Question: John Henry Reynolds was a British astronomer who served as the president of the Royal Astronomical Society who frequently corresponded with American astronomer Edwin Hubble, developed a formula for measuring the surface brightness of what? 
Sentence (from "John Reynolds (astronomer)"): In 1899, at age 25, he was elected a Fellow of the Royal Astronomical Society and in 1907, he financed the construction of a 30-inch reflecting telescope in Helwan, Egypt, the first large telescope to study objects in the such southerly skies.
Relevant evidence: No