Note 12 — VI END OF THE SUN—ORIGIN OF NEBULÆ
H. Borns translation
Stars are classified in magnitude, the order being such that the most luminous stars have the lowest numbers. A star of the first magnitude is 2.52 times brighter than a star of the second magnitude; this, again, 2.52 times brighter than a star of the third magnitude, and so on. All this from the point of view of an observer on the earth.