202 



NATURE 



[December 31, 1891 



evidently proceeding from an unconscious perception 

 of the right means havin^ been employed to combine 

 solidity, lightness, and, if necessary, mobility, with the 

 greatest possible profit in the transmission of force, 

 and the smallest waste of material. A driving-belt 

 is certainly neither attractive nor unattractive ; but it 

 pleases the " visits ertiditus " to see a connecting-rod 

 thicken from the ends towards the middle, where it has 

 to bear the greatest strain. Of course this kind of 

 beauty is of recent origin. I remember Halske telling 

 me that, as regards the construction of physical and 

 astronomical instruments, it was, to his knowledge, first 

 understood and established as a principle in Germany 

 by Georg von Reichenbach in Munich. Berlin and 

 Munich workshops produced instruments of perfect 

 mechanical beauty at a time when those supplied by 

 France and England were still often disfigured by 

 aimlessly ornamented columns and cornices, unpleasantly 

 recalling the impure features of Rococo furniture and 

 architecture. 



I forget which French mathematician of the last century, 

 in sight of the cupola of St. Peter's at Rome, tried to 

 account for the sense of perfect satisfaction it gives to 

 the eye. He measured out the curves of the cupola, and 

 found that, according to the rules of higher statics, its 

 shape supplies the exact maximum of stability under the 

 given circumstances. Thus Michael Angelo, guided by an 

 unerring instinct in the construction of his model (the 

 cupola was not erected till after his death), unconsciously 

 solved a problem the true nature of which he could 

 hardly have understood, and which was even beyond the 

 reach of the mathematical knowledge of his age. Ap- 

 parently, however, there are several roots to this equation 

 of beauty ; at least there is one other type, for which I 

 quote the cupola of Val de Grace in Paris, which, if 

 not as imposing, is quite as gratifying to the eye, as 

 Michael Angelo's. 



It will be observed that in this case mechanical beauty 

 becomes part of the art of architecture ; and instances of 

 this kind are daily growing more frequent, our modern 

 iron structures being more favourable to its display than 

 stone buildings. In the Eiffel Tower we see mechanical 

 beauty struggling with the absence of plastic beauty. On 

 this occasion it was probably revealed for the first time 

 to many who hitherto had no opportunity of experiencing 

 its effect. It is certainly not wanting in the new Forth 

 Bridge. There is no doubt, however, that in stone 

 structures too, together with much that pleases from 

 habit or tradition, there are certain features which 

 evidently attract through mechanical beauty — such as the 

 outline of the architectural members of a building, or the 

 gentle swelling and tapering of the Doric column towards 

 the top, and its expansion in the echinus and abacus ; and 

 there are others which offend a refined taste through the 

 absence of this beneficial element, such as the meaning- 

 less ornamentations of the Rococo style. 



Even in organic nature mechanical beauty prevails to 

 such an extent that it transforms many objects into a 

 source of delight and admiration to the initiated, which 

 are naturally repulsive to the untrained eye. Anatomists 

 recognize it with pleasure in the structure of the bones, 

 especially of the joints. In their opinion the " Dance of 

 Death " outrages good taste from more reasons than 

 because it differs from the classical conception of death. 

 Mechanical beauty was already perceived by Benvenuto 

 Cellini in the skeleton, much to his credit ; and but for 

 our imperfect knowledge, it would invest with its glory 

 every organic form, down to the inhabitants of the 

 aquarium, even under the very microscope. According 

 to Prof Schwendener, even plants are constructed on the 

 same principle of fitness combined with thrift ; and some- 

 thing of this we feel at sight of a spreading oak-tree, 

 proudly distending its vigorous branches towards air and 

 sunlight. 



NO. I 157, VOL. 45] 



Again, our appreciation of the forms of animals, 

 especially of noble breeds, is greatly influenced by 

 mechanical beauty. The greyhound and the bulldog, 

 the full-bred race-horse and the brewer's dray-horse, the 

 Southdown and the Merino sheep, the Alpine cattle and 

 the Dutch milch-cow, all are beautiful in their kind ; even 

 though a bulldog or a Percheron may appear ugly to the 

 uninitiated, because in each the type of the species has 

 been modified to the utmost degree of fitness. 



Though science is unable, as we have seen, to check 

 the occasional decline of art and inspire it with fresh 

 vigour, yet it renders invaluable services of a difterent 

 kind to artists, by increasing their insight, improving 

 their technical means, teaching them useful rules, and 

 preserving them from mistakes. I do not allude to any- 

 thing so primitive as the manufacture of colours or the 

 technique of casting in bronze ; the less so, as, curiously 

 enough, our modern colours are less durable than those of 

 entirely unscientific ages, and the unsurpassed thinness of 

 the casting of Greek bronzes is regarded as a proof of 

 their authenticity. Nor does it seem necessary to recall 

 the notorious advantages of this kind for which art is 

 indebted to science. Linear perspective was invented by 

 Lionardo and Diirer— artists themselves. It was followed 

 by the laws of reflection — unknown to ancient painters, as 

 would appear from the Pompeian frescoes of Narcissus — 

 and by the geometrical construction of shadows. The 

 rainbow, which had better not be attempted at all, has 

 been sinned against cruelly and persistently by artists, in 

 spite of optics. Statics furnished the rules of equilibrium, 

 so essential to sculptors. Aerial perspective, again, owes 

 its development to painters chiefly of northern climates. 



But to this fundamental stock of knowledge the pro- 

 gress of science has added various new and important 

 acquisitions, which philosophers, some of first-rate ability, 

 have endeavoured to place within the reach of artists. 

 The great masters of by-gone ages were taught by instinct 

 to combine the right colours, as women of taste, accord- 

 ing to John Miiller, always know how to blend the right 

 shades in their dress ; and Oriental carpet-weavers have 

 not been behindhand with them in that respect. But 

 the reason why they unconsciously succeed was not 

 revealed till the elder Darwins, Goethe, Purkinye, John 

 Miiller, and others, called into existence a subjective 

 physiology of the sense of sight. A member of this 

 Academy,' Prof, von Briicke, in his " Physiology of 

 Colours"! and " Fragments from the Theory of the Fine 

 Arts in relation to Industrial Art,"- treats these subjects 

 with such intimate knowledge as could only be obtained 

 by one who enjoyed the rare advantage of combining 

 physiological learning with an artistic education acquired 

 in his father's studio. In France, Chevreul pursued 

 similar aims. Even Prof, von Helmholtz, in his popular 

 lectures, has devoted his profound knowledge of physio- 

 logical optics, to the service of art, which already owes 

 him important revelations on the nature of musical 

 harmony. Amongst other things, he explained the rela- 

 tion between the different intensities of light in objects of 

 the actual world and those on the painter's palette ; and 

 pointed out the means by which the difficulties arising 

 therefrom may be overcome.'' Thus painters, as von 

 Briicke remarks, have it in their power to reproduce the 

 dazzling effect of the disk of the sun by imitating the irra- 

 diation— a defect of our visual perception the true nature 

 of which was recognized by von Helmholtz. An example 

 of this, interesting through its boldness, is the lovely 

 Castell Gandolfo in the Raczynski gallery. 



There are so many and striking instances of such 

 imperfections of the human eye that, notwithstanding its 

 marvellous capabilities, von Helmholtz has observed that 

 " he would feel himself justified in censuring most severely 



I 2nd edition, Leipzig, J 8S7. ^ Leipzig, 1877. ^^ __ 



3 Prof, von Helmholtz, "Collected Essays and Addresses, vol. 11., 

 Brunswick, 1884. 



