The British navy appointed its first hydrographer in 1795, and the United States established a naval observatory and hydrographical office in 1854.
The only way a hydrographer could chart the seabed before underwater echo sounding and television became available was to cast overboard at intervals a sounding line with a lead weight at the end and measure the length of the line paid out when the weight hit the bottom.
Born the son of a master ceiling plasterer, Mechain early in life showed mathematical prowess and worked as a hydrographer for the Naval Map Archives at Versailles during the 1770s.
The terms hydrography and hydrographer are based on an analogy with geography and geographer and date from the mid-16th century.
The terms hydrography and hydrographer date from the mid-16th century; their focus has become restricted to studies of ocean depths and of the directions and intensities of oceanic currents; though at various times they embraced much of the sciences now called hydrology and oceanography.
Pierre Mechain, (born Aug. 16, 1744, Laon, Fr. died Sept. 20, 1804, Castellón de la Plana, Spain) French astronomer and hydrographer who, with Jean Delambre, measured the meridian arc from Dunkirk, Fr., to Barcelona.
The British East India Company employed hydrographers in the 18th century, and the first hydrographer of the Royal Navy, Alexander Dalrymple (1737 1808), was appointed in 1795.
July 5, 1805 Ampton Hall, England April 30, 1865 Norwood, England Robert Fitzroy, (born July 5, 1805, Ampton Hall, near Bury St. Edmunds, Suffolk, Eng. died April 30 , 1865 Norwood, Surrey), British naval officer, hydrographer, and meteorologist who commanded the voyage of HMS Beagle, which sailed around the world with Charles Darwin aboard as naturalist.
In the early part of this century, several Scandinavian hydrographers called attention to the existence of submarine waves, but another generation was to elapse before science had the instruments to study them thoroughly.
In the years 1800-1870, an eclectic group of sailors, artists, chemists, astronomers, hydrographers, businessmen, mathematicians and adventurers invented the weather forecast that we now take for granted.
Relying on detailed geological and geophysical surveys by scientists and hydrographers, any state can delineate a new "continental shelf outer limit" that can extend up to 350 miles from its shoreline.
