Engineering Wonders of the World
Volume I

THE MARCONI TOWERS, POLDHU, CORNWALL. 439 importance, and for this reason materials were utilized that could be most readily obtained. THE CIRCLE OF MASTS THAT PRECEDED THE TOWERS —AFTER COLLAPSE. These masts were 215 feet high. The history of events leading up to the building of the towers is typical of the dogged perseverance of that scientific genius, Guglielmo , Marconi. In 1899 the directors Their - . . Antecedents. °* hlS comPany decided that the time had arrived to essay the stupendous task of bridging the 3,000 miles of the Atlantic by wireless telegraphy, and issued instructions for a station to be proceeded with. At the outset it was decided to erect one mast, 160 feet high, and a small power-house to contain a 30 horse-power oil engine, estimates being based on the results of experiments over distances varying between 10 and 100 miles. It was soon found, how- ever, that these comparatively short distances gave very misleading indications of the power and size of aerial actually nocossary. The term aerial is th© name by which, is known the wire or combination of wires suspended in the air, from which electrical discharges ar© produced, in th© atmosphere, or, moro correctly, ether, and by which electrical dis- charges produced at another station are transmitted to the instruments. As the experimental work progressed and the dis- tances covered increased, the results proved the inadequacy of the original plant, and the number of the masts was added to from time to time, until finally orders were issued for no less than twenty masts, each composed of four spars, having a total height of 215 feet, to be placed in a circle 200 feet in diameter. A cor- responding circle of masts was to be erected simultaneously at Cape Cod. In September 1901 a serious disaster occurred at Poldhu Station. The last of Downfall, the twenty masts was being raised, when the combination of the strain caused thereby, a THE COMMENCEMENT OF A TOWER. defective mast cap, and a strong wind, caused one of the stay lugs to give» way. Unfortu- nately, the design on which the masts were stayed was such as to make them all de- pendent on one another for support, and the sudden breakage of that single lug brought the whole forest of masts down like a house of cards, not one of the eighty spars being left standing in its original position. A very good representation of the station immediately after the collapse is reproduced above. I he result of this catastrophe was a hurried consultation between Mr. Marconi and his engineers, the matter being left ultimately in the hands of the writer, with instructions to design supports of an efficient character for an Designs for Towers. aerial of a certain size and height. Ten days later two schemes were ready to be submitted to Mr. Marconi for his selection—one a re-