Littell's Living Age/Volume 134/Issue 1731/Distances of the Stars
From The Popular Science Review.
DISTANCES OF THE STARS.
Mr. Stone astronomer-royal at Cape Town, has gone over a portion of the evidence relative to the distribution of the fixed stars with respect to distance. It is singular that a matter so well known should still attract the attention of astronomers, more especially of official astronomers, whose duties in reality have no relation to such questions. "It may have been shown," says Mr. Stone, referring to Mr. Proctor's researches, "that some astronomers have attached undue importance to the numerical accuracy of the results obtained by W. Struve; but I cannot consider that the average distribution of stars according to apparent brightness has been, or indeed ever will be, disproved. I do not know that there is much novelty in my views," etc. And then he proceeds to go over the old ground, very nearly along the old course, coming naturally to nearly the very same goal that W. Struve, Von Littrow, and others have reached. Mr. Stone’s mathematical treatment of the portion of the evidence which he selects is of course perfectly sound and if only that portion is considered, then unquestionably the conclusion at which he arrives must be regarded, not indeed as demonstrated, but as the conclusion which has in its favor the greatest weight of probability. But as there is a great deal of much weightier evidence, which he entirely omits to consider, and as that evidence is not merely opposed to the general conclusion at which Mr. Stone arrives, but demonstrates the incorrectness of that conclusion, the care and skill with which the imperfect evidence is dealt with, are in reality thrown away. Mr. Stone deals with the observed increase of numbers in stars down to Argelander's ninth magnitude, comparing that increase with what would occur if stellar brightness depended on general distance, stars being scattered with general uniformity throughout space and he finds a general accordance between this theory and the observed facts, whence he deduces the conclusion that the theory is sound. But as it is certain that if the theory were sound there would be no real aggregations or rather segregations (in space) of stars of many orders of real magnitude, and as if there were no such aggregations there would certainly be no apparent aggregations of stars of many orders of apparent magnitude on the star-vault, it follows certainly that if such apparent aggregations exist, the theory of general uniformity of distribution is incorrect. It would not follow certainly, if no such aggregations existed, that the theory was sound, but it is certain that if they exist the theory is unsound. But it has been shown that they exist. They are made manifest to the eye in Mr. Proctor’s equal-surface chart of three hundred and twenty-four thousand stars, where in some parts stars are so closely set that there is barely room for them, minute though their discs are, while elsewhere they are strewn very sparsely, the regions rich in stars of the leading orders of apparent magnitude being those very portions of the Milky Way in which stars down to the twentieth magnitude are found in greatest numbers. The theory, then, of a general equality in the distribution of stars in space, even in the neighboring parts of the system of stars, cannot be sound. As Mr. Procter pointed out in a paper read at the May meeting of the Astronomical Society, if a surveyor were to urge against a theory respecting certain mounds that the mounds have in reality no existence, seeing that, if they were levelled, the general level of the ground would be very nearly the same as though the mounds had not been there, his arguments would not be thought to have much weight. Mr. Stone’s theory (sound though its mathematical portion is) is of a similar kind. It is simply a demonstration of the fact that if we leave out of consideration the aggregations of stars on the star-vault, these aggregations no longer afford any evidence of the real aggregation of stars in space.