test, are put into freezing mixtures! Yet, so beautifully made are these triumphs of human ingenuity—so well is their mechanism ‘corrected’ for compensating the expansion caused by the heat, and the contraction induced by the cold—that an even rate of going is established, so nearly, that its variation under opposite circumstances becomes a matter of close and certain estimate. The rates of chronometers on trial for purchase by the Board of Admiralty, at the Observatory, are posted up and printed in an official form. Upon looking to the document for last year, we find a statement of their performances during six months of 1849, with memoranda of the exact weeks during which the chronometers were exposed to the open air at a north window; the weeks the Chronometer-room was heated by a stove, the chronometers being dispersed on the surrounding shelves; and the weeks during which they were placed in the tray above the stove. The rate given during the first week of trial is in every case omitted; like newly entered schoolboys their early vagaries are not taken into account; but after that, every merit and every fault is watched with jealous care, and, when the day of judgment comes, the order of the arrangement of the chronometers in the list is determined solely by consideration of their irregularities of rate as expressed in the columns, ‘Difference between greatest and least,’ and, ‘Greatest difference between one week and the next.’ The Royal Observatory, according to a superstition not wholly extinct, is the headquarters, not only of Astronomy, but of Astrology. The structure is awfully regarded, by a small section of the community which ignorance has still left amongst us, as a manufactory of horoscopes, and a repository for magic mirrors and divining-rods. Not long ago a well-dressed woman called at the Observatory gate to request a hint as to the means of recovering a lost sum of money; and recently, somebody at Brighton dispatched the liberal sum of five shillings in a post-office order to the same place, with a request to have his nativity cast in return! Another, only last year, wrote as follows:—‘I have been informed that there are persons at the Observatory who will, by my enclosing a remittance and the hour of my birth, give me to understand _who is to be my wife_? An early answer, stating all particulars, will oblige,’ &c.