160 ON COLOUR. Part I. 



though the pattern in the lower part is graceful, is deficient 

 in colour as it is in form in the upper part, and so much green 

 and blue together are not desirable. 



There are many other interesting illustrations in this work 

 which are admirably executed, but which I need not mention 

 as they do not offer illustrations of coloured ornaments suited 

 to our purpose, and I have only selected those which are most 

 applicable to the present subject. 



XX. The next problem that I shall offer is, when two or 

 more colours are given, which are discords, to add others to 

 them, and so combine them as to form concords, and when 

 united together in a composition to produce a harmonious 

 effect. The case is parallel to having two notes which are 

 discordant in music, and by adding others to them to form 

 harmony. We will therefore suppose that purple and green 

 are presented to us, which are a discord. These, by the addition 

 of orange, blue, and red, or rather a scarlet, may be made 

 into a harmonious combination ; and some patterns are im- 

 proved by a fillet of yellow placed between each, and by a 

 small quantity of black to balance it. {See also Sect. XVII. 

 Blue C 8 ; E 1 ; and Black C 3.) 



Another disagreeable union of colours is black, red, and 

 green ; which by adding orange and blue, becomes a pleasing 

 concord. Black, and green, and white are " wanting" but by 

 adding blue and orange they harmonise. Black, and orange, 

 and green, and lilac are wanting and disagreeable, but by 

 adding blue and scarlet they also become harmonious. Of 

 the necessary corrections for such discords the reader may 

 obtain a notion by observing the colours used in the har- 

 monious combinations given in the lists of Sects. XVI. and 

 XVII. 



XXI. An interesting series of experiments have been made 

 by Mr. Babbage on the employment of coloured papers for 

 printing, by which the effect of black ink on tinted papers 



