Harriet Brooks (July 2, 1876 – April 17, 1933) was the first Canadian female nuclear physicist. She is most famous for her research on nuclear transmutations and radioactivity. Ernest Rutherford, who guided her graduate work, regarded her as comparable to Marie Curie in the calibre of her aptitude. She was among the first persons to discover radon and to try to determine its atomic mass. Biography Early years Harriet Brooks was born in Exeter, Ontario, on July 2, 1876 to George and Elizabeth Warden Brooks. She was the third of nine children. Her father, George Brooks, worked at his own flour mill until it burned down and was not covered by insurance. He then supported the family by working as a commercial traveler for a flour firm. Brooks moved around Quebec and Ontario with her family during her childhood. At some point, she attended the Seaforth Collegiate Institute in Ontario. Her family finally settled in Montreal. Education and research Of the nine Brooks children, only Harriet and her sister Elizabeth would attend university. Harriet Brooks entered McGill University in 1894, only six years after McGill graduated its first female student. Brooks won a scholarship for the final two years of her Bachelor's degree, but being a woman disqualified her from receiving a scholarship for her first two years. Brooks graduated with a first-class honours B.A. in mathematics and natural philosophy in 1898, and was awarded the Anne Molson Memorial prize for outstanding performance in mathematics. Brooks was the first graduate student in Canada of Sir Ernest Rutherford, under whom she worked immediately after graduating. With Rutherford, she studied electricity and magnetism for her master's degree. Even before her thesis was completed, her work was published in the Transactions of the Canadian Section of the Royal Society in 1899. The same year, Brooks received an appointment as nonresident tutor at the newly formed Royal Victoria College, the women's college of McGill University. In 1901, she became the first woman at McGill to receive a master's degree. After her master's degree under Rutherford, she also did a series of experiments to determine the nature of the radioactive emissions from thorium. These experiments served as one of the foundations for the development of nuclear science. Papers by Rutherford and Brooks in 1901 and 1902 were published in Royal Society Transactions and in the Philosophical Magazine. In 1901, Brooks obtained a fellowship to study