Flood Lighting

Collier's New Encyclopedia (1921)

a term now used to describe the intense ornamental illumination of architectural structures, monuments, etc., accomplished by the concentration of powerful lights on such objects by means of reflectors suitably placed. The Statue of Liberty in New York Harbor is so illuminated. During the World War the system of flood lighting was employed in the protection of munitions factories and navy yards en- direction finder, together with the use of gaged in night work. FOG SIGNALS. Marine. - The first scientific studies of fog signals were those made by Gen. James C. Duane and Prof. Joseph Henry in America and by Prof. Tyndall in England. All were undertaken with a primary view to discoveraudiing the cause of variations in the bility of sounded signals, such variations amounting in some cases to entire absence of sound within certain zones. The range of signals is also variable, but this may usually be explained by variations in atmospheric conditions, more particularly by winds. Several theories have been proposed to account for the phenomenon of inaudibility within certain zones about the sources of sound, but opinions still differ in regard to these theories, the only agreement being that the silence is not due in any way to the muffling of sound by fog itself. The same zones of silence occur in clear weather, and fog, in fact, is usually accompanied by improved conditions of the audibility in the atmosphere. On been shown other hand, it has recently that banks of fog may reflect sound very . Extensive investigations have strongly been made by Prof. L. V. King of McGill University with a view to improving the efficiency of existing types of fog signals. The importance of unfailing signals is obvious. A number of historic marine disasters have been due to the failure of signals to be heard, and lesser accidents are still of common occurrence. The fog-signaling system of the U. S. Government service includes, in addition to newer devices, steam whistles and whistling buoys, steam sirens, shore bells, bell buoys, and trumpets. International rules have also been agreed upon providing for whistles, sirens, fog horns, Devices for locating and bells on ships. the direction of signals have been invented, since the human ear is not capable of locating the direction of sounds with certainty; and a system of determining distances from known points was invented during the World War and employed with success by British monitors operating in the English Channel. A grenade was exploded under the water ignal same time. The reception of the sound waves caused by the grenade was recorded on a special receiving apparatus and thus the distance of the ship from the shore point was easily determined from the known speed of sound in water. More recently the advent of wireless devices, including both wireless telegraphy and telephony and the radio compass or the submarine bell, has of course replaced in considerable degree the dependence of ships on the types of signals which are affected by atmospheric conditions. Aeronautical.-Fog signals for aeronauts in relation to landing places have also become of large importance, in view of the growth of established air routes regularity both and the need of unfailing in the air mail service and in passenger lines in order to make them thoroughly satisfactory, fog of course being the greatest present obstacle in the way of such regularity of service. Systems of and kite balloons above landing places above the ordinary heights of fogs have been tried or suggested, and more-promising tests have recently been made with cables laid around landing fields, these cables being charged with electric currents whose magnetic influences have been found to be detectable by sensitive airplane apparatus at a distance of a mile above the field. FOREIGN DEBTS. An official statement of July, 1921, gave the foreign as totaldebts due to the United States $10,084,367,706.59, with unpaid ining terest up to July 1, 1921, amounting to over a billion dollars additional. The principal debtors were given as follows: Great Britain.. .$4,166,318,358.44 3,350,762,938.19 France. 1,648,034,050.90 Italy.. 375,079,647.65 Belgium. 192,195,215.07 In February, 1922, an Allied Debt Refunding Commission was established by act of Congress, with authority, subject to approval of the President, to refund, convert, or extend the time of payment of any of these debts, subject to the provision that the time of no obligation shall be extended beyond 1947. The commisof five members, of sion is composed whom the Secretary of the Treasury is chairman ex-officio.