time begin to lose its temperature. Then, of course, its capacity for radiating heat will begin to abate. The heat received by the earth from the great centre of our system must, of course, decline.

Fig. 33.—Solar Eruption, April 8, 1892.

There seems no escape from the conclusion that the continuous loss of solar heat must still go on, so that the sun will pass through the various stages of brilliant incandescence, of glowing redness, of