How to paint a picture, that is the question. Although imagination ought to be brought with us when we come to nature, it should be as our own bicycle under us, and not like our neighbour's bicycle, riding over us. We must give the spirit of what we see, and no more; for we shall commit a hundred errors if we vainly attempt to give the spirit of the oak while we are painting its bark. Of course we know what the oak has done, we recall all that we have read of Nelson, Collingwood, and other hearts of oak who have spilt good blood to prove that 'Britons never shall be slaves'; and although, perhaps, it ought to give an oak-tree an air of all this as it stands before us, yet there it stands before us, full of knots and wrinkles, with its gnarled limbs flung about it, and its green moss, silver lichen, and amber and purple darting between; and I take it, this is what our painter has to get into his head and imitate. We cannot see past its bark unless it is torn open, and then we may not see the bark, and we must never think of painting what we cannot see. If, by the help of our poetic taste, we can convey to the spectator the sentiment we do see about it, of a hardy, sturdy, rugged sentinel that has done duty there before our grandfathers were born, which goes on in the same impassive way while we lie dead in sleep, and may go on ever the same when perhaps we make up part of the earth and fungus about its roots, unless God's swift telegram, the mighty lightning-flash, or man's paltry axe, gives it its furlough,--if we can do this, as well as give an image of the reality, we have done all we can do--made a noble work and created a poem. Never mind what anyone else sees in the subject, stick resolutely to what your own eyes tell you, and you must be right. Say someone tells you there is a man coming along the road; you think it does look like a man, but you only see a splash of mixed colours with a _certain_ sweep about it; put that in, and someone else looking at your picture will say, 'You have made a man.' This is the grand trick of landscape figure painting, for if anyone can see a single line of detail about your figure more than the tree, or stone, or hedge beside him, your figure is a failure and should come out, for it is spoiling the unity of your picture. So with clouds, water, mountains, trees, everything created above us, beneath us, about us. My harp has only three strings, and were I to finger it for a thousand hours, to a thousand different tunes, it would be with the same variations. What paints sunset, paints sunrise, midday, moonlight; the same colours that sparkle in the bright patch sparkle in the deep shadow, and the variations of yellow, red, and blue are as pronounced and apart in each blade of grass as they are in the white clouds rolling above it, and as distinct in the dazzling snowdrift as in the burning sunset skies,--there is not an inch without its variety, but only a variety of three.