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Plack Stall Dectorum 21
Page 06
It acquires a yellowish tinge. As it continues to contract it grows hotter and hotter until its temperature reaches a maximum as a white star. At this point the contraction process does not stop, but the heating process does. Further contraction is now accompanied by cooling, and the star goes through its colour changes again, but this time in the inverse order. It contracts and cools to yellow and finally to red. But when it again becomes a red star it is enormously denser and smaller than when it began as a red star. Consequently the red stars are divided into two classes called, appropriately, Giants and Dwarfs. This theory, which we owe to an American astronomer, H. N. Russell, has been successful in explaining a variety of phenomena, and there is consequently good reason to suppose it to be true. But the question as to how the red giant stars were formed has received less satisfactory and precise answers.
The river was smooth for a little distance, when we proceeded once more with our navigation; but soon it became narrow--only 40 to 50 m. wide--with strong eddies in its deep channel between rocky sides. Some magnificent sand beaches 15 to 20 ft. high were observed, particularly on the right bank, not far from a tributary 3 m. wide which entered the main river on the left side. Lower down, the river described a sharp turn, and there we met another most dangerous rapid. It was entered by a passage 50 m. wide, after which a circular basin of rock--evidently an ancient crater--100 m. in diameter appeared; then the water flowed out with terrific force by a channel only 30 m. wide. The stream produced prodigious eddies in the circular basin. Waves of great height were dashed to and fro from one side to the other of the narrow channel, between high rocks on either side. The water flowed first in a direction E.S.E. for 500 m., then turned off suddenly to due east for a distance of 400 m. That spot was most difficult for us to go through.
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