Boston whaler getting ready to take batteries and Minirangers to stations. Boston whaler off of PEIRCE

Taking a bar check to calibrate fathometer. Note transducer clamped to side of boat - officer on right monitoring fathometer

Monark outfitted for hydrography in Indian River Inlet, Delaware coast. Motorola Miniranger secured on mast and covered with red flagging. Boat was being used for range-azimuth hydrography. Detached party from NOAA Ship PEIRCE

Quartermaster Burke checks out the distance to warmer places

Charles Schott with Davidson meridian instrument. Eclipse expedition of 1870

Meridian telescope

Zenith telescope at the Ukiah Latitude Observatory. Showing latitude levels. Part of international effort to observe small changes in latitude

Zenith telescope at the Ukiah Latitude Observatory. Wooden frame built around supporting stand. Protecting instrument from accidental disturbance. Part of international effort to observe small changes in latitude

Bamberg astronomical transit. In use 1914 - 1960. Used for both latitude and longitude observations

Portable observing tripod made of poplar. Astro party of C. V. Hodgson

Lightweight aluminum observing tripod. Astro party of C. V. Hodgson. Note remains of old observing stand to left

Assembling lightweight aluminum observing tripod. Astro party of C. V. Hodgson

Observing longitude with Bamberg broken telescope instrument. Astro party of George D. Cowie

Ed Brown's astro outfit. Astro party of E. J. Brown

World longitude network setup at Manila. Note radio gear to receive time ticks. Chronograph is drum-like instrument to right

Bamberg transit set up at Station NIU Hawaii. Astro party of E. J. Brown

Bamberg transit set up. Astro party of E. J. Brown. Part of World Longitude Campaign

Short wave radio recorder. Astro party of E. J. Brown. Part of World Longitude Campaign

E. J. Brown using Davidson meridian telescope. Astro party of E. J. Brown. Part of World Longitude Campaign

E. J. Brown at astro setup checking chronograph. Astro party of E. J. Brown

Early morning computing - verifying last night's work. Astro party of Ralph Pfau

Station NIU during reobservation of World Longitude stations. Looking for evidence of continental drift. Instruments too crude to measure small earth movements. Astro party of Joseph Lushene

Joseph Lushene operating long-wave radio receiver. Attempting to receive time ticks. Astro party of Joseph Lushene

Bamberg transit and equipment. Astro party of Charles Whitten

Chronograph drum without paper. Used to record time ticks during longitude observations. Astro party of Charles Whitten

Bamberg transit set up on Guatemala - El Salvador border. Border determined by C&GS. Astro party of Ralph W. Woodworth

At astro station on Honduras - Guatemala border. L. to R. - Honduras commissioner, Joseph Lushene, recorder. Recorder later died of malaria. Astro party of Joseph Lushene

Station Eskimo on Honduras - Guatemala border. Border determination a combination of astro and triangulation work. Astro party of Joseph Lushene

Guards accompanying Guatemala - Honduras boundary surveyors. Astro party of Joseph Lushene

Transportation by mules. Guatemala-Honduras boundary survey. Astro party of Joseph Lushene

Transportation by mules. Guatemala-Honduras boundary survey. Astro party of Joseph Lushene

Composite photo of many aspects of astro work. El Salvador - Guatemala boundary survey. Astro party of Ralph W. Woodworth

Ralph Woodworth at Bamberg broken telescope instrument. El Salvador - Guatemala boundary survey. Astro party of Ralph W. Woodworth

Installation at Station Observatorio. El Salvador - Guatemala boundary survey. Astro party of Ralph W. Woodworth

Installation at Station El Sitio. El Salvador - Guatemala boundary survey. Astro party of Ralph W. Woodworth

Lieutenant Eugene Taylor observing with Bamberg instrument. Astro party of Lieutenant Eugene Taylor

Vernon Burns setting up Wild T-4. Astro party of Lt.(j.g.) Albert Theberge

Astro setup in Mojave Desert. Richard Cohen preparing to record in truck. Astro party of Lt.(j.g.) Albert Theberge

Vernon Burns preparing Wild T-4 for observations. Astro party of Lt.(j.g.) Albert Theberge

Richard Maxey setting up Wild T-4. Astro party of Robert A. Pryce

Vernon Burns at twilight - determining initial azimuth. Astro party of Lt.(j.g.) Albert Theberge

A. E. Theberge discussing Wild T-4 with Afghani student. Astro party of Lt.(j.g.) Albert Theberge

A. E. Theberge discussing Wild T-4 with Afghani student. Astro party of Lt.(j.g.) Albert Theberge

Latitude observatory at Ukiah, California. International program to determine variation of latitude

Use of Navy Transit satellite receiver. Determining latitude and longitude simultaneously. Multiple passes over several hours to get good position

Texas Instruments TI4100 GPS receiver. Determining latitude and longitude simultaneously

Use of Texas Instruments TI4100 GPS receiver. Determining latitude and longitude simultaneously

Use of Navy Transit satellite receiver. Determining latitude and longitude simultaneously

Jasper Bilby with light reconnaissance buggy. Recon work on the 98th Meridian

500 lb. stone being lowered for Brown Valley Base. 98th Meridian survey. Jasper Bilby on right