HUDSON RIVER BRIDGE RIVALED FOR FAME BY NEW ARCHES
While the completion of the great George Washington suspension bridge, which has hurled itself in one bold leap across 3,500 feet of the Hudson River from Manhattan to the New Jersey shore, is being celebrated, two other bridges, likewise the largest in the world of their kind, are being given finishing touches preparatory to their christening in the mighty stream of modern traffic.
They are twin bridges, or nearly so, for one is only 2 feet and 1 inch longer than the other; and they are built after exactly the same type of construction. They are steel arch structures that exceed their greatest predecessors even as the bridge across the Hudson surpasses the next mightiest suspension span.
These two structures are the Kill Van Kull steel arch bridge connecting Staten Island, a borough of New York City, with the mainland of New Jersey; and the Sydney harbor bridge in distant Australia.
NEW DEVICE LESSENS DANGER FROM TREATMENT WITH X RAYS
The danger of burns during X-ray treatments has been greatly lessened, according to Dr. Lauriston Taylor of the U.S. Bureau of Standards, by the completion and final testing of an apparatus designed to measure the intensity of X-ray doses.
Until now, no exact and uniform measurement of the strength of X rays has been possible, explains Dr. Taylor, who has just returned from Europe with the primary X-ray standard which he designed for the United States. Now a doctor may calibrate his apparatus to learn the intensity of his X-ray doses without the necessity of guesswork. He will not burn his patient, nor will he commit the worse crime, in cases such as cancer, of undertreating him.
FLOODLIGHTS TO ILLUMINATE WASHINGTON MONUMENT
Soon the Washington Monument, a 555-foot marble obelisk, will never be left in darkness again.
To eliminate the hazards the monument presents to aviators, 20 new floodlights will be switched on about November 15, completely illuminating it for the first time. But all 20 will be regularly used only on foggy nights. Tests showed too much light gave the monument a rounded appearance, thus reducing its visibility.
Engineers, in considering illumination schemes, at first doubted the effectiveness of floodlights. They favored searchlights, located several hundred feet from the monument.
Experiments with both types showed the searchlights to be unsuitable. Instead of concentrating on the monument itself, their beams extended across the road about the monument grounds. Now floodlights, in groups of five, will be placed 40 feet from each side of the monument.
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