Natural Gas Pipeline #1
Inga Spence
Horse-drawn Fire Truck, C. 1890s-1900s
H. Armstrong Roberts/ClassicStock
Construction Workers Raising Steel
H. Armstrong Roberts/ClassicStock
Florence Nightingale, English Nurse
Science Source
Engineers At Drafting Tables, C.1960s
H. Armstrong Roberts/ClassicStock
Building Of The Temple Of Jerusalem
Science Source
Fingerprints Of Vincenzo Peruggia, Mona
Photo Researchers
Robber Barons Crushing Workers
Science Source
Apollo Capsule Going In For Repairs
Science Source
Honeybee Workers And Queen
Mark Bowler
Florence Nightingale, English Nurse #5
Science Source
Entering The California Desert
Photo Researchers
Men Working On Power Line, C.1930-40s
H. Armstrong Roberts/ClassicStock
Unloading A Titan Ivb Rocket
Science Source
U.s. Navy Mailmen, 1890s
Science Source
Nurse Using Digital Tablet With Binary
Ikon Ikon Images
Carpenter Ants
Theodore Clutter
Olympic And Titanic At Belfast
Photo Researchers
John Deere Cotton Pickers Harvesting
Inga Spence
Natural Gas Pipeline
Inga Spence
Overhead View Of Jet Airplane Assembly
H. Armstrong Roberts/ClassicStock
Ant Colony With Larvae
Matthias Lenke
Construction Of Central Pacific #1
Science Source
American Civil War, Union Mail Wagon
Science Source
Doctors And Nurses Giving Patient
Ikon Ikon Images
Doctor Prescribing Medicine For Elderly
Ikon Ikon Images
Businesswoman With Arrow Leading Tied
Ikon Ikon Images
Postman In Tuxedo Delivering Letter
Ikon Images
Florida Juke Joint, 1941 #2
Science Source
The Lady With The Lamp, Florence
Science Source
Captured Confederate Soldiers, C.1860s
H. Armstrong Roberts/ClassicStock
Ant Communication
Frank Fox
Migrant Workers
Photo Researchers, Inc.
Workers Planting Tree
Inga Spence
Butcher, Medieval Tradesman #2
Science Source
Florence Nightingale, English Nurse #7
Science Source
Union Membership Card, 1886
Photo Researchers
Air Traffic Controllers
Susan Leavines
Medieval Construction, 15th Century
Photo Researchers
Two Children Playing Doctor, C.1950s
H. Armstrong Roberts/ClassicStock
Construction Of Central Pacific #3
Science Source
Child Playing Doctor With Dolls, C.1940s
H. Armstrong Roberts/ClassicStock
Doctors Looking Into Mans Head
Ikon Ikon Images
Busy Chaotic Vet Waiting Room
Ikon Images
Steelworks
U.S. Department of Energy
Roof Thatching, Denmark
Photo Researchers, Inc.
Woman Sewing Curtain
George Mattei
Harvesting Valencia Oranges
Inga Spence
Tractor Planting Trees #1
Inga Spence
Watermelon Harvest
Inga Spence
Holding A Halved Watermelon
Inga Spence
Harvesting Organic Lettuce
Inga Spence
Pacific Dampwood Termites
Ted Kinsman
Pacific Dampwood Termites #1
Ted Kinsman
Chinese Stonemason
Science Source
Scientists Working Together Searching
Ikon Ikon Images
Male And Female Doctors Superimposed
Ikon Images
Worker Harvesting Kona Coffee
Inga Spence
Worker Pruning Date Palm
Inga Spence
Worker Punching Time Card, C.1930s
H. Armstrong Roberts/ClassicStock
Worker On Telephone Pole
Scimat
Telecommunications Workers Maintaining
Ikon Images
Paul Robeson Singing With Workers, 1942
Science Source
Building The Transcontinental Railroad
Omikron
Man In Deep Sea Diving Suit, C.1940s
H. Armstrong Roberts/ClassicStock
Repairing Mississippi Levee, 1903
Science Source
Ford Assembly Line
Omikron
Florence Nightingale English Nurse #19
Science Source
Termite Nest
Science Source
Florence Nightingale, English Nurse #8
Science Source
Chuck Wagon
Photo Researchers, Inc.