March 31, 1921] 



NATURE 



153 



index, giving prices of forty-five commodities since 1800, 

 together with the records of the prices of French wheat 

 since 1250, and constructs some interesting curves. 

 He is thus led to predict that all fuel will be too high 

 in price for the profitable working of vessels for at 

 least thirty years to come. The motor clipper appears 

 to be the type of the immediate future, in which the 

 auxiliary propulsion machinery would be used in 

 calms only. The following figures are for the year 

 19 13-14, and give the percentage earnings on invest- 

 ments with freight at 205. : — Motor-ship, two-cycle, 

 260 ; motor-ship, four-cycle, 36-2 ; steamship, super- 

 heat, 385 ; and motor clipper, auxiliary sailing vessel, 

 "jol. Comparative figures for the year 1920 with 

 freight at 555. are as follows : — Motor-ship, four-cycle, 

 285 ; steamship, superheat, 255 ; motor clipper, 

 7150 tons, 560; and motor clipper, 11,600 tons, 630. 



Among the forthcoming books announced by the 

 Cambridge University Press we notice " Scientific 

 Papers of Henry Cavendish," in 2 vols. Vol. i. (The 



Electrical Researches) is a reprint of the volume 

 edited by Clerk Maxwell (1874-79), ^^ith additional 

 notes by Sir Joseph Larmor. Some changes have 

 been made in the arrangement of headlines, etc., 

 and it is hoped that the revised volume will bring 

 out more clearly both the extraordinary range and 

 value of Cavendish's work and the magnitude and 

 importance of the task which Clerk Maxwell accom- 

 plished in the last five years of his life. The volume 

 also includes a reprint of the biographical sketch of 

 Cavendish which Dr. T. Young contributed to the 

 "Encyclopaedia Britannica." Vol. ii. (Chemical and 

 Dynamical), edited by Sir Edward Thorpe, includes 

 the pa{>ers published in the Philosophical Transactions 

 and much unpublished material from the papers in 

 the possession of the Duke of Devonshire. It also 

 contains an account of the researches in dynamics, 

 astronomy, geology, and magnetism, in arranging 

 which the editor has been assisted by Sir Joseph 

 Larmor, Sir Archibald Geikie, Sir Frank Dyson, 

 and Dr. C. Chree. 



Our Astronomical Column. 



toNS-WiNNECKE's CoMET. — The failure to find this 

 comet up to the present suggests that the date of 

 perihelion may be later than those assumed. 

 Ephemerides for April have therefore been prepared 

 with the addition of a third assumed date, June 29-5. 

 They are for Greenwich midnight : 



T assumed June 13-5. 



T assumed June 21-5. 



March 31 143223 3926 0-1729 98064 



April 8 14 35 18 4257 0-1519 97602 



16 143645 4620 0-1306 97135 



24 143740 4921 0-1091 9-6641 



May 2 1437 12 52 3 0-0879 9-6100 



T assumed June 29-5. 



March 31 13 39 i 42 i 0-1932 98483 



April 8 13 33 41 45 1 0-1729 9-8130 



16 132458 4728 0-1519 97789 



24 I3H44 4915 0-1306 97452 



May 2 13 4 28 50 XI o 1091 97092 



These three ephemerides define curves neat- which the 

 comet should be found. Owing to its high north de- 

 clination it is observable throughout the night. 



Comet Reid 192 la.^ — A third observation of this 

 comet was obtained at Algiers on March 25. The 

 following is the orbit deduced from this, combined 

 with those of March I4 and 18 : 



T = 1921 May 10*297 G.M.T. 

 at = 64'' 25' 24" 



.9, =268° 28' 53" 



z =131° 36' 42" 

 log ^ =0*00582 



NO. 2683, VOL. 107] 



Ephemeris of Greenwich Midnight. 



R.A. 



Decl. 



March 

 April 



16 

 24 



20 24 4 

 20 28 51 

 20 34 40 



20 44 29 



21 12 30 



Logr 



0-0843 

 00596 

 0-0379 

 0-0206 

 00095 



Log.^ 



00928 

 00012 

 9-9007 

 9-8190 

 9-8127 



in bright 



7 iS. 

 2 23 N. 

 17 2 



... 39 37 

 May 2 21 12 30 67 28 N. 



The comet was observed on March 2^ __. _..j,,.. 

 moonlight. There is reason to expect that it will 

 attain at least faint naked-eye visibility. The elements 

 do not closely resemble those of any known comet i 



Large Detonating Fireball. — Mr. Denning writes : 

 — "On March 16, 8h. 33m. G.M.T., a magnificent 

 meteor was observed from Scotland and the north of 

 England. It occasioned a brilliant illumination of 

 sky and landscape, and was followed several minutes 

 afterwards by loud detonations, which some of the 

 observers likened to the bursting of high explosive 

 shells. At Edinburgh the sound came in about 

 d minutes after the meteor had passed, at Duns the 

 interval was 2i minutes, at Kelso 80 seconds, while 

 at Berwick-on-Tweed the fireball's flash and sound 

 of disruptive explosions were almost simultaneous. 

 There seems to have been little doubt that the meteor 

 may have fallen in or near the latter town, or in that 

 part of the North Sea contiguous to it. 



".\ large number of observations were made of the 

 object, but they are mostly of the popular type. It 

 appears highly probable, however, that the' meteor 

 moved in a direction from south-west bv west to 

 north-east bv east, and that its flight was from over 

 Moffat to Berwick-on-Tweed. Its height was about 

 71 miles at the outset of its luminous career, and 

 after traversini? about 7? miles of its path it seems 

 to have been about 24 miles high between Kelso and 

 Coldstream, while at Berwick the meteor gave evi- 

 dence of very near approach to the earth's surface. 

 The fireball was a late Taurid from a radiant at 

 80° 4-22°, but it is rather difficult to fix wi'th accuracy 

 and certainty th<=» point of radiation. The duration 

 of the meteor's flight was about 6 seconds, and this 

 would give a velocity of about la miles per second. 

 Up to the time of writing no fragments of the meteor 

 have been found, but thev might easily have fallen 

 into the sea unperceived." 



m 



