AVE6322496: United States, 1980s:women work in lab / Bridgeman Images

AVE6322497: United States, 1950s: Animation of sound waves hitting ear, entering brain / Bridgeman Images

AVE6322499: United States, 1980s:lady counts bacteria growth in gel / Bridgeman Images

AVE6322501: United States, 1950s: Boys singing in choir / Bridgeman Images

AVE6322506: United States, 1980s:scientists prepare experiments for astronauts in space / Bridgeman Images

AVE6324525: Fruit Picker Picking Fruit from a Tree / Bridgeman Images

AVE6324532: Monkeys in Cages in a Science Laboratory / Bridgeman Images

AVE6324544: White Rat Being Given Drop of TEPP in Eye / Bridgeman Images

AVE6324557: Researcher Assesses Ability of Clothing to Protect Farmer from Chemical Sprays / Bridgeman Images

AVE6324559: Scientist Moves Pads from Man's Outfit Ready for Testing / Bridgeman Images

AVE6324560: Lady Picks up Apple from Basket / Bridgeman Images

AVE6324566: Scientist Pours Liquid into Glass Beaker in Lab / Bridgeman Images

AVE6324575: Warning Label on Bottle of Pesticide / Bridgeman Images

AVE6324576: Man in Yard Works with Pesticides / Bridgeman Images

AVE6324586: Men Collect Medicines from Pharmacy / Bridgeman Images

AVE6324589: 1910s: Young girl gazes out of window at other girls playing outside / Bridgeman Images

AVE6324596: 1910s: Girl sits in cramped space playing with a doll / Bridgeman Images

AVE6324597: 1910s: Girl sits in cramped space playing with a doll and accidentally breaks it / Bridgeman Images

AVE6324650: United States, 1930s: Pointer showing the layout and structure of the middle ear as seen through an otoscope / Bridgeman Images

AVE6324657: United States, 1930s: Diagram showing the transmission sound from the inner ear to the brain via the frontal, ethmoid, and maxillary sinuses / Bridgeman Images

AVE6324659: United States, 1930s: Close up diagram showing the external ear, shell (pinna), and auditory canal (meatus) / Bridgeman Images

AVE6324668: 1910s: Couple speaks in a kitchen, elderly man walks past outside / Bridgeman Images

AVE6324671: 1910s: Man and woman speak heatedly to each other, young woman talks to herself outside and eventually shoots a gun / Bridgeman Images

AVE6324672: United States, 1930s: Picture showing the inner ear structure / Bridgeman Images

AVE6324678: 1910s: Young woman enters a parlor and overhears people outside concerned that they heard a gunshot, she looks guilty/worried / Bridgeman Images

AVE6324679: United States, 1930s: Close up view of the cochlear on a diagram / Bridgeman Images

AVE6324683: 1910s: Young woman sneaks into a house and looks shocked by what she sees / Bridgeman Images

AVE6324693: 1910s: Man shows woman some papers and then they talk excitedly / Bridgeman Images

AVE6324696: 1910s: Young couple has a disagreement / Bridgeman Images

AVE6324699: 1910s: Young woman hurries out of room, two men on stairs outside notice a spot of blood on the stairs / Bridgeman Images

AVE6324710: 1910s: Man kisses woman on the neck, she doesn’t look happy about it / Bridgeman Images

AVE6325340: 1940s: Map of North America / Bridgeman Images

AVE6325341: 1940s: Map of world / Bridgeman Images

AVE6325350: 1940s: Family picks up Menorahs from dirt and talk to one another / Bridgeman Images

AVE6325351: 1940s: Map of continents and Pacific Ocean / Bridgeman Images

AVE6325352: 1940s: Dates appear over map of continents and Atlantic Ocean / Bridgeman Images