Thus in 1856 Norman Pogson of Oxford proposed that a logarithmic scale of √ 100 ≈ 2.512 be adopted between magnitudes, so five magnitude steps corresponded precisely to a factor of 100 in brightness. Every interval of one magnitude equates to a variation in brightness of √ 100 or roughly 2.512 times. Consequently, a magnitude 1 star is about 2.5 times brighter than a magnitude 2 star, about 2.5 times brighter than a magnitude 3 star, about 2.5 times brighter than a magnitude 4 star, and so on.