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WOODEN TOWERS & SIGNAL POLES
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Coast-Geodetic-Survey
Geodesy
Triangulation
Wooden Towers & Signal Poles
Geodesy
Pole signal with tin cone for reflecting sunlight.Constructed by survey crews under direction of Ferdinand Hassler.Sketch by Assistant John Farley - view looking to south across Long Island Sound
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Tripod signal with tin cone for reflecting sunlight.At signal West Base, west end of Great Fire Island Base Line.Constructed by survey crews under direction of Ferdinand Hassler.Sketch by Assistant John Farley - view looking to east
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Wooden tower within a tower.Outer tower supports personnel - inner tower supports instrument.First devised by Assistant Edmund Blunt to see over marshes in Delaware Bay area
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Survey tower with signal pole and tin cone.At west end of Epping Base Line.Survey monument shows below tower.Stakes on graded surface were for aligning base measuring instruments
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Signal pole with flag and tin cone for reflecting sunlight.Epping Plains area of Maine
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Signal at Stillpond, Maryland.Instrument height of 120 feet - top of signal 275 feet.39th Parallel Survey.Record signal height from wooden tower
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Field sketch of signal pole on tree stump.Sketch by Cephas Sinclair
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129 foot wooden tower at Station Tate.Horse and buggy at lower right corner for scale.Triangulation party of A. T. Mosman
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Station Tate showing attached signal pole.Top of signal pole is 175 feet above ground.Triangulation party of A. T. Mosman
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Station Greene, Indiana.Instrument height is 152 feet above ground.39th Parallel Survey.Triangulation party of George A. Fairfield
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Station Greene, Indiana.Instrument height is 152 feet above ground.39th Parallel Survey.Triangulation party of George A. Fairfield
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Great Caspar Signal - built around tree trunk.Note boatswain chair transporting man to top.135-foot signal --- main wood scaffold supports instrument.Tree trunk supports small scaffolding and observer at top.Western terminus of 39th Parallel Survey
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Wooden signal being built in Alaska.
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Jasper Bilby setting up 60' reconnaissance pole.At Station Elbow - connecting with 98th Meridian Survey
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John F. Hayford observing from 60' reconnaissance pole.On 98th Meridian Survey.Checking for intervisibility between stations.Helping plan for necessary height of tower at station
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Jasper S. Bilby observing from short reconnaissance pole attached to tree.On 98th Meridian Survey.Checking for intervisibility between stations.Helping plan for necessary height of tower at station
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Jasper S. Bilby observing from reconnaissance pole attached to tree.Top of pole is 104 feet above ground.Checking for intervisibility between stations.Helping plan for necessary height of tower at station
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Beginning to erect tower at Station Hugo.Lines snapped dropping pole seconds after picture.Triangulation party of William H. Burger
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Raising one side of instrument tripod at Station Hugo.Triangulation party of William H. Burger
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Raising third leg of instrument tripod at Station Hugo.Triangulation party of William H. Burger
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