Also the sun’s disk cannot be much larger, Nor its heat be much less, than to our sense They appear to be. For from whatever distance Fires can fling light, and breathe upon our limbs Their warming heat, these intervening spaces Take away nothing from the body of flame; The fire is not shrunken visibly. So since the sun’s heat and the light it sheds Both reach our senses and caress our limbs, The form also and contour of the sun Must needs be seen from the earth in their true scale, With neither addition nor diminishment. Also the moon, whether it moves along Illuminating earth with borrowed light, Or throws out its own rays from its own body, Howe’er that be, moves with a shape no larger Than seems that shape which our eyes contemplate. For all things which we look at from far off Through much air, seem to our vision to grow dim Before their contours lessen. Therefore the moon, Seeing that it presents a clear aspect And definite shape, must needs by us on earth Be seen on high in its defining outline Just as it is, and of its actual size. Lastly consider all those fires of aether You see from the earth. Since fires, which here below We observe, for so long as their flickering Remains distinct, and their heat is perceived, Are sometimes seen to change their size to less Or greater to some very slight extent According to their distance, you may thence Know that the fires of aether can be smaller Only by infinitesimal degrees, Or larger by the tiniest minute fraction. This also is not wonderful, how the sun Small as it is, can shed so great a light, As with its flood to fill all seas and lands And sky, with warm heat bathing everything. For from this spot perhaps a single well For the whole world may open and gush out, Shooting forth an abundant stream of light, Because from everywhere throughout the world In such wise do the particles of heat Gather together, and their united mass Converges in such wise, that blazing fire Streams forth here from a single fountain-head. See you not too how wide a meadow-land One little spring of water sometimes floods, Overflowing whole fields? It may be also That from the sun’s flame, though it be not great, Heat pervades the whole air with scorching fires, Should the air chance to be susceptible And ready to be kindled, when it is struck By tiny heat-rays. Then we sometimes see A wide-spread conflagration from one spark Catch fields of corn or stubble. Perhaps too The sun shining on high with ruddy torch May be surrounded by much fire and heats Invisible, fire which no radiance Reveals, but laden with heat it does no more Than reinforce the stroke of the sun’s rays.