Horse-drawn Fire Truck, C. 1890s-1900s
H. Armstrong Roberts/ClassicStock
Charles R. Drew #1
Science Source
Engineers At Drafting Tables, C.1960s
H. Armstrong Roberts/ClassicStock
New England To Virginia, 1651
Photo Researchers
Red X
Photo Researchers, Inc.
Prehistoric Drawings
Adam Sylvester
Charles R. Drew
Science Source
Grading
Photo Researchers, Inc.
New York Elevated Railway, 19th Century
Wellcome Images
Red Pencil Tip
Photo Researchers, Inc.
Hand Drawn Map By G. Washington
Photo Researchers
Horse-drawn Wheat Harvesting, C.1920-30s
H. Armstrong Roberts/ClassicStock
Amish In Horse-drawn Buggy, C.1930s
H. Armstrong Roberts/ClassicStock
Horse-drawn Plow, C. 1930s
H. Armstrong Roberts/ClassicStock
Horse-drawn Wagon And Tractor In Field
H. Armstrong Roberts/ClassicStock
Horse-drawn Wheat Harvest, C.1930s
H. Armstrong Roberts/ClassicStock
Man Riding Reindeer-drawn Sleigh
Wellcome Images
Young Girl Playing Hopscotch On Pavement
Bill Bachmann
Benjamin Franklins Printing Press
Science Source
Checking The Box
Photo Researchers, Inc.
Nineteeth-century Transportation
Science Source
Grading #1
Photo Researchers, Inc.
Crayons
Photo Researchers, Inc.
Grading #2
Photo Researchers, Inc.
Guy Fawkes, English Soldier Convicted
Photo Researchers
Broadway And City Hall, New York
Omikron
Mars, Roman God Of War #2
Photo Researchers
Marble Sewing Machine By Leonardo Da
Science Source
Central Park, New York, 1869
Photo Researchers
Spill Out On The Snow
Photo Researchers
American Winter 1870
Photo Researchers
Mars, Roman God Of War #5
Photo Researchers
Flooding On The Mississippi River, 1909
Library of Congress
Moth At Lightbulb
Scott Linstead
Animal Cell
Carlyn Iverson
Crystallography Of Riboflavin
Vem
Amish Buggy
Richard and Ellen Thane
Drawing With A Ruler
Steve Gorton / Dorling Kindersley
Shark, Illustration
Gwen Shockey
Shark, Illustration #1
Gwen Shockey
The Human Heart, Illustration
Monica Schroeder
The Human Heart, Illustration #1
Monica Schroeder
Cupid Hitches A Ride, 19th Century
Science Source
Boy Drawing Duck, C.1950s
H. Armstrong Roberts/ClassicStock
Dueling Cowboys, C.1950-60s
D. Corson/ClassicStock
Swiss Nomads And Gypsy Wagon, C.1930s
H. Armstrong Roberts/ClassicStock
Cowboy Sheriff Making Arrest, C.1950-60s
D. Corson/ClassicStock
Cowboy Taking Aim, C.1920s
H. Armstrong Roberts/ClassicStock
Circus Bandwagon, C.1920-30s
H. Armstrong Roberts/ClassicStock
William Herschels Nebulae
Wellcome Images
Robert Hooke Microscope, 17th Century
Science Source
Map Used To Predict Location Of Oil
Science Source
Nyc, Times Square, 1915
Science Source
Nyc, Broadway And Times Building
Science Source
Nyc, Times Square, 1911
Science Source
Two Children Coloring, C.1940s
H. Armstrong Roberts/ClassicStock
Deadwood Stagecoach, 1889
Science Source
Eryops Megacephalus
Millard H. Sharp
Meteorologia, Neptune, 1709
Science Source
Lobster Dinner At Bar Harbor, Maine
Theodore Clutter
Plowing With Oxen, Mexico
J. Gerard Sidaner
Overhead View Of Airplane
Ikon Ikon Images
Range Of Healthy Fruit, Nuts And Seeds
Ikon Ikon Images
Slice Of Bread And Jar Of Jam
Ikon Ikon Images