text: " Unless the pictures are intended to be seen at twilight we do not see how this can bear upon the question; if it does we would notice what we have often observed that at twilight blue almost entirely disappears to such a degree that in a landscape where the blue has even been deep and the sky by no means the lightest part of the picture at twilight the whole landscape comes out too hard upon the sky which with its colour has lost its tone and become with relation to the rest by far too light