C&GS Launch 66 - wiredrag tender in Long Island Sound. Mate Franz Okeson facing camera on right

Wiredrag at Mitchell-Jordan Reservoir. Site for seaplane ferrying landing site . Wiredrag party of Max Ricketts

Some tools of the trade - wiredrag at Mitchell-Jordan Reservoir. Sextants for shooting horizontal angles, 3-arm protractor for plotting positions . Wiredrag party of Max Ricketts

Wiredrag operations at Elephant Butte Reservoir for seaplane landing site. Wiredrag party of Max Ricketts

Leadline sounding during wiredrag operations. Wiredrag party of Max Ricketts

Wiredrag gear on the stern of the LESTER JONES.

Buoys crushed from being swept under by tidal currents. Operations on the LESTER JONES

Current meter being deployed. Operations on the LESTER JONES

Wiredrag operations on the LESTER JONES.

Launch wiredrag operations. L to r - guide launch, tender, end launch. Launches off of PATHFINDER

Diagram of wiredrag operations ca. 1980. Basically the same system as devised in the early Twentieth Century

Chain drag operation - hung up on obstruction. Launches off of PEIRCE

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

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

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

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

Signal pole with flag and tin cone for reflecting sunlight. Epping Plains area of Maine

Signal at Stillpond, Maryland. Instrument height of 120 feet - top of signal 275 feet. 39th Parallel Survey. Record signal height from wooden tower

Field sketch of signal pole on tree stump. Sketch by Cephas Sinclair

129 foot wooden tower at Station Tate. Horse and buggy at lower right corner for scale. Triangulation party of A. T. Mosman

Station Tate showing attached signal pole. Top of signal pole is 175 feet above ground. Triangulation party of A. T. Mosman

Station Greene, Indiana. Instrument height is 152 feet above ground. 39th Parallel Survey. Triangulation party of George A. Fairfield

Station Greene, Indiana. Instrument height is 152 feet above ground. 39th Parallel Survey. Triangulation party of George A. Fairfield

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

Wooden signal being built in Alaska.

Jasper Bilby setting up 60' reconnaissance pole. At Station Elbow - connecting with 98th Meridian Survey

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

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

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

Beginning to erect tower at Station Hugo. Lines snapped dropping pole seconds after picture. Triangulation party of William H. Burger

Raising one side of instrument tripod at Station Hugo. Triangulation party of William H. Burger

Raising third leg of instrument tripod at Station Hugo. Triangulation party of William H. Burger

Framing first and third leg of instrument tripod at Station Hugo. Triangulation party of William H. Burger

Completed instrument tripod at Station Foss. Photo #1 of sequence

First side of observer scaffolding being raised at Station Foss. Photo #2 of sequence

Both sides of observer scaffolding in place at Station Foss. Photo #3 of sequence

Putting ties on scaffolding at Station Foss. Photo #4 of sequence

Completed tower with internal instrument tripod at Station Foss. This station took 1 and 1/2 days to complete. Photo #5 of sequence

Station Pen in Washington. Triangulation party of O. B. French - occupied by J. S. Hill. Instrument was mounted on tree trunk. Instrument remained steady in azimuth but unsteady in level

Station Gibuson - a 68 foot tree signal. Party of John F. Pratt - off of PATHFINDER

White River West Base on the 141st Meridian Survey. International Boundary Commission surveyors

Rock cairn signal at divide between two main forks of the Ladue River. International Boundary Commission surveyor

Platform and stand built between two trees on Olympic Peninsula. Note man standing on platform. Triangulation party of H. A. Seran

The crow's nest at Station Moclips - 215 feet above the ground. Note spikes driven into tree - builders would drive spikes and go hand over hand . Triangulation party of H. A. Seran. According to Seran: "It took men of uncommon nerve to do this work."

239-foot tower built on Bugsuk Island in southwest Philippines. This tower was built completely from native timber cut on location. It took 19 men off the PATHFINDER three weeks to build this signal. This was the largest wooden tower ever built by the C&GS. Used for both observing and as a signal

Wind tarps draping tower at Station Bippus. Wind tarps protect inner instrument tower from wind. Triangulation party of Earl O. Heaton

Removing wind tarps at Station Umbarger. Wind tarps protect inner instrument tower from wind. Triangulation party of Earl O. Heaton

100-foot tower at Bozeman NW Base. Note man at top. Triangulation party of William M. Scaife

115-foot tower built around tree on Sarangani Island.

Tower at Station Mangal. Topographic party working on the beach