This book project takes the thaumatrope – a nineteenth century educational toy – as a starting point and uses it to trace a history of women computers (women mathematicians who worked in groups to process complex equations), and highlight a history of women in science and technology. The book compares the thaumatrope to modern day computers as both technologies use binary systems to work. Readers are invited to construct the thaumatropes featured in it. As readers spin the disks, the women depicted on one side of the thaumatrope are “inserted” into visuals, on the other side of the thaumatrope, that represent the fields they worked within, whether astronomy, ballistics or computing. The spinning of the thaumatrope thus becomes a symbolic, feminist action that represents the inclusion of women in histories that have traditionally omitted or ignored their contributions.