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THE POPULAR SCIENCE MONTHLY. 



we get the indistinct effect of both ; but it must be observed that the 

 lines must neither be too near together, nor too far apart, else the 

 effect of the parallelism is either impaired or entirely destroyed. The 

 whole surface of an object, as, for instance, of a vase, may be orna- 

 mented by a great number of parallel lines, and this is often the case 

 in primitive or rude art ; but, with culture, comes the tendency to 

 draw more or less narrow bands of lines following the most important 

 lines of the object. 



A further step is taken in the attempt to make two parallel lines 

 more agreeable to the eye by filling in the space between them with 

 lines, drawn in various directions, and it is in this way that the frets 

 have originated. By drawing equidistant parallel lines directly across 

 between the two main lines, as in Fig. 3, we make a series. This, as 



Fig. 3. 



Fig. 4. 



1 



I 



1 I 



J 1 I 



it exists in the drawing, is a series in space, but, as it grows up under 

 the hand, or is examined by the eye, it is a series in time; and, in look- 

 ing from A to B, an effect is produced upon the eye analogous to that 

 produced upon the ear by the repetition of a musical note, with the 

 same interval. 1 If lines be drawn only part way across, from each 

 side alternately, as in Fig. 4, we have a sort of rhythm produced. If 

 the lines all reach the centre, they may be, and often are, even in very 

 savage art, connected together by twos, as in Fig. 5. This produces 

 a series of units, each one of which is pleasant to examine with the 



Fig. 5. 



Fig. 6. 





eye. This is the simplest form of the fret. If the lines are drawn 

 not quite to the centre, they may be united by oblique lines, as in 

 Fig. 6, A, and lines drawn past the centre may be connected in the 

 same way, as in (7, but neither of the resulting units is very agreeable 

 to the eye, and such attempts are characteristic, either of a rude stage 



1 Irregularity in the interval interrupts the aesthetic effect. As each unit in the series 

 falls on the yellow spot and is distinctly perceived, an effect is produced upon the brain 

 which has a certain duration, gradually fading away. If the units are separated by the 

 same intervals, these aesthetic effects will be alike ; but, if they follow one another irregu- 

 larly, the effect produced will be irregular, unexpected, and consequently disagreeable. 

 The lengthening or diminution of the intervals, according to certain laws, heightens the 

 aesthetic effect by relief from monotony ; and this appears to be the least of the pleasure 

 we derive from gradation in tint or shade. 



