ys: Coal was produced of pipe are laid and the trench filled. wires must be laid underground, and the question now is as in other sections of the State of which no returns could be to the best way of doing it. A. noted enterprise of this kind secured, but it is believed that 100,000 tons will cover… … One of the objections to the pipes The glass is printed with this ink, DUGGAN'S SYSTEM OF UNDERGROUND ELECTRIC WIRE now in use for underground wires and then dusted over with finely pulverized Syrian asphalt and is, that the cable inserted from any heated in a sheet iron muffle until the ink and…
Patents · Patented · Water · Scientific American · Improved · Trade catalogs · Conical rollers · Patent office · Electric light · Portable electric · Bell company · Sewing machine · Horse power · Car truck
Internet Archive · Public domain (published before 1931). Free to use for anything.