4i8 



NATURE 



[July 



1918 



and are heard squealing and complaining as the ship 

 rolls. 



When a vessel proved a heavy toller, a cure could 

 be made by fitting bilge-keels, but at a permanent loss 

 of speed in all weather, rough or smooth, of a knot or 

 two. Schlick's sea gyroscope will cure the rolling 

 with no sacrifice of speed ; it need not be put in action 

 until wanted, and requires little power to keep it 

 going. 



The gyroscope consists of a heavy horizontal fly- 

 wheel harnessed in gimbals, ' and controlled by a 

 hydraulic buffer in the line of the keel. The damping 

 action of the buffer can be regulated by a valve to 

 suit the period of the waves, and it makes the flywheel 

 react against the rolling and kill it out. 



The inventor is said to have been offended when 

 his apparatus was found more useful still in increasing 

 the rolling and maintaining it, in the case of an ice- 

 breaker, to worry a way easier through the pack or 

 even in working off a sandbank. A different setting 

 of the buffer valve was all required. 



A spinning-top stands up vertical in a smooth cup 

 even when the cup is moved about, as on a rolling 

 ship, as we can show here with the Maxwell top ; so 

 that if the top carries a polished mirror across the axle, 

 it can serve as the mercurial horizon does on terra 

 firma, and so give an altitude when the sea horizon is 

 obscured. 



The idea was suggested by Serson in 1744, and the 

 enterprising Admiralty of the day did not crab the 

 idea straight off with the usual "won't work," but 

 sent him to sea in the Victory to make a practical 

 test; unfortunately the ship was lost with all hands 

 on the Casquets, near Alderney. 



A specimen from the King's collection is preserved 

 in King's College, Strand. The idea has been revived 

 of late years by French navigators as the Fleuriais 

 gyroscopic horizon ; it is claimed to give good results 

 in skilful hands where an ordinary observation would 

 be impracticable through fog. 



But the most important service to navigation in 

 recent times of the top in harness is the gyroscopic 

 compass. The idea was suggested by Sir William 

 Thomson, but the high spin requisite could not be 

 realised in his day until the great improvement arrived 

 in modern mechanical skill of an Anschutz or Sperry, 

 as a steel flywheel was required, some 4 in. in dia- 

 meter, spun at 20,000 revolutions a minute. The 

 axle, mounted freely, is always striving after the posi- 

 tion as close as it can get to the direction of the 

 polar axis, and so carries the. compass-card with it 

 Dointing due north, with no magnetic variation requir- 

 ing? constant correction. 



Because in modern swift steamship navigation across 

 the Atlantic, where the great circle course must be 

 maintained, practically the only nautical observation 

 required is for azimuth, in its correction of magnetic 

 variation; ani there Is no variation In the gyro- 

 compass. A specimen would be too complicated and 

 delicate to show off in this room. And If any young 

 researcher should take it into his head to test the 

 action by pushing the card away from Its course. It 

 would take an hour or more to swing back into place 

 again. 



But the greatest snlnnlng-too we know Is this Earth 

 Itself, spinning round once a dav, with the axis point- 

 ing near to the Pole Star. Ancient observation reveals 

 a precession Cas in the Maxwell too here, twirled with 

 the left hand), so that the oole is making a circuit 

 among the stars, which will be completed in 26,000 

 years. Since Homer's day the pole has made more 

 than one-tenth of the way round, and the constella- 

 tions have changed from one sign of the zodiac well 

 back through the next, and beyond. 



NO. 2543. VOL. lOl] 



We are able thence to assign a date to Homer and 

 Hesiod from their astronomical allusions. Thus 

 the nymph Calypso gives Ulysses his final instruc- 

 tions how to keep oft Africa before he sets sail on 

 his raft from Gibraltar : " Never to let the Bear take 

 a bath. He alone should be unsharing of the baths 

 of Ocean," not setting below the horizon any star of 

 the constellation. To-day these instructions would 

 land Ulysses well ashore, some six hundred miles on 

 Africa, 



Ulysses could take his latitude with a piece of 

 string, one end held up to the pole, and sliding the 

 other finger to cover some well-known star, then 

 sweeping the hand round to see if the star would 

 graze the horizon, in which case the polar distance 

 of the star is equal to the latitude. 



Two such observations on different stars would fix 

 his position, on Sumner's method, provided he had a 

 chart; and Lord Kelvin amused himself on his 

 yacht In testing the primitive methods of Ulysses 

 and the old Greek navigators against the most modern 

 Instruments of observation, sextant and chronometer, 

 with Nautical Almanac. 



In the ancient tradition there .was formerly no 

 obliquity of the ecliptic, and the year was one per- 

 petual spring. But after the Fall of Man, in the 

 Greek legendary astronomical theory Milton has 

 thrown into verse in "Paradise Lost" — 



Some say be bid his angels turn askance 

 The poles of Karth, twice ten degrees and more, 

 From the Sun's axle. They with labour pushed 

 Oblique the centric globe. 



No particular labour would be requirefl, as we see 

 with the Maxwell top, if only the polar axis pro- 

 jected, as the angel could move the poles by holding 

 his finger against the axle and letting it run up. A 

 reverse action at the Millennium will restore eternal 

 spring. 



UNIVERSITY AND EDUCATIONAL 

 INTELLIGENCE. 



LoNDON.^ — A generous offer made by Sir Basil 

 Zaharoff, G.B.E., through the Air Ministry, to provide 

 a sum of 25,000!. for the establishment of a chair of 

 aviation has been accepted by the Senate with cordial 

 thanks, and steps have been taken to secure a speedy 

 appointment to the post. 



New regulations have been adopted by ihe Senate 

 under which extended facilities are offered to graduates 

 of other universities, especially to students from over- 

 seas with suitable qualifications, to register as Interna] 

 students and as candidates for higher degrees (except 

 In medicine and surgery). 



ThQ following doctorates have been conferred : — 

 D.Sc. in Biochemistry: Mrs. M. T. Ellis, an intefnal 

 student, of the Physiological Laboratory and the South- 

 western Polytechnic Institute, for a thesis entitled 



1 " A Contribution to our Knowledge of the Plant 

 Sterols." D.Sc. in Chemistry: Mr. L. H. Parker, 



' an Internal student, of the Imperial College, Royal 

 College of Science, for a thesis entitled " (i) Reactions 

 between Solid Substances, and (il) The Interaction of 

 Sodium Amalgam and Water." Mr. O. C. M. Davis, 

 an external student, for a group of papers dealing with 

 steric Influence and other subjects. D.Sc. in Statistics : 

 Mr. Alexander Ritchie-Scott, an Internal student, of 

 University College, for a thesis entitled "(i) The Cor- 

 relation Coefficient of a Polychoric Table, and {il) A 

 First Study of Polvchoric Functions and the Incom- 

 plete Moments of a Normal Correlation Siirface." D.Sc. 

 (Engineering) : Mr. James Montgomerie, an internal 

 student, of the West Ham Municipal Technical Insti- 



