George Russell Harrison invented the echelle spectrograph, developed a high-speed automatic comparator for measuring the intensities and wavelengths of spectral lines, and compiled the MIT Wavelength Tables, a comprehensive catalogue of more than 10,000 spectrum lines. He designed the first practical ruling engine, controlled by optical interferometric techniques, for producing high-quality diffraction gratings. He wrote several books explaining scientific principles to children, textbooks explaining much more advanced principles, and the best-seller Atoms in Action, describing how advances in physics had been adapted to practical uses in agriculture, aviation, communications, medicine, radio, weather forecasting, and other technologies. His second wife was a well-known romance, mystery, and children's novelist, writing under pseudonyms including Betsy Allen, Betty Cavanna, and Elizabeth Headley. Harrison provided the illustrations for many of her books.
