R

• Born in England.
• He designed an instrument, the rectangulus, which used seven straight pivoted rods, to solve problems in geometry of the sphere.
• He developed the albion, which used discs to calculate planetary equations.

Earl of Rosse (1800-1868)

• Born in Ireland.
• He built a 36-inch reflector for his telescope, and, later, a 72-inch one.
• He found spiral systems that are not of the Milky Way.
• With his assistants, he made numerous other discoveries.

Henry Norris Russell (1877-1957)

• Born in USA.
• He developed a theory of evolutionary sequence of a star.
• He drew a diagram (H-R) similar to that of hertzsburg, but independently.

Martin Ryle (1918-1984)

• Born in England.
• He studied radio waves from the Sun and more distant stars with an interferometer.
• He proved the theory of no big bang to to wrong.