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Rh points were near each other, and their light was pale and weak. The third, which he judged to be about three English miles in diameter, exhibited a much stronger and a redder light. This he compared to a burning coal covered with ashes. These points he immediately conceived to be burning mountains, the two first being either nearly extinguished or beginning to burn, and the other in a state of actual eruption. Mr. Herschel did not fail to communicate his observation to the Royal Society; and the philosophers in this metropolis waited impatiently for the next new moon, which would necessarily confirm the observation, because the eruption would probably not continue above a month, and consequently the phenomena would be then very different, if Mr. Herschel's conjecture was well founded. Friday last, the 18th, the first day of the new moon, several philosophical gentlemen attended Mr. Herschel at his house in the country; but the weather was too cloudy to permit any observation. The next day I did myself the honour to visit him, with two of my friends. Fortunately, the sky was perfectly clear. After having examined, during two hours, the enlightened part of the moon, by means of Mr. Herschel's astonishing instruments, of which it is impossible to form an adequate idea without having seen them, we directed the telescope to the dark part of this satellite, and the conjecture of this great astronomer was instantly confirmed. The two first-mentioned luminous points had totally disappeared, and the fire of the other was become pale and weak. The diameter of its crater was increased to about six miles. Next month it will probably be entirely invisible. This discovery of volcanoes in the moon is a