March 28, 19 18] 



NATURE 



All agree that the indigenous Australian mammalian 

 fauna should ibe considered a Tertiary one. 



"The Mesozoic marsuoials \ver(> probably exceedingly 

 generalised or primitive in type throughout their whole 

 structure, whereas the numerous widely diversified 

 forms of present-tlay Australian marsupials show a 

 high degree of structural specialisation which can 

 only be considered modern in character. The fauna of 

 Ihe early Tertiary, so far as Ave know it from the very 

 imperfect fossil records, contains relatively few marsu- 

 pials, and there seems to be as marked differences 

 between these and their Jiving relatives as between 

 i)lacentals of that time and their living relatives. 

 j)hologically, therefore, I should consider the Aus- 

 iin fauna quite modern." (J. W. Gidley.) 

 )i. W. D. Matthew states that "the amount of 

 rsity among Eocene mammals is not greater than 

 amount among modern marsupials," and thinks 

 1' can fairly say that the amount of adaptive special- 

 ion among modern marsupials compares fairly well 

 \\ that of Eocene placentals." Moreover, the brain 

 lopment and teeth afford other evidence. The 

 ais of Eocene mammals are fairly comparable with 

 tnose of Australian marsupials, and ihe teeth have 

 about the same stage of molar specialisation as Eocene 

 placentals. The predaceous marsupials of Australia are 

 also still in the Eocene stage, such as is seen in the 

 Eocene Creodonts. The skeletal adaptations of the 

 ^"^tralian fauna are comparable with the more primi- 

 Eocene and Oligocene specialisations. 

 ; lie continent of Australia seems to have ibeen 

 isolated either before the placentals reached that con- 

 tinent, or, poss'ibly, some predaceous marsupial 

 destroyed the early arrivals. The evidence points to 

 the Basal Eocene as the time during which occurred 

 the submergence which separated Australia from the 

 other continents of the world. H. F. Cleland. 



Williams College, Department of Geology, 

 \\'illianist()wn, M,'iss.. February 15. 



liib: BUMJiARJJMENT OF PARIS BY 

 LONG-RANGE GUNS. 



I\ the language of sport, the German gunner 

 has "wiped the eye" of our artillery science 

 and defied all the timid preconceived notions of 

 our old-fashioned traditions. The Jubilee long- 

 range artillery experiments of thirty years ago 

 Avere considered the ne plus ultra of our authori- 

 ties, and we were stopped at that, as they were 

 declared of no military value. To-day we have 

 the arrears to make up of those years of delay. 

 But the German watched our experiments with 

 great interest, resumed them where we had left 

 off, and carried the idea forward until it has cul- 

 minated to-day in his latest achievement in artil- 

 lery of a gun to fire 75 miles and bombard Paris 

 from the frontier. 



From a measurement of the fragments of a 

 shell a calibre is inferred of 240 mm., practically 

 the same as the 9*2 in. of our Jubilee gun, which, 

 firing a shell weighing 380 lb. at elevation 40°, 

 with muzzle velocity nearly 2400 ft. per sec, 

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

 This was much greater than generally anticipated, 

 but in close agreement with the previous calcula- 

 tions of Lieut. Wolley Dod, R. A., who had allowed 

 carefully for the tenuity of the air while the shot 

 " '■< flying for the most part 2 or 3 miles high. 



NO. 2526, VOL. lOl] 



The German shell is likely to be made much 

 heavier and very nearly a solid shot, better bv 

 its weight to overcome air resistance, the chief 

 factor to be considered in the problem of the tra- 

 jectory. If it was not for this air resistance a 

 range of 75 miles with 45'' elevation could be 

 reached, on the old parabolic theory of Galileo, 

 with so moderate a velocity as V= \/ {gR) = 2200 it. 

 per sec, with ^ = 32-2, R = 75x5280; in a time 

 of flight of about 2h mins., an average speed 

 over the ground of 30 miles per min. 



A velocity of 3200 ft. per sec. was obtained by 

 Sir Andrew Noble in his experiments at Newcastle 

 about twenty years ago with a 6-in. loo-calibre 

 gun, with a charge of 27^ lb. of cordite and a 

 shot of unspecified weight, so it may have been 

 the usual 100 lb. 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 2400 ft. to about 

 6000 ft. per sec. to increase the range from 12 

 to 75 miles; such a high velocity must be ruled 

 out as unattainable with the material at our dis- 

 posal. 



But in this range of 75 miles the German shot 

 would reach a height of more than 18 miles and 

 would be travelling 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 3200 ft. 

 per sec velocity obtained by Sir Andrew Noble 

 a surprising increase in range can be expected 

 over the 12-mile Jubilee range when this extra 

 allowance of tenuity is taken into account, and 

 a range of 60 miles be almost attainable. 



A committee should be formed at once, com- 

 posed of the artillery experts available, theo- 

 retical and practical, to make a start to recover 

 our lost ground. If these long-range guns are 

 now mounted afloat our Fleet is outclassed and 

 cannot return their fire. A start could be made 

 with no delay on one of our present 9-in..guns, 

 strengthening the breech with wire coil and 

 lengthening it with a chase of tubes screwed 

 together, as in the Noble experimental 6-in. gun, 

 to a length of something like 80 ft. 



With a charge of 100 lb. of the newest powder 

 to a shot weighing 400 lb.. Sir Andrew Noble's 

 velocity should be reached and exceeded and a 

 comparison be drawn between calculation and 

 practice. Meanwhile experiments on the model 

 scale should not be despised, as they will give 

 rapid and economical results, from which it is 

 possible to predict a full-scale performance on the 

 laws of mechanical similitude. 



With the extra metal for strengthening the 

 breech the gun would be heavy enough to prevent 

 the recoil becoming unmanageable; and if the 

 long chase should be too flexible, droop, and 

 whip, it can be rigged like the bowsprit of a ship. 

 We can rely on our chemical, metallurgical, and 



