8 3 o 



NA TURE 



[December 16, 1922 



gyrostatic fly-wheel is mounted with its axle vertical 

 in a frame, which can both rock about and slide 

 along an axis transverse to the ship. In an aeroplane 

 the problem of combining automatic stability with 

 mobility while avoiding dangerous stresses was 

 discussed. Angular velocity of the aeroplane about 

 a vertical axis causes a tendency to precess in a 

 gyroscope rotating about an horizontal axis. This 

 is balanced by a gravity control, and the angle 

 moved through in attaining a balance affords a 

 measure of the required angular velocity. In models 

 of mono-rail gyrostatic apparatus the fly-wheel is 

 mounted with its axle vertical in a frame which can 

 tilt in a fore-and-aft plane and also slide sideways 

 under gravity. The frame is mounted by a pinion 

 co-axial with and geared down from the fly-wheel ; 

 the pinion lies between, but normally clear of, 

 two parallel fixed racks mounted on the carriage, 

 and having their lengths in a fore-and-aft direction. 

 In practice the gyrostatic apparatus would form 

 from 3 per cent, to 5 per cent, of the load of a ship, 

 and from 5 per cent, to 10 per cent, of the load of a 

 mono-rail carriage. — P. Ditisheim : A new balance 

 for compensating the temperature error of watches 

 and chronometers. Elinvar, an alloy invented by 

 Dr. Ch. Ed. Guillaume, the elasticity of which is not 

 affected by changes of temperature, is used for the 

 hair-spring. Satisfactory timing can thus be obtained 

 up to certain limits with a plain solid uncut balance. 

 To apply the elinvar spring to higher-grade watches 

 a new compensation balance has been designed. 

 It is made from a plain monometallic uncut ring 

 into which two very small symmetrical bimetallic 

 blades are inserted. The latter will enable small 

 corrections to be made in order to obtain very fine 

 rates. 



Aristotelian Society, November 27. — Prof. A. N. 

 Whitehead, president, in the chair. — R. F. A. 

 Hoernle : Notes on the treatment of " Existence " in 

 recent philosophical literature. The ontological argu- 

 ment is treated in current philosophical literature (a) 

 in a restricted form, in which it applies only to the 

 unique case of God, and (b) in a generalised form, in 

 which it is one with the problem of the validity (or 



reference to reality ") of thought in general. Prof. 

 A. E. Taylor's criticisms of the restricted argument, 

 in his article on "Theism" in the "Encyclopedia of 

 Religion and Ethics," are mutually contradictory, but 

 they contain the valuable suggestion that the validity 

 of the argument depends on the meaning of the term 

 " God," or of the terms defining " God." What 

 these terms mean can be decided only bv asking what 

 they e \ press, and this requires that we should not 

 divorce the language of the argument from the 

 religious experience ( = Anselm's fides) which under- 

 lies it. Thus, the restricted argument appears as 

 but a special case of the generalised argument which 

 depends on the principle that experience, as the union 

 of " that " and " what," " existence " and " essence," 

 supplies the missing existential premise for all mean- 

 ings which are well-founded. The generalised argu- 

 ment depends on maintaining consistently the 



epistemic " against the " formal-logic " point of 

 view. In formal logic, no definition, as such, can 

 imply the existence of the thing defined ; no class- 

 concept can imply that the class has members. But, 

 if instead of beginning with definitions, concepts, 

 suppositions {Annahmen), we take the epistemic 

 point of view and ask what the terms of the definition, 

 etc., mean, i.e. what they express, or what we are 

 asked to think with, we are driven back to concrete 

 experience in which meanings are realised, and in 

 which, therefore, essence is not divorced from, but is 

 one with, existence. 



NO. 2772, VOL. I IOJ 



Linnean Society, November 30. — Dr. A. Smith 

 Woodward, president, in the chair. — R. J. Tillyard : 

 The wing-venation of the order Plectoptera or May- 

 flies. — D. S. M. Watson and E. L. Gill : The structure 

 of certain palaeozoic Dipnoi (fishes). — J. Duncan 

 Peirce : The Giant Trees of Victoria. The tallest 

 trees grow in gullies between ridges, the greater 

 moisture and abundance of leaf-mould conducing to 

 their height ; the highest tree measured was 326 ft. 

 1 in. 



Cambridge. 



Philosophical Society, November 13. — Mr. C. T. 

 Heycock, president, in the chair. — A. Smith Wood- 

 ward : The skulls of palaeolithic men. — W. M. H. 

 Greaves : On a system of differential equations 

 which appear in the theory of Saturn's rings. — 

 C. G. Darwin and R. H. Fowler : Fluctuations in an 

 assembly in statistical equilibrium. 



Sheffield. 

 Society of Glass Technology, November 22. — W. E. 

 S. Turner : The glass industrv and methods of manu- 

 facture in Czecho-Slovakia. The technical side of the 

 glass industry has not in recent years made anything 

 like the progress that it has in this country. The 

 Bohemian glass industry is living largely on its old 

 tradition and the existing store of knowledge. Machin- 

 ery scarcely exists for the manufacture of glassware. 

 A great deal of money was made in the industry in the 

 boom years of 1919 and 1920, but very little was put 

 into the industry to improve it. In many methods, 

 from a technical point of view, Great Britain leads the 

 Continent at the present time. — A. Cousen : Selenium 

 in the production of colourless glass. A large number 

 of experimental melts were made to determine the 

 effect of various batch materials on the decolourising 

 power of selenium and the effect of the duration of 

 melting on the colour developed. 



Dublin. 



Royal Dublin Society, November 28. — Mr. G. 

 Fletcher in the chair. — J. Wilson : On the variation 

 of milk-yield with the cow's age and the length of 

 the lactation period. Ten years ago, working on data, 

 from the cows exhibited at the London Dairy Shows, it 

 was found that, if cows' yields at eight years old be 

 set down as 100, the yields at earlier ages work out 

 at about 67 for 3-year-olds ; 81 for 4-year-olds ; 90 

 for 5-vear-olds ; 95 for 6-year-olds ; and 98 for 7- 

 vear-olds. Recently Dr. Raymond Pearl of Washing- 

 ton and Dr. Tocher of Aberdeen, working with data 

 collected by the Ayrshire Cattle Milk Records Com- 

 mittee, have found yields for the younger ages to be 

 considerably higher, but the Ayrshire records cannot 

 be used to find how yield increases with age, because 

 the breed has been out of equilibrium since about 

 twenty years ago ; the records are loaded in favour of 

 those of the younger ages. If twelve months from 

 calf to calf be taken as the normal lactation period, 

 the annual yield is reduced by about 20 gallons in an 

 eleven months lactation, and increased by about 35, 

 65, and 90 gallons in thirteen, fourteen, and fifteen 

 months lactation periods. — H. H. Poole : On the de- 

 tonating action of a - particles. Experiments show 

 that the probability of detonation of a specimen of 

 iodide of nitrogen by n-particles is proportional to 

 the concentration of the particles, and not to the 

 square, or a higher power, of the concentration. 

 I tence, detonation is caused by a single a-particle, 

 and not by the joint effect of two or more particles, 

 and it is reasonable to assume that detonation is 

 caused by the collision of the particle with a nitrogen 

 or a hydrogen nucleus. Fulminate of mercury, silver 



