[173] I may remark, that Poinsinet, in this passage, substitutes “umbra” for “umbræque,” contrary to the authority of all the MSS., merely because it accords better with his ideas of correct reasoning. Although it may be of little consequence in this particular sentence, yet, as such liberties are not unfrequently taken, I think it necessary to state my opinion, that this mode of proceeding is never to be admitted, and that it has proved a source of serious injury to classical literature. In this account of the astronomical phenomena, as well as in all the other scientific dissertations that occur in our author, my aim has been to transfer into our language the exact sense of the original, without addition or correction. Our object in reading Pliny is not to acquire a knowledge of natural philosophy, which might be better learned from the commonest elementary work of the present day, but to ascertain what were the opinions of the learned on such subjects when Pliny wrote. I make this remark, because I have seldom if ever perused a translation of any classical author, where, on scientific topics, the translator has not endeavoured, more or less, to correct the mistakes of the original, and to adapt his translation to the state of modern science. [174] The terms here employed are respectively _interventus_, _objectio_, and _interpositus_; it may be doubted whether the author intended to employ them in the precise sense which is indicated by their etymology. [175] “metæ et turbini inverso.” The _metæ_ were small pyramids placed at the two extremities of the spina, or central division of the circus: see Montfaucon, v. iii. p. 176; Adam, p. 341. [176] The eclipses of the moon are only visible when the spectator is so situated as to be able to observe the shadow of the earth, or is on that side of the earth which is turned from the sun. [177] “non semper in scrupulis partium congruente siderum motu.” On the term _scrupulus_ Hardouin remarks, “Scrupuli, nodi sunt, in quibus circuli, quos in suo cursu Sol et Luna efficiunt, se mutuo secant.” Lemaire, ii. 251. Ptolemy, Magn. Const. vi. 6-11, gives a full and generally correct account of the principal phænomena of eclipses. [178] Marcus conceives that our author must here mean, not the actual, but the apparent size of these bodies; Ajasson, ii. 295; but I do not perceive that the text authorizes this interpretation. [179] I have given the simple translation of the original as it now stands in the MSS.; whether these may have been corrupted, or the author reasoned incorrectly, I do not venture to decide. The commentators have, according to their usual custom, proposed various emendations and explanations, for which I may refer to the note of Hardouin in Lemaire, ii. 252, with the judicious remarks of Alexandre, and to those of Marcus in Ajasson, ii. 295-298, who appear to me to take a correct view of the subject.