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182 may owe "their existence to inherent fires acting with great violence." "Nay, we have pretty good reason to believe," he said, "that probably all the planets emit light in some degree; for the illumination which remains on the moon in a total eclipse cannot be entirely ascribed to the light which may reach it by the refraction of the earth's atmosphere." This idea is not borne out by recent observations.

The first two papers Herschel wrote on Saturn, containing the record of more than fourteen years' work, cover nearly ninety pages quarto. Fifty of these pages are merely extracts from his journal, showing the nightly work in which he was engaged, jottings, it may be, all of which required from him time and care, before they could be put down on paper. Here is a specimen of two nights' work, done shortly before midnight:—

"Nov. 7: 22, 9. At the end of the p. arm is a place that is brighter than nearer to the body.

"23, 12. The preceding arm has still the appearance of a small protuberant point towards the south, near the end of the arm.

"Nov. 8: 23, 40. There is a protuberant point on the preceding arm besides the 7th sat.; so that at present I cannot tell whether the satellite be the nearest or farthest of them."

By patient, long-continued labour, carried on at all hours of the day and night, is a way prepared for advancing the boundaries of human knowledge, though few are capable of estimating, far less of bearing, the