The Zamar following in her wake, Reaches that fatal line; Her bows plunge under it like lead, The Eagle of the sky has tamed Call, Wireless!-call to all the land, Tell her steel ships are cockle shells-- Of all the victories of earth, None were like this before; Others have conquered gallant foes But we have conquered War! (d) Notes by AMOS MATRU of 2000 A. D. in His History of War. (a) The advent of the dirigible war balloon capable of dropping bombs vertically, either filled with high explosives or mephitic gases, at once rendered fighting tops and masts useless, and led to the "turtle shell" form of construction; strangely enough resembling somewhat the "Merrimac" of our Civil War. (b) The Paige Deflector is still a state secret, but is supposed to embrace some form of radio activity-The display in the War Museumin which two huge cannon balls suspended by great chains repel each other with such force that their chains remain almost horizontal, like pith balls suspended by threads and similarly electrified, as shown in the school experiments-is, to say the least, impressive. (c) The composition of the Kessel bomb is also a government secret; all that is known of it is its astounding effect. Its explosion produces a vast volume of dense vapor, the slightest breath of which produces asphyxiation, and with such affinity for water that it is immediately absorbed by it, producing a new fluid, chemically known as (H,O,X) of a specific gravity of about one-fourth that of water. These bombs can be electrically guided against the ship attacked, and exploded at the desired instant, stifling the crew with their deadly fumes, and changing the ocean in the immediate vicinity to a fluid in which the ship sinks like lead. (d) In view of the great Peace Pact at the conference called at The Hague in the following August, this boast is not without support. GREAT SCIENTISTS VII. GEORGE ELLERY HALE By F. R. Moulton, Ph. D. This article is the seventh in the series, "The Twelve Great Scientists". As has been previously explained, twelve names, representing men who are considered the greatest American scientists, were selected by a thousand of their colleagues. This vote was taken at the special request of the Editors of TECHNICAL WORLD MAGAZINE. Sketches of Professor A. Michelson, Dr. Alexis Carrel, Colonel G. W. Goethals, Dr. Wm. C. Gorgas, Dr. Simon Flexner, and Thomas Alva Edison have been given in previous issues.-The Editors. B EFORE he had reached the age of forty-five years George Ellery Hale had planned, built, and been director of two of the greatest astronomical observatories in the world. He had founded the Astrophysical Journal and, by his editorial management, had made it without an equal in its field. He had invented and applied some of the most valuable astronomical instruments, and had made. discoveries of the highest order of importance. He had been elected to honorary membership in the Royal Society and many other academies of Europe and America, and had been given honorary degrees by Oxford, Cambridge, Berlin, and other universities. In his scientific life, Hale is peculiarly American. He violates nearly all the traditions of Europe. Instead of being a sombre and inaccessible genius, forever brooding on the mysteries of the celestial bodies, he is eminently human, a delightful companion, and is devoted to such sports as golf, tennis, and fly-fishing. His interests include art, architecture, education, international politics, and the history of civilization. For example, he is the president of an art association in Hale inherited from his father, who 1 OUR TWELVE GREAT SCIENTISTS In 1886, at the age of eighteen, Hale entered the Massachusetts Institute of Technology. Before his course was half finished he erected behind his father's house in Chicago a spectroscopic laboratory. Shortly after his graduation, in 1890, he built an observatory equipped with a twelve-inch telescope. In 1893, he began the plan of what later became the Yerkes Observatory. This institution contains the forty-inch refracting telescope which is still the largest instrument of its kind in the world. In 1903, in order to carry his researches to their logical conclusion, he began to plan the Solar Observatory on Mount Wilson, California, which is now equipped with a sixty-inch reflecting telescope. This instrument is the largest and most effective telescope in light-gathering power in the world, but he will soon have another on the same mountain nearly three times as powerful. Hale's pre-eminence as an observatory builder is not so much the result of good fortune as of unusual ability. When opportunities did not present themselves he made them. For instance, when he learned, in 1893, that an observatory project in California had failed, he immediately set to work to secure funds to purchase the fortyinch 343 disks of glass which had been ordered for it, and to make a greater telescope than then existed. The late President Harper of the University of Chicago became enthusiastic, and chose Hale to direct the founding of a great observatory. After delays delays and discouragements, Charles T. Yerkes, of Chicago, was induced to give the money to buy the glass, build the telescope, and erect one of the finest observatories in the world, at Williams Bay, Wisconsin. Hale threw himself with untiring energy into the problem of making plans for the great telescope, securing funds for numerous other instruments, and erecting the buildings. In these early days he not only drew no salary for his services, but he gave to the University the twelve-inch telescope from his private observatory. Work was begun in 1895 and the observatory was dedicated in 1897. The two intervening years were busy ones. Many instruments besides the big telescope were to be designed and made. Their construction was begun in Hale's observatory in Chicago, and the work was transferred to the Yerkes Observatory when the building had advanced far enough to make it possible. The early period of the exist ence of the Yerkes Observ THE SPECTROSCOPIC LABORATORY OF THE SOLAR OBSERVATORY, PASADENA, CALIFORNIA use day and night whenever it was clear; and when it was not, the dark rooms, measuring instruments, and machine shops were worked to their full capacity. The history of the Mount Wilson Solar Observatory, of the Carnegie Institution of Washington, is similar in many respects to that of the Yerkes Observatory. The project of founding a solar observatory was considered in the early days of the Carnegie Institution, but it was |