinese computations.
Chinese gnomon 40 ft high in brick tower at Yang-chheng, 120 ft shadow scale and waterchannel for level control.
Torquetum by Kuo-Shou-Ching in Peking.
Kuo Shou-Ching's observatory at Peking.
Spina and Armati invented spectacles.
Bacon studied properties of mirrors and plano convex lenses.
Al-Urdi al-Dimashqi improved ancient Indian circles method for Azimuth fixes.
al-Marrekushi's 134 geog coords froim astrofixes.
Bowl compass in Chinese waters for navigation.
Seismograph at Maraghah Observatory
to 17th C England. Open field system. Unit length, reach of a barge pole.
Jacob staff by Levi ben Gershon.
Decimal point by Yang Hui.
Chu Ssu-Pen atlas of China.
Edward I, unit of length 1 inch of 3 grains of barley.
Grid map of Palestine. by Sanuto.
Portolan charts with rectangular grids by Pietro.
Gough map of England with 3 different miles- 2230 yard in England; 2250 yard in Wales;' 2800 yard in Cheshire.
Gough's Itinerary map of Gt Britain.
Relief map of Gibraltar by Ibn Battutah
Oresme used terms longitudo, latitudo.
Chinese road alignments by compass.
First European mechanical astronomical clocks.
Henry the Navigator founded School of Navigation in Sagres.
Polish topographical map.
Ulug Beg Star Almanac. Had quadrant 180 ft high for star obs.
Gutenberg invented letterpress. Maps mainly cut in wood.
Sea quadrant by de Cintra.
Diaz rounded Cape of Good Hope.
Ivan the Terrible established unique library under the Kremlin.
Zacuto published perpetual almanac in Hebrew.
Intaglio printing by Durer.
Behaim's Nurnberg globe with prime meridian 2º W of Canary Is.
Pope Alexander VI divided map of world in two by meridian in mid Atlantic.
Columbus discovered discrepancy between Flemish and Italian compasses.
Bronze rod yard standard in Britain.
Vasco da Gama sailed to India.
Purbach geometric square . Tables of sines and tangents.
de Cusa supported heliocentric theory and diurnal rotation of earth.
L da Vinci - Visible masses on the earth's surface are in equilibrium.
Organum viatorum. Pocket size combination of compass + sundial
Copernicus wrote De revolutionibus orbium coelestium.
Portable clock in Europe
Waldseemuller's polimetrum for bearings and altitudes.
Evidence of nautical cartography in Java
Piri Rei of Turkey, sea chart of Atlantic with American Coast.
Fitzherbert. First book on surveying; Boke of Surveyinge.
Tartaglia box compass with altitude on circular graduated board.
French topographical maps by Fine and Coline
Russian topographic maps made by invited foreigners.
Guillen combined gnomon and compass for variations in magnetic declination.
Fernel measured distance Paris-Amiens by carriage wheel.
Topographic maps in Russia and Poland by Wapowski.
Term chronometer suggested by Frisius.
Agricola wrote De re metallica on mine surveying
Arsenius added a compass to an astrolabe.
Frisius wrote on triangulation.
Frisius portable equatorial armillary sphere.
de Benese wrote The Boke of Measuringe Lande.
Distance by wooden rod of 1 perch = 5½ yards long.
Nunez designed the nonius for reading quadrants.
Quality woodcut map of Bavaria by Apian.
Box compass by Neudorfer
Differential quadrant by Rotz for navigation. Simul: det: lat and Az.
Hartmann discovered inclination of magnetic needle.
Marine Jacob's staff by de Medina
Tartaglia reported on survey methods in Italy.
Brahe designed 19 ft quadrant for his Danish observatory.
Mercator recognised existence of magnetic poles.
Ryff improvement of theodolite
De Roja's book on astrolabium published.
Foulon with plane table plus holometre.
Munster designed trigonus- three straight rods in triangle vide triquetum
Mohit used Jacob staff with various sliding plates for star altitudes.
King Akbar decreed 25 Indus inch = 1 gaz (= the Ilahi gaz or Akbar yard)
Modern = sign by Recorde
Cunningham described triangulation
Bartoli different design of polimetrum
Mercator true bearing chart for navigators.
Rheticus taught proper survey control for mapping.
World map by Ortelius
Theodolitus by Digges. Also the instrument topographicall
Torquetum by Regiomontanus
Kepler succeeded Brahe in Prague.
Gutmann wrote Felsmessen,gewiss.richtig und kurz gestellt. (On proper
Reinhold similar book to Gutmann. Preferred a wire to hemp cord for distance.
Brahe connected Denmark and Sweden via Oresund.
Saxton's English county maps with triangulation control
Galilei observed swinging chandelier
Ricci world map with flattened sphere projection.
Decimal arithmetic introduced by Stevin.
Sea charts by Mercator son Rumold.
Q Elizabeth I St. yard of 36 inch = 3 ft.......1760 yds to mile
First Italian telescope by Porta.
Chinese reel of measuring tape similar to modern
Hulsius elaborate quadrant with compass sundial
Praetorius ball and socket head for plane table tripod.
Errard de Bar-le-Duc telemetre
Werner's Jakob staff 7 ft long with 2000 divisions for angle measure
Davis back staff for use at sea.
French astrolabe - graphometre by Danfrie.
de Subermille designed Henry metre- a combination of rods.
Pfintzing surveyors carriage with dial recording hodometer
Hommel (1518-1562) Leipzig, promoted surveying.
Seven European astro instruments with 360º divs. reached China via Persia.
Leonard and Thomas Digges experimented with telescope making.
Decimal division. 1 chain = 100 links
Germany. Miner's Lachter-Kette or brass chain was 8-12 m long.
X sign introduced by Viete
Pitiscus published his Trigonometriae
Clavius wrote Operum Mathematicorum.
Topographic map of Japan.
Snellius described compass declination of 11º 15'
First 6 of the 15 books of Euclid translated into Chinese by Ricci.
Logarithms by Burgi.
Dutch trunks (telescopes) by Lippershey.
First two of Kepler's Laws published.
Kepler's astronomical telescope for surveyors. Huygens refined lens making.
Galilei observed Jupiter with 30X telescope. His sector for computations.
French toise marked by iron rod in foot of stairs of Le Chatelet.
Word telescope used by Lagalla but ascribed to Demisiani
Harriot went as surveyor to Virginia.
Dou's Holland circle made in Amsterdam. It had a cross swivel joint tripod.
Word telescope used by Lagalla.
Napier's addit. logs and natural functions.
Snellius introduced base extension and resection into triangulation.
Used large 4 or 5 ft diam copper quadrant with transversal to 1'.
Kepler's Doliometria described vol. calculations by prismoidal rule.
Dias in China mentioned telescope in his Explanation of the Celestial Sphere.
Rathborne's The Surveyor. Described theodelite, playne table, circumferentor.
First telescope arrived in China.
Third law of Kepler published.
Introduction of slide rule
Snellius' sine law of refraction
Oughtred invented straight log. slide rule.
Briggs logs to base 10
Log slide rule by Gunter
Gunter's Description and Use of the Sector... published.
Chinese book on telescopes.
Wingate's straight edge slide rule. Two scales.
Bleau alleged to have measured base between Maas and Texel.
Algebraic geometry by Gethaldi.
Oughtred described a circular slide rule.
Norwood's measure London to York by chain. What else?
Mersenne's reflecting telescope.
Descartes work on lenses.
Descartes cartesian analytical geometry and integral exponents.
Telescopes fitted with cross hairs of silk by Gascoigne.
Gascoigne's movable hair in telescope. Hence gradienter method.
Gascoigne's knife edge eyepiece micrometer.
Adding machine suggested by Ciermans. (Scierman)
Theory of numbers and analytical geometry by Fermat.
Leibniz coined terms abscissa and ordinata.
Pascal's adding machine.
Torricelli had idea of mercury barometer
Viviani experimented on making a vacuum.
Mersenne observed free fall acc due to gravity by pendulum
Riccioli & Grimaldi arc measure Mt Serra-Paderno-Modena. Unreliable.
Hevelius' 150 ft long telescope. Pub. Selenographia and Machinae coelestis
Pascal's Lunar tables.
Pascal taught use of barometer for height difference with Torricelli barometer
Divini and Campani made long focus object glasses.
De La Hire suggested engraving cross hairs by diamond.
Gilbert considered earth as a large magnet.
First use of logs in China.
Partridge modern slide rule with movable centrepiece.
Improvement of level by Strumienski of Cracow
Claramontius improved level.
Leybourn published his The Compleat Surveyor. Went to 5 Edns by 1722
Barometric measures demonstrated to the Regensburg Reichstag.
Jakob Bernouilli started his work on catenary, loxodrome, spirals etc
Huygens grandfather clock.
Atwell published his The Faithful Surveyor.
Hooke's spiral spring for pocket watches.
Huygens and Hooke micrometer designs. Intro of virgula = tapered metal bar and hair micrometer
Italian level with floating gunsights by Schoff
Division sign introduced
Tilas of Sweden- mining compass
Picard - semi-automatic levels. One with telescope and water level container other with plumb bob forcing telescope into horizontal position.
Chinese obtained slide rule from Europe.
Mouton suggested an unalterable universal measure for the metre.
Thevonet invented spirit bubble.
Van Breen (Holland) improved nautical staff with coloured observer's glass
Reticule micrometer with several silver wires by Malvasia.
Gregory - two mirror combination for reflecting telescope proposed
Newton postulated earth as oblate spheroid.
Newton clarified distinction between spherical and chromatic aberration.
Foundation of Academie des Sciences, Paris.
Auzout filar micrometer.
Praetorius wrote on diving rods in Gazophylaci gaudium.
to 1670. Picard, Auzout and Romer established precision astronomy.
Godunov's first map of Siberia
Hooke's shortened telescope and lens grinding machine.
Newton's reflecting telescope.
Riccioli and Picard observed free fall acc due to gravity by pendulum
Chains in use- Rathborne 1 perch = 100 links; Gunter 4 perches or poles = 100 links
Verbiest reequippoed Peking astronomical observatory.
to 70. Picard determined arc from Amiens to Malvoisin
His quadrant used on arc was 10 ft radius with telescopic sights and cross hairs
and on. Newton and law of gravitation.
Differential calculus by Leibniz, Briggs, Napier and Newton
to 90. Observatories built in Paris, Greenwich and Berlin.
Hooke suggested clockwork driven telescope.
Mouton proposed a linear scale based on a geodetic minute.
Picard suggested a Universal Foot as function of sec pendulum
Cassegrain suggested reflecting telescope
to 1695. Leibniz Staffelwalzenmachine for multiplication and tens transmission
Richer in Cayenne observed parallax to Mars
Noticed that his pendulum had to be shortened at Cayenne to keep time.
G D Cassini I determined distance earth-sun.
Hooke and Hevelius compared merits of gunsights with telescope pointing.
Loevenhoek showed great skill in lens grinding.
Montanari used stadia method for distance.
Foster in Boston USA First American map in woodcut.
Flamsteed equatorial sextant. Wrote Historia Coelestis.
Pendulum observations by Halley, Varin, Deshayes, de Glos and Goree.
Seki Kowa wrote on determinants.
Cassini I extended Picard's arc north to Dunkirk
Cassini II wrote on barometric levelling.
Romer's transit instrument at Copenhagen.
Halley deduced crude relation for pressure v height
to 1743 Maharajah Jai Sing set up over 40 astro. instruments in various cities.
Hooke suggested a Pole finding telescope with concentric circles.
Newton wrote Philosophiae naturalis principia mathematica.
Chinese scholar gave details of ancient Chinese standards of length.
Leibniz wrote on determinants
Contour lines introduced by Ancelin, Rotterdam
Leybourn published method of closing traverses.
Beginning of modern Geodesy
Jesuits arrived in China.They had a cosmos of the closed Ptolemaic-Aristotelian geocentric universe of solid concentric crystalline spheres. This opposed the doctrine of the floating of heavenly bodies of Hsuan-Yeh.
Roman Catholic & Protestant clergy supplied "all round" geodesists to Europe.
eg Cusa, Copernicus, Picard, Boscovich, Bohnenburger.
La Hire began extension of Picard arc to the south.
It reached Colliure by 1716 or 18. gave prolate figure !! See entry p 46
Halley's charts of magnetic declination across continents and oceans.
Newton designed first octant. He wrote on ancient metrology.
Leibniz had idea of using elastic deformation of metal for pressure measure.
Antoine Thomas arc measure in China. See entry p 46
Mallet described spirit levels.
Romer's meridian circle.
Le Blon experimented on colour effects in printing.
Sherwin 7 figure log tables.
to 1717. Complete resurvey of China by Jesuits.
Euler started teaching in Basel, Petersburg and then Berlin.
to 12. Hooke and Flamsteed used van Breen's ideas on the quadrant.
Bion described octagonal surveyor's cross for 45º and 90º horz. angles.
Peter the Great (Russia) ordered linear scale (fuss) supposedly equivalent
to ancient Chinese foot, to be made equal to English foot.
Bernouill binomial distribution.
Board of Longitude offered £20000 for solution to longitude.
Halley succeeded Flamsteed as Director Greenwich Observatory
Cassini proposed a geodetic ft = 1 terrestrial minute of arc
Hadley reflecting telescope 200X Mag 6 ft long
La Hire. Level instrument with floating gun sights.
Burgh (Dublin) used double meridian distance to compute areas.
New observatory in Japan. Accepted Copernican system.
Petersburg Acad.Sc.founded by Peter the Great.
Bradley aberration of stars idea conceived.
Sisson making theodolites with micrometers.
Godfrey's sea quadrant. (USA)
Hadley's octant reading to 1 min arc.
George Washington born
De Moivre's normal distribution.
Herschel introduced reflecting telescope used in today's 1" theodolites.
Cassini began parallel arc measure St Malo to Strasbourg.
Publication of first Russian Atlas.
Start of Peru arc expedition. Used Toise de Perou.
La Condamine observed free fall acc due to gravity by pendulum
to 7 La Condamine, Godin and Bouguer found length equat: secs pendulum
Invariable pendulum by Mairan used by Maupertuis at Pello 1736
French arc by Maupertuis in Lapland. See p 50 for details
Bouguer at foot of Chimborazo to experiment of deflection of vertical.
Six Roman linear standards on tablet in Rome measured by Folkes of Roy.Soc.
De L'isle measured base on ice Petersburg to Cronstadt.
Clairaut, Maclaurin proved Newton's law of gravitation.
Clairaut proved Newton's hypothesis of oblate earth.
Leigh - sextant with artificial fluid horizon
French Acad. announced that Cassini prolate earth had been rejected.
to 40. C F Cassini III, and Lacaille repeated earlier Cassini II arc measure.
to 40. Cassini and LaCaille resurveyed Picard arc and added 5 bases.
Age of scientific instrument makers began with Langlois
Celcius discovered short period variations of magnetic declinations.
His temperature scale used.
Bradley succeeded Halley as Director Greenwich Observatory.
Roy.Soc.organised manufacture of Yard measure based on Elizabeth's of 1588
Results from Peru expedition- oblate earth.
Clairaut published Theorie de la Figure de la terre. See p 52
Cassini de Thury IV began Carte topographique de la France
to 99. Triangulation linking Greenwich and Paris.
C F Cassini's (III) transversal cylindrical projection.
Murdoch Mackenzie's hydrographic surveys of Orkneys.
to 1803. Survey of British Isles.
La Condamine proposed length equatorial secs pendulum as standard.
Bradley described nutation.
Faye found free air reduction of g.
D'Alembert proved Bradley theory of precession
La Caille catalogued 10 000 stars at Capetown in two years.
to 69. Arc measure of Liesganig, Varasdin-Brno.
Meridian arc Rome - Rimini by Boscovich and Meyer.
Stuart and Revett measured Parthenon.
Chezy internal grinding of spirit level vials.
Naime, London. Manufacturing barometers, thermometers etc
Boscovich compensation theory of crustal masses.
to 1753. La Caille arc in S Africa.
Marine chart of English Channel by Buache (France) Or 1737. See R107p141
Bird made a standard for Parliamentary committee
Cook charted St Lawrence river.
Breithaupt - hanging theodolite.
to 60. Beccaria arc in Piemont near Turin.
Chinese azimuth compass in gimbal mounting for use at sea.
Cassini III began parallel arc Brest to Vienna
Ramsden opened workshop in London.
Harrison and Leroy. First ship chronometer.
Brander theodolite maker.
Osterwald used a wooden bridge to support measuring rods on Bavarian base
to 68. Mason-Dixon arc measure. Wooden box-type rods
Meyer's widow received payment for his lunar tables.
Louis XIV edict on Toise de Perou.
Bird wrote The Method of Dividing Astronomical Instruments.
Maskelyne- first nautical almanac
Transit of Venus.
to 83. Guinand (Swiss) worked on improving flint glass.
Mayer suggested to Ramsden using his dividing engine for full circles
Hahn (G) -first reliable and durable calculating machines, different sizes.
Mining Academies established Berlin, Pribram (CZ), Sopron (Hun), Petersburg
Watts stadia tacheometry
Lambert's conic projection
Radcliffe observatory founded in Oxford. Since 1948 has been in S Africa
Adams artificial horizon for sextant.
Maskelyne and Hutton plummet method for g, Mt Schehallien.
Harrison finally got his reward for chronometer.
to 77. Ramsden constructed dividing engine.
Mining Acad. established in Clausthal inHasrz Mts.
to 83. Introduction of 4 screw theods in USA
Green inserted a micrometer in the eyepiece
French weavers used punch cards. Jacquard of Lyons
Troughton Bros took over Rowley old shop.
Roy began triangulation in England.
Roy base on Hounslow Heath with glass rods.
Prony produced 17 vols of Tables du Cadastre with logs nat. figs to 14 decs. 1 - 200 000. Used centesimal angular division.
Theodolite by Ramsden
Boscovich observed free fall acc due to gravity by pendulum
Borda's repeating circle with two telescopes.
Remeasure Hounslow base by Williams, Mudge andDalby.
Rittenhouse used spider webs as cross hairs
Ramsden made 3 ft diameter circle to 1 sec by micrometer.
His direction theodolite
French instrument makers (Fortin etc) formed a corporation.
Channel crossing by triangulation. Roy, Cassini,Legendre and Mechain
Legendre's solution of fundamental geodetic triangle computation
Sir John R Miller raised the decimal question in House of Commons.
400g to circle introduced in France, S Germany and Switzerland.
French repetition theodolite
Cary apprentice under Ramsden.
Metric committee in France. Borda, Condorcet,Lagrange, Laplace,Monge
Borda et al expressed planetary distances in earth radii; need for R value
Suggested quadrant as 10 000 000 m
Barrow meridian arc lat 23º 18'
Talleyrand proposed length of secs. pendulum as a unit of length.
Fr. Decimal Committee recommended 1/10M of quadrant as a metre.
Longitude and horary graphs for mariners.
Borda and Cassini IV pendulum obs at Paris Observatory.
First contour maps in France.
French baselines by 30 ft firwood rods.
to 99 Br Admiralty Hydrographer, Hurd, charted Bermuda.
OS of Great Britain founded.
Sawitch flattening from pendulum obs.
to 99 Delambre and Mechain arc in France as part solution to metre value.
22 September. French Republic established.
Third Report by Decimal Committee. 1 prov. m = 443.44 P Lines.
Vega, Nautical Almanac, also log. slide rule replacing Galilei sector.
Metric system legalised in France.
Czar Paul instituted the Dépot of Maps.
Dallabella,Lisbon, inverse square law of magnetic force.
Cavendish determined earth density. His torsion balance.
Napoleon's officers discovered the nilometer on Elephant Is in the Nile.
Mechain & Delambre submitted their results.
Prototype legal metre in France.
Delambre published Methodes analytiques pour la determination ....meridien.
English scientists used French pied du roi of 144 Paris lines (=325 mm).
Horrebow-Talcott latitude method.
Lehmann (1765-1811) put shape of hachures on a mathematical basis.
Munich becoming centre of continental instrument making.
Senefelder introduced flatbed on stone block and offset printing
Depot General de la Guerre began production of Carte de la Baviere.
Paris parallel arc begun. Strassburg-Munich.
Svanberg reobserved Lapland arc of Maupertuis.
Flinders hydrographic surveys of Gulf of Carpenteria.
Laplace proved Mayer correct (1765) and added term to moon latitude equation.
Hence reversed process and found earth flattening.
to3 Laplace derivation of pressure-height relationship.
von Zach & von Muffling baseline for Thuringian triag. near Gotha.
Terminal points as cannons set vertically. First used by Roy in 1791
to 1822. Triangulation began in India.
Repetition theodolite by Reichenbach.
Sacharof and Robertson balloon ascent from St Petersburg.
Mechain proposed extension of French arc to Balearic Is.
Mechain died in despair at errors in astro. lat of Barcelona. See p 60
to 1811. Lambton parallel arc through Madras
Legendre applied least squares to French arc of 1792. See p 60
Senefelder invented zincography
Legendre- length of a geodesic.
to 08. Biot and Arago extended French arc to Formentera on Balearic Is.
Arago wrote about it in his Historie de ma jeunesse.
Illig. In papermaking, replaced animal glue by resin or alum.
Hassler founded US Coast & Geodetic Survey.
Arago suggested use of sound to measure depths.
Gauss astrolabe. Simultaneous determination of lat. and long.
to 25. Biot, Mathieu, theory of mathematical pendulum.
Soldner replaced plane rect. coords. by spherical rect. coords.
Senefelder invented transfer printing.
Review of French arc measures revealed short comings.
Napoleon refused permission to re survey Lapland arc.
Mechanical press by Konig.
Laplace induced French to survey parallel arc of Marennes to Fiume (Istria)
Interrupted by war of 1813-14.
Bohnenberger suggested an inverted (reversible) pendulum
French troops noticed an English built transit in Moscow and saved it
from the big fire lit by Russians in self defence.
Pond catalogue of polar distances of 43 stars.
First survey ships on British Navy list
Planimeter by Herman.
Triangulation in Italy.
Start of Struve triangulation.
to 17. First US baseline by Hassler at Tinively Valley.
Second base on Long Island.
Struve initiated his meridian arc
Kater reversible pendulum. Suggested by Prony 1792 & Bohnenberger 1811
Laplace published Theorie analytique des probabilités
Brousseaud & Nicollet observed Brest to Strasbourg on parallel of Paris.
Bohnenberger gyroscopic theory and construction of his precession machine.
Young's modulus of elasticity
Fraunhofer engraved cross hairs by diamond.
Thomas (F) Arithmometer
Struve baseline near Dorpat.
Schumacher baseline in Holstein
Gauss used heliotrope on Hanover arc.
to 24; and 1838-53. Complete triangulation of Great Britain.
Topographic survey began in Russia under Schubert
Carline and Plana recomputed Beccaria's arc.
Carlini deflection of plumb line at Mt Cenis
Gauss triangulation and arc measure adjusted by least squares.
to 22. Carlini and Plana filled gap between Alps and Turin in arc of Marennes.
Rockets or powder signals for simult. obs. for longitudes.
Babbage Difference machine.
Fitzroy on Beagle in Sydney to determine longitude of Parramatta Obsy.
Parramatta observatory established by Sir Thomas Brisbane.
Memphis cubit rod (pre Rameses I) found at Jomar.
Bonne baseline at Brest for parallel arc
to 28. 30 000 miles of African coast charted by Owen.
First standard yard reached Sydney
Bessel refined Kater pendulum
Parallel arc Munich to Budapest
India confirmed the 1556 Akbar yard of 33 E Inch = 25 Indus inch
= the Indian yard.
OS of Ireland begun by Colby.
Drummond invented heliostat and limelight.
Troughton and Simms partnership in instrument making.
Niepce photoengraving = photo intaglio
Babinet suggested light wave as natural unit of length
math. figure of earth in terms of geometric measurements.
Schmidt compuation of Hannover triangulation. To Gauss instructions.
Bohnenberger used spherical coordinates.
to 32. Map of nineteen counties by Thomas Mitchell, Australia
Ramsden 10 ft rod arrived in Sydney to standardise chains.
Cooke began instrument making career
Russian triangulation connected to Konigsberg observatory. Hence parallel arc England-France-Prussia-Russia.
Prussia took lead in geodesy from S Germany.
Foundation of Trigonometrische Abteilung des Preuss.
to 41. Bessel triangulation in E Prussia.
to 33. Henderson further meridian arc obs. CapeTown.
Related computations by Olufsen, Breen and Stone.
Everest baseline at Calcutta using Colby apparatus.
Hengler horizontal pendulum for deflection of plumbline.
Poisson work on seismic waves.
Stokes formula for distance between geoid and spheroid.
Jacobi triaxial ellipsoid. Followed by Clarke and Schubert.
Baeyer and Bessel on Prussian oblique arc. Base at Trenk
to 48. Babbage analytical engine.
Gauss and Weber fundamental study of geomagnetism
Mayer idea tpo determine eccentricty of ellipsoid by triang. of skew meridian
Poisson distribution. See p 48 for other names.
First astronomical observatory in USA at Williamstown.
Daguerre-Niepce reproduction of pictures by photographic emulsion.
Bessel spheroidal formulae
Blondat rubber hose over 50 m for hydrostatic levelling
Weisbach triangle in mine surveying
Everest theodolite, Indian subtense bar.
Precise traversing heads for mine survey by Breithaupt Kassel
to 80. S Australian triangulation included 7 bases. see Frome on Surveying.
Talbot developed photographic negative
Puissant discovered error of 68t in distance Formentera-Montjouy
to 78. Great Lakes triangulation USA suffered from bad base. (Sacle)
Everest base at Bidar by Colby bars.
J F Herschel discovered method of sun printing in blue
Ertel level with stadia hairs and horizontal circle
Chesterman cloth tape reinforced by wire.
Sumner, USA used position lines
Struve obtained permission to extend his arc to Tornea
Belgian triangulation using broken ray technique.
Chambers log tables
Staffel of Warsaw. Calculator
Stampfer discussed precision of pointing in relation to target shape
to1902. USCGS arc measures
to 56. Parallel arc Astrachan-Kishinev
to 56. Brest-Tchernowitz parallel arc observed. Extended to 20º by Wrochenko.
Many Laplace stns around Moscow by Schweizer.
Maclear remeasure of La Caille arc in S Africa.
Roche density of the earth
Maurel & Jayet (F) calculator
Kellner compound eyepiece.
Stokes on variation of gravity at surface of earth
Laussedat architectural photographs for measurements.
Vidie, Bourdon and Schinz independently invented metal capsule barometer
Foucault pendulum used to prove rotation of earth.
Reichenbach perfected his stadia hair method
-51. Le Gray and Archer. Photographic plates
Airy transit circle installed at Greenwich
Struve arc extended by Tenner towards Murmansk and Danube estuary.
Stampfer optical plumbing in mines.
Oppert found Assyrian ft standard at Babylon to be 329 mm for 30 shusi
Porro anallactic lens
-58. Porro, Koppe & Meydenbaur developed principles of photogrammetry.
Amsler polar planimeter
Airyu flotation theory of earth crust.
Alum lithoplates by Poitevin
Balloon photography in Paris by Nadar alias Tournachon
and in Boston, USA and Solferino, Italy
Pratt observed deflection of plumbline in Himalayas.
Levelling used to determine settlement for first time. Near Stuttgart.
Stokes theory of physical pendulum
Parallel arc from Valencia (Eire) to Orsk suggested by Struve
Error or standard ellipse by Andrae.
Anaglyphic stereoscopic viewing by d'Almada
-59. Bertaud objective + Brunner camera box + theodolite for contours by photo.
to 77.Spanish triangulation. Connected to N Africa at Laghouat, Algiers
Schubert computed tri-axial ellipsoid
Eckholdt omnimeter measured a tangent ratio by screw.
Amsler reversible level.
Hayford clarified concepts of isostasy.
Triangulation England-France. Clarke computed arc and again in 1866 and 1880
Base in Victoria, Australia 5½ miles long. Took 9 months
in 1876-7. On to Tunisia in 1884-5
-80. Andrae, Sonderhof & Helmert discussed lateral refraction.
Sir Wm Thompson (Lord Kelvin) pressure tube for water depths.
Bessel ideas on reversible pendulum constructed by Lohmeier of Hamburg.
Norwegian geodetic commission formed
Gen Baeyer plan of international cooperation in geodesy. Became IUGG
-72. Central European parallel arc from Haverford to Orsk.
Third connection England-France. Others 1787 and 1822
Kelvin theory of tides of earth crust.
Hoskold put plane mirror in front of theodolite for optical plumbing.
First meeting of IUGG
Baselines at terminals of Norwegian Trig. Christiana and Rinderleret.
Italian geodetic commission formed.
Precise levelling in Saxony by Nagel and Prussia and Bavaria in 1867
Pujo fundamentals of photogrammetry
Villarceau general formula of Laplace equation.
Clarke computed triaxial ellipsoid
Hydrographic Office of U S Navy formed.
Von Wullerstorf idea of aneroid for relative gravimetry.
Spain, Portugal and Russia join IUGG
Precise levelling with Breithaupt instruments in Berlin.
New S Wales. Baselines at Lake George and Richmond.
Helmert worked on error ellipse
Villarceau and Bruns computations of geoid.
Creation of Prussian Geodetic Institute in Berlin.
Zollner horizontal pendulum
-70. Viertel, theodolite + eccentric telescope set vertical by autocollimation.
Helmert became Director of Zentral Bureau der Int. Erdmessung in Berlin.
Gauss five figure log tables.
-88. Revision of French arc Perpignan-Melun. Used Brunner theodolites.
Maddox photogelatine printing, dry plates.
Jordan optical plummet by refracting line of sight from 45 deg. mirror.
Brunner baseline equipment for European work
-98. Arc measure on 39th parallel in USA from Atlantic to Pacific
Thin, 66 ft, tape of crinoline steel introduced in Australia.
Barrel type calculating machine with toothed wheel. By Baldwin, USA
Schreiber test of circle graduations
Nagel designed and constructed theodolite for optical plumbing.
Jordan, Finsterwalder mapping from photographs.
Colour photography by Vogel, Clark Ducos du Hauron. After idea by Maxwell 1857
Listing introduced tem Geoid
Todhunter book on History of Theory... published.
10 Laplace stations in Harz mountains.
Transit of Venus in NSW
Hansen testing line scales.
New International metre standard deposited at Paris.
Marc St Hilaire dead reckoning for position lines.
18 countries sign Treaty in Paris to establish Int.Bur.of Wts and Measures
Helmert method of accuracy of graduation of horizontal circles.
Peirce, USA determined vibration (or flexure) of pendulum support.
Algiers parallel reached Kap Bon and Sicily
Helmert defined line of sight in telescopes
Zacharie (Denmark) rectangular spherical computations.
Lord Kelvin harmonic analyser for tidal prediction.
Ohdner calculating machine.
Couturier reflection level with suspended telescope.
Ibanez and Perrier observed quad across Mediterranean to join French arc to N African parallel.
German level datum in Berlin connected to Amsterdam gauge.
Geoid map of Central Asia by Fergana
Nagel-Hildebrand optical plummet on interchangeable traverse heads.
Forster, Eggert, Broun, increase of visual acuity by coincidence method
Hollerith punch cards with electrical switch feeler
Von Sterneck pendulum with coincidence apparatus.
Term nomograph coined by D'Ocagne
Jaderin introduced new baseline technique with thin steel wires.
Mendenhall deflection of vertical at Mt Fujiyama
Offset printing by Champenois
Free swinging plumb bobs used in German shaft plumbing
Harmonic analysis of tides by G H Darwin and J C Adams
Longitude connection Singapore-Darwin-Sydney by Barrachi & Darwin
First geoid maps of Harz by Andrae
Fergola suggested Int. latitude service
-91. Queensland triangulation
Helmert dynamic correction
Great Britain joined Metric Convention
-90. Development of several types of camera including photo-theo.by Paganini
Algiers parallel reached Tunisia
Report from Berlin on 14 differing toise scales unsed in Europe Triangulation.
Scholz worked on error ellipse
Lallemand- orthometric correction
-92. Michelson and later Benoit determined number of red waves in cadmium
in one metre.
Lorenzoni, Italy, determined vibration (or flexure) of pendulum support.
Penrose measured the Parthenon in Athens.
Introduction of terrestrial photogrammetry by Deville, Canada
-96. Eotvos torsion balance for gravity components
Bllee calculating machine
Austrian, French and German officers mapped Greece.
More countries join IUGG
Barr and Stroud glass wedge for optical distance measurement.
Dutton coined term isostasy
-93. Various experiments with horizontal pendulum
Rotogravure by Klie
Algraphy= aluminium sheet printing by Scholz, Mullaly and Bullock (1891).
Fennel, Kassel theodolite with in built optical plummet
-03. Precise levelling Kronstadt - Black Sea -Sea of Azov
-35. Triangulation Brest - Astrachan
De Grousilliers suggested to Zeiss idea of stereophotogrammetry
Chile, Peru covered with triangulation
Brunsvega twin desk calculator
French physicists introduce wavelength method to define the metre
Pulfrich constructed a rangefinder with floating mark (of Stolze)
-10. First geodetic levelling of Finland.
Three colour process by Kurtz
-98. Diagram tacheometer by Poncagli, Urbani and Hammer. Italy.
Double image optical distance measurement. Richards USA
Guilleaume suggested use of hypsometer with mercury barometer for g at sea
First stereo plotter by Machand, Deville in Canada
Relief printing mechanical press
Guilleaume developed invar for survey tapes.
Finsterwalder and Hugerhoff phototheodolite.
Geoidal profiles computed in Berlin
-03. Work of Scheimpflug on photogrammetry
-06. Helmert experiment on fluctuation of equipotential surface.
Russian Engineers used photos to locate railways near Chinese borders
Act of Parliament in GR to legalise metric system
Russian-Swedish expedition to Spitzbergen. Used Jaderin wires
Hildebrand optical plummet for nadir and zenith plumbing
-05. Four metre subtense bar used in German E Africa
Austrian Marine obs of refraction at sea horizon
Turkey mapped by Austrian Military surveyors
Bulgaria mapped by Russian officers
1400 absolute gravity stations observed. Used to adjust Helmert formula
Kites with combined cameras used in Moscow by Thiele.
Geoid map of Switzerland by Messerschmitt
Stereocomparator by Abbe, Pulfrich and Zeiss.
Helmert work on spheroidal formulae
Invar staves used for precise levelling in Europe.
-06. Reobservation of Peru arc. See p 76.
-09. Hayford ellipsoid. Also topo.-isostatic reduction formula.
First geoid map of US East coast by USCGS
Double point resection by Finsterwalder
Albrecht test to determine long. diff. Potsdam-Brocken Mt by wireless
in comparison with telegraphic transmission.
Absolute gravity observed at Dehra Dun
Rudski inversion method for reduction of masses above geoid
Wild theodolite with microscope for both verniers next to telescope
Bykow. Suggested level recording inst. using pendulum and rev. counter.
-54. Triangulation Cape to Cairo. ie 30th meridian
Photocomposing machine in lithography by Huebner
Helmert method to find earth axes from trig and gravity obs.
Stereoplotter by Thompson
Schweydar theory of coeff of rigidity of earth.
Wild.Coincidence setting of both verniers with microscope.
Stereo autograph by von Orel of Vienna.
Carl Zeiss Jena established geodetic instrument section
-11. Triangulation in Fiji by Lee, Rimmer, McCaw
Zeiss parallelogram by Bauersfeld
Prismastrolabium by vonClaude & Driencourt.
Pratt-Hayford isostatic system
Hayford investigated mean ellipsoid from gravity data
Zwicky tacheometer with two telescopes.
Photographic cross-sections of tunnel profiles in Austria
-13. Antarctic triangulation Ross Sea area by Debenham
Further 2736 absolute garvity stations. Helmert forula readjusted 1915
Hammer method of adjusting trilateration.
Wilski double wire shaft plumbing.
Wild's Zeiss III precision level with parallel plate micrometer.
Bowie working on isostasy
Foundation of International Time Bureau in Paris. (BIH).
Kruger method to transform conformal coords to adjacent zones
-13. Wegener found large vertical refraction in Greenland
-17. Bowie gravity obs in USA, Canada, India and Europe.
-21. Second geodetic levelling of Great Britain
Tardivo at Int. Cong. described aerial photog. from aeroplanes for mapping.
Haussmann suggested a gyrotheodolite
-18. Karolus, Mittelstadt & Huttel determined speed of light on geodetic base near Leipzig.
Bowie published "Investigations of gravity and isostasy.
IUGG formed. Germany only joined in 1956
Karolus constructed modern Kerr cell as used in geodimeter.
Astrolabe attachment for theodolite by Reeves.
Stein found evidence of Indus inch inGobi desert.
Wild founded own workshop in Heerbrugg
Anschutz constructed first gyrotheodolite.
Parana river crossing. Levels by simult. z.d.
-27. Athanassiadis (Gk) suggested to link Crete with N Africa by flare
triangulation with balloons
Vening Meinesz working on isostasy
Plane parallel plate for Vaisala interference comparator.
Design of Wild T2 complete
Vening Meinesz gravity obs in submarine
Glass circles & optical micrometer designed by Wild, built by Zeiss.
Zeiss-Bosshardt double-image tacheometer.
Barometric lapse rate formula.
Acceptance of Hayford ellipsoid as Int. Ellipsoid of IUGG
Foundation of Baltic GeodeticCommission by Bonsdorff
-38. Heiskanen observed over 2000 gravity stations.
-38. Airy-Heiskanen isostatic system
Launch of Wild T3
Defant- tidal theory
Research into vertical refraction by Geiger and Kukkamaki
Astro levelling by Aguilar in Argentina.
CTS 1" theodolite
Sun compass by Bumstead for polar flights.
Coast to coast precise levelling in USA
Somigliani derived major axis of geoid from gravity measures alone
Differential analyser for use in digital computer By Bush, USA
Experiments with echosounders by Behm (G)
Triangulation of Alai-Pamir by Germans under Finsterwalder
IAG first published International Bibliography.
Static quartz gravimeter by Noergaard
Empirical gravity formula by Heiskanen
Deflection of dams by precise geodetic methods. Lang, Switzerland
Vening-Meinesz three pendulum gravimeter for use at sea
Somigliani and Cassini added theoretical term to to Heiskanen 1928 formula
Holweck-Lejay astatic pendulum
Lejay, S.J. director of Observatory Zi-Ka-Wei near Shanghai
Gravimeters specifically for oil exploration. Truman, USA
45º prismatic astrolabe by Baker.
Pendulum astrolabe by Willis.
Error analysis by Ljutz.
Spring balance principle gravimeter
-31. Wegener Greenland crossing. Used trig. levelling.
Haalck gravimeter on barometric principle
Heiskanen tables of isostatic reductions
Hildebrand special optical plummet for shipbuilding.
Gas pressure gravimeter
-41. Vening-Meinesz modified Airy regional floating theory.
Heiskanen definition of spheroidal earth. See p 83
and also equilibrium earth.
Photo.registration of horz. circle reading on theodolites. Berroth
Bifilar gravimeter by Tomaschek
Berroth established procedures for flare triangulation
Triangulation of Nanga-Parbat
Hirvonen used Stokes formula to recompute geoid.
-35. Heye, Cooke absolute gravity in washington.
N African parallel arc Nemours - Carthago and W to Casablanca.
Echo sounder improved by Wood and others.
Germany instructed Surveyors to switch to centesimal circle graduations
Australian SArmy Svy Corp bought first metric tapes
-55. Secoind Geodetic levelling of Finland by Kukkamaki et al.
Int.Lat. Service moved to Naples from Kimura
Hilger Watts 1" microptic theodolite
Three way optical plumb by Zeiss
Norlund pioneered hydrostatic precise levelling
-38. J S Clark NPL absolute gravity
Charter for OS recommended metric grid.
Plane parallel plate for precise level by Wild(Zeiss).
Calibration od invar base wires by Vaisala interference comparator
Cowle, USA had idea of adjustment by electrical analogue
Graf, Berlin. static gravimeter
Test of Berroth flare triangulation inGermany
Automatic level compensator by Meissner
Hinterkeuser error theory of flare triangulation
Gulf underwater gravimeter
Roelofs solar prism
ICAN Standard Atmosphere for barometric levelling.
HARVARD MARK 1 by Aiken. Electronic computer with punch tape.
Underwater photogrammetry began in USA
Multiplex radar controlled air photography.
ENIAC by Mauchly et al. USA.
Norlund levelled 21 km across Baltic Sea using lead pipe.
Split of Carl Zeiss Jena to give Carl-Zeiss Obserkochen & VEB Carl Zeiss
-46. Flare triangulation by British, US and Norway
-51. Rice and van Steenwijk studies on deflection of plumbline
Absolute gravity work by Bullard, Ivanov, Browne, Morelli, Jeffreys, Woollard
Russian tri-axial ellipsoid. See p 84
Dutch discovered radio astro with ex-war radar.
Vaisala stellar triangulation
Speert, USGS adjustment by electrical analogue.
Electric eye for telescopes by Gigas
-48. Fully automatic elevation recorders
-48. Global triangulation initiated by Finns. Hirvonen in Brazil and
Kukkamaki in W Africa
Mears, Whitford USA telescope for occultation obs.
Jungwirth modified submarine gyro compass to fit theodolite
Invention of transistor by Bell Laboratories USA
-65. Level testers of high precision. See p 85
Reflecting telescope by Kern for 1st order triangulation
Gyroscopes in aerial cameras. (Italy)
Gyroscopes in theodolites by Fennel.
Moves by Hotine, Marussi, Levallois, Dufour to replace geoid by quasi geoid
Molodensky and Hirvonen defined by space coords instead of siurface coords.
Hough & Whitten adjusted SW European & N African trig. blocks
Van Heel,Moonen & Richardus used interference patterns in alignment svy.
Honkasalo inver-mercury thermometer for baselines
Automatic level Ni2 by Zeiss Oberkochen
Fourth connection UK - France by triangulation.
-59. Third geodetic levelling of Great britain
Askania Askania micro-barometer for diff. of height.
Random disturbances of earth rotation. Brouwer, USA.
VEB Carl Zeiss 1" theodolite 010
Wankie and Sabi bases (S Rhod) by Bradford. Invar resistance thermometer.
Ellenberger reported on elasticity of earth.
Invention of geodimeter ??
Diff. between dynamic and orthometric hts discussed in Rome
Advent of satellites
Irene Fisher geoid chart of USA
Hough ellipsoid of Western hemisphere
Obs of satellites by interferometer, Doppler effect and radar.
Sea surface gravimeter by Graf.
Fisher- Chovitz figure of earth. See p 88
Jerie analogue computer
-58. International Geophysical Year
Baker-Nunn camera for satellite obs.
Several independent adjustments of 68 European level loops. See pp 88,89
Tellurometer traverses replace triangulation in Australia
Development of super wide angle camera by Wild
First spatial photograph of moon by Lunik III
Prismastrolabium by Danjou.
Fennel, Kassel gyrotheodolite with suspended gyroscope.
Int. agreement of metre as 1 650 763.73 wavelengths krypton 86 in vacuo
Yard - metre relation as 0.9144 m
De Graaff Hunter theory on shape of earth suirface
Harrison USA gravity measurement in aeroplane
Astro-geodetic World Datum for geoid.
Also agreement on standards of length. See p 89
Mobile cameras for satellite geodesy
Irene Fischer comprehensive study of shape of geoid.
Cooperation between NASA and USCGS in geodetic satellite programme
Fifth connection England - France by triangulation & trilateration
Hydrostatic levelling using frozen lake Ijsselmeer
Automatic level Zeiss Ni4 by Drodofsky. Spirit bubble as pendulum
Light weight gyrotheodolites by Wild, MOM etc
VEB Carl Zeiss astro-geodetic theo 0.2"
Daylight signalling lamp with quartziodine globes. Australia
Geodolite by Spectra Physics, USA