Camper was one of the first to reduce these observations to some kind of system. He was no longer satisfied with merely superficial evidence, but wished to give his proofs a mathematical foundation; he tried to define anatomically the differences between races. He succeeded in establishing a strict method that left no room for doubt, and his views gained the numerical accuracy without which there can be no science. His method was to take the front part of the skull and measure the inclination of the profile by means of two lines which he called the _facial lines_. Their intersection formed an angle, the size of which gave the degree of elevation attained by the race to which the skull belonged. One of these lines connected the base of the nose with the orifice of the ear; the other was tangential to the most prominent part of the forehead and the jut of the upper jaw. On the basis of the angle thus formed, he constructed a scale including not only man but all kinds of animals. At the top stood the European; and the more acute the angle, the further was the distance from the type which, according to Camper, was the most perfect. Thus birds and fishes showed smaller angles than the various mammals. A certain kind of ape reached 42°, and even 50°. Then came the heads of the African negro and the Kalmuck, which touched 70°. The European stood at 80°, and, to quote the inventor’s own words, which are very flattering to our own type, “On this difference of 10° the superior beauty of the European, what one might call his ‘comparative beauty,’ depends; the ‘absolute beauty’ that is so striking in some of the works of ancient sculpture, as in the head of Apollo and the Medusa of Sosicles, is the result of a still greater angle, amounting in this instance to 100°.”[51] This method was attractive by its simplicity. Unhappily, the facts are against it, as against so many systems. By a series of accurate observations, Owen showed that, in the case of monkeys, Camper had studied the skulls only of the young animals; but since, in the adults, the growth of the teeth and jaws, and the development of the zygomatic arch, were not accompanied by a corresponding enlargement of the brain, the numerical difference between these and human skulls was much greater than Camper had supposed, since the facial angle of the black orang-outang or the highest type of chimpanzee was at most 30° or 35°. From this to the 70° of the negro and the Kalmuck the gap was too great for Camper’s scale to have any significance. Camper’s theory made considerable use of phrenology. He attempted to discover a corresponding development of instinct as he mounted his scale from the animals to man. But here too the facts were against him. The elephant, for example, whose intelligence is certainly greater than the orang-outang’s, has a far more acute facial angle; and even the most docile and intelligent monkeys do not belong to the species which are the “highest” in Camper’s series.