Democratic Sentinel, Volume 14, Number 52, Rensselaer, Jasper County, 16 January 1891 — Cast-Iron Tunnels. [ARTICLE]

Cast-Iron Tunnels.

Two tunnels of cast iron for an electric railway have been built in London and put in operation for rapid transit. They are three miles in length and lie between forty and sixty feet below the surface of London streets. The tunnels for the up and down lines are formed of cast iron from beginning to epdp spve whejre *the stations, are built, and their diameter is 10 and 10£ feet. The tubes are formed of rings 1 foot 7 inches long, made in sections and bolted together. The tunnels were driven by means of a short cylinder, a trifle larger in its inner dimensions than the exterior diameter of the cast iron tunnel lining. This cylinder has a a cutting edge, and is forced forward by \bydrdmic-jacks, cutting a circular way -into %hieh thd lining plates are fitted. The narrow space between the lining and the soil was filled with lime cement forced in under high pressure. In their course the tunnels, pass beneath the bed of the Thames and through the bed of an pld water course, loose, wet gravel offered some trying obstacles for the engineers to overcome. The entire cost of the line fully equipped was less than $3,750,000. g: r The greatest marvel in telegraphy is said to be the synchronous multiplex, an instrument by means of which six messages can be transmitted over one wire, either all from one ptfction or in opposite directions. A vouNfi lady who expected a telegraphic message from her “best fellow” waited in the office for it. Aftera while the little machine began to click. “That’s from Jack,” she said. “I know his stutter.” The rule of interest that a* broker feels in a woman whom he is courting is liable to depeSd upon the amount of her fortune. Heard at a matinee: Mamma Say what you like, there’s a good deal in her faoe. Fair Daughter—And plenty on it. ,