292 



NA rURE 



[March 2, 1922 



EOYAL Society, at 4.30.— Prof. T. R. Merton and S. Barratt : The 

 Spectrum of Hydrogen (Bakerian Lecture). 



London Mathematical Society (at Royal Astronomical Society), at 6. 

 — W. H. Young : The Theory of Functions of Two Complex Variables. 

 —Col. R. L. Hippisley : The Nodes of the Three Bar Sextic— R. P. 

 Whitehead : The Number of Solutions in Positive Integers of the 

 Equation 2/3+zz+a:j/=n.— T. Stuart: The Determination of the 

 Criterion to prevent " Hunting " in Hartnell's Governor.— N. Wiener : 

 The Average Value of a Functional.— Lt.-Col. A. Cunningham : On 

 Least Primitive Roots. 



Royal College op Physicians, at 5.— Dr. M. Greenwood : The 

 Influence of Industrial Employment on General Health (Mlh-oy 

 Lectures) (1). 



Child-study Society (at Royal Sanitary Institute), at 6. — Miss 

 Coombs, Mrs. Bottrill, and others : Discussion on the Family Group 

 System in Infant Schools. 



Optical Society (at Imperial College of Science and Technology), 

 at 7.30.— T. Smith and J. 8. Anderson : A Criticism of the Nodal 

 SUde as an Aid in Testing Photographic Lenses.— A. J. Bull : A 

 Non-polarising Spectrophotometer.— J. Guild : The Photometry of 

 Optical Instruments.— T. Smith : A Projective Treatment of the 

 Submarine Periscope. — A. J. Dalladay : Some Measurements of the 

 Stresses Produced at the Surfaces of Glass by Grinding with Loose 

 Abrasives. 



Institute of Metals (London Section), (at Sir John Cass Technical 

 Institute), at 8. — Dr. D. Hanson: Microstructure and Physical 

 Properties of Alloys. 



FBIDAY, MARCH 10. 



Royal Astronomical Society, at 5. 



Physical Society of London (at Imperial College of Science and 

 Technology), at 5. — R. L. Smith-Rose : The Electromagnetic Screen- 

 ing of a Triode Oscillator. — Dr. H. P. Waran : A New Form of High 

 Vacuum Automatic Mercury Pump.— W. N. Bond : Viscosity 

 Determinations by means of Orifices and Short Tubes. 



Malacological Society of London (at Linnean Society). 



Royal Institution of Great Britain, at 9. — Prof. T. R. Merton : 

 Problems in the Variability of Spectra. 



SATVRBAY, MARCH 11. 

 Royal Institution of Great Britain, at 3.— Sir Ernest Rutherford : 

 Radioactivity (2). 



PUBLIC LECTURES. 



(A number in brackets indicates the number of a lecture 

 in a series.) 



MONDAY, MARCH 6. 

 City of London (Boys') School, Victoria Embankment, at 5.30. — 

 Miss Rosa Bassett : The Dalton Plan of Self-education (5). 



University College, at 5.; 

 Ancient Buildings. 



-A. R. Powys : The Preservation of 



TUESDAY, Uxncn 7. 

 Imperial College — Royal School of Mines, at 5.30. — Col. N. T. 



Belaiew : The Crystallisation of Metals (3). 

 King's College, at 5.30.— F. H. Rolt : Accurate Measurements in 



Mechanical Engineering : The Use and Testing of Gauges (4). 

 London School of Economics, at 6.— Sir Josiah C. Stamp : The 



Administrative Factor in Government (4). 



WEDNESDAY, March 8. 



East London College, at 4. — Prof. F. E. Fritch : Certain Aspects of 

 Freshwater Algal Biology (4). 



London (R.F.H.) School of Medicine for Women (Hunter Street, 

 W.C.I), at 5.— Dr. H. H. Dale: Some Recent Developments in Phar- 

 macology (3). 



King's College, at 5.15.— Prof. N. Bohr: The Quantum Theory of 

 Radiation and the Constitution of the Atom (1). 



HORNIMAN Museum (Forest Hill), at 6.— W. W. Skeat : The Living 

 Past in Britain (7). 



University College, at 8.— The Current Work of the Biometric and 

 Eugenics Laboratory (4). E. C. Rhodes : The Relation of Caries in 

 the Teeth of School Children to Health and Home Conditions. 



THURSDAY, March 9. 

 Infants' Hospital (Vincent Square, S.W.I), at 4.— Dr. W. M. Feld- 

 man : The Physiology of the Infant. 



School of Oriental Studies, at 5. — Dr. L. D. Barnett : The Hindu 

 Culture of India (2). 



University College, at 5.15.— Sir Robert Blaur : The Education 

 Programme of the Labour Party. — Prof. J. E. G. de Montmorency : 

 Welsh and Irish Tribal Customs (5). 



■ King's College, at 5.30.— Dr. O. Faber : Reinforced Concrete (8). 



FRIDAY, MARCH 10. 

 Meteorological Office (South Kensington, S.W.7), at 3.— Sir 

 Napier Shaw : The Structure of the Atmosphere and the Meteorology 

 of the Globe (8). 



Tavistock Clinic for Functional Nerve Cases (at Mary Ward 

 Settlement, Tavistock Place, W.C.I), at 5.30.— Dr. H. C. Miller : 

 The New Psychology and its Bearing on Education (7). 



SATURDAY, March 11. 



London Day Training College, at ll. — Prof. J. Adams : The School 

 Class (8). 



Horniman Museum (Forest Hill), at 3.30.— Miss M. A, Murray : 

 Cleopatra's Needle and Sun-worship. 



CONTENTS. PAGE 



Cycles in the Yield of Crops 261 



A Searchlight on Solids. {Illustrated). By Prof. A. 



Smithells, C.M.G., F.R.S. 262 



Pictish Stone Circles. By The Rev. John Griffith . 265 



Thorpe's Dictionary. By J. F. T 266 



A New View of Fertility 267 



Travel and Exploration. By R. N. R. B. . 268 



Our Bookshelf 268 



Letters to the Editor : — 



The Directive Tendency of Elongated Bodies — W. 



D. Lambert 271 



Revival of Sporophores of SchizopkyUum com/mme, 



Fr. {Illustrated.)— ¥. A. Mason . . .272 

 Statistical Studies of Evolution.— C. F. Pantin ; Dr. 



J. C. Willis, F.R.S., and G. Udny Yule, 



C.B.E., F.R.S 273 



Columnar Structure in Sandstone Walls of a Glass 



P'urnace. {Illustrated. ) — Dr. James Weir French 274 



The Action of Sunlight ; A Case for Inquiry. — Dr.C. 



W. Saleeby 274 



The Mechanism of Heredity. — II. {With diagrams.) 



By Prof. T. H. Morgan 275 



Science in Poland. {Illustrated). By L. N. . . 278 



Current Topics and Events 279 



Our Astronomical Column : — 



Relation of Spectral Type to Magnitude . . . 281 



Research Items 282 



The Jubilee of the Institution of Electrical Engineers 284 



The American Association at Toronto. By Dr. 



Burton E. Livingston 285 



The Use of Light as an Aid to Aerial Navigation 286 



The Preservation of Stone 287 



Mathematics in Japan. By G. B. M. , . . 287 



University and Educational Intelligence . . 288 



Calendar of Industrial Pioneers 289 



Societies and Academies 289 



Diary of Societies 291 



For Subscription and Advertisement 

 Rates of NATURE see p. Ixxi. 



NO. 2731, VOL. 109] 



