and in ever-changing combination. In the Gobi
Desert of Central Asia, in the Egyptian Desert, in the Arabian Desert,
in Arizona, I have seen sunsets that thrill one with delight. But
nowhere have I seen more glorious sunsets than in the highlands of
Tibet. And what makes them there so remarkable is that the plains
themselves are 15,000 feet above sea-level, so that the atmosphere is
exceptionally clear. Great distances are therefore combined with
unusual clearness. The country is open enough and the air clear
enough for us to see far distances. And extent is a prime essential in
the glory of a sunset.

It is difficult to make those who have never been outside Europe
understand what sunsets can be. In England, as Turner has shown,
there are sunsets to be seen containing in abundance many such
elements of beauty as varied and varying and great extent of colour.
But the atmosphere here is so thick that the colours appear as if
thrown on to a solid background. So the sunsets look opaque. On the
continent of Europe the atmosphere is clearer and the opaqueness
less pronounced. The colouring is in consequence more vivid.
But--except in high Alpine regions--the clearness does not approach the
clearness of Tibet. And neither in England nor on the Continent do
we get the great _distances_ of desert sunsets. And great distances
increase immeasurably that feeling of _infinity_ which is the chief
glory in a sunset.

The clearness of the atmosphere is important in this respect also,
that it produces the effect upon the colours of the sunset that they
seem more like the colours we see in precious stones than the
colours a painter throws on a canvas. There is no milkiness or
murkiness in them. The sky is so clear that we see a colour as we see
the red in a ruby. We see deep into the colour. The colour comes
right _out_ of the sky and has not the appearance of being merely
plastered on the surface.

And the variety of the colours and the rapidity with which they
change and merge and mingle into one another is another wonder of
these desert sunsets. It would be wholly impossible to paint a picture
of them which would adequately express the impression they give,
for the main impression is derived from light, and the colours are
therefore far more glowing than they could ever be reproduced on
canvas. Nor can the changing effects be reproduced on a stationary
medium. The nearest approach to the glory of a Tibet sunset which I
have seen