stratum may be supposed to be produced by some gaseous substance pressing up through the structural pores of the photosphere, and the prominences rising above the general level have been regarded as the same gaseous product issuing in greater volume from the spots or perforations. The stratum of smoke hanging over a large manufacturing town presents an appearance similar to that of the rose-coloured stratum of the sun. The smoke issuing from the innumerable chimneys of private houses corresponds to the red substance issuing from the pores of the photosphere, and a uniform stratum is in this way produced. Above the general level are the tall chimneys of factories, vomiting forth their volumes of smoke, which is carried away by the wind, parallel to the murky stratum beneath. The shapes, however, of the red prominences give us rather the idea of tongues of flame than of volumes of smoke, and the red stratum looks like a sea of flame violently agitated by the wind. The section of the red stratum, seen in the total eclipse, and represented in our illustrative figure, suggests the idea of the line of fire presented by a burning forest in Canada, or a pine barren in Florida. As the tide of fire sweeps along, there is a general level, but the flame is broken up into distinct tongues and waves; and when it meets with some ancient and lofty clump of trees, it rushes up to the topmost point, and this burning spire towers far above the sea of fire beneath. In some places there may be a calm, and the tongues shoot straight up;
