The Complete Works of Thomas Dick, Ll. D

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1854 edition. Excerpt: ...assured him that he had seen eight stars among the Pleiades, where common eyes can discover but six; and Kepler says of his tutor Maestlinus, that " he could reckon fourteen stars in the Pleiades without any glasses." This difference in the number seen by different persons in this group is obviously owing to the different degrees of acuteuess of vision possessed by the respective individuals. However small the number perceived by the naked eye, the telescope shows them to be a pretty numerous assemblage. Dr. Hook, formerhy professor of geometry in Gresham College, informs us that, directing his twelvefeet telescope (which could magnify only about seventy times) to the Pleiades, he did in that small compass count seventy-eight stars; and making use of longer and more perfect telescopes, he discovered a great many more of different magnitudes. The ingenious ML Mitchell, more than fifty years ago, started the uiea of the stars being formed into groups or systems which are entirely detached from one another, and have no immediate connection. In reference to the Pleiades, he conducted his reasoning as follows:--" The Pleiades are composed of six remarkable stars, which are placed in the midst of a number of others that are all between the third and sixth magnitudes; and comparing this number six with the whole number visible in the heavens to the naked eye, he calculated, by the doctrine of chances, that among all this number, if they had been dispersed arbitrarily through the celestial vault, it was about five hundred millions to one that six of them should be placed together in so small a space. it is therefore so many chances to one that this distribution was the result of design, or that there is a reason or cause for...