William Herschel

“I compared it to H Geminorum and the small star in the quartile between Auriga and Gemini, and finding it so much larger than either of them, suspected it to be a comet.”

“A knowledge of the construction of the heavens has always been the ultimate object of my observations...”

“I must freely confess that by continuing my sweeps of the heavens my opinion of the arrangement of the stars and their magnitudes, and of some other particulars, has undergone a gradual change...”

“An equal scattering of the stars may be admitted in certain calculations; but when we examine the milky way, or the closely compressed clusters of stars... this supposed equality of scattering must be given up.”

“'We may... have surmised nebulae to be no other than clusters of stars disguised by their very great distance, but a longer experience and better acquaintance with the nature of nebulae, will not allow a general admission of such a principle, although undoubtedly a cluster of stars may assume a nebulous appearance when it is too remote for us to discern the stars of which it is composed.”

“An object may not only contain stars, but also nebulosity not composed of them.”

“A nebulous matter, diffused in such exuberance throughout the regions of space, must surely draw our attention to the purpose for which it probably may exist; and it must be the business of a critical inquirer to attend to all the appearances under which it will be exposed to his view...”

“A proportional condensation of the nebulous matter in the brighter places will sufficiently account for their different degree of shining.”

“We may conceive that, perhaps in progress of time these nebulæ which are already in such a state of compression, may be still farther condensed so as actually to become stars.”

“We can hardly suppose a possibility of the production of a globular form without a consequent revolution of the nebulous matter, which in the end may settle in a regular rotation about some fixed axis.”

“The starlike appearance of the following six nebulæ is so considerable that the best description... was to compare them to stars with certain deficiencies.”

“I have made it a rule never to employ a larger telescope when a smaller will answer the purpose.”

“The number of stands I invented for these telescopes it would not be easy to assign. ...In 1781 I began to construct a thirty foot aërial reflector, and having made a stand for it, I cast the mirror thirty-six inches in diameter. This was cracked in cooling. I cast it a second time, and the furnace I had built in my house broke.”

“According to my theory, a dark spot in the sun is a place in its atmosphere which happens to be free from luminous decompositions [above it].”

“That the emission of light must waste the sun, is not a difficulty that can be opposed to our hypothesis. Many of the operations of Nature are carried on in her great laboratory which we cannot comprehend. Perhaps the many telescopic comets may restore to the sun what is lost by the emission of light.”

“In future... we shall look upon those regions into which we may now penetrate by means of such large telescopes, as a naturalist regards a rich extent of ground or chain of mountains containing strata variously inclined and directed, as well as consisting of very different materials. The surface of a globe or map therefore will but ill delineate the interior parts of the heavens.”

“It is very probable that the great stratum called the Milky Way is that in which the sun is placed, though perhaps not in the very centre of its thickness. ...We gather this from the appearance of the Galaxy, which seems to encompass the whole heavens, as it certainly must do if the sun is within it.”

“A standard of reference for the arrangement of the stars may be had by comparing their distribution to a certain properly modified equality of scattering. The equality which I propose does not require that the stars should be at equal distances from each other, nor is it necessary that all those of the same nominal magnitude should be equally distant from us.”

“Nebulæ can be selected so that an insensible gradation shall take place from a coarse cluster like the Pleiades down to a milky nebulosity like that in Orion, every intermediate step being represented. This tends to confirm the hypothesis that all are composed of stars more or less remote.”