Fording the Danjek River. Sedan delivery truck 5025. Triangulation party of John Bowie

Crossing Amargosa River after spring rains. Level crew of Paul Taylor.

A dry lake bed flooded by late spring rains. Level crew of Paul Taylor.

En route to Cape Nome. Triangulation party of A. Newton Stewart.

Moving headquarters in the snow. Level crew of Ira Rubottom.

Sounding boat off of NATOMA.

Skiff outfitted for hydrography. Party off of HYDROGRAPHER.

Leadline survey from catamaran hull.

Using sounding pole to measure depth in shallow water. Combined operations party of B. H. Rigg

Using sounding pole to measure depths. Combined operations party of William D. Patterson

Sounding pole with walk hydro outfit. Hydrographic party of Kathryn Andreen

Measuring three-point sextant fix during launch hydrography.

Measuring three-point sextant fix during launch hydrography. Launch off of LESTER JONES

The end of a hard day of launch hydrography. Launch off of PATHFINDER

Taking horizontal sextant angles from ship's mast. Photograph from 1931 Hydrographic Manual

Coast and Geodetic Survey Steamer BLAKE. In service 1874-1905. Atlantic service. Classic Gulf Stream studies, many instrument innovationsTopographic Survey. Pioneered deepsea anchoring

Tanner Sounding Machine. Designed by Zera Luther Tanner, first captain of the ALBATROSS I

Leadline sounding operations. Wind that sucker up and let her fly

Lieutenant Roswell Bolstad measuring a horizontal angle. On LYDONIA

Life imitating art in the Indian Ocean - celestial navigation. Very similar to Winslow Homer print of navigators on Georges Bank. Navigating on the PIONEER

Winslow Homer sketch of navigators on the Grand Banks.

C&GS Building at 119 D. Street NE. Figure 5, page 6 of the History of Flight and Photogrammetry

C&GS Ship HYDROGRAPHER as seen from photogrammetric aircraft. First photo mission for C&GS was an attempt to determined depths in clear water . Project in Florida Keys - ship was used as fixed reference program. Cooperative project with Aeroplane Service of the Navy

The key chart showing flight lines and photo locations. Mapping of Mississippi Delta and Passes

Section of mosaic of photos along Atlantic shore. Cooperative project with Army Air Service. C. G. Quillian was C&GS officer in charge of running project

K-1 camera.

Geometry of aerial photography.

Making a pantograph reduction of New Jersey shore photographs. Changing scales and transferring points from photos to map sheet

Using a stereoscope to bring images on adjacent photographs into coincidence.

Navy crewman holding K-1 camera. Used on Mississippi Delta mapping project

K-1 camera. Used on Mississippi Delta mapping project

Opening in bottom of plane for K-1 camera. Used on Mississippi Delta mapping project

The start of a mapping flight. Cooperative use of a Navy Air Service float plane for photographic duty

Waiting for a tow at the end of the flight. Cooperative use of a Navy Air Service float plane for photographic duty

Dry-docking of float plane after return to base. Cooperative use of a Navy Air Service float plane for photographic duty

Comparison of a plane table sheet (on the left) and aerial photography. Cooperative project with Army Air Service

Aerial photography vs. plane table mapping.

Army Air Force 3-lens camera.

Aerial photograph from 5-lens camera.

Nine-lens camera fully assembled. This camera was designed by Oliver Scott Reading in the early 1930's. It was the state-of-the-art aerial camera for many years

Nine-lens photograph and composite image of Washington, D.C.

Martin B-10-B bomber used to test nine-lens camera. Wright-Patterson Army Air Force Base

The nine-lens aerial camera.

Nine-lens photograph of New York City.

Portion of composite image of New York City.

Martin B-10-B bomber used to test nine-lens camera. Second photo shows transportation unit for bringing camera to aircraft

Coast Guard PBY flying boat used for nine-lens camera photography.

Coast Guard PBY hitching a tow after landing.

Coast Guard pilot Lieutenant Vaughan with salmon berries.

Edgar Bergin and Ophelia at Sand Point. USO show.