Rensselaer Union, Volume 7, Number 30, Rensselaer, Jasper County, 15 April 1875 — Packages Forwarded Eight Miles in Two Seconds. [ARTICLE]

Packages Forwarded Eight Miles in Two Seconds.

On Sunday, Feb. 23, the pneumatic mail system was opened for public use in the city of Vienna, and for the few days of its working it appears to have been eminently satisfactory. By this method letters and packages not exceeding two ounces in weight can he sent from one end of the city to another — a distance of about eight miles—in something less than two seconds, so that, adding to this the time necessary for making up packages, assorting them and delivering them, the whole is just about one hour. But this only covers extreme distances, and the managers of this system in Vienna say that in a short time the time between the receipt and delivery will be greatly reduced. In fact, between stations only two or three miles distant from each other, such packages are even now delivered within twenty minutes after being deposited. Any Postmaster in this city or Postmas-ter-General who could inaugurate such a reform in the local mail arrangements of the metropolis might achieve immortal fame. As the general Postoffice in Vienna is also in the building of the general telegraph office, powerful steam engines are constantly at work compressing atmospheric air in a mammoth reservoir, from which the double system of cast-iron pipes, laid three feet under the surface of the streets, are fed. One system of pipe serves to carrying packages, and the other for pushing them ahead in the other direction. At the seven principal stations, in various parts of the city, similar engines are kept at work day and night, drawing the air from the pipes, and creating a vacuum in front of the packages, which aie thus more rapidly pressed forward by the expansive force of the compressed air behind them. The sixty sub-stations are connected not only with the two central offices but also with each other by this double system of pipes. The dispatch of each package is announced by telegraph to the office to which it is sent, and to all intervening offices to advise the latter not to stop it on its way. The pipes are six inches in diameter, with a perfectly smooth, polished inner surface, and the packages are made up in india-rubber cylinders of various lengths. The postage on mail matter must be prepaid at the rate of two kreutzers (one cent) for each half ounce or fraction, which is evidently much cheaper than the two-cent postage for theTity letters in this country. This is the first instance of a large city —Vienna has about 900.000 inhabitants—giving its people such facilities of correspondence at moderate cost. —AT. Y. Mercury.

—A favorite subject of speculation among those devoted to the science of geology has been the state of the interior of the earth, and the source of the high temperature observed at all considerable depths beneath its surface. Prof Hopkins makes the interesting * statement, in this connection, that the terrestrial temperature At a certain depth in each locality—about eighty feet in England —remains constant during j>the whole year, being sensibly unaffected by the changing temperature of the seasons. The same, of course, holds true at greater depths; but the lower the descent, the greater is this invariable temperature, the increase being proportional to the depth and at the rate of one deg. Fah. for about every or feet. Prof. Hopkins says that, assuming such rate of increase to continue to the depth of fifty miles, a temperature would there be reached about twice as great as that necessary to fuse iron, and"sufficient, l is supposed, to reduce nearly the whole mass of the earth’s solid crust to a state of fusion. From this is derived the opinion of many geologists that our globe does really consist of a solid shell, not exceeding forty or fifty miles in thickness, and an interior fluid nucleus, maintained ip a state of fusion by the existing redisins of the heat to which the whole terrestrial mass was originally subjected.