PICTURE CREDITS

here: Drawn from a painting in the caves of Cueva de la Arana by Achillea / GNU General Public Licence version 2.

here: Su Song clock tower illustration by Aubrey Smith.

here: Carole Raddato / Flickr / CC BY-SA 2.0

here: Gift of Theodore M. Davis, 1907 (07.226.1), Theodore M. Davis Collection, Bequest of Theodore M. Davis (30.8.54), Metropolitan Museum of Art, New York.

here: Early distillation process illustration by Aubrey Smith.

here: Rogers Fund, 1936, Metropolitan Museum of Art, New York.

here: From Science and Civilisation in China: Volume 5, Part 1, Paper and Printing by Joseph Needham, Caves Books Ltd., Taipei 1986.

here: An Old Sufi Laments His Lost Youth , ink and pigments on laid paper, 1597–1598 (Mughal), W.624.35A, acquired by Henry Walters, The Walters Museum of Art, Baltimore, USA.

here: Queen Nefertari playing chess: fresco from the tomb of Nefertari, Thebes, 13 th century B.C. / The Yorck Project, 10,000 Meisterwerke der Malerei , DIRECTMEDIA Publishing GmBH.

here: Illustration from Knight’s American Mechanical Dictionary, Houghton, Mifflin and Company, Boston, 1882.

here: Clipart.com .

here: Science and Society Picture Library / Getty Images.

here: Matyas Rehak / Shutterstock.

here: Eric Gaba / CC SA-BY 4.0

here: Archimedes screw illustration by Aubrey Smith.

here: MatthiasKabel / CC SA-BY 3.0

here: Windmills of Nashtifan, Khaf, Khorasan Razavi, Iran; photo by Ahmad Hassanzadeh / CC SA-BY 4.0

here: Bequest of Richard B. Seager, 1926 / Metropolitan Museum of Art, New York.

here: Purchased with the assistance of the National Art Collections Fund / British Museum (M&ME 1958.12–2.1); photo by Marie-Lan Nguyen / CC BY-SA 2.5

here: DerHexer / Wikimedia Commons / CC SA-BY 4.0

here: The Nimrud lens or Layard lens, British Museum (BM number 90959); photo by Geni / CC SA-BY 4.0

here: Mogi / CC SA-BY 3.0

here: Archimedes’ heat ray illustration by Aubrey Smith.

here: Reconstructions of ancient mechanical artillery, Saalburg Museum, Hesse, Germany; photo by SBA73 / Flickr / CC SA-BY

here: Illustration from Discorso della Religione Antica de Romani , 1569.

here: Illustration from The Crossbow by Sir Ralph Payne-Gallwey, Longmans, Green and Co., London 1903.

here: Mary Evans / Natural History Museum.

here: Universal History Archive / UIG / Getty Images

here: Camera obscura illustration by Aubrey Smith.