An invention by Captain Groetaers of the Belgian engineers has been lately tested at Woolwich. It is a simple means of ascertaining the distance of any object against which operations may have to be directed, and is composed of a staff about an inch square and three feet in length, with a brass scale on the upper side, and a slide, to which is attached a plate of tin six inches long and three wide, painted red, with a white stripe across its centre. A similar plate is held by an assistant, and is connected with the instrument by a fine wire. When an observation is to be taken, the observer looks at the distant object through a glass fixed on the left of the scale, and adjusts the striped plate by means of the slide; the assistant also looks through his glass, standing a few feet in advance of his principal at the end of the wire, and as soon as the two adjustments are effected and declared, the distance is read off on the scale. In the three trials made at Woolwich, the distance in one case, although more than 1000 yards, was determined within two inches; and in two other attempts, within a foot. It is obvious that such an instrument, if to be depended on, will admit of being applied to other than military surveys and operations, and may be made useful in the civil service. * * * * * SIGNOR GORINI, of the University of Lodi, has recently made some important discoveries which have been much discussed in the scientific journals. His experiments to illustrate the origin of mountains are most interesting. He melts some substances, known only to himself, in a vessel, and allows the liquid to cool. At first it presents an even surface, but a portion continues to ooze up from beneath, and gradually elevations are formed, until at length ranges and chains of hills are formed, exactly corresponding in shape with those which are found on the earth. Even to the stratification the resemblance is complete, and M. Gorini can produce on a small scale the phenomena of volcanoes and earthquakes. He contends, therefore, "that the inequalities on the face of the globe are the result of certain materials, first reduced by the application of heat to a liquid state and then allowed gradually to consolidate." The professor, has also, it is said, succeeded, to a surprising extent, in preserving animal matter from decay without resorting to any known process for that purpose. Specimens are shown by him of portions of the human body which, without any alteration in their natural appearance, have been exposed to the action of the atmosphere for six and seven years; and he states that, at a trifling cost, he can keep meat for any length of time in such a way that it can be eaten quite fresh. * * * * *