But if fleeting natural phenomena become disturbing to the observer of a picture, how much more objectionable are the quickly disappearing effects of artificial devices, as the lights from explosions. In a battle scene covering a wide area of ground, a small cloud of smoke here and there is not out of place, because under natural conditions such a cloud lasts for an appreciable time; but no good artist will indicate in his work a flash from a gun, for this would immediately become stagy and unreal to the observer. Nor can fireworks of the ordinary kind be properly represented in a picture. The beauty of these fireworks lies in the appearance out of nothing, as it were, of brilliant showers of coloured lights, and their rapid disappearance, to be replaced by others of different form and character, the movement and changes constituting important elements in their appreciation. But the painter can only indicate them by fixed points of light which necessarily appear abnormal. Stationary points of light can have no resemblance whatever to fireworks, and if the title of the picture forces the imagination to see in them expiring sparks from a rocket, the impression can only last a moment, and will be succeeded by a revolt in the mind against so glaring an impossibility as a number of permanent sparks. The only painted firework display that does not appear abnormal is a fountain of fire and sparks which may be presumed to last for some time, and therefore would not quickly tire the mind.[a] [a] See examples by La Touche, notably La Fête de Nuit, Salon, 1914. CHAPTER XIII STILL-LIFE Its comparative difficulty--Its varieties--Its limitations. Right through the degrees of the art of the painter till we reach still-life, the difficulty in producing the art is in proportion to the general beauty therein, but in the case of still-life the object is much less readily gained than in simple landscape which is on a higher level in painting. The causes of this apparent anomaly appear to be as follows:--Firstly in miniature painting one does not expect such close resemblance to nature as in still-life which usually represents things in their natural size: secondly, in still-life the relative position of the parts can never be such as to appear novel, whereas in landscape their position is always more or less unexpected: thirdly, in still-life the colours are practically fixed, for the painter cannot depart from the limited variety of tints commonly connected with the objects indicated, while in landscape the colouring may vary almost indefinitely from sun effects without appearing to depart from nature.