412 



SCIENCE 



[N. S. Vol. SLVII. No. 1217 



brates) and Invertebrate Embryology, by Pro- 

 fessor Harold Heath; General Physiology and 

 Eesearch in Physiology, by Professors E. G. 

 Martin and F. W. Weymouth; The Algae and 

 an advanced course in Botanical Survey, by 

 Mr. J. I. W. McMurphy. 



President Wilbur has appointed W. K. 

 Fisher, of the Department of Zoology, director 

 of the station. 



W. K. Fisher 



SCIENTIFIC EVENTS 



THE BOMBARDMENT OF PARIS BY LONG- 

 RANGE GUNS 



Professor G. Greenhill writes in Nature 

 that the Jubilee long-range artillery experi- 

 ments of thirty years ago were considered the 

 ne plus ultra by the British authorities, and 

 were stopped at that, as they were declared of 

 no military value. But the Germans are said 

 to have watched the experiments with great in- 

 terest, and to have carried the idea forward 

 until it has culminated to-day in his latest 

 achievement in artillery of a gun to fire 75 

 miles and bombard Paris from the frontier. 

 Professor Greenhill writes : 



From a measurement of the fragments of a shell 

 a caliber is inferred of 240 mm., practically the 

 same as the 9.2 inch of our Jubilee gun, which, fir- 

 ing a shell weighing 380 pounds at elevation 40°, 

 with a muzzle velocity nearly 2,400 feet per second, 

 gave a range of 22,000 yards — say, 12 miles. This 

 was much greater than generally anticipated, but 

 in close agreement with the previous calculations 

 of Lieutenant WoUey Dod, B.A., who had allowed 

 carefully for the tenuity of the air while the shot 

 was flying for the most part two or three miles 

 high. 



The German shell is likely to be made much 

 heavier and very nearly a solid shot, better by its 

 weight to overcome air resistance, the chief factor 

 to be consdered in the problem of the trajectory. 

 If it was not for this air resistance a range of 75 

 miles with 45° elevation eould be reached, on the 

 old parabolic theory of Galileo, with so moderate a 

 velocity as F = V (gB) = 3,200 feet per second, 

 with f? = 32.2, B = 75x 5,280; in a time of flight 

 of about 2J minutes, an average speed over the 

 ground of 30 miles per minute. 



A velocity of 3,200 feet per second was obtained 

 by Sir Andrew Noble in his experiments at New- 



castle about twenty years ago with a 6-inch 100- 

 caliber gun, with a charge of 27i pounds of cordite 

 and a shot of unspecified weight, so it may have 

 been the usual 100 pound or perhaps an aluminium 

 shot of half the weight. 



Double velocity is usually assumed to carry twice 

 as far; at this rate the velocity of our gun would 

 require to be raised from 2,400 feet to about 6,000 

 ieet per second to increase the range from 12 to 

 75 miles; such a high velocity must be ruled out aa 

 unattainable with the material at our disposal. 



But in this range of 75 miles the German shot 

 would reach a height of more than 18 miles and 

 would be traveling for the most part in air so thin 

 as to be practically a vacuum, and little resistance 

 would be experienced. 



So it is possible a much lower velocity has been 

 found ample, with the gun elevated more than 45°, 

 for the shot to clear quickly the dense ground 

 strata of the atmosphere. Even with the 3,200 feet 

 per second velocity obtained by Sir Andrew Noble 

 a surprising increase in range can be expected 

 over the 12-mLle Jubilee range when this extra al- 

 lowance of tenuity is taken into account, and a 

 range of 60 miles be almost attainable. 



SOME TUNGSTEN ORES IN THE NATIONAL 

 MUSEUM 



For some years the department of geology 

 in the United States National Museum has 

 been making a si)ecial effort to build up its 

 collections of the so-called rare earths and rare 

 metals, many of which have assumed excep- 

 tional importance since the outbreak of the 

 war. These collections include a considerable 

 range of substances which have proved of com- 

 mercial value only within the past decade, one 

 of the most important of which is the metal 

 tungsten, invaluable in steel manufacture. 

 During the past year the department has re- 

 ceived, principally through the intervention of 

 Mr. F. L. Hess, of the F. S. Geological Survey, 

 three most remarkable specimens illustrating 

 the three types of ore of this metal. In its 

 own way, each of the three is unique and un- 

 doubtedly the largest of its kind ever mined. 



The first is a mass of ferberite (iron tung- 

 state) from the ITo. 7 lease of the Vasco 

 Mining Co., at Tungsten, Boulder County, 

 Colorado, which was presented by the Vasco 

 Mining Co., and Messrs. Stevens and HoUand. 

 The si)ecimen is roughly oval in form, 2 feet 



