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(104th YEAR) 


lPTEMBER 5-12 








Officers and Council, 1934-35 v 

Sectional Officers, Aberdeen Meeting, 1934 ix 

Annual Meetings : Places and Dates, Presidents, Attendances, 
Receipts, Sums Paid on account of Grants for Scientific 
Purposes (1831-1934) xii 

Narrative of the Aberdeen Meeting xvii 

Report of the Council to the General Committee (1933-34) . . xx 

General Treasurer's Account (1933-34) xxx 

Research Committees (1934-35) xlii 

Resolutions and Recommendations (Aberdeen Meeting) xlviii 

The Presidential Address : 

The New World-Picture of Modern Physics. By Sir James H. 

Jeans, F.R.S i 

Sectional Presidents' Addresses : 

Theories of Light. By Prof. H. M. Macdonald, O.B.E., F.R.S. 19 

Physical Methods in Chemistry. By Prof. T. M. Lowry, 

C.B.E., F.R.S 29 

■►Plant Life and the Philosophy of Geology. By Prof. W. T. 

Gordon 49 

The Study of Behaviour. By Dr. E. S. Russell 83 

Co-operative Research in Geography ; with an African Example. 

By Prof. A. G. Ogilvie, O.B.E 99 

The Future of Rail Transport. By H. M. Hallsworth, C.B.E. 119 

Sources of Cheap Electric Power. By Prof. F. G. Baily 145 

The Use and Origin of Yerba Mate. By Capt. T. A. Joyce, 

O.B.E 161 

*Normal and Abnormal Colour Vision. By Prof. H. E. Roaf 169 

*Psychology and Social Problems. By Dr. Shepherd Dawson 183 

Some Aspects of Forest Biology. By Prof. A. W. Borthwick, 

O.B.E 19s 

Science at the Universities : Some Problems of the Present and 

Future. By H. T. Tizard, C.B., F.R.S 207 

Scientific Progress and Economic Planning in relation to Agri- 
culture and Rural Life. By Prof. J. A. S. Watson 223 


See note on following page. 



Reports on the State of Science, etc 233 

Sectional Transactions 269 

Conference of Delegates of Corresponding Societies 406 

Evening Discourses : 

Transport and Storage of Food. By Sir Frank Smith, K.C.B., 

C.B.E., Sec. R.S. (The Hardy Memorial Discourse) . . 419 

The Exploration of the Mineral World by X-Rays. By Prof. 

W. L. Bragg, F.R.S. . . . • . . -437 

Photoelectricity, Art and Politics : An Historical Study. 

By N. R. Campbell and C. C. Paterson, O.B.E 445 

Underground Water Supply. By Prof. W. S. Boulton 456 

References to Publication of Communications to the Sections 463 


A Scientific Survey of Aberdeen and District 1-123 

Index 125 

Publications of the British Association (At end) 


Section C : President's Address. 

Page 51, footnote. Read Cochran Patrick, R. W., Early Records relating to Afininp, in 
Scotland, 1878. An undated lease of rather earlier date, probably before the end of the 
twelfth century, is recorded in Chalmers' Caledonia, n.e., 1889, vol. iv, p. 866. See also 
Cadell, H. M., The Rocks of West Lothian, 1925, p. 313. 

Page 57, line 13. For " elephant " read " elephants' bones." 

Page 63, line 7 from foot. After " not " read " to." 

Page 65, line 12 from foot. For " re-Palasozoic " read " pre-Pal£Bozoic." 

Page 70, line 4. For " Wegner " read " Wegener." 

Page 71, line 14. Read " precursors." Line 18, read " Alpine." 

Page 75, line 7. For " mistaken " read " misunderstood." 

Page 79, line 2 from foot. For " little " read " practically no." 

Section I : President's Address. 

Page 178, Note 18. For lines 7 to 11, commencing " This matter " and ending " sensa- 
tion of blue," read " The matter must be left in abeyance, but the use of the term ' violet 
receptor ' is to be understood to mean either the receptor for violet or blue. Owing to 
the fact that fatigue to ' red ' causes violet to appear more blue, Wright believes that the 
single receptor gives rise to a sensation of blue." 

Section J : President's Address. 
Page 190, line 19. For 99 read 109. 

pSvitis]^|.ssariatt0n for t^t g^bbanamjeut 

0f Sritnct. 




Sir James H. Jeans, D.Sc. Sc.D., LL.D., F.R.S. 


Prof. W. W. Watts, Sc.D., LL.D., F.R.S. 


Sir George Abercromby, Bt., D.S.O. 

Sir Arthur Keith, LL.D., D.Sc, 

The Hon. the Lord Provost of 
Aberdeen (Henry Alexander, 
J.P., M.A.). 

The Principal and Vice-Chancellor 
of the University of Aberdeen 
(Sir George Adam Smith, D.D., 
LL.D., Litt.D., F.B.A.). 

The Rt. Hon. the Earl of Caithness, 
C.B.E., LL.D., D.L. 

The Rt. Hon. the Viscount Arbuth- 


The Rt. Hon. Lord Meston, K.C.S.L, 

The Rt. Hon. Sir Godfrey P. Collins, 
P.C, K.B.E., C.M.G., M.P. 

The Rt. Hon. Walter E. Elliot, P.C, 
D.Sc, LL.D., M.P. 

Sir Thomas Jaffrey, Bt., LL.D. 

Sir Robert Williams, Bt., D.L., J.P. 

Prof. Sir John Marnoch, K.C.V.O., 
LL.D., D.L. 

Sir Ashley W. Mackintosh, K.C.V.O., 

Sir Alexander M. MacEwen. 

James R. Rust, LL.D., D.L. 

Charles Murray, C.M.G., LL.D. 

Prof. H. M. Macdonald, O.B.E., 

Prof. J. J. R. MACLEOD, D.Sc, LL.D., 

Prof. J. A. MacWilliam, LL.D., F.R.S. 

J. B. Orr, D.S.O., D.Sc, F.R.S. 

Prof. R. W. Reid, LL.D. 




The Lord Mayor of Norwich (Percy 
W. Jewson). 

The Ex-Lord Mayor of Norwich 
(Alderman F. C. Jex, J. P.). 

The Sheriff of Norwich (Councillor 
W. E. Walker, J. P.). 

The Ex-Sheriff of Norwich (Coun- 
cillor E. J. Motum). 

The Deputy Lord Mayor of Nor- 
wich (Alderman H. N. Holmes, 

H.M. Lieutenant for Norfolk 

(Russell J. Colman, J.P.)- 
The High Sheriff of Norfolk, 1935. 
The Mayor of Great Yarmouth 

(Alderman A. Harbord, M.P.). 
The Mayor of King's Lynn (J. Har- 

wooD Catleugh, M.B.E.). 
The Mayor of Lowestoft (Major 

Selwyn W. Humphery). 
The Mayor of Thetford (Sir William 

Gentle, J.P.)- 
The Most Hon. the Marquess of 

Lothian, C.H. 

The Rt. Hon. the Earl of Albemarle, 

G.C.V.O., C.B., T.D. 
The Rt. Hon, the Earl of Leicester, 

G.C.V.O., C.M.G. 
The Lord Bishop of Norwich (Rt. 

Rev. Bertram Pollock, K.C.V.O., 

The Rt. Hon. Lord Hastings. 
The Rt. Hon. Sir Samuel Hoare, Bt., 

G.C.S.I., G.B.E., M.P. 
Sir Edward Mann, Bt., J.P. 
Sir Bartle H. T. Frere, K.C, J.P. 
Alderman Sir G. Ernest White, J.P. 
The Dowager Lady Suffield, J.P. 
The Dean of Norwich (Very Rev. 

D. F. S. Cranage, B.D., Litt.D.). 
G. H. Shakespeare, M.P. 
Geoffrey R. R. Colman. 
Miss Ethel M. Colman. 
John Cator, D.L., J.P. 
Alderman G. J. B. Duff, M.C, D.L., 

Major E. H. Evans-Lombe, D.L., J.P. 

Rev. C. T. Rae, B.D. 


Sir Josiah Stamp, G.B.E., D.Sc, F.B.A. 


Prof. F. J. M. Stratton, D.S.O., 
O.B.E.. M.A. 

Prof. P. G. H. Boswell, O.B.E., D.Sc. 


O. J. R. Howarth, O.B.E., Ph.D. 

H. Wooldridge, B.Sc. 


Prof. F. Aveling. 

Sir T. Hudson Beare. 

Prof. R. N. RuDMOSE Brown. 

Prof. F. Balfour Browne. 

Dr. W. T. Calman, F.R.S. 

Sir Henry Dale, C.B.E., F.R.S. 

Prof. J. Drever. 

Prof. A. Ferguson. 

Prof. R. B. Forrester. 

Prof. W. T. Gordon. 

Prof. Dame Helen Gwynne-Vaughan, 

H. M. Hallsworth, C.B.E. 

Prof. F. E. 

Dr. H. S. Harrison. 

Sir James Henderson. 

ProL A. V. Hill. 

Prof. G. W. O. Howe. 

Dr. C. W. Kimmins. 

Sir P. Chalmers Mitchell, C.B.E. 

Dr. N. V. Sidgwick, F.R.S. 
Dr. G. C. Simpson, C.B., F.R.S. 
H. T. TizARD, C.B., F.R.S. 
Prof. A. M. Tyndall, F.R.S. 
Dr. W. W. Vaughan. 
Dr. J. A. Venn. 
Weiss, F.R.S. 




Past Presidents of the Association, the President for the year, the President 
and Vice-Presidents for the ensuing Annual Meeting, past and present General 
Treasurers and General Secretaries, and the Local Treasurers and Local Secretaries 
for the Annual Meetings immediately past and ensuing. 


Sir J. J. Thomson, O.M., F.R.S. 

Sir E. Sharpey-Schafer, F.R.S. 

Sir Oliver Lodge, F.R.S. 

Sir Arthur Evans, F.R.S. 

Prof. Sir C. S. Sherrington, O.M., 

G.B.E., F.R.S. 
The Rt. Hon. Lord Rutherford of 

Nelson, O.M., F.R.S. 
H.R.H. The Prince of Wales, K.G., 

D.C.L., F.R.S. 

Prof. Sir Arthur Keith, F.R.S. 
Prof. Sir William H. Bragg, O.M., 

K.B.E., F.R.S. 
Sir Thomas H. Holland, K.C.I.E., 

K.C.S.I., F.R.S. 
Prof. F. O. Bower, F.R.S. 
Gen. The Rt. Hon. J. C. Smuts, P.C, 

C.H., F.R.S. 
Sir Alfred Ewing, K.C.B., F.R.S. 
Sir F. Gowland Hopkins, Pres.R.S. 


Sir E. Sharpey-Schafer, F.R.S. 

Sir Frank Smith, K.C.B., C.B.E., Sec. 
Prof. J. L. Myres, O.B.E., F.B.A. 

Prof. A. L. BowLEY. | Prof. A. Ferguson. 


Sir BucKSTON Browne, F.R.C.S., F.S.A. 



The Hon. the Lord Provost of Aberdeen (Henry Alexander, J. P., M.A.). 


The Principal and Vice-Chancellor of the University of Aberdeen 
(Sir George Adam Smith, M.A., D.D., LL.D., D.Litt., F.B.A. ). 

Lt.-Col. Edward W. Watt, T.D., M.A. 
Prof. H. M. Macdonald, O.B.E., 
LL.D., F.R.S. 

Marianus Lunan, J. p. 

D. B. Gunn, M.B.E., M.A., LL.B. 


Miss Evelyn M. Shearer, M.A. 

R. G. Duthie, J. p., F.I.M.T.A. 





Sir Ernest White, J. P. 

Percy W. Jewson (Lord Mayor of Norwich). 

Herbert P. Gowen. 


Noel B. Rudd, M.A. 



President. — Prof. H. M. Macdonald, O.B.E., F.R.S. 

Vice-Presidents. — Sir Frank Dyson, K.B.E., F.R.S. , Sir Arthur Eddington, 
F.R.S. , Dr. A. E. M. Geddes, O.B.E., Dr. Ezer Griffiths, F.R.S., J. W. 
Robertson, Prof. E. T. Whittaker, F.R.S. 

Recorder. — Prof. Allan Ferguson. 

Secretaries. — M. G. Bennett, Dr. Ezer Griffiths, F.R.S., Dr. R. O. Redman, 
Dr. Dorothy M. Wrinch. 

Local Secretary. — Prof. J. A. Carroll. 


President.— Proi. T. M. Lowry, C.B.E., F.R.S. 

Vice-Presidents. — Prof. A. Findlay, Dr. W. Maitland, Prof. J. C. Philip, 

O.B.E., F.R.S., Prof. R. Robinson, F.R.S. 
Recorder. — Prof. T. S. Moore. 

Secretaries. — Prof. J. E. Coates, Dr. J. M. Gulland. 
Local Secretary. — Dr. R. B. Strathdee. 


President. — Prof. W. T. Gordon. 

Vice-Presidents. — Dr. R. Campbell, Prof. W. G. Fearnsides, F.R.S., Prof. 

A. W. Gibe, Sir A. Kitson, C.M.G., C.B.E., Dr. M. Macgregor, Prof. H. H. 

Read, Dr. A. W. Rogers, F.R.S. 
Recorder. — Dr. A. K. Wells. 

Secretaries. — B. Hilton Barrett, Dr. H. C. Versey. 
Local Secretary. — Dr. A. Bremner. 


President. — Dr. E. S. Russell, O.B.E. 

Vice-Presidents. — Prof. J. H. Ashworth, F.R.S., Dr. J. Gray, F.R.S., Prof. J. 

Graham Kerr, F.R.S., Prof. J. Ritchie, Prof. D'Arcy W. Thompson, 

C.B., F.R.S., Prof. D. M. S. Watson, F.R.S. 
Recorder. — G. L. Purser. 

Secretaries. — Dr. G. S. Carter, Prof. W. M. Tattersall. 
Local Secretary. — R. M. Neill. 


President. — Prof. A. G. Ogilvie, O.B.E. 

Vice-Presidents. — Dr. W. A. Edward, Prof. C. B. Fawcett, J. McFarlane. 

Rt. Hon. Lord Meston, K.C.S.L, Prof. J. L. Myres, O.B.E., F.B.A., 

Sir George Adam Smith, F.B.A. 
Recorder. — H. King. 

Secretaries. — J. N. L. Baker, Dr. R. O. Buchanan. 
Local Secretary. — J. Hay. 



President. — H. M. Hallsworth, C.B.E. 

Vice-Presidents. — R. H. Cowie, James Fiddes, Prof. A. Gray, Prof. J. H. Jones, 

A. T. McRoBERT, W. B. Milne, R. M. Williamson. 
Recorder. — Dr. K. G. Fenelon. 
Secretaries. — Dr. P. Ford, J. Morgan Rees. 
Local Secretary. — Dr. H. Hamilton. 

A Department of Industrial Co-operation — Chairman, Dr. J. A. Bowie ; Secretary, 
R. J. Mackay, Management Research Groups, Astor House, Aldwych, 
London, W.C. 2 — arranged a special programme in connection with this and 
other Sections. 


President. — Prof. F. G. Baily. 

Vice-Presidents. — R. W. Allen, C.B.E., Prof. W. Blackadder. 

Recorder. — J. S. Wilson. 

Secretaries. — Dr. S. J. Davies, Dr. A. H. Davis. 

Local Secretary. — J. C. Grassie. 


President. — Capt. T. A. Joyce, O.B.E. 

Vice-Presidents. — Prof. V. Gordon Childe, Prof. R. A. Fisher, F.R.S., Prof. 
H. J. Fleure, Prof. A. Low, Dr. Margaret A. Murray, Rt. Hon. Lord 
Raglan, Prof. R. W. Reid, R. U. Sayce, Rev. E. W. Smith. 

Recorder and Local Secretary. — Dr. J. F. Tocher. 

Secretaries. — K. H. Jackson, V. E. Nash-Williams. 


President. — Prof. H. E. Roaf. , 

Vice-Presidents. — Prof. J. J. R. Macleod, F.R.S., Prof. J. A. MacWilliam, 

F.R.S., Prof. H. S. Raper, C.B.E., F.R.S., Prof. J. Tait. 
Recorder. — Prof. R. J. Brocklehurst. 
Secretary. — Dr. F. J. W. Roughton. 
Local Secretary. — Dr. J. M. Peterson. 

President. — Dr. Shepherd Dawson. 
Vice-Presidents. — Prof. F. Aveling, R. J. Bartlett, E. Farmer, Prof. G. A. 

Jaederholm, Dr. Ll. Wynn Jones, Prof. D. Katz, A. Rex Knight. 

A. W. Wolters. 
Recorder. — Dr. Mary Collins. 

Secretaries. — Dr. S. J. F. Philpott, Dr. P. E. Vernon. 
Local Secretary. — G. J. Aitken. 


President. — Prof. A. W. Borthwick, O.B.E. 

Vice-Presidents. — Dr. Dorothy G. Downie, Prof. F. E. Lloyd, Prof. J. R. 

Matthews, Dr. W. G. Ogg, Dr. J. D. Sutherland, C.B.E. 
Recorder. — Prof. H. S. Holden. 

Secretaries. — Dr. B. Barnes, Dr. E. V. Laing, Miss L. I. Scott. 
Local Secretary. — Miss E. C. Barnett. 



President.— U. T. Tizard, C.B., F.R.S. 

Vice-Presidents. — Dr. W. A. Edward, J. L. Holland, Dr. N. T. Walker. 

Recorder. — G. D. Dunkerley. 

Secretaries. — S. R. Humby, Miss Helen Masters. 

Local Secretary. — D. M. Morton. 


President. — Prof. J. A. S. Watson. 

Vice-Presidents. — J. Cruickshank, Rt. Hon. Walter Elliot, P.C, M.P., 

Prof. J. Hendrick, Dr. A. Lauder, J. Mackie, A. Murdoch. Dr. J. B. 

Orr, F.R.S. , J. Duthie Webster. 
Recorder. — Dr. E. M. Crowther. 
Secretary. — W. Godden. 
Local Secretary. — -A. Hill. 


President. — Col. Sir Henry Lyons, F.R.S. 
Secretary. — Dr. C. Tierney. 




Date of Meeting 




Sept. 27 

June 19 
June 25 
Sept. 8 .... 
Aug. 10.... 
Aug. 22 .... 
Sept. II.... 

Aug. 10 

Aug. 26.... 
Sept. 17 .. 
July 20 .... 

June 23 

Aug. 17.... 
Sept. 26.... 
June 19 
Sept. 10.... 
June 23 
Aug. 9 .... 

Sept. 12 

July 21 .... 
July 2 .... 
Sept. I .... 
Sept. 3 .... 
Sept. 20.... 
Sept. 12.... 
Aug. 6 .... 
Aug. 26.... 
Sept. 22.... 
Sept. 14.... 
June 27 
Sept. 4 .... 
Oct. I .... 
Aug. 26.... 

Sept. 13 

Sept. 6 .... 

Aug. 22 

Sept. 4 .... 
Aug. 19.... 
Aug. 18.... 
Sept. 14.... 

Aug. 2 

Aug. 14.... 
Sept. 17.... 
Aug. 19.... 
Aug. 25.... 
Sept. 6 .... 
Aug. 15.... 
Aug. 14.... 

Aug. 20 

Aug. 25.... 
Aug. 31.... 
Aug. 23.... 
Sept. 19.... 
Aug. 27.... 
Sept. 9 .... 

Sept. I 

Aug. 31.... 
Sept. 5 .... 
Sept. II.... 
Sept. 3 .... 
Aug. 19.... 
Aug. 3 .... 
Sept. 13 . 
Aug. 8 .... 
Sept. II.... 
Sept. i6.... 
Aug. 18.... 
Sept. 7 .... 
Sept. 13.... 

Where held 







































































Viscount Milton, D.C.L., F.R.S 

The Rev. W. Buckland, F.R.S 

The Rev. A. Sedgwick, F.R.S 

SirT. M. Brisbane, D.C.L., F.R.S. ... 
The Rev. Provost Lloyd, LL.D., F.R.S. 
The Marquis of Lansdowne, F.R.S. ... 

The Earl of Burlington, F.R.S 

The Duke of Northumberland, F.R.S. 
The Rev. W. Vernon Harcourt, F.R.S. 
The Marquis of Breadalbane, F.R.S. 

The Rev. W. Whewell, F.R.S 

The Lord Francis Egerton, F.G.S 

The Earl of Rosse, F.R.S 

The Rev. G. Peacock, D.D., F.R.S. ... 
Sir John F. W. Herschel, Bart., F.R.S. 
Sir Roderick I. Murchison, Bart., F.R.S. 
Sir Robert H. Inglis, Bart., F.R.S. ... 
The Marquis of Northampton, Pres.R.S. 
The Rev. T. R. Robinson, D.D., F.R.S. 

Sir David Brewster, K.H., F.R.S 

G. B. Airy, Astronomer Royal, F.R.S. 

Lieut.-General Sabine, F.R.S 

WilUam Hopkins, F.R.S 

The Earl of Harrowby, F.R.S 

The Duke of Argyll, F.R.S 

Prof. C. G. B. Daubeney, M.D., F.R.S. . 

The Rev. H. Lloyd, D.D., F.R.S 

Richard Owen, M.D., D.C.L., F.R.S. 

H.R.H. The Prince Consort 

The Lord Wrottesley, M.A., F.R.S. ... 

William Fairbaim, LL.D., F.R.S 

The Rev. Professor Willis, M.A., F.R.S. 
Sir William G. Armstrong, C.B., F.R.S. 
Sir Charles Lyell, Bart., M.A., F.R.S. 
Prof. J. Phillips, M.A., LL.D., F.R.S. 

William R. Grove, Q.C., F.R.S 

The Duke of Buccleuch.K.C.B., F.R.S. 

Dr. Joseph D. Hooker, F.R.S 

Prof. G. G. Stokes, D.C.L., F.R.S. 
Prof. T. H. Huxley, LL.D., F.R.S. 
Prof. Sir W. Thomson, LL.D., F.R.S 

Dr. W. B. Carpenter, F.R.S 

Prof. A. W. Williamson, F.R.S 

Prof. J. Tyndall, LL.D., F.R.S 

Sir John Hawkshaw, F.R.S 

Prof. T. Andrews, M.D., F.R.S 

Prof. A. Thomson, M.D., F.R.S 

W. Spottiswoode, M.A., F.R.S 

Prof. G. J. Allman, M.D., F.R.S. ... 

A. C. Ramsav, LL.D., F.R.S 

Sir John Lubbock, Bart., F.R.S. ... 

Dr. C. W. Siemens, F.R.S 

Prof. A. Cayley, D.C.L., F.R.S. ... 

Prof. Lord Rayleigh, F.R.S 

Sir Lyon Playfair, K.C.B., F.R.S. 
Sir J. W. Dawson, C.M.G., F.R.S. 

Sir H. E. Roscoe, D.C.L., F.R.S 

Sir F. J. Bramwell, F.R.S 

Prof. W. H. Flower, C.B., F.R.S.... 

Sir F. A. Abel, C.B., F.R.S 

Dr. W. Huggins, F.R.S 

Sir A. Geikie, LL.D., F.R.S 

Prof. J. S. Burdon Sanderson, F.R.S. 
The Marquis of Salisbury', K.G., F.R.S 
Sir Douglas Galton, K.C.B., F.R.S. 
Sir Joseph Lister, Bart., Pres. R.S. 
Sir John Evans, K.C.B., F.R.S. .. 

Sir W. Crookes, F.R.S 

Sir Michael Foster, K.C.B., Sec. R.S. 

Old Ufe 

New Life 

























































































































Ladies were not admitted by purchased tickeU until 1843. f Tickets of Admission to Sections only. 

[Continued on p. xiv. 












Sums paid 
on account 
of Grants 




for Scientific 


— j 


— . 





. . 1 






























. — 





. — 



1840 ; 


922 12 6 



1 1 10* 




932 2 2 





1438 i 


1595 II 






1546 16 4 








1235 10 II 









1449 17 8 1 








1565 10 2 









981 12 8 









831 9 9 









685 16 









208 5 4 









275 I 8 









159 19 6 









345 18 









391 9 7 







1 108 


304 6 7 


















380 19 7 









480 16 4 









734 13 9 









507 15 4 









618 18 2 









684 II I 









766 19 6 









IIII 5 10 









1293 16 6 









160S 3 10 









1289 15 8 









1591 7 10 









1750 13 4 









1739 4 




































1472 2 6 



























1151 16 





1 672 









i 712 




1092 4 2 





' 283 




1128 9 7 









725 16 6 









1080 II II 



' 41 






731 7 7 





1 514 




476 8 I 



1 79 






1126 I II 



! 323 




1 2714 


1083 3 3 






26 & 60H.S 

i 1777 


I173 4 





1 447 













995 6 









I186 18 









1511 5 









1417 11 









789 16 8 









1029 10 





1 439 




864 10 









907 15 6 









583 15 6 









977 15 5 





' 873 




I 104 6 I 









1059 10 8 








i 2399 










■1430 14 2 


J Including Ladies. § Fellows of the American Association were admitted as Hon. Members for this Meeting. 

[Continued on p. xv. 



Table of 

Date of Meeting 


Sept. 5 ... 
Sept. II.., 
Sept. 10.. 
Sept. 9 .. 
Aug. 17.. 
Aug. 15 .. 
Aug. I .. 
July 31 •• 
Sept. 2 .. 
Aug. 25 .. 
Aug. 31 .. 
Aug. 30.. 
Sept. 4 .. 
Sept. 10... 
Sept. 7 .. 
Sept. 5 .. 

Sept. 9.. 

Where held 






South Africa 












(No Meeting) 

(No Meeting) 



1920, Aug. 24 Cardiff Prof. W. A. Herdman, C.B.E., F.R.S. 

1921, Sept. 7 Edinburgh Sir T. E. Thorpe, C.B., F.R.S 

1922, Sept. 6 Hull Sir C.S.Sherrington, G.B.E.,Pres.R.S, 






Sir William Turner, D.C.L.,F.R.S. ... 
Prof. A. W. Riicker, D.Sc, Sec. R.S. 

Prof. J. Dewar, LL.D., F.R.S 

Sir Norman Lockyer, K.C.B., F.R.S. 
Rt. Hon. A. J.Balfour, M.P., F.R.S.... 
Prof. G. H. Darwin, LL.D., F.R.S. ... 
Prof. E. RayLankester, LL.D., F.R.S. 

Sir David Gill, K.C.B., F.R.S 

Dr. Francis Darwin, F.R.S 

Prof. Sir J. J. Thomson, F.R.S 

Rev. Prof. T. G. Bonney, F.R.S 

Prof. Sir W. Ramsay, K.C.B., F.R.S. 

Prof. E. A. Schafer, F.R.S 

Sir Oliver J. Lodge, F.R.S 

Prof. W. Bateson, F.R.S 

Prof. A. Schuster, F.R.S 

r Sir Arthur Evans, F.R.S -1 

Hon. Sir C. Parsons, K.C.B., F.R.S. ... 


Sept. 12 Liverpool 

Aug. 6 Toronto 

Aug. 2 6 . 
Aug. 4 . 

Aug. 31 . 
Sept. 5 . 
July 22 . 



South Africa 

Sept. 3 ' Bristol 

Sept. 23 1 London 

Aug. 31 ! York 

Sept. 6 \ Leicester 

Sept. 5 j Aberdeen 

Sir Ernest Rutherford, F.R.S 

Sir David Bruce, K.C.B., F.R.S 

Prof. Horace Lamb, F.R.S 

H.R.H. The Prince of Wales, K.G, 


Sir Arthur Keith, F.R.S 

Sir WiUiam Bragg, K.B.E. 
Sir Thomas Holland, 

K.C.I.E., F.R.S 

Prof. F. O. Bower, F.R.S 

Gen. the Rt. Hon. J. C. Smuts, P.C 

p TT p R Q 

Sir F. Gowland Hopkins, Pres. R.S. ., 
Sir James H. Jeans, F.R.S." 



Old Life 

New Life 






























































' Including 848 Members of the South African Association. 

" Including 137 Members of the American Association. 

° Special arrangements were made for Members and Associates joining locally in Australia, see 
Report, 1914, p. 686. The numbers include 80 Members who joined in order to attend the Meeting of 
L'Association Fran?aise at Le Havre. 

' Including Students' Tickets, los. 

' Including Exhibitioners granted tickets without charge. 

" Including grants from the Caird Fund in this and subsequent years . 

' Including Foreign Guests, Exhibitioners, and others. 



Annual Meetings- 


Sums paid 





on account 








of Grants 




for Scientific 










£1072 10 









920 9 II 




647 305 













845 13 2 









887 18 II 









928 2 2 









882 9 









757 12 10 









1157 18 8 









1014 9 9 









963 17 














1292 1 359 




845 7 6 









978 17 I 








1861 16 4« 









1569 2 8 









985 18 10 









677 17 2 









326 13 3 











Annual Members 
















1272 10 

1251 13 0' 









2599 15 

518 I 10 









1699 5 

722 7 











2735 15 

777 18 6' 









3165 19 


1197 5 9 









1630 5 











917 I 6 









2414 5 

761 10 









3072 10 

1259 10 





. — 




1477 15 

1838 2 I 









2481 15 

683 5 7 









4792 10 

1146 7 6 





45 214 



1724 5 

1183 13 II 





82 147 



2428 2 

412 19 11" 





181 280 



2900 13 


739 4 


' The Bournemouth Fund for Research, initiated by Sir C. Parsons, enabled grants on account of 
scientific purposes to be maintained. 

• Including grants from the Caird Gift for research in radioactivity in this and subsequent years 
to 1926. 

'° Subscriptions paid in Canada were $5 for Meeting only and others pro rata ; there was some gain 
on exchange. 

" Including 450 Members of the South African Association. 

•' Including 413 tickets for certain meetings, issued at 5s. to London County Council school-teachers. 

" For nine months ending March 31, 1933. 

" Sir William B. Hardy, F.R.S., who became President on January i, 1934, died on January 23. 



On Wednesday, September 5, at 8.30 p.m., the Inaugural General Meeting 
was held in the Capitol Cinema (generously placed by the management 
at the disposal of the Association), when the Hon. the Lord Provost ot 
Aberdeen (Mr. Henry Alexander, J.P.) and the Principal and Vice-Chan- 
cellor of the University (the Very Rev. Sir George Adam Smith, D.D.) 
welcomed the Association to Aberdeen. The President of the Association 
Sir James H. Jeans, F.R.S., delivered an Address (for which see p. i) 
entitled The New World Picture of Modern Physics. 

Before delivering his Address, the President read the followmg message 
which had been forwarded to The King at Balmoral, and His Majesty s 
gracious reply : — 

Your Majesty,— We, the Members of the British Association for the 
Advancement of Science assembled in the City of Aberdeen m annual 
session, desire humbly to recall to Your Majesty that it was m this City 
that His Royal Highness The Prince Consort assumed the Presidency ot 
the Association in the year 1859- From the Presidential Chair, he con- 
veyed to the assembled members of the Association ^ gracious message 
from Her Majesty Queen Victoria, and delivered an Address which dis- 
closed his own profound interest in the advancement of Science, ihe 
many marks of Royal favour which have been extended to our Association 
on subsequent occasions have provided further signal encouragement to 
us in our pursuit of the aims defined by His Royal Highness and on all 
these counts we now desire to express to Your Majesty our humble gratitude. 

{Signed) J. H. Jeans, 


To The President, 

The British Association, Aberdeen. r u u v u 

I am commanded by the King to thank the members of the British 
Association for the Advancement of Science for the loyal message which 
they have addressed to His Majesty, their Patron, from the Inaugural 
General Meeting in the Ancient City of Aberdeen. 

His Majesty appreciates their kind remembrance of the occasion when 
the Prince Consort, as President of the Association delivered a message 
from Queen Victoria to the members assembled in this City three-quarters 

° TheTingTsires me to assure the members of his unabated interest in 
their Meetings and his confidence that their investigations into the manifold 
problems confronting present day Scientists will continue to be productive 
of resuhs which will benefit mankind. ^^,^^^^^ ^^^^^ ^^^^^ 

5th September, 1934- 

On Friday, September 7, in the MacRobert Hall, Gordons College, 
at 8.30 P.M.; Sir Frank Smith, K.C.B., Sec. R.S delivered an Evemng 
Discourse entitled The Storage and Transport of Food (see p. 419), being 

* b 


a Memorial Lecture for the late President of the Association, Sir William 
Hardy, F.R.S. 

On Monday, September lo, in the same hall, at 8.30 p.m.. Prof. W. L. 
Bragg, F.R.S., delivered an Evening Discourse entitled The Exploration 
of the Mineral World by X-rays (p. 437). 


The Lord Provost, Magistrates, and Town Council of Aberdeen enter- 
tained members of the Association at a Reception in the Art Gallery and 
adjacent buildings on Thursday evening, September 6. 

The University of Aberdeen entertained members of the Association 
at a Garden Party in King's College on Monday afternoon, September 10. 

A dance wzs held in the Beach Ball Room on Tuesday evening, Sep- 
tember II. 

The students of Aberdeen University produced a play, Town & Gown, 
during the week beginning on September 10, and the productions on this and 
the following nights were regarded as ' British Association performances.' 

By the courtesy of the owners, the exhibits shown at the Telford 
Centenary Exhibition in the Institution of Civil Engineers, London, in 
June, 1934, were displayed in the Engineering Department of Gordon's 
College during the week of the meeting. The exhibition was opened 
by Sir Alexander Gibb, G.B.E., on Friday, September 7. 

Visits were arranged to the Rowatt Research Institute, the Macaulay 
Research Institute, the Torry Research Station of the Department of 
Scientific and Industrial Research, and the research vessel (the Explorer) 
of the Fishery Board for Scotland ; and numerous other institutions and 
works in the city and neighbourhood afforded facilities and entertainment 
to members during the meeting. 


A special service was held in the West Church of St. Nicholas, when 
officers and other members of the Association accompanied the Lord 
Provost in state. The service was conducted by the Rev. P. C. Millar, 
O.B.E., Minister of the Church, and the preacher was the Very Rev. 
Principal Sir George Adam Smith, D.D. The service was broadcast, 
and the sermon was published in The Listener, September 26. Other 
special services were held in St. Andrew's Cathedral, St. Mary's Roman 
Catholic Cathedral, and Belmont Congregational Church. 


On Saturday, September 8, general excursions were arranged to Royal 
Deeside, the Highlands (Spey Valley, Aviemore, Culloden Moor, Inver- 
ness), Moray (Elgin, Pluscarden Abbey, etc.), Mearns (Glen of Dye, Cairn 
o' Mount road, Fettercairn, Edzell, Brechin, Stonehaven). Among other 
excursions and visits, those devoted to the interests of special Sections during 
the Meeting are mentioned among the Sectional Transactions in later pages. 

*J£. ^ J^ JL Jt, 

^ "A" TT "Jp TP 

At the final meeting of the General Committee, on Tuesday, Sep- 
tember II , it was resolved : 

(i) That the British Association places on record its warm thanks for 
the hospitable reception afforded to it by the City of Aberdeen. The 


generous co-operation of the Lord Provost, Magistrates, and Town Council, 
and the thorough preparations made by the local officers and committees, 
have been deeply appreciated, while the large local membership has been 
highly gratifying to the Association. 

(2) That the British Association most cordially thanks the University 
Court of the University of Aberdeen for their hospitality to the Association, 
for the use of their buildings, and for the valuable assistance given by the 
University authorities and staff. 

(3) That the British Association most cordially thanks the scientific 
educational, commercial, and industrial institutions in Aberdeen and tht 
neighbourhood, for the accommodation and facilities so generously provided 
for meetings and visits. 

On Wednesday, September 12, the President and General Officers, 
Members of the Council and Presidents of Sections, entertained the 
principal local officers at luncheon. 


Presidency, 1934. 

I. — The Association suffered a grievous loss in the death of its President, 
Sir William Hardy, F.R.S., on January 23. 

The Council adopted the following resolution : — 

That the Council deeply deplore the death of the President of the Associa- 
tion, Sir William Hardy, remember with gratitude his eminent services in 
the advancement of science, and record their sincere condolence with the 
members of his family in their bereavement. 

A letter was received from the Lord Provost of Aberdeen (Mr. Henry 
Alexander) expressing the regret of the Local General Committee for the 
Aberdeen Meeting. 

The Association was represented at the funeral of the late President 
by Prof. Lord Rutherford, F.R.S., ex-President, by Prof. F. J. M. 
Stratton, General Secretary, and by Mr. D. B. Gunn, Town Clerk Depute 
of Aberdeen, on behalf of the Local General Committee. 

Sir William Bragg, O.M., K.B.E., F.R.S.,' occupied the Chair of the 
Council at the meetings in February and March. 

The Council resolved that one of the Evening Discourses at the Aberdeen 
Meeting should be announced as a Sir William Hardy Memorial Lecture. 

H. — On the nomination of the Council, Sir James Jeans, F.R.S. , was 
appointed to succeed Sir William Hardy as President of the Association 
for the current year, at a meeting of the General Committee convened on 
March 2 by the Council under Statute 0,3. 


HL — The Council have had to deplore the loss by death of the following 
office-bearers and supporters : — 

Most Hon. the Marquis of Aber- Prof. A. B. Macallum, F.R.S. 

deen Prof. J. E. Marr, F.R.S. 

Dr. F. A. Bather, F.R.S., amember Sir Ernest Moir, Bt. 

of the present Council Dr. Marion Newbigin 

Sir John H. Biles, F.R.S. The Hon. Lady Parsons 

Dr. Lilian Clarke Dr. W. Rosenhain, F.R.S. 

Prof. Sir Edgworth David, F.R.S. Dr. D. H. Scott, F.R.S., General 
Prof. J. Cossar Ewart, F.R.S. Secretary, 1900-03 

Prof. W. M. Hicks, F.R.S. Prof. J. Y. Simpson 

Prof. J. Joly, F.R.S. Prof. S. H. Vines, F.R.S. 

Sir Donald Macalister, K.C.B. Prof. R. Ramsay Wright 

The Association was represented at the funeral of Dr. Bather by 
Prof. P. G. H. Boswell, F.R.S., General Secretary, and at that of Dr. D. H. 
Scott by Prof. F. E. Weiss, F.R.S. 



IV. — Representatives of the Association have been appointed as 
follows : — 

Central Conference for Health Education, 

London ...... Dr. C. W. Kimmins 

National Committee for Geodesy and 

Geophysics ..... Prof. A. O. Rankine, 

American Association for the Advance- 
ment of Science, Boston Meeting . Prof. F. E. Lloyd and 

Prof. A. E. Kennelly 
British Film Institute, Advisory Com- 
mittee ...... Prof. J. L. Myres 

International Congress of Anthropology 

and Ethnology, London . . . Capt. T. A. Joyce 

Edinburgh Geological Society, Centenary . Prof. P. G. H. Boswell, 


The Council have given general approval to a suggestion that, except 
on occasions of special formality or otherwise in the discretion of the 
General Secretaries, it should be competent for the Secretary to send a 
letter to inviting bodies indicating that representatives are not nominated 
unless special circumstances make such action desirable, but that among 
such circumstances would be included any specific proposal or suggestion 
for collaboration between the inviting society and the Association or any 
of its sectional or research committees, with the object of the advancement 
of science in any department within the scope of the Association. 


V. — Resolutions referred by the General Committee to the Council for 
consideration, and, if desirable, for action, were dealt with as follows. 
The resolutions will be found in the Report for 1933, p. xliv. 

(a) The recommendation received from the General Officers was in 
the following terms : — 

That it be a recommendation to the General Committee to request 
the Council to consider by what means the Association, within the 
framework of its constitution, may assist towards a better adjustment 
between the advance of science and social progress, with a view to 
further discussion at the Aberdeen Meeting. 

A committee of the Council considered this recommendation, and 
drew up a Memorandum which, after amendment and adoption by the 
Council, was circulated to all Organising Sectional Committees. As a 
result, numerous subjects appropriate to the terms of the recommenda- 
tion have been included for discussion in sectional programmes for the 
Aberdeen Meeting, and the Council themselves have had the recom- 
mendation in mind when arranging the evening meetings. 

xxii REPORT OF THE COUNCIL, 1933-34 

(b) A letter was addressed to the Ministry of Agriculture and Fisheries 
expressing the hope that no effort would be spared to exterminate the 

• musk-rat completely in this country. A reply was received to the 
effect that the danger was fully appreciated, and that suitable measures 
were being taken. (Resolution of Section D, Zoology.) 

(c) After inquiry, no action was taken upon a recommendation that 
the inclusion of population maps in the Census returns should be 
urged upon the proper authorities. (Resolution of Section E, 

(d) The attention of the Colonial Office was drawn to the backward 
state of geodetic surveys in the British colonies and dependencies, and 
a reply was received to the effect that the question was continually 
engaging the attention of the Secretary of State, and that the Council's 
representation would not be overlooked, but that it was difficult for 
most of the dependencies to find funds for survey work outside 
ordinary revenue purposes. (Resolution of Section E, Geography.) 

(e) A communication on the desirability of accelerating the revision 
of the large-scale maps of the Ordnance Survey was addressed to the 
Ministry of Agriculture and Fisheries. (Resolution of Section E, 

(/) The attention of the Ministry of Agriculture and Fisheries was 
drawn to the desirability of investigating diseases of the cricket-bat 
willow, and a reply was received to the effect that research into the 
diseases mentioned was already being carried on under the Forestry 
Commission, and that some work had also been done at Long Ashton 
Research Station. (Resolution of Section K, Botany.) 

(g) The separate issue of the reports on Science in Adult Education 
and on General Science with special reference to Biology was authorised 
as requested in the resolution of Section L (Educational Science). 

VL — In the Report of the Council for last year (Report, 1933, p. xx) 
it was stated that the Council had forwarded a resolution to H.M. Secretary 
of State for the Colonies, dealing with the archaeological and geological 
interest of the Kendu-Homa area in Kenya. A reply was received to 
the effect that the Acting Governor of Kenya had taken steps to exclude 
the site in the Kendu-Homa area, on which archaeological and geological 
discoveries had been made, from the area in respect of which application 
for exclusive mineral prospecting licences had been invited. The Council 
ordered an expression of their satisfaction to be conveyed to the 
authorities concerned. 

Vn. — Correspondence on a proposal to establish a nature reserve in 
the Galapagos Islands was reported to the Council, and it was resolved 
that a communication be forwarded to the Carnegie Institution, expressing 
the hope that such proposal might be carried out, having regard especially 
to the fact that it was contemplated that the reserve should be established 
as a memorial to Charles Darwin. A reply was received from the 
Institution, expressing appreciation of the Council's communication, and 
indicating that discussion was in progress with the authorities concerned. 

REPORT OF THE COUNCIL, 1933-34 xxiii 

Down House. 

VIII. — The following report for the year 1933-34 has been received 
from the Down House Committee : — 

The number of visitors to Down House during the year ending June 6, 
1934, has been 8,536, compared with 7,022 in 1932-33. The increase 
is beheved to be due, at least in part, to the estabhshment of an omnibus 
service to the village of Downe. 

Sir Buckston Browne has generously presented to the house his portrait 
by Mr. Robin Darwin. It is peculiarly appropriate that this work of 
Darwin's great-grandson should find its place here. 

Several gifts of letters and other Darwiniana have been received during 
the past year and duly acknowledged, and have also been recorded in an 
addendum to the catalogue recently compiled. 

Under a scheme in which Mr. G. C. Robson, Prof. J. W. Munro, Miss 
Saunders of Goldsmiths' College, and others are interested, opportunity has 
been given teachers in training and other students to do work on plant ecology 
in the neighbourhood of Downe , and they have made some use of accommoda- 
tion at Down House in this connection. The Committee feel that it is 
most appropriate that the Association should be able to grant such facilities. 

The Secretary and Mrs. Howarth have written, and published at their 
own charges, a History of Darivin's Parish : Doivne, Kent, to which Sir 
Arthur Keith has contributed a foreword. The Committee have consented 
to the announcement of this work along with other announcements relating 
to Down House in Association programmes, and have allowed it to be on 
sale at the house, as well as through ordinary channels. 

The following financial statement shows income and expenditure on 
account of Down House for the financial years ending March 31, 1933 and 
1934. For the latter year, a balance of income over expenditure amounting 
to £45 9^- 85^. is shown. The gift from the Pilgrim Trust, acknowledged 
in the last report of the Committee, has thus relieved the general funds of 
the Association. As the Council were advised last June, the present and 
any subsequent balance on the side of receipts will not be payable auto- 
matically to general funds, but will be placed in a suspense or maintenance 
fund for the house. If any payment to general funds should ultimately be 
considered possible, it will be by way of interest upon the so-called capital 
expenditure incurred on the property from general funds. 

It was explained in last year's report that the figure for income from the 
endowment fund for 1932-33 was deceptive, as certain dividends included 
both a gross payment for the year and a refund of income tax on the pre- 
ceding year. This accounts for the apparent, but not actual, decrease in 
the returns on the invested fund. 


By Dividends on endowment fund and 
income tax recovered . 
„ Grant from Pilgrim Trust 
,, Rents ..... 
,, Donations .... 
,, Sale of Postcards and Catalogues 
,, Balance, being excess of expenditure, 
as below, over income . 


£ s. d. 

£ s. d. 


1,030 I 10 


24 17 

978 17 6 
140 IS 

6 iij 
34 14 2I 


40 7 11^ 


£1,240 II i^ 1,310 7 8 

xxiv REPORT OF THE COUNCIL, 1933-34 

Expenditure (running costs) 









To Wages and National Insurance 







,, Rates, Land Tax, Insurances . 






10 J 

,, Coal, Coke, etc. .... 







,, Water 







,, Lighting and Drainage Plants (includ- 

ing petrol and oil) 







,, Repairs and Renewals 






,, Garden Materials .... 







,, Household Requisites, etc. 







,, Transport and Carriage . 







,, Auditors ..... 







,, Printing, Postages, Telephone, Sta- 

tionery, etc. 







,, Donations to Village Institutions 





,, Legal Charges (lease of ' Homefield ') . 






,, Purchase of Darwin's dining table 






,, Balance, being excess of income over 

expenditure .... 






£1,240 II i^ 1,310 7 8 


IX. — The Council have received reports from the General Treasurer 
throughout the year. His account has been audited and is presented to 
the General Committee. 

X. Bernard Hobson Trust. — As stated in last year's Report of the 
Council, the Association was a beneficiary in the sum of £1,000 under the 
will of Mr. Bernard Hobson, the income from which is to be devoted 
to the promotion of definite geological research. The Council have 
confirmed the proposals indicated in the last report, in the following 
terms : — 

(i) The fund is administered by the Council. 

(ii) It shall be competent for the Committee of Section C (Geology) at 
the Annual Meeting to recommend to the Council that one or more of 
the applications for grants to research committees shall be earmarked as 
a charge on the Bernard Hobson Fund. 

(iii) Council reserves the right to make a grant, or grants, from the 
fund in response to special applications arising in the course of the year. 

The Council undertook to consider the payment of travelling expenses 
(fares) in connection with grants made from the fund. 

XI. Sir Charles Parsons^ Legacy. — The legacy of £3,000 left to the 
Association by the Hon. Sir Charles Parsons, K.C.B., F.R.S., has been 

XII. Leicester and Leicestershire Fund (1933). — On behalf of the Local 
Committee for the Leicester Meeting, 1933, Dr. C. J. Bond and Mr. Colin 


Ellis presented a cheque for ^^ 1,000 as a gift to the Association, being 
unexpended balance of the fund raised locally for the purposes of the 
meeting. The following conditions were proposed : — 

(i) That the sum of £1,000 be given to the British Association for the 
Advancement of Science to be invested by them, the interest to be used 
to assist by scholarship or otherwise a student or students working for 
the advancement of science. 

(2) That the fund be administered solely by the Council of the British 

(3) That when possible assistance be given preferably to a Leicester 
or Leicestershire student or worker. 

(4) That the fund be called the ' Leicester and Leicestershire Fund,' 
or in some other way be identified with Leicester and Leicestershire, and 
that it be referred to in each year in the annual statement of the British 

It was resolved that the Council accept with gratitude from the Com- 
mittee for the Leicester Meeting (1933) their gift of the sum of £1,000 to 
the Association, to form the Leicester and Leicestershire Fund for the 
prosecution of scientific work ; that the terms of trust accompanying the 
gift be accepted, and that the Council record their appreciation of the 
action of the committee in thus confirming, in a manner without precedent 
in the history of the Association, their interest in the advancement of 

XIIL Grants. — The Council made the following grants from funds 
under their control : — 

From the Caird Fund. 
Committee on Seismology . . . . .100 

20 (contingent) 



15 (contingent) 

Critical Sections in Palaeozoic Rocks 
,, ,, Plymouth Table ... 

„ ,, Zoological Record ... 

,, ,, Naples Table .... 

,, ,, Fresh Water Biological Station, Winder 

mere (out of total grant of £75) 
„ ,, Derbyshire Caves . . . 

,, ,, Prehistoric Site in Rio Tinto 

„ ,, Routine Manual Factor in Mechanical 

Ability ...... 20 „ 

(The above gave effect to recommendations made at the Leicester 


Committee on Mathematical Tables, toward the pub- 
lication of Bessel Function Tables . . . . £100 

Contribution toward expenses of Sixth International 

Congress for Scientific Management . . ■ £5 5^- 

Committee on Human Geography of Tropical Africa, 
not exceeding ....... £5 

From the Bernard Hobson Fund. 

Committee on Character of the Palaeozoic Rocks under- 
lying the Carboniferous of the Craven area . . £30 

(Giving eflfect to a recommendation made at the Leicester Meeting.) 

b 2 



From the Cunningham Bequest. 

Prof. W. E. H. Berwick in connection with Table of 
Reduced Ideals ....... 

£io lOS. 

XIV. — The Council propose the following additional Statute, to form 
paragraph (v) of section 3 in Chapter X, on the Admission and Privileges 
of Members : — 

Corporation membership may be acquired by any British corporate 
body approved by the Council on payment of the sum of thirty guineas 
which shall entitle the corporation to appoint one representative to attend 
each annual meeting in perpetuity, or on payment of the sum of fifty 
guineas, two representatives, and on payment of each further sum of fifteen 
guineas, an additional representative. Such subscription shall entitle 
the corporation or each of its representatives to receive the annual report 
on demand. 

President (1935), General Officers, Council and Committees. 

XV. — The Council's nomination to the Presidency of the Association 
for the year 1935 (Norwich Meeting) is Prof. W. W. Watts, F.R.S. 

XVI. — The General Officers have been nominated by the Council as 
follows : — 

General Treasurer, Sir Josiah Stamp, G.B.E. 

General Secretaries, Prof. F. J. M. Stratton, D.S.O., O.B.E., Prof. 
P. G. H. Boswell, G.B.E. , F.R.S. 

XVII. Council. — The retiring Ordinary Members of the Council 
are : Sir Henry Fowler, K.B.E., Dr. Tate Regan, F.R.S., Prof. J. F. 
Thorpe, F.R.S., and Sir John Russell, F.R.S. A further vacancy was 
created by the death of Dr. F. A. Bather, F.R.S., to which previous 
reference has been made. 

The Council have nominated as new members Sir T. Hudson Beare, 
Prof. A. V. Hill, F.R.S., and Dr. W. W. Vaughan, leaving two vacancies 
to be filled by the General Committee without nomination by the Council. 

The full list of nominations of Ordinary Members is as follows : — 

Prof. F. Aveling 

Sir T. Hudson Beare 

Prof. R. N. Rudmose Brown 

Prof. F. Balfour Browne 

Sir Henry Dale, C.B.E., Sec. R.S. 

Prof. J. Drever 

Prof. A. Ferguson 

Prof. R. B. Forrester 

Prof. W. T. Gordon 

Prof. Dame Helen Gwynne- 

Vaughan, G.B.E. 
Dr. H. S. Harrison 

Sir James Henderson 

Prof. A. V. Hill, F.R.S. 

Prof. G. W. O. Howe 

Dr. C. W. Kimmins 

Sir P. Chalmers Mitchell, C.B.E. 

Dr. N. V. Sidgwick, F.R.S. 

Dr. G. C. Simpson, C.B., F.R.S. 

H. T. Tizard, C.B., F.R.S. 

Prof. A. M. Tyndall, F.R.S. 

Dr. W. W. Vaughan 

Dr. J. A. Venn 

Prof. F. E. Weiss, F.R.S. 



XVIII. Secretary. — At their meeting in February the Council con- 
gratulated Dr. O. J. R. Howarth, Secretary, on completing twenty-five 
years in office. 

XIX. General Committee. — The following have been admitted as 
members of the General Committee, mostly on the nomination of the 
Organising Sectional Committees under Regulation i : — 

Dr. S. Bryan Adams 

Mrs. Robert Aitken 

Prof. G. C. Allen 

Dr. C. B. Allsopp 

Prof. E. V. Appleton, F.R.S. 

Mr. W. T. Astbury 

Dr. W. A. Bain 

Dr. Helen Bancroft 

Dr. H. Banister 

Dr. B. Barnes 

Mr. B. Hilton Barrett 

Mr. R. J. Bartlett 

Mr. M. G. Bennett 

Dr. J. D. Bernal 

Miss D. Bexon 

Mr. E. G. Bowen 

Dr. J. A. Bowie 

Mr. M. C. Burkitt 

Dr. J. A. V. Butler 

Mr. L. H. Dudley Buxton 

Prof. H. Graham Cannon 

Miss G. Caton-Thompson 

Dr. A. W. Chapman 

Prof. V. Gordon Childe 

Prof. J. E. Coates 

Dr. J. D. Cockcroft 

Miss E. R. Conway, C.B.E. 

Dr. R.S. Creed 

Mr. E. H. Davison 

Prof. J. Doyle 

Prof. J. C. Drummond 

Miss M. Drummond 

Mr. T. S. Dymond 

Prof. L. E. S. Eastham 

Mr. W. N. Edwards 

Mr. A. C. G. Egerton, F.R.S. 

Capt. F. Entwistle 

Mr. E. Farmer 

Mrs. Allan Ferguson 

Prof. R. A. Fisher, F.R.S. 

Prof. P. Sargant Florence 

Prof. C. Daryll Forde 

Mr. C. H.H.Franklin 

Mr. J. A. Eraser 

Dr. R. G. Gordon 

Dr. Ezer Griffiths, F.R.S. 

Dr. J. M. Gulland 

Dr. R. T. Gunther 

Dr. T. M. Harris 

Mr. R. F. Harrod 

Prof. H. R. Hasse 

Prof. H. L. Hawkins 

Prof. W. N. Haworth, F.R.S. 

Prof. I. M. Heilbron, F.R.S. 

Dr. E. L. Hirst 

Mr. S. R. Humby 

Dr. J. O. Irwin 

Dr. J. Wilfred Jackson 

Mr. H. E. O. James 

Dr. S. W. Kemp, F.R.S. 

Prof. L. A. L. King 

Mr. J. F. Kirkaldy 

Mr. A. R. Knight 

Dr. Margery Knight 

Dr. S. K. Kon 

Dr. E. V. Laing 

Prof. J. E. Lennard- Jones, F.R.S. 

Mr. A. G. Lowndes 

Dr. W. H. McCrea 

Prof. B. A. McSwiney 

Dr. T. G. Maitland 

Capt. L. W. G. Malcolm 

Dr. F. G. Mann 

Dr. S. M. Manton 

Miss H. Masters 

Prof. J. R. Matthews 

Prof. E. Mellanbv, F.R.S. 

Dr. G. H. Miles ' 

Mr. A. A. Miller 

Prof. E. A. Milne, M.B.E., F.R.S. 

Dr. E. M. Musgrave 

Mr. V. E. Nash-Williams 

Mr. R. M. Neill 

Prof. J. J. Nolan 

Mr. J. R. Norman 

Dr. W. G. Ogg 

Prof. L. S. Palmer 

Mr. C. F. A. Pantin 

Dr. S. J. F. Philpott 

Prof. W. J. Pugh 

Dr. A. Raistrick 

Dr. F. Raw 

xxviii REPORT OF THE COUNCIL, 1933-34 

Prof. H. H. Read Dr. R. Stoneley 
Prof. E. K. Rideal, M.B.E., Dr. J. D. Sutherland 

F.R.S. Prof. E. G. R. Taylor 

Mr. N. D. Riley Mr. T. W. J. Taylor 

Prof. G. W. Robinson Mr. E. R. Thomas 

Mr. G. C. Robson Dr. R. H. Thouless 

Dr. F. J. W. Roughton Mr. E. Tillotson 

Rev. J. P. Rowland, S.J. Dr. J. F. Tocher 

Mr. R. U. Sayce Dr. W. S. Tucker, O.B.E. 

Miss L. I. Scott Dr. G. W. Tyrrell 

Mr. D. J. Scourfield Miss M. D. Vernon 

Dr. L. Simons Dr. H. C. Versey 

Prof. J. L. Simonsen, F.R.S. Prof. J. Walton 

Dr. Bernard Smith, F.R.S. Dr. R. E. Mortimer Wheeler 
Prof. J. G. Smith ' Mr. W. Hamilton Whyte 

Mr. T. Smith, F.R.S. Prof. F. J. Wilson 

Mr. W. Campbell Smith Dr. J. Wishart 

Dr. F. G. Soper Dr. A. Wohlgemuth 

Mr. A. Stevens Dr. S. W. Wooldridge 

Dr. James Stewart Dr. Dorothy M. W^rinch 

XX. Corresponding Societies Committee. — The Corresponding Socie- 
ties Committee has been nominated as follows : — The President of the 
Association {Chairman ex-officio), Mr. T. Sheppard (Vice-Chair man), 
Dr. C. Tierney (Secretary), the General Treasurer, the General Secre- 
taries, Mr. C. O. Bartrum, Sir Richard Gregory, F.R.S., Sir David Prain, 
F.R.S., Dr. A. B. Rendle, F.R.S., Prof. W. M. Tattersall, Prof. W. W. 
Watts, F.R.S., Dr. R. E. Mortimer Wheeler. 

Future Annual Meetings. 

XXI. — It has been reported to the Council that invitations have been 
received for the Association to meet in Cambridge in 1938 and in Dundee 
in 1940 ; and these will be laid before the General Committee. 


XXII. Commemorative Rolls and Panels. — The Council Iiave con- 
sidered schemes alternative to the presidential banners formerly exhibited 
in the Reception Rooms at Annual Meetings, and have adopted a scheme 
which they hope will commend itself to members of the Association 

XXIII. The Catalogue of Bronze Age Implements, compiled by a 
committee of the Association, has been taken over by the British Museum. 

XXIV. Mathefnatical Tables. — The Council desire to call the attention 
of the General Committee to the following appreciation of the work of 
the Mathematical Tables Committee. It appears in the preface to 
Funktionentafein by Jahnke and Emde (Teubner, 1933), and runs (in 
translation) as follows : — 

As in the first edition, great use has been made of the work of the 
British Association Mathematical Tables Committee. Fortunately this 
committee has decided to publish collections of the very accurate tables 
which they have calculated in past years. Two volumes have already 

REPORT OF THE COUNCIL, 1933-34 xxix 

been published. The mathematicians, physicists, and engineers of the 
whole world regard with the greatest wonder and gratitude this colossal 
undertaking of their English colleagues, who have taken upon themselves 
almost entirely the load of new computation. It is hardly to be conceived 
that other countries will continue much longer to look idly on without 
helping in this work. 

XXV. Town and Country Planning. — The Council approved a pro- 
posal to receive information from the Ministry of Health relating to town 
and country planning, with a view to reporting upon areas which appear 
to require protection for scientific reasons. Such information is now 
being received, and communication is proceeding between the Association 
and those of its own Corresponding Societies which may be concerned 
in this important matter, while other interested bodies are also being 

XXVI. Inland Water Survey. — Following upon the issue last year of 
a report by the Committee on an Inland Water Survey, the co-operation 
of the Institution of Civil Engineers in the further consideration of this 
question was invited and generously afforded. A letter and memorandum 
on the desirability of a complete and systematic survey of the water re- 
sources of the country were addressed, by the Presidents of both bodies, 
to the Prime Minister, and a representative deputation subsequently 
waited upon the Minister of Health to discuss the matter. The Minister 
promised careful consideration of the suggestions made. 



The outstanding incident during the financial year ending March 31, 
1934, was the presentation to the Association of the sum of ;^i,ooo on 
behalf of the Leicester Committee, being the balance in excess of 
expenditure on the fund raised (as usual) locally in connection with the 
Leicester Meeting. This gift, which is more fully referred to in the 
Report of the Council, is to be regarded as an unprecedented compli- 
ment to the Association, for hitherto balances (if any) on local funds 
have been disposed of by local committees themselves, although in 
two instances (I^iverpool and Oxford) they have been devoted to the 
assistance of students attending Association meetings. 

The payment of the legacy from Sir Charles Parsons reminds us of 
all that the Association previously owed to this splendid benefactor. 

Apart from this and other matters mentioned in the Report of the 
Council there is little to report in matters of detail. In my report 
last year I expressed the hope that the excess of expenditure over 
income on account of Down House would not recur, thanks to the 
generous gift of the Pilgrim Trustees ; and this hope has been fulfilled. 
I also stated that the growth of advertisement revenue, under the then 
existing conditions of depression, could not be expected to continue ; 
and the revenue from this source is in fact seriously diminished. 

The usual practice of furnishing in the year's accounts comparative 
figures for the preceding year is intermitted in the present instance 
because the accounts presented last year, owing to the change of dates 
for the financial year, covered a period of nine months only, and com- 
parisons would therefore be of no value. The practice will be resumed 
next year. 

The form in which the accounts are presented has been altered so 
as to bring more readily to the eye the position of the various funds 
administered by the Association. In working out this new scheme, 
occasion was taken to note certain legacies and other gifts which, not 
being given for special purposes, have not appeared individually in the 
accounts since the years in which they were received, In this year of 
meeting at Aberdeen, where the Prince Consort presided at the first 
meeting, in 1859, it is appropriate to recall that in 1846-7 he made 
a donation of ;^ioo to the Association. The list of legacies, apart 



from those recently received from the estates of Sir Charles Parsons, 
Mr. Bernard Hobson, and Lt.-Col. Alan Cunningham, is as follows : 

I 870-1 
I 920-1 

Beriah Botfield, of Ludlow 
Alexander Robb 
William Palmer . 
T. W. Backhouse 
Professor A. W. Scott 

£ s- 


10 10 

. 100 

. 104 4 

. 500 

. 250 

JosiAH C. Stamp, 

General Treasurer. 



General Purposes : — 

Sundry Creditors 68 13 9 

Hon. Sir Charles Parsons' gift (£10,000) and 

legacy {£2,QQQ) 12,000 

Tarrow Fund 

As per last Account . . ;£6,142 14 8 

Less Transferred to Income 
and Expenditure Account 
under terms of the gift . 4110 

Balance Sheet as 

£ s. d. £ s. d. 

5,731 14 8 

Life Compositions 

As per last Account . . 2,079 12 2 

Add Received during year . 462 

2,541 12 2 

Less Transferred to Income 

and Expenditure Account 51 

2,490 12 2 

Contingency Fund 

As per last Account . . 375 

*Add Amount transferred from 
Income and Expenditure 
Account . . . . 394 17 11 

769 17 11 

Accumulated Fund 

As at 1st April, 1933 . 17,701 16 

Less Down House Suspense 
Account written off as per 
contra .... 1,213 7 

16,488 9 

37,549 7 6 

Carried forward . . 37,549 7 6 

• The amount which should, in accordance with Council's resolution, have been in the Contingency 
Fund at 31st March, 1934, was £875, but the surplus income available for this purpose has been insuffi- 
cient by £105 2s. Id. to meet the full annual amount transferable. 



at 31st March, 1934 


General Purposes : — 
Investments, as scheduled with Income and Expendi 
ture Account, No. 1 ... 

Catalogues in Stock, at cost (Down House) 
Sundry debtors and payments in advance 
Cash at bank ..... 
Cash in hand (as per contra) 

£ s. d. 

36,770 1 11 

83 17 

73 16 9 

601 16 7 

19 15 3 

£ s- >i. 

37,549 7 6 

Carried forward . . 37, 549 7 6 

Continued on pages zxxiv and xxxv 



Balance Sheet as 

LIABILITIES (continued) 

Brought forward 

Special Purposes : — 

Caird Fund 

Balance at 1st April, 1933 . 
Add Excess of Income over Ex- 
penditure for year 

Cunningham Bequest 

Balance at 1st April, 1933 . 

Less Transferred to Income 

and Expenditure Account . 

Less Excess of Expenditure 
over Income for the year . 

Toronto University Presentation Fund 
Capital .... 
Revenue .... 

Bernard Hobson Fund 

Capital .... 

Revenue — Excess of Income 

over Expenditure for year 

Leicester and Leicestershire Fund, 1933 
Capital .... 

Down House 

Endowment Fund 
Sundry Creditors 
Suspense Account 

£ s. d. 

9,741 14 11 
25 16 1 

2,968 10 3 
551 12 

2,416 18 


131 19 


178 11 


4 7 


22 10 6 

28 4 2 
45 9 8J 



9,767 11 

2,284 19 1 

182 18 10 

1,022 10 6 


20,073 13 lOi 

37,549 7 6 

34,331 13 3i 
£71,881 9J 

NOTE. — There are contingent Liabilities in respect of grants voted to Research Committees at Leicester 
in 1933, but not claimed at 31st March, 1934, amovmting to £478 18s. Zd. and £130 in respect of 
Grants voted by Council to other objects. 

I have examined the foregoing' Account with the Books and Vouchers and certify 
Investments, and the Bank have certified to me that they hold the Deeds of Down 
year and I have verified the receipt of the proceeds. 

Approved, \ 

Arthur L. Bowtley , ,., 
W. W. Watts ^"'^''°"- 

21 St June, 1934. j 


at 31st March, 1934 (continued) 

ASSETS (continued) 

£ s. d. £ s. d. £ s. d. 

Brought forward . . . 37,549 7 6 

Special Purposes : — 
Caird Fund 

Investments (see Income and Ex- 
penditure Account, No. 2) . 9,582 16 3 
Cash at bank . . . , 184 14 9 

— 9,767 11 

Cunningham Bequest 

Investments (see Income and Ex- 
penditure Account, No. 3) . 2,151 7 2 
Gash at bank . . . . 133 11 11 

2,284 19 1 

Toronto University Presentation Fund 
Investments (see Income and Ex- 
penditure Account, No. 4) . 178 11 4 
Cash at bank . . . . 4 7 6 

182 18 10 

Bernard Hobson Fund 

Investments (see Income and Ex- 
penditure Account, No. 5) . 1,000 
Cash at bank . . . . 22 10 6 

1,022 10 6 

Leicester and Leicestershire Fund, 1933 
Investments (see Income and Ex- 
penditure Account, No. 6) . 1,000 

Down House 
Endowment Investments (see 

Income and Expenditure 

Account, No 7) . . . 20,000 

Cash at bank . . . . 37 3 

Cash m hand . . . 14 11 10^ 

Sundry debtors and payments in 

advance . . . 22 1 9 

20,073 13 10^ 

34,331 13 3i 

£1\,S^\ 9^ 

the same to be correct. I have also verified the Balances at the Bankers and the 
House. The Mortgage on Isleworth House has been paid ofT since the close of the 

W. B. Keen, 

Chartered Accountant. 













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ABERDEEN, 1934. 

Grants of money, if any, from the Association for expenses connected 
with researches are indicated in heavy type. 


Seismological Investigations. — Dr. F. J. W. Whipple [Chairman) , Mr. J. J. Shaw, 
C.B.E. [Secretary], Prof. P. G. H. Boswell, O.B.E., F.R.S., Dr. C. Vernon 
Boys, F.R.S., Sir F. W. Dyson, K.B.E., F.R.S., Dr. Wilfred Hall, Dr. H. 
Jeffreys, F.R.S., Prof. Sir Horace Lamb, F.R.S., Mr. A. W. Lee, Prof. H. M. 
Macdonald, O.B.E., F.R.S., Prof. E. A. Milne, M.B.E., F.R.S., Mr. R. D. 
Oldham, F.R.S., Prof. H. H. Plaskett, Prof. H. C. Plummer, F.R.S., 
Prof. A. O. Rankine, O.B.E., Rev. J. P. Rowland, S.J., Mr. D. H. Sadler, 
Prof. R. A. Sampson, F.R.S., Mr. F. J. Scrase, Capt. H. Shaw, Sir Frank 
Smith, K.C.B., C.B.E., Sec. R.S., Dr. R. Stoneley, Mr. E. Tillotson, Sir G. T. 
Walker, C.S.I., F.R.S. £150 (i;ioo Caird Fund grant). 

Calculation of Mathematical Tables. — Prof. E. H. Neville [Chairman), Dr. L. J. 
Comrie [Secretary), Prof. A. Lodge [Vice-Chairman), Dr. J. R. Airey, 
Prof. R. A. Fisher, F.R.S. . Dr. J. Henderson, Dr. E. L. Ince, Dr. J. O. 
Irwin, Dr. J. C. P. Miller, Mr. F. Robbins, Mr. D. H. Sadler, Dr. A. J. 
Thompson, Dr. J. F. Tocher, Dr. J. Wishart. £100 (Council to consider 
additional grant not exceeding ;£200 to expedite printing). 



The direct determination of the Thermal Conductivities of Rocks in mines or 
borings where the temperature gradient has been, or is likely to be, 
measured. — Dr. Ezer Griffiths, F.R.S. [Convener) , Dr. E. C. Bullard, Dr. H. 
Jeffreys, F.R.S. [from Section A) ; Mr. E. M. Anderson, Prof. W. G. 
Fearnsides, F.R.S., Prof. A. Holmes, Dr. D. W. Phillips, Dr. J. H. J. 
Poole, Mr. W. Campbell Smith [from Section C). £30 (part on Bernard 
Hobson Fund). 


To inquire into the position of Inland Water Survey in the British Isles and the 
possible organisation and control of such a survey by central authority. — 
Vice-Adml. Sir H. P. Douglas, K.C.B., C.M.G. [Chairman), Lt.-Col. E. Gold, 
D.S.O., F.R.S. [Vice-Chairman), Capt. W. N. McClean [Secretary), Mr. E. G. 
Bilham, Prof. W. S. Boulton, Dr. Brysson Cunningham, Prof. C. B. Fawcett, 
Prof. W. G. Fearnsides, F.R.S., Prof. A. Ferguson, Mr. H. J. F. Gourley, 
Dr. Ezer Griffiths, F.R.S., Mr. W. T. Halcrow, Mr. T. Shirley Hawkins, 
O.B.E., Prof. G. Hickling, Dr. Murray Macgregor, Mr. W. J. M. Menzies, 
Mr. H. Nimmo, Dr. A. Parker, Mr. D. Ronald, Capt. J, C. A. Roseveare, 
Dr. Bernard Smith, F.R.S., Mr. C. Clemesha Smith, Dr. L. Dudley Stamp, 
Mr. F. O. Stanford, O.B.E., Mr. A. Stevens, Mr. R. C. S. Walters, Brig. H. S. L. 
Winterbotham. C.M.G., D.S.O., Dr. S. W. Wooldridge. £10. 




The possibility of quantitative estimates of Sensory Events. — Prof. A. Ferguson 
{Chairman), Dr. C. S. Myers, C.B.E., F.R.S. (V ice-Chairman). Mr. R. J. 
Bartlett [Secretary), Dr. H. Banister, Prof. F. C. Bartlett, F.R.S., Dr. Wm. 
Brown, Dr. N. R. Campbell, Dr. S. Dawson, Prof. J. Drever, Mr. J. Guild, 
Dr. R. A. Houstoun, Dr. J. O. Irwin, Dr. G. \V. C. Kaye, Dr. S. J. F. 
Philpott, Dr. L. F. Richardson, F.R.S. , Dr. J. H. Shaxby, Mr. T. Smith, 
F.R.S. , Dr. R. H. Thouless, Dr. W. S. Tucker, O.B.E. 


To advise the Sectional Committee as to the best method of meeting the 
wishes of Council as expressed in the memorandum on the Relation between 
the Advance of Science and the Life of the Community. — 
(Chairman), (Secretary), Dr. N. V. Sidgwick, F.R.S., 

Prof. J. F. Thorpe, C.B.E., F.R.S., Mr. H. T. Tizard, C.B., F.R.S. 


To excavate critical geological sections in Great Britain.- — Prof. W.'T. Gordon 
[Chairman), Prof. W. G. Fearnsides, F.R.S. (Secretary), Prof. E. B. Bailey, 
F.R.S., Mr. H. C. Berdinner, Mr. W. S. Bisat, Dr. H. Bolton, Prof. P. G. H. 
Boswell, O.B.E. , F.R.S., Prof. W. S. Boulton, Dr. E. S. Cobbold, Prof. 
A. H. Cox, Miss M. C. Crosfield, Mr. E. E. L. Dixon, Dr. Gertrude EUes, 
M.B.E., Prof. E. J. Garwood, F.R.S., Mr. F. Gossling, Prof. H. L. 
Hawkins, Prof. G. Hickling, Prof. V. C. IlUng, Prof. O. T. Jones, F.R.S., 
Dr. Murray Macgregor, Dr. F. J. North, Dr. J. Pringle, Dr. T. F. Sibly, 
Dr. W. K. Spencer, F.R.S., Prof. A. E. Trueman, Dr. F. S. Wallis, Prof. 
W. W. Watts, F.R.S., Dr. Whittard, Dr. S. W. Wooldridge. £40 (Bernard 
Hobson Fund, contingent grant). 

The Collection, Preservation, and Systematic Registration of Photographs of 
Geological Interest. — Prof. E. J. Garwood, F.R.S. (Chairman), Prof. S. H. 
Reynolds [Secretary), Mr. C. V. Crook, Mr. J. F. Jackson, Mr. J. Ranson, 
Prof. W. W. Watts, F.R.S., Mr. R. J. Welch. 

The Stratigraphy and Structure of the Pateozoic Sedimentary Rocks of West 
Cornwall. — Mr. H. Dewey [Chairman), Mr. E. H. Davison (Secretary), 
Mr. H. G. Dines, Miss E. M. Lind Hendriks, Mr. S. Hall, Dr. S. W. Wooldridge. 

To consider and report upon Petrographic Classification and Nomenclature. — 
Dr. H. H. Thomas, F.R.S. [Chairman), Dr. A. K. Wells [Secretary), Prof. E. B. 
Bailey, F.R.S., Prof. P. G. H. Boswell, O.B.E., F.R.S., Prof. A. Brammall, 
Dr. R. Campbell, Prof. A. Holmes, Prof. A. Johannsen, Dr. W. Q. Kennedy, 
Dr. A. G. MacGregor, Prof. P. Niggli, Prof. H. H. Read, Prof. S. J. Shand, 
Mr. W. Campbell Smith, Prof. C. E. Tilley, Dr. G. W. Tyrrell, Dr. F. 
Walker. £5. 

To prove the character of the Palaeozoic Rocks underlying the Carboniferous of 
the Craven area. — Prof. W. G. Fearnsides, F.R.S. (Chairman) , Dr. R. G. S. 
Hudson (Secretary), Prof. O. T. Jones, F.R.S., Prof. W. B. R. King, O.B.E., 
Mr. W. H. Wilcockson. 

To make recommendations to the International Geological Congress for the 
formation of a committee to consider geological evidence of climatic change. — 
Dr. W. B. Wright [Chairman), Mr. M. B. Cotsworth (Secretary), Prof. E. B. 
Bailey, F.R.S., Prof. W. N. Benson, Dr. G. W. Grabham, Dr. E. M. Kindle, 
Dr. .\. Raistrick, Dr. S. W. Wooldridge. 


To administer a grant in support of a topographical and geological survey of 
the Lake Rudolph area in E. Africa.— Sir Albert E. Kitson, C.M.G., C.B.E. 


{Chairman), Dr. A. K. Wells (Secretary). Mr. S. J. K. Baker, Prof. F. 
Debenham, Dr. V. Fuchs, Prof. W. T. Gordon, Brig. H. S. L. Winterbotham, 
C.M.G., D.S.O. £35 (Unexpended balance). 


To nominate competent Naturalists to perform definite pieces of work at the 
Marine Laboratory, Plymouth. — Prof. J. H. Ashworth, F.R.S. {Chairman 
and Secretary), Prof. H. Graham Cannon, Prof. H. Munro Fox, Prof. J. 
Stanley Gardiner, F.R.S. £50 (Caird Fund grant). 

To co-operate with other Sections interested, and with the Zoological Society, 
for the purpose of obtaining support for the Zoological Record. — Sir Sidney 
Harmer, K.B.E., F.R.S. {Chairman). Dr. W. T. Caiman, F.R.S. {Secretary), 
Prof. E. S. Goodrich, F.R.S., Prof. D. M. S. Watson, F.R.S. £50 (Caird 
Fund grant). 

To consider the position of Animal Biology in the School Curriculum and matters 
relating thereto. — Prof. R. D. Laurie {Chairman and Secretary), Mr. H. W. 
Ballance, Prof. E. W. MacBride, F.R.S., Miss M. McNicol, Miss A. J. 
Prothero, Prof. W. M. Tattersall, Dr. E. N. Miles Thomas. 

The progressive adaptation to new conditions in Artemia salina (Diploid and 
Octoploid, Parthenogenetic v. Bisexual). — Prof. R. A. Fisher, F.R.S. {Chair- 
man). Dr. F. Gross {Secretary) , Dr. J. Gray, F.R.S., Dr. E. S. Russell, O.B.E., 
Prof. D. M. S. Watson, F.R.S. 

To revise the leaflet on Biological Measurements and to consider what steps 
should be taken to increase the use made of the archives for the reception 
of such measurements now established at the British Museum (Natural 
History), South Kensington. — Prof. J. S. Huxley {Chairman), Prof. R. A. 
Fisher, F.R.S. {Secretary). Dr. W. T. Caiman, F.R.S., Dr. J. Gray, F.R.S. 


To aid competent investigators selected by the Committee to carry on definite 
pieces of work at the Zoological Station at Naples. — Prof. J. H. Ashworth, 
F.R.S. {Chairman and Secretary), Prof. J. Barcroft, C.B.E., F.R.S., Prof. 
E. W. MacBride, F.R.S., Dr. Margery Knight. £50 (Caird Fund grant). 


To aid competent investigators selected by the Committee to carry out definite 
pieces of work at the Fre.shwater Biological Station, Wray Castle, Winder- 
mere. — Prof. F. E. Fritsch, F.R.S. {Chairman) , Mr. J. T. Saunders {Secretary), 
Miss P. M. Jenkin, Dr. C. H. O'Donoghue {from Section D) ; Dr. W. H. 
Pearsall {from Section K). £75. 


To co-operate with bodies concerned with the cartographic representation of 
population, and in particular with the Ordnance Survey, for the production 
of population maps. — {Chairman), Prof. C. B. 

Fawcett (Secretary) , The Director General of the Ordnance Survey, Col. Sir 
Charles Close, K.B.E., C.B., C.M.G., F.R.S., Prof. H. J. Fleure. £3. 

To inquire into the present state of Knowledge of the Human Geography of 
Tropical Africa, and to make recommendations for furtherance and develop- 
ment. — Prof. P. M. Ro.xby (Chairman), Prof. A. G. Ogilvie, O.B.E. (Secretary), 
Dr. A. Geddes (Assistant Secretary), Mr. S. ]. K. Baker, Prof. C. B. Fawcett, 
Mr. W. Fitzgerald, Prof. H. J. Fleure, Mr. E. B. Haddon, Mr. R. H. Kinvig, 
Mr. J. McFarlane, Col. M. N. MacLeod, D.S.O., Prof. J. L. Myres, O.B.E., 
F.B.A., Mr. R. A. Pelham, Mr. R. U. Sayce, Rev. E. W. Smith, Brig. H. S. L. 
Winterbotham, C.M.G., D.S.O. £25. 


To investigate the mapping of historical data for medieval England and to take 
steps to advance such work. — Mr. J. N. L. Baker {Chairman), Dr. H. C. 
Darby, Mr. E. W. Gilbert, Mr. F. G. Morris, Dr. S. W. Wooldridge. 


To report on the present position of Geographical Teaching in Schools, and of 
Geography in the training of teachers, and, as occasion arises, to report to 
Council through the Organising Committee of Section E upon the practical 
working of Regulations issued by the Board of Education or the Scottish 
Education Department affecting the position of Geography in Schools and 
Training Colleges. — {Chairman), Mr. J. McFarlane 

{Secretary), Dr. W. Edward, Sir Richard Gregory, Bt., F.R.S., Prof. J. L. 
Myres, O.B.E., F.B.A., Mr. A. Stevens. 


Chronology of the World Crisis from 1929 onwards. — Prof. J. H. Jones {Chairman), 
Dr. P. Ford {Convener), Mr. H. M. Hallsworth, C.B.E., Mr. R. F. Harrod, 
Mr. A. Radford, Prof. J. G. Smith. £25. 

To consider the ways in which the relationship of Science to the Community 
may be most usefully investigated and to inquire in what directions, if any, 
Section F might assist such investigations. — Mr. H. M. Hallsworth, C.B.E. 
{Chairman) , Dr. K. G. Fenelon {Secretary) , Prof. R. B. Forrester, Prof. D. H. 
Macgregor, Prof. J. G. Smith. 


Industrial Co-operation : to report on the provisions for co-ordinating and 
stimulating scientific work bearing on business practice, and to make 
recommendations. — Dr. J. A. Bowie {Chairman), Mr. R. J. Mackay {Secre- 
tary), Prof. J. G. Smith, Major L. Urwick {from Section F) ; Prof. W. 
Cramp {from Section G) ; Mr. G. P. Crowden {from Section I) ; Dr. C. S. 
Myers, C.B.E., F.R.S. {from Section J) ; Sir Richard Gregory, Bt., F.R.S. 
{from Section L). 


Earth Pressures. — Mr. F. E. Wentworth-Sheilds, O.B.E. {Chairman), Dr. J. S. 
Owens {Secretary), Prof. G. Cook, Mr. T. E. N. Fargher, Prof. A. R. Fulton, 
Prof. F. C. Lea, Prof. R. V. Southwell, F.R.S., Dr. R. E. Stradling, C.B., Dr. 
W. N. Thomas, Mr. E. G. Walker, Mr. J. S. Wilson. £7 4s. Id. (Unexpended 
balance) . 

Electrical Terms and Definitions. — Prof. Sir J. B. Henderson {Chairman), Prof. 
F. G. Baily and Prof. G. W. O. Howe {Secretaries), Prof. W. Cramp, Prof. 
W. H. Eccles, F.R.S., Prof. C. L. Fortescue, Sir R. T. Glazebrook, K.C.B., 
F.R.S., Prof. A. E. Kennelly, Prof. E. W. Marchant, Sir Frank Smith, 
K.C.B., C.B.E., Sec. R.S., Prof. L. R. Wilberforce. 

Stresses in Overstrained Materials. — Sir Henry Fowler, K.B.E. {Chairman), 
Dr. J. G. Docherty {Secretary), Prof. G. Cook, Prof. B. P. Haigh, Mr. J. S. 
Wilson. £5 (Unexpended balance). 

To review the knowledge at present available for the reduction of noise, and 
the nuisances to the abatement of which this knowledge could best be 
applied. — Sir Henry Fowler, K.B.E. {Chairman), Wing-Commander T. R. 
Cave-Browne-Cave, C.B.E. {Secretary), Mr. R. S. Capon, Dr. A. H. Davis, 
Prof. G. W. O. Howe, Mr. E. S. Shrapnell-Smith, C.B.E. £5. 


To report on the Classification and Distribution of Rude Stone Monuments in 
the British Isles. — Mr. H. J. E. Peake {Chairman), Dr. Margaret A. Murray 


{Secretary), Mr. A. L. Armstrong, Mr. H. Balfour, F.R.S., Prof. V. Gordon 
ChHde, Dr. Cyril Fox, Mr. T. D. Kendrick. 

To report on the probable sources of the supply of Copper used by the Sumerians. 
—Mr. H. J. E. Peake [Chairman), Dr. C. H. Desch, F.R.S. [Secretary), 
Mr. H. Balfour, F.R.S., Mr. L. H. Dudley Buxton, Prof. V. Gordon Childe. 
Mr. O. Davies, Prof. H. J. Fleure, Sir Flinders Petrie, F.R.S., Dr. A. Rais- 
trick, Dr. R. H. Rastall. £15. 

To conduct Archaological and Ethnological Researches in Crete. — Prof. J. L. 
Myres, O.B.E., F.B.A. [Chairman), Mr. L. Dudley Buxton [Secretary), Dr. 
W. L. H. Duckworth, Dr. F. C. Shrubsall. 

To co-operate with the Torquay Antiquarian Society in investigating Kent's 
Cavern. — Sir A. Keith, F.R.S. [Chairman), Prof. J. L. Myres, O.B.E., F.B.A. 
[Secretary), Mr. M. C. Burkitt, Dr. R. V. FaveU, Miss D. A. E. Garrod, 
Mr. A. D. Lacaille. £5. 

To co-operate with a Committee of the Royal Anthropological Institute in the 
exploration of Caves in the Derbyshire district. — Mr. M. C. Burkitt [Chair- 
man), Dr. R. V. Favell [Secretary), Mr. A. Leslie Armstrong, Prof. H. J. 
Fleure, Miss D. A. E. Garrod, Dr. J. Wilfrid Jackson, Prof. L. S. Palmer, 
Mr. H. J. E. Peake. 

To co-operate with Miss Caton-Thompson in her researches in prehistoric sites in 
the Western Desert of Egypt. — Prof. J. L. Myres, O.B.E., F.B.A. [Chair- 
man), Mr. H. J. E. Peake [Secretary), Mr. H. Balfour, F.R.S. 

To report to the Sectional Committee on the question of re-editing ' Notes and 
Queries in Anthropology.' — Rev. E. W. Smith [Chairman), Prof. H. J. Fleure 
[Secretary), Dr. H. S. Harrison, Prof. C. G. Seligman, F.R.S. 

To carry out the excavation of Palaeolith cave deposits on Mt. Carmel, Palestine. 
— Prof. J. L. Myres, O.B.E., F.B.A. [Chairman), Mr. M. C. Burkitt [Secretary), 
Miss G. Caton-Thompson, Miss D. A. E. Garrod. £20. 

To carry out research among the Ainu of Japan. — Prof. C. G. Seligman, F.R.S. 
[Chairman), Mrs. C. G. Seligman [Secretary), Dr. PI. S. Harrison, Capt. 
T. A. Joyce, O.B.E., Rt. Hon. Lord Raglan. £50. 

To co-operate with the local committee in the excavation of Pen Dinas hill fort, 
Cardiganshire.- — Dr. Cyril Fox [Chairman), Mr. V. E. Nash- Williams [Secre- 
tary), Prof. V. Gordon Childe, Prof. C. Daryll Forde, Rt. Hon. Lord Raglan, 
Dr. R. E. M. Wheeler. £20. 


To deal with the use of a Stereotactic Instrument. — Prof. J. Mellanby, F.R.S. 
[Chairman and Secretary). 

To investigate the alleged differences in distribution of rods and cones in the 
retinae of various animals. — Prof. H. E. Roaf [Chairman), Dr. F. W. Edridge- 
Green, C.B.E. [Secretary), Prof. J. P. Hill, F.R.S., Dr. F. W. Law, Dr. S. 
Zuckerman. £10. 


The conditions of vertigo and its relation to disorientation. — 

[Chairman), Dr. T. G. Maitland [Secretary), Group-Capt. Clements, 
Squadron-Leader E. D. Dickson, Prof. J. H. Burn, Dr. R. S. Creed, Prof. 
J. Drever, Prof. J. T. MacCurdy. £20 (Unexpended balance). 


To develop tests of the routine manual factor in mechanical ability. — Dr. C. S. 
Myers, C.B.E. , F.R.S. [Chairman), Dr. G. H. Miles [Secretary), Prof. C. 
Burt, Dr. F. M. Earle, Dr. LI. Wynn Jones, Prof. T. H. Pear. £30 (Leicester 
and Leicestershire Fund). 


The nature of perseveration and its testing. — Prof. F. Aveling (Chairman), 
Mr. E. Farmer (Secretary), Prof. F. C. Bartlett, F.R.S.. Dr. Mary Collins, 
Dr. W. Stephenson. 

To consider definite lines of research in social psychology. — Dr. Shepherd Dawson 
(Chairman), Mr. Eric Farmer (Secretary), Prof. F. Avehng, Prof. F. C. 
Bartlett, F.R.S., Prof. C. Burt, Dr. Mary Collins, Dr. C. S. Myers, C.B.E., 


Transplant Experiments. — Sir Arthur Hill, K.C.M.G., F.R.S. (Chairman), Dr. 
W. B. Turrill (Secretary), Prof. F. W. Oliver, F.R.S., Prof. E. J. SaUsbury, 
F.R.S., Prof. A. G. Tansley, F.R.S. £5. 

The anatomy of timber-producing trees. — Prof. H. S. Holden (Chairman), Dr. 
Helen Bancroft (Secretary), Prof. J. H. Priestley, D.S.O. £10. 


To consider and report on the possibility of the Section undertaking more definite 
work in promoting educational research. — Dr. W. W. Vaughan, M.V.O. 
(Chairman), Miss H. Masters (Secretary), Mr. E. R. B. Reynolds, Mr. N. F. 
Sheppard. £5 (Unexpended balance). 


To co-operate with the staff of the Imperial SoU Bureau to examine the soil 
resources of the Empire. — Sir John Russell, O.B.E., F.R.S. (Chairman), 
Mr. G. V. Jacks (Secretary), Dr. E. M. Crowther, Dr. W. G. Ogg, Prof. G. W. 
Robinson (from. Section M) ; Prof. C. B. Fawcett, Mr. H. King, Dr. L. D. 
Stamp, Mr. A. Stevens, Dr. S. W. Wooldridge ^rom Section E). 


Corresponding Societies Committee. — The President of the Association (Chairman 
ex-officio), Mr. T. Sheppard (V ice-Chairman), Dr. C. Tierney (Secretary), 
the General Secretaries, the General Treasurer, Mr. C. O. Bartrum, Sir 
Richard Gregory, Bt., F.R.S., Sir David Prain, CLE., C.M.G., F.R.S., 
Dr. A. B. Rendle, F.R.S., Prof. W. M. Tattersall, Prof. W. W. Watts, F.R.S., 
Dr. R. E. Mortimer Wheeler. 



The following resolutions and recommendations were referred to the 
Council by the General Committee at the Aberdeen Meeting for con- 
sideration, and, if desirable, for action : — 

From Sections A {Mathematical and Physical Sciences), C {Geology), 
E {Geography), and G {Engineering). 
That the British Association awaits with great interest the result of the 
careful consideration which His Majesty's Government has promised to 
give to the question of an Inland Water Survey, and trusts that the Govern- 
ment will be favourable to the establishment of an organised survey of the 
water resources of the country on a scientific basis. 

From Section C {Geology). 
Section C recommends that the Government be urged to make compulsory 
the registration of wells, borings and excavations exceeding lOO feet in depth, 
under conditions similar to those for the notification and registration of 
shafts and boreholes for miineral, contained in the Mining Industry Act 
of 1926. 

From Section D {Zoology). 

The Committee of Section D draws the attention of the General Com- 
mittee to the fact that, although technical cinematograph filnrxs for the 
advancement of scientific knowledge may be imported duty free for exhibi- 
tion before scientific institutions, there is no provision for the free importa- 
tion of films for the teaching of science in universities and similar institutions ; 
and requests them to instruct Council to take steps to secure the duty-free 
importation, by recognised teaching bodies, of technical films to be used 
solely for the teaching of science, under conditions similar to those which 
apply to films for scientific institutions, provided such films are unobtainable 
in Great Britain. 

From Section E {Geography). 

The Committee of Section E invites the Council of the British Association 
to make a vigorous appeal to the Lord President of the Council and to the 
Minister of Agriculture and Fisheries to take such measures as may ensure 
the provision of ample funds to carry out a far-sighted policy of large-scale 
maps revision in the general interest of the community. 

(The above resolution was supported by Sections C, D, F, G, H, J, K, 

From Section E {Geography). 

The Committee of Section E desires Council to bring to the notice of the 
Board of Education and the Scottish Education Department the Atlas of 
Geographical Types of the British Isles (of which one sheet has been pub- 
lished), and in view of the support lent by the Ordnance Survey to urge the 
desirability of continuing its production. 

From Section K {Botany). 
This Section requests the Council of the Association to urge upon the 
Department of Education in England and the Scottish Education Depart- 
ment, the need for instruction in all schools on the importance of the 
preservation of amenities, and in particular;D«:^-^^tj^^rotection of trees, 
woodlands and all natural vegetation. j-^-'f^^ ^s ^i^^ 

-r— I— V AfK^r^ 




Aberdeen, 1934. 






The British Association assembles for the third time in Aberdeen — 
under the happiest of auspices. It is good that we are meeting in 
Scotland, for the Association has a tradition that its Scottish meet- 
ings are wholly successful. It is good that we are meeting in the 
sympathetic atmosphere of a university city, surrounded not only 
by beautiful and venerable buildings, but also by buildings in which 
scientific knowledge is being industriously and successfully accumu- 
lated. And it is especially good that Aberdeen is rich not only in 
scientific buildings but also in scientific associations. Most of us 
can think of some master-mind in his own subject who worked here. 
My own thoughts, I need hardly say, turn to James Clerk Maxwell. 
Whatever our subject, there is one man who will be in our thoughts 
in a very special sense to-night — Sir William Hardy, whom we had 
hoped to see in the presidential chair this year. It was not to be, 
and his early death, while still in the fulness of his powers, casts a 
shadow in the minds of all of us. We all know of his distinguished 
work in pure science, and his equally valuable achievements in 
applied science. I will not try to pay tribute to these, since it has 
been arranged that others, better qualified than myself, shall do so 
in a special memorial lecture. Perhaps, however, I may be per- 
mitted to bear testimony to the personal qualities of one whom I 
was proud to call a friend for a large part of my life, and a colleague 
for many years. Inside the Council room, his proposals were always 
acute, often highly original, and invariably worthy of careful con- 
sideration ; outside, his big personality and wide range of interests 
made him the most charming and versatile of friends. 


And now I must turn to the subject on which I have specially 
undertaken to speak — the new world-picture presented to us by 
modern physics. It is a full half-century since this chair was last 
occupied by a theoretical physicist in the person of the late Lord 
Rayleigh. In that interval the main edifice of science has grown 
almost beyond recognition, increasing in extent, dignity and beauty, 
as whole armies of labourers have patiently added wing after wing, 
story upon story, and pinnacle to pinnacle. Yet the theoretical 
physicist must admit that his own department looks like nothing so 
much as a building which has been brought down in ruins by a 
succession of earthquake shocks. 

The earthquake shocks were, of course, new facts of observation, 
and the building fell because it was not built on the solid rock of 
ascertained fact, but on the ever-shifting sands of conjecture and 
speculation. Indeed it was little more than a museum of models, 
which had accumulated because the old-fashioned physicist had a 
passion for trying to liken the ingredients of Nature to familiar 
objects such as billiard-balls, jellies and spinning tops. While he 
believed and proclaimed that Nature had existed and gone her way 
for countless aeons before man came to spy on her, he assumed that 
the latest newcomer on the scene, the mind which could never get 
outside itself and its own sensations, would find things within its 
limited experience to explain what had existed from all eternity. 
It was expecting too much of Nature, as the ruin of our building 
has shown. She is not so accommodating as this to the limita- 
tions of the human mind ; her truths can only be made compre- 
hensible in the form of parables. 

Yet no parable can remain true throughout its whole range to the 
facts it is trying to explain. Somewhere or other it must be too wide 
or too narrow, so that ' the truth, the whole truth, and nothing but 
the truth ' is not to be conveyed by parables. The fundamental 
mistake of the old-fashioned physicist was that he failed to distinguish 
between the half-truths of parables and the literal truth. 

Perhaps his mistake was pardonable, perhaps it was even natural. 
Modern psychologists make great use of what they describe as ' word- 
association.' They shoot a word at you, and ask you to reply im- 
mediately with the first idea it evokes in your uncontrolled mind. 
If the psychologist says ' wave,' the boy-scout will probably say 
' flag,' while the sailor may say 'sea,' the musician ' sound,' the 
engineer ' compression,' and the mathematician ' sine ' or * cosine.' 
Now the crux of the situation is that the number of people who will 
give this last response is very small. Our remote ancestors did not 
survive in the struggle for existence by pondering over sines and 
cosines, but by devising ways of killing other animals without being 
killed themselves. As a consequence, the brains we have inherited 


from them take more kindly to the concrete facts of everyday life 
than to abstract concepts ; to particulars rather than to universals. 
Every child, when first it begins to learn algebra, asks in despair 
* But what are x, y and z ? ' and is satisfied when, and only when, 
it has been told that they are numbers of apples or pears or bananas 
or something such. In the same way, the old-fashioned physicist 
could not rest content with x, y and 0, but was always trying to ex- 
press them in terms of apples or pears or bananas. Yet a simple 
argument will show that he can never get beyond x, y and z. 

Physical science obtains its knowledge of the external world by 
a series of exact measurements, or, more precisely, by comparisons 
of measurements. Typical of its knowledge is the statement that 
the line Ha in the hydrogen spectrum has a wave-length of so many 
centimetres. This is meaningless until we know what a centimetre 
is. The moment we are told that it is a certain fraction of the earth's 
radius, or of the length of a bar of platinum, or a certain multiple 
of the wave-length of a line in the cadmium spectrum, our know- 
ledge becomes real, but at that same moment it also becomes purely 
numerical. Our minds can only be acquainted with things inside 
themselves — never with things outside. Thus we can never know 
the essential nature of anything, such as a centimetre or a wave- 
length, which exists in that mysterious world outside ourselves to 
which our minds can never penetrate ; but we can know the 
numerical ratio of two quantities of similar nature, no matter how 
incomprehensible they may both be individually. 

For this reason, our knowledge of the external world must always 
consist of numbers, and our picture of the universe- — the synthesis 
of our knowledge — must necessarily be mathematical in form. All 
the concrete details of the picture, the apples and pears and bananas, 
the ether and atoms and electrons, are mere clothing that we ourselves 
drape over our mathematical symbols — they do not belong to Nature, 
but to the parables by which we try to make Nature comprehensible. 
It was, I think, Kronecker who said that in arithmetic God made 
the integers and man made the rest ; in the same spirit, we may 
add that in physics God made the mathematics and man made the 

The modern physicist does not use this language, but he accepts 
its implications, and divides the concepts of physics into obser- 
vables and unobservables. In brief, the observables embody facts of 
observation, and so are purely numerical or mathematical in their 
content ; the unobservables are the pictorial details of the parables. 

The physicist wants to make his new edifice earthquake-proof — 
immune to the shock of new observations — and so builds only on 
the solid rock, and with the solid bricks, of ascertained fact. Thus 
he builds only with observables, and his whole edifice is one of 


mathematics and mathematical formula — all else is man-made 

For instance, when the undulatory theory had made it clear that 
light was of the nature of waves, the scientists of the day elaborated 
this by saying that light consisted of waves in a rigid, homogeneous 
ether which filled all space. The whole content of ascertained fact 
in this description is the one word ' wave ' in its strictly mathe- 
matical sense ; all the rest is pictorial detail, introduced to help out 
the inherited limitations of our minds. 

Then scientists took the pictorial details of the parable literally, 
and so fell into error. For instance, light-waves travel in space and 
time jointly, but by filling space and space alone with ether, the 
parable seemed to make a clear-cut distinction between space and 
time. It even suggested that they could be separated out in practice 
— by performing a Michelson-Morley experiment. Yet, as we all 
know, the experiment when performed only showed that such a 
separation is impossible ; the space and time of the parable are 
found not to be true to the facts — they are revealed as mere stage- 
scenery. Neither is found to exist in its own right, but only as a way 
of cutting up something more comprehensive — the space-time 

Thus we find that space and time cannot be classified as 
realities of nature, and the generalised theory of relativity shows 
that the same is true of their product, the space-time continuum. 
This can be crumpled and twisted and warped as much as we please 
without becoming one whit less true to nature — which, of course, 
can only mean that it is not itself part of nature. 

In this way space and time, and also their space-time product, 
fall into their places as mere mental frameworks of our own con- 
struction. They are of course very important frameworks, being 
nothing less than the frameworks along which our minds receive 
their whole knowledge of the outer world. This knowledge comes 
to our minds in the form of messages passed on from our senses ; 
these in turn have received them as impacts or transfers of electro- 
magnetic momentum or energy. Now Clerk Maxwell showed that 
electromagnetic activity of all kinds could be depicted perfectly as 
travelling in space and time — this was the essential content of his 
electromagnetic theory of light. Thus space and time are of pre- 
ponderating importance to our minds as the media through which 
the messages from the outer world enter the ' gateways of know- 
ledge,' our senses, and in terms of which they are classified. Just 
as the messages which enter a telephone exchange are classified by 
the wires along which they arrive, so the messages which strike our 
senses are classified by their arrival along the space-time framework. 

Physical science, assuming that each message must have had a 


starting-point, postulated the existence of ' matter ' to provide such 
starting-points. But the existence of this matter was a pure hypo- 
thesis ; and matter is in actual fact as unobservable as the ether, 
Newtonian force, and other unobservables which have vanished 
from science. Early science not only assumed matter to exist, but 
further pictured it as existing in space and time. Again this 
assumption had no adequate justification ; for there is clearly no 
reason why the whole material universe should be restricted to the 
narrow framework along which messages strike our senses. To 
illustrate by an analogy, the earthquake waves which damage our 
houses travel along the surface of the ground, but we have no 
right to assume that they originate in the surface of the ground ; 
we know, on the contrary, that they originate deep down in the 
earth's interior. 

The Newtonian mechanics, however, having endowed space and 
time with real objective existences, assumed that the whole universe 
existed within the limits of space and time. Even more character- 
istic of it was the doctrine of ' mechanistic determinism,' which 
could be evolved from it by strictly logical processes. This reduced 
the whole physical universe to a vast machine in which each cog, 
shaft, and thrust bar could only transmit what it received, and wait 
for what was to come next. When it was found that the human body 
consisted of nothing beyond commonplace atoms and molecules, 
the human race also seemed to be reduced to cogs in the wheel, and 
in face of the inexorable movements of the machine, human effort, 
initiative, and ambition seemed to become meaningless illusions. 
Our minds were left with no more power or initiative than a sen- 
sitised cinematograph film ; they could only register what was 
impressed on them from an outer world over which they had no 

Theoretical physics is no longer concerned to study the Newtonian 
universe which it once believed to exist in its own right in space and 
time. It merely sets before itself the modest task of reducing to 
law and order the impressions that the universe makes on our senses. 
It is not concerned with what lies beyond the gateways of knowledge, 
but with what enters through the gateways of knowledge. It is 
concerned with appearances rather than reality, so that its task 
resembles that of the cartographer or map-maker rather than that of 
the geologist or mining engineer. 

Now the cartographer knows that a map may be drawn in many 
ways, or, as he would himself say, many kinds of projection are 
available. Each one has its merits, but it is impossible to find all 
the merits we might reasonably desire combined in one single map. 
It is reasonable to demand that each bit of territory should look its 
proper shape on the map ; also that each should look its proper 


relative size. Yet even these very reasonable requirements cannot 
usually be satisfied in a single map ; the only exception is when the 
map is to contain only a small part of the whole surface of the globe. 
In this case, and this only, all the qualities we want can be combined 
in a single map, so that we simply ask for a map of the county of 
Surrey without specifying whether it is to be a Mercator's or ortho- 
graphic or conic projection, or what not. 

All this has its exact counterpart in the map-making task of the 
physicist. The Newtonian mechanics was like the map of Surrey, 
because it dealt only with a small fraction of the universe. It was 
concerned with the motions and changes of medium-sized objects — 
objects comparable in size with the human body — and for these it was 
able to provide a perfect map which combined in one picture all the 
qualities we could reasonably demand. But the inconceivably great 
and the inconceivably small were equally beyond its ken. As soon 
as science pushed out — ^to the cosmos as a whole in one direction and 
to sub-atomic phenomena in the other — the deficiencies of the New- 
tonian mechanics became manifest. And no modification of the 
Newtonian map was able to provide the two qualities which this 
map had itself encouraged us to expect— a materialism which ex- 
hibited the universe as constructed of matter lying within the frame- 
work of space and time, and a determinism which provided an 
answer to the question ' What is going to happen next ? ' 

When geography cannot combine all the qualities we want in a 
single map, it provides us with more than one map. Theoretical 
physics has done the same, providing us with two maps which are 
commonly known as the particle-picture and the wave-picture. 

The particle-picture is a materialistic picture which caters for 
those who wish to see their universe mapped out as matter existing 
in space and time. The wave-picture is a determinist picture which 
caters for those who ask the question ' What is going to happen 
next ? ' It is perhaps better to speak of these two pictures as the 
particle-parable and the wave-parable. For this is what they really 
are, and the nomenclature warns us in advance not to be surprised 
at inconsistencies and contradictions. 

Let me remind you, as briefly as possible, how this pair of pictures 
or parables have come to be in existence side by side. 

The particle-parable, which was first in the field, told us that the 
material universe consists of particles existing in space and time. 
It was created by the labours of chemists and experimental physi- 
cists, working on the basis provided by the classical physics. Its 
time of testing came in 191 3, when Bohr tried to find out whether 
the two particles of the hydrogen atom could possibly produce the 
highly complicated spectrum of hydrogen by their motion. He found 
a type of motion which could produce this spectrum down to its 


minutest details, but the motion was quite inconsistent with the 
mechanistic determinism of the Newtonian mechanics. The elec- 
tron did not move continuously through space and time, but jumped, 
and its jumps were not governed by the laws of mechanics, but to 
all appearance, as Einstein showed more fully four years later, by 
the laws of probability. Of looo identical atoms, loo might make 
the jump, while the other 900 would not. Before the jumps oc- 
curred, there was nothing to show which atoms were going to jump. 
Thus the particle-picture conspicuously failed to provide an answer 
to the question * What will happen next ? ' 

Bohr's concepts were revolutionary, but it was soon found they 
were not revolutionary enough, for they failed to explain more 
complicated spectra, as well as certain other phenomena. 

Then Heisenberg showed that the hydrogen spectrum — and, as 
we now believe, all other spectra as well — could be explained by the 
motion of something which was rather like an electron, but did not 
move in space and time. Its position was not specified by the 
usual co-ordinates x, y, z of co-ordinate geometry, but by the 
mathematical abstraction known as a matrix. His ideas were rather 
too abstract even for mathematicians, the majority of whom had 
quite forgotten what matrices were. It seemed likely that Heisenberg 
had unravelled the secret of the structure of matter, and yet his 
solution was so far removed from the concepts of ordinary life that 
another parable had to be invented to make it comprehensible. 

The wave-parable serves this purpose ; it does not describe the 
universe as a collection of particles but as a system of waves. The 
universe is no longer a deluge of shot from a battery of machine- 
guns, but a stormy sea with the sea taken away and only the abstract 
quality of storminess left — or the grin of the Cheshire cat if we can 
think of a grin as undulatory. This parable was not devised by 
Heisenberg, but by de Broglie and Schrodinger. At first they 
thought their waves merely provided a superior model of an ordinary 
electron ; later it was established that they were a sort of parable 
to explain Heisenberg's pseudo-electron. 

Now the pseudo-electron of Heisenberg did not claim to account 
for the spectrum emitted by a single atom of gas, which is something 
entirely beyond our knowledge or experience, but only that emitted 
by a whole assembly of similar atoms ; it was not a picture of one 
electron in one atom, but of all the electrons in all the atoms. 

In the same way the waves of the wave-parable do not picture 
individual electrons, but a community of electrons — a crowd — as 
for instance the electrons whose motion constitutes a current of 

In this particular instance the waves can be represented as travel- 
ling through ordinary space. Except for travelling at a different 


speed, they are very like the waves by which Maxwell described the 
flow of radiation through space, so that matter and radiation are much 
more like one another in the new physics than they were in the old . 

In other cases, ordinary time and space do not provide an adequate 
canvas for the wave-picture. The wave-picture of two currents of 
electricity, or even of two electrons moving independently, needs 
a larger canvas — six dimensions of space and one of time. There 
can be no logical justification for identifying any particular three of 
these six dimensions with ordinary space, so that we must regard 
the wave-picture as lying entirely outside space. The whole picture, 
and the manifold dimensions of space in which it is drawn, become 
pure mental constructs — -diagrams and frameworks we make for 
ourselves to help us understand phenomena. 

In this way we have the two co-existent pictures — the particle- 
picture for the materialist, and the wave-picture for the determinist. 
When the cartographer has to make two distinct maps to exhibit 
the geography of, say, North America, he is able to explain why two 
maps are necessary, and can also tell us the relation between the 
two — he can show us how to transform one into the other. He will 
tell us, for instance, that he needs two maps simply because he is 
restricted to flat surfaces — pieces of paper. Give him a sphere 
instead, and he can show us North America, perfectly and completely, 
on a single map. 

The physicist has not yet found anything corresponding to this 
sphere ; when, if ever, he does, the particle-picture and the wave- 
picture will be merged into a single new picture. At present some 
kink in our minds, or perhaps merely some ingrained habit of 
thought, prevents our understanding the universe as a consistent 
whole — just as the ingrained habits of thought of a ' flat-earther ' 
prevent his understanding North America as a consistent whole. 
Yet, although physics has so far failed to explain why two pictures 
are necessary, it is, nevertheless, able to explain the relation between 
the particle-picture and the wave-picture in perfectly comprehensible 

The central feature of the particle-picture is the atomicity which 
is found in the structure of matter. But this atomicity is only one 
expression of a fundamental coarse-grainedness which pervades the 
whole of nature. It crops up again in the fact that energy can only 
be transferred by whole quanta. Because of this, the tools with 
which we study nature are themselves coarse-grained ; we have only 
blunt probes at our disposal, and so can never acquire perfectly 
precise knowledge of nature. Just as, in astronomy, the grain of our 
photographic plates prevents our ever fixing the position of a star 
with absolute precision, so in physics we can never say that an electron 
is here, at this precise spot, and is moving at just such and such a 


speed. The best we can do with our blunt probes is to represent 
the position of the electron by a smear, and its motion by a moving 
smear which will get more and more blurred as time progresses. 
Unless we check the growth of our smear by taking new observations, 
it will end by spreading through the whole of space. 

Now the waves of an electron or other piece of matter are simply 
a picture of just such a smear. Where the waves are intense, the 
smear is black, and conversely. The nature of the smear — whether 
it consists of printer's ink, or, as was at one time thought, of elec- 
tricity — is of no importance ; this is mere pictorial detail. All 
that is essential is the relative blackness of the smear at different 
places — a ratio of numbers which measures the relative chance of 
electrons being at different points of space. 

The relation between the wave-picture and the particle-picture 
may be summed up thus : the more stormy the waves at any point 
in the wave-picture, the more likely we are to find a particle at that 
point in the particle-picture. Yet, if the particles really existed as 
points, and the waves depicted the chances of their existing at 
different points of space — as Maxwell's law does for the molecules 
of a gas — then the gas would emit a continuous spectrum instead 
of the line-spectrum that is actually observed. Thus we had 
better put our statement in the form that the electron is not a point- 
particle, but that if we insist on picturing it as such, then the waves 
indicate the relative proprieties of picturing it as existing at the 
different points of space. But propriety relative to what ? 

The answer is — relative to our own knowledge. If we know 
nothing about an electron except that it exists, all places are equally 
likely for it, so that its waves are uniformly spread through the whole 
of space. By experiment after experiment we can restrict the 
extent of its waves, but we can never reduce them to a point, or 
indeed below a certain minimum ; the coarse-grainedness of our 
probes prevents that. There is always a finite region of waves left. 
And the waves which are left depict our knowledge precisely and 
exactly ; we may say that they are waves of knowledge — or, 
perhaps even better still, waves of imperfections of knowledge — 
of the position of the electron. 

And now we come to the central and most surprising fact of the 
whole situation. I agree that it is still too early, and the situation is 
still too obscure, for us fully to assess its importance, but, as I see it, 
it seems likely to lead to radical changes in our views not only of the 
universe but even more of ourselves. Let us remember that we 
are dealing with a system of waves which depict in a graphic form 
our knowledge of the constituents of the universe. The central 
fact is this : the wave-parable does not tell us that these waves 
depict our knowledge of nature, but that they are nature itself. 


If we ask the new physics to specify an electron for us, it does not 
give us a mathematical specification of an objective electron, but 
rather retorts with the question : ' How much do you know about 
the electron in question ? ' We state all we know, and then comes 
the surprising reply, ' That is the electron.' The electron exists 
only in our minds^ — what exists beyond, and where, to put the idea 
of an electron into our minds we do not know. The new physics 
can provide us with wave-pictures depicting electrons about which 
we have varying amounts of knowledge, ranging from nothing at all 
to the maximum we can Icnow with the blunt probes at our command, 
but the electron which exists apart from our study of it is quite 
beyond its purview. 

Let me try and put this in another way. The old physics im- 
agined it was studying an objective nature which had its own exist- 
ence independently of the mind which perceived it — which, indeed, 
had existed from all eternity whether it was perceived or not. It 
would have gone on imagining this to this day, had the electron 
observed by the physicists behaved as on this supposition it ought 
to have done. 

But it did not so behave, and this led to the birth of the new physics, 
with its general thesis that the nature we study does not consist so 
much of something we perceive as of our perceptions ; it is not the 
object of the subject-object relation, but the relation itself. There 
is, in fact, no clear-cut division between the subject and object ; 
they form an indivisible whole which now becomes nature. This 
thesis finds its final expression in the wave-parable, which tells us 
that nature consists of waves and that these are of the general 
quality of waves of knowledge, or of absence of knowledge, in our 
own minds. 

Let me digress to remind you that if ever we are to know the true 
nature of waves, these waves must consist of something we already 
have in our own minds. Now knowledge and absence of knowledge 
satisfy this criterion as few other things could ; waves in an ether, 
for instance, emphatically did not. It may seem strange, and almost 
too good to be true, that nature should in the last resort consist of 
something we can really understand ; but there is always the simple 
solution available that the external world is essentially of the same 
nature as mental ideas. 

At best this may seem very academic and up in the air — at the 
worst it may seem stupid and even obvious. I agree that it would 
be so, were it not for the one outstanding fact that observation 
supports the wave-picture of the new physics whole-heartedly and 
without hesitation. Whenever the particle-picture and the wave- 
picture have come into conflict, observation has discredited the 
particle-picture and supported the wave-picture — not merely, be it 


noted, as a picture of our knowledge of nature, but as a picture of 
nature itself. The particle-parable is useful as a concession to the 
materialistic habits of thought which have become ingrained in our 
minds, but it can no longer claim to fit the facts, and, so far as we 
can at present see, the truth about nature must lie very near to the 

Let me digress again to remind you of two simple instances of 
such conflicts and of the verdicts which observation has pro- 
nounced upon them. 

A shower of parallel-moving electrons forms in effect an 
electric current. Let us shoot such a shower of electrons at a thin 
film of metal, as your own Prof. G. P. Thomson did. The particle- 
parable compares it to a shower of hailstones falling on a crowd 
of umbrellas ; we expect the electrons to get through somehow or 
anyhow and come out on the other side as a disordered mob. But 
the wave-parable tells us that the shower of electrons is a train of 
waves. It must retain its wave-formation, not only in passing 
through the film, but also when it emerges on the other side. And 
this is what actually happens : it comes out and forms a wave-pattern 
which can be predicted — completely and perfectly — from its wave- 
picture before it entered the film. 

Next let us shoot our shower of electrons against the barrier 
formed by an adverse electro-motive force. If the electrons of the 
shower have a uniform energy of ten volts each, let us throw them 
against an adverse potential difference of a million volts. According 
to the particle-parable, it is like throwing a handful of shot up into 
the air ; they will all fall back to earth in time — the conservation 
of energy will see to that. But the wave-parable again sees our 
shower of electrons as a train of waves— like a beam of light — and 
sees the potential barrier as an obstructing layer — like a dirty window 
pane. The wave-parable tells us that this will check, but not 
entirely stop, our beam of electrons. It even shows us how to 
calculate what fraction will get through. And just this fraction, in 
actual fact, does get through ; a certain number of ten-volt electrons 
surmount the potential barrier of a million volts — as though a few 
of the shot thrown lightly up from our hands were to surmount the 
earth's gravitational field and wander off into space. The pheno- 
menon appears to be in flat contradiction to the law of conservation 
of energy, but we must remember that waves of knowledge are not 
likely to own allegiance to this law. 

A further problem arises out of this experiment. Of the millions 
of electrons of the original shower, which particular electrons will 
get through the obstacle ? Is it those who get off the mark first, 
or those with the highest turn of speed, or what ? What little extra 
have they that the others haven't got ? 


It seems to be nothing more than pure good luck. We know of 
no way of increasing the chances of individual electrons ; each just 
takes its turn with the rest. It is a concept with which science has 
been familiar ever since Rutherford and Soddy gave us the law of 
spontaneous disintegration of radioactive substances— of a million 
atoms ten broke up every year, and no help we could give to a 
selected ten would cause fate to select them rather than the ten of 
her own choosing. It was the same with Bohr's model of the atom ; 
Einstein found that without the caprices of fate it was impossible 
to explain the ordinary spectrum of a hot body ; call on fate, and 
we at once obtained Planck's formula, which agrees exactly with 

From the dawn of human history, man has been wont to attribute 
the results of his own incompetence to the interference of a malign 
fate. The particle-picture seems to make fate even more powerful 
and more all-pervading than ever before ; she not only has her finger 
in human affairs, but also in every atom in the universe. The new 
physics has got rid of mechanistic determinism, but only at the price 
of getting rid of the uniformity of nature as well ! 

I do not suppose that any serious scientist feels that such a state- 
ment must be accepted as final ; certainly I do not. I think the 
analogy of the beam of light falling on the dirty window-pane will 
show us the fallacy of it. 

Heisenberg's mathematical equation shows that the energy of a 
beam of light must always be an integral number of quanta. We 
have observational evidence of this in the photoelectric effect, in 
which atoms always suffer damage by whole quanta. 

Now this is often stated in parable form. The parable tells us that 
light consists of discrete light-particles, called photons, each carrying 
a single quantum of energy. A beam of light becomes a shower of 
photons moving through space like the bullets from a machine-gun ; 
it is easy to see why they necessarily do damage by whole quanta. 
When a shower of photons falls on a dirty window-pane, some of 
the photons are captured by the dirt, while the rest escape capture 
and get through. And again the question arises : How are the 
lucky photons singled out ? The obvious superficial answer is a 
wave of the hand towards Fortune's wheel ; it is the same answer 
that Newton gave when he spoke of his ' corpuscles of light ' experi- 
encing alternating fits of transmission and reflection. But we readily 
see that such an answer is superficial. 

Our balance at the bank always consists of an integral number of 
pence, but it does not follow that it is a pile of bronze pennies. A 
child may, however, picture it as so being, and ask his father what 
determines which particular pennies go to pay the rent. The father 
may answer ' Mere chance ' — a foolish answer, but no more foolish 


than the question. Our question as to what determines which 
photons get through is, I think, of a similar kind, and if Nature seems 
to answer * Mere chance,' she is merely answering us according to 
our folly. A parable which replaces radiation by identifiable photons 
can find nothing but the finger of fate to separate the sheep from 
the goats. But the finger of fate, like the photons themselves, 
is mere pictorial detail. As soon as we abandon our picture of 
radiation as a shower of photons, there is no chance but complete 
determinism in its flow. And the same is, I think, true when the 
particle-photons are replaced by particle-electrons. 

We know that every electric current must transfer electricity 
by complete electron-units, but this does not entitle us to replace 
an electric current by a shower of identifiable electron-particles. 
Indeed the exclusion-principle of Pauli, which is in full agreement with 
observation, definitely forbids our doing so. When the red and white 
balls collide on a billiard table, red may go to the right and white 
to the left. The collision of two electrons A and B is governed by 
similar laws of energy and momentum, so that we might expect 
to be able to say that A goes to the right, and B to the left or vice- 
versa. Actually we must say no such thing, because we have no 
right to identify the two electrons which emerge from the collision 
with the two that went in. It is as though A and B had temporarily 
combined into a single drop of electric fluid, which had subsequently 
broken up into two new electrons, C, D. We can only say that 
after the collision C will go to the right, and D to the left. If we are 
asked which way A will go, the true answer is that by then A will 
no longer exist. The superficial answer is that it is a pure toss-up. 
But the toss-up is not in nature, but in our own minds ; it is an even 
chance whether we choose to identify C with A or with B. 

Thus the indeterminism of the particle-picture seems to reside 
in our own minds rather than in nature. In any case this picture 
is imperfect, since it fails to represent the facts of observation. The 
wave-picture, which observation confirms in every known experi- 
ment, exhibits a complete determinism. 

Again we may begin to feel that the new physics is little better 
than the old — ^that it has merely replaced one determinism by 
another. It has ; but there is all the difl'erence in the world between 
the two determinisms. For in the old physics the perceiving mind 
was a spectator ; in the new it is an actor. Nature no longer forms 
a closed system detached from the perceiving mind ; the perceiver 
and perceived are interacting parts of a single system. The nature 
depicted by the wave-picture in some way embraces our minds 
as well as inanimate matter. Things still change solely as they 
are compelled, but it no longer seems impossible that part of the 
compulsion may originate in our own minds. 


Even the inadequate particle-picture told us something very 
similar in its own roundabout stammering way. At first it seemed 
to be telling us of a nature distinct from our minds, which moved 
as directed by throws of the dice, and then it transpired that the dice 
were thrown by our own minds. Our minds enter into both pic- 
tures, although in somewhat different capacities. In the particle- 
picture the mind merely decides under what conventions the map 
is to be drawn ; in the wave-picture it perceives and observes and 
draws the map. We should notice, however, that the mind enters 
both pictures only in its capacity as a receptacle — ^never as an 

The determinism which appears in the new physics is one of 
waves, and so, in the last resort, of knowledge. Where we are not 
ourselves concerned, we can say that event follows event ; where 
we are concerned, only that knowledge follows knowledge. And 
even this knowledge is one only of probabilities and not of cer- 
tainties ; it is at best a smeared picture of the clear-cut reality which 
we believe to lie beneath. And just because of this, it is impossible 
to decide whether the determinism of the wave-picture originates 
in the underlying reality or not — Can our minds change what is 
happening in reality, or can they only make it look different to us by 
changing our angle of vision ? We do not know, and as I do not 
see how we can ever find out, my own opinion is that the problem of 
free-will will continue to provide material for fruitless discussion 
until the end of eternity. 

The contribution of the new physics to this problem is not that 
it has given a decision on a long-debated question, but that it has 
reopened a door which the old physics had seemed to slam and bolt. 
We have an intuitive belief that we can choose our lunch from the 
menu or abstain from housebreaking or murder ; and that by our 
own volition we can develop our freedom to choose. We may, of 
course, be wrong. The old physics seemed to tell us that we were, 
and that our imagined freedom was all an illusion ; the new physics 
tells us it may not be. 

The old physics showed us a universe which looked more like a 
prison than a dwelling-place. The new physics shows us a building 
which is certainly more spacious, although its interior doors may be 
either open or locked — ^we cannot say. But we begin to suspect it 
may give us room for such freedom as we have always believed we 
possessed ; it seems possible at least that in it we can mould events 
to our desire, and live lives of emotion, intellect, and endeavour. 
It looks as though it might form a suitable dwelling-place for man, 
and not a mere shelter for brutes. 

The new physics obviously carries many philosophical implica- 
tions, but these are not easy to describe in words. They cannot be 


summed up in the crisp, snappy sentences beloved of scientific 
journalism, such as that materialism is dead, or that matter is no 
more. The situation is rather that both materialism and matter 
need to be redefined in the light of our new knowledge. When this 
has been done, the materialist must decide for himself whether the 
only kind of materialism which science now permits can be suitably 
labelled materialism, and whether what remains of matter should be 
labelled as matter or as something else ; it is mainly a question 
of terminology. 

What remains is in any case very different from the full-blooded 
matter and the forbidding materialism of the Victorian scientist. 
His objective and material universe is proved to consist of little more 
than constructs of our own minds. To this extent, then, modern 
physics has moved in the direction of philosophic idealism. Mind 
and matter, if not proved to be of similar nature, are at least found 
to be ingredients of one single system. There is no longer room for 
the kind of dualism which has haunted philosophy since the days of 

This brings us at once face to face with the fundamental difficulty 
which confronts every form of philosophical idealism. If the 
nature we study consists so largely of our own mental constructs, 
why do our many minds all construct one and the same nature ? 
Why, in brief, do we all see the same sun, moon and stars ? 

I would suggest that physics itself may provide a possible although 
very conjectural clue. The old particle-picture which lay within 
the limits of space and time, broke matter up into a crowd of distinct 
particles, and radiation into a shower of distinct photons. The 
newer and more accurate wave-picture, which transcends the frame- 
work of space and time, recombines the photons into a single beam 
of light, and the shower of parallel-moving electrons into a continuous 
electric current. Atomicity and division into individual existences 
are fundamental in the restricted space-time picture, but disappear 
in the wider, and as far as we know more truthful, picture which 
transcends space and time. In this, atomicity is replaced by what 
General Smuts would describe as ' holism ' — the photons are no 
longer distinct individuals each going its own way, but members of 
a single organisation or whole— a beam of light. The same is true, 
mutatis mutandis, of the electrons of a parallel-moving shower. The 
biologists are beginning to tell us, although not very unanimously, 
that the same may be true of the cells of our bodies. And is it not 
conceivable that what is true of the objects perceived may be true 
also of the perceiving minds ? When we view ourselves in space 
and time we are quite obviously distinct individuals ; when we pass 
beyond space and time we may perhaps form ingredients of a con- 
tinuous stream of life. It is only a step from this to a solution of 


the problem which would have commended itself to many philoso- 
phers, from Plato to Berkeley, and is, I think, directly in line with 
the new world-picture of modern physics. 

I have left but little time to discuss affairs of a more concrete 
nature. We meet in a year which has to some extent seen science 
arraigned before the bar of public opinion ; there are many who 
attribute most of our present national woes — ^including unemploy- 
ment in industry and the danger of war — to the recent rapid advance 
in scientific knowledge. 

Even if their most lurid suspicions were justified, it is not clear 
what we could do. For it is obvious that the country which called 
a halt to scientific progress would soon fall behind in every other 
respect as well — in its industry, in its economic position, in its 
naval and military defences, and, not least important, in its culture. 
Those who sigh for an Arcadia in which all machinery would be 
scrapped and all invention proclaimed a crime, as it was in Erewhon, 
forget that the Erewhonians had neither to compete with highly 
organised scientific competitors for the trade of the world nor to 
protect themselves against possible bomb-dropping, blockade or 

But can we admit that the suspicions of our critics are justified ? 
If science has made the attack more deadly in war, it has also made 
the defence more efficient in the long run ; it shows no partiality in 
the age-long race between weapons of attack and defence. This 
being so, it would, I think, be hard to maintain in cold blood that its 
activities are likely to make wars either more frequent or more pro- 
longed. It is at least arguable that the more deadly a war is likely 
to be, the less likely it is to occur. 

Still it may occur. We cannot ignore the tragic fact that, as our 
President of two years ago told us, science has given man control 
over Nature before he has gained control over himself. The tragedy 
does not lie in man's scientific control over Nature but in his absence 
of moral control over himself. This is only one chapter of a long 
story — human nature changes very slowly, and so for ever lags 
behind human knowledge, which accumulates very rapidly. The 
plays of Aeschylus and Sophocles still thrill us with their vital human 
interest, but the scientific writings of Aristarchus and Ptolemy are 
dead — mere historical curiosities which leave us cold. Scientific 
knowledge is transmitted from one generation to another, while 
acquired characteristics are not. Thus, in respect of knowledge, 
each generation stands on the shoulders of its predecessor, but in 
respect of human nature, both stand on the same ground. 

These are hard facts which we cannot hope to alter, and which 
— ^we may as well admit — may wreck civilisation. If there is an 
avenue of escape, it does not, as I see it, lie in the direction of less 


science, but of more science — psychology, which holds out hopes 
that, for the first time in his long history, man may be enabled to 
obey the command ' Know thyself ' ; to which I, for one, would 
like to see adjoined a morality and, if possible, even a religion, 
consistent with our new psychological knowledge and the established 
facts of science ; scientific and constructive measures of eugenics 
and birth control ; scientific research in agriculture and industry, 
sufficient at least to defeat the gloomy prophecies of Malthus and 
enable ever larger populations to live in comfort and contentment on 
the same limited area of land. In such ways we may hope to restrain 
the pressure of population and the urge for expansion which, to my 
mind, are far more likely to drive the people of a nation to war 
than the knowledge that they — and also the enemies they will have 
to fight — are armed with the deadliest weapons which science can 

This last brings us to the thorny problem of economic depression 
and unemployment. No doubt a large part of this results from the 
war, national rivalries, tariff barriers, and various causes which have 
nothing to do with science, but a residue must be traced to scientific 
research ; this produces labour-saving devices which in times of 
depression are only too likely to be welcomed as wage-saving 
devices and to put men out of work. The scientific Robot in 
Punch's cartoon boasted that he could do the work of 100 men, 
but gave no answer to the question — ' Who will find work for the 
displaced 99 ? ' He might, I think, have answered — ' The pure 
scientist, in part at least.' For scientific research has two products 
of industrial importance — the labour-saving inventions which dis- 
place labour, and the more fundamental discoveries which originate 
as pure science, but may ultimately lead tp new trades and new 
popular demands providing employment for vast armies of labour. 

Both are rich gifts from science to the community. The labour- 
saving devices lead to emancipation from soul-destroying toil and 
routine work, to greater leisure and better opportunities for its enjoy- 
ment. The new inventions add to the comfort and pleasure, health 
and wealth of the community. If a perfect balance could be main- 
tained between the two, there would be employment for all, with 
a continual increase in the comfort and dignity of life. But, as 
I see it, troubles are bound to arise if the balance is not maintained, 
and a steady flow of labour-saving devices with no accompanying 
steady flow of new industries to absorb the labour they displace, 
cannot but lead to unemployment and chaos in the field of labour. 
At present we have a want of balance resulting in unemployment, so 
that our great need at the moment is for industry-making discoveries. 
Let us remember Faraday's electromagnetic induction. Maxwell's 
Hertzian waves, and the Otto cycle — each of which has provided 


employment for millions of men. And, although it Is an old story, 
let us also remember that the economic value of the work of one 
scientist alone, Edison, has been estimated at three thousand million 

Unhappily, no amount of planning can arrange a perfect balance. 
For as the wind bloweth where it listeth, so no one can control the 
direction in which science will advance ; the investigator in pure 
science does not know himself whether his researches will result in 
a mere labour-saving device or a new industry. He only knows 
that if all science were throttled down, neither would result ; the 
community would become crystallised in its present state, with 
nothing to do but watch its population increase, and shiver as it 
waited for the famine, pestilence or war which must inevitably come 
to restore the balance between food and mouths, land and population. 

Is it not better to press on in our efforts to secure more wealth 
and leisure and dignity of life for our own and future generations, 
even though we risk a glorious failure, rather than accept inglorious 
failure by perpetuating our present conditions, in which these 
advantages are the exception rather than the rule ? Shall we not 
risk the fate of that over-ambitious scientist Icarus, rather than 
resign ourselves without an effort to the fate which has befallen the 
bees and ants ? Such are the questions I would put to those who 
maintain that science is harmful to the race. 






Early speculations as to how impressions were produced on the senses 
ascribed the sensations associated with the senses of taste and smell to 
the emanation of small particles of the substances involved, and ascribed 
the sensations associated with the sense of sound to undulations or pulses 
in the air. The sensations associated with the sense of sight were assumed 
by some philosophers to be produced in a manner similar to those belong- 
ing to the senses of taste and smell, while by others they were assumed to 
be produced in a manner similar to those of sound. In the first case 
they were assumed to be produced by emanations from the body seen, 
in the second case by undulations due to the body. Among the Greeks 
Empedocles was an exponent of the first view, while Aristotle supported 
the second view. It should be noted that different views were held by 
those who supported an emanation theory as to the nature of the emana- 
tion. Some held that the emanation consisted of small particles of 
matter, while others held that the emanation was something different from 

In the fifteenth and sixteenth centuries, when attention was being 
directed again to the study of natural phenomena, the two types of theory 
were revived. The form of the emanation theory which was adopted 
ultimately is that due to Newton, usually referred to as the corpuscular 
theory of light. In this theory light is regarded as consisting of very 
small particles of matter emitted by luminous bodies with the same 
velocity, the velocity of light. These light particles are supposed to be 
repelled or attracted by the molecules of material bodies according to 
some law depending on the distance between them. It is further assumed 
that the law is such that the force can change from an attraction to a 
repulsion or from a repulsion to an attraction, that these forces are 
insensible at sensible distances, that the motion of a light particle 
satisfies the ordinary laws of dynamics, and that, as the light particle 


moves, it passes through states which have been termed ' fits of easy 
transmission and easy reflexion ' by Newton, these states recurring 

The form of the undulating theory which was adopted is due to 
Huygens. On this theory light consists of undulations propagated 
through an elastic medium which fills all space ; it is assumed that the 
elasticity of this medium is different in different material bodies and 
different from its elasticity in free space, and that therefore the velocity 
of propagation of light in a material medium is different from its 
velocity of propagation in free space. It is a consequence of either theory 
that when all the media are isotropic S^i? along the path of a ray from 
one point to another point is stationary, and this relation is sufficient to 
give the results which are classed under the term of Geometrical Optics. 
The modification necessary in this result to make it applicable to the 
case of crystalline media was effected by Laplace, who made use of the 
corpuscular theory of light in his investigation and assumed that the 
velocity of the light particles in a crystalline medium depended on 
the direction. The same result was also derived from the undulatory 

At the end of the eighteenth century the corpuscular theory of light 
was the theory which was accepted generally ; one of the main arguments 
against an undulatory theory was its failure to explain the formation of 
shadows. Early last century the principle of interference was put 
forward by Young to account for the formation of shadows on the un- 
dulatory theory, and somewhat later, though independently, Fresnel 
arrived at the same result. In 1816 Arago and Fresnel showed that 
light polarised in perpendicular planes did not interfere. It is not 
improbable that Fresnel had inferred already that the direction of the 
disturbance which constituted light was transverse to the direction of 
propagation, and that these experiments confirmed it, but he makes no 
reference to the principle of transversality in his writings for a con- 
siderable time. The earliest explicit reference to the principle I have 
been able to find is contained in a letter from Young to Arago written in 
January 18 17. Young had visited Arago after the experiments had been 
carried out in 1816 and discussed them with him, and he appears to have 
been the only one who saw the importance of Fresnel's inference and who 
agreed with it. In his essay on diffraction (1818) Fresnel does not refer 
to the principle ; he uses Huygens' principle and the principle of inter- 
ference to obtain his results, principles which are independent of the 
direction of the disturbance. After the publication of his essay on 
diffraction, Fresnel applied his law of transversality to the phenomena 
of polarisation, the propagation of light in crystalline media and other 
problems. He obtained and verified by observation relations between 
the intensities of the incident, transmitted, and reflected light, when light 
is incident on a surface which separates two isotropic transparent media, 
and these relations have ever since been regarded as conditions which 
any adequate theory of light must satisfy. This is also true of the results 
he obtahied for the propagation of light in crystalline media. Fresnel's 


method of attack is to a great extent geometrical and independent of any 
hypothesis as to the nature of a medium. 

The developments which had taken place in analytical mathematical 
methods beginning with the work of the Bernoullis on strings which led 
to Fourier's work and Lagrange's treatment of dynamical problems made 
it possible to submit the hypothesis that light is due to the vibrations of 
an elastic medium to a more rigorous analysis. The earliest investigation 
of this kind is due to Cauchy. In Cauchy's treatment the elastic medium 
is supposed to consist of small particles or molecules which act on each 
other, and the further hypothesis is made that the force between any two 
particles is along the line joining the two points which are taken to 
represent the two particles. As the same problem was discussed by 
Green in a more general way in 1837 it is unnecessary to refer to Cauchy's 
results in detail. 

The hypothesis which Green made with respect to the mutual actions 
of portions of the elastic medium was that they possessed a work function. 
He investigated the form of this function and proved that when the medium 
is isotropic and homogeneous it involves two constants, and that, if trans- 
verse waves are propagated in the medium independently of normal 
waves, the velocity of propagation of normal waves must be either in- 
definitely great or indefinitely small. He further proved that if the 
elastic medium is stable the velocity of propagation of normal waves in it 
must be indefinitely great. 

The difference between two isotropic homogeneous media is assumed 
to be a difference between their densities,^ and on this assumption the 
relations between the amplitudes of the incident, the transmitted, and the 
reflected waves are obtained when waves are incident on a surface 
separating two such media. For waves polarised in the plane of incidence 
the relations are the same as Fresnel's, and for waves polarised per- 
pendicularly to the plane of incidence the relations are very approxi- 
mately the same as Fresnel's except when the index of refraction is great. 
The difference between Cauchy's hypothesis as to the nature of the 
mutual actions of the medium and Green's hypothesis has been referred to 
above ; another important difference in their treatments is that Cauchy 
assumes that the direction of the disturbance in the medium is parallel 
to the plane of polarisation, while Green, in accordance with Fresnel's 
view, assumes that this direction is perpendicular to the plane of 

Green's investigation is of special interest, as it is the first where 
Lagrange's dynamical method is used for the treatment of a physical 
problem, and where the advantages of using a general dynamical principle 
as the basis of the argument rather than hypotheses which involve the 
assumption of particular modes of action are recognised. 

In 1839 Green applied the same method of treatment to the investiga- 

* The assumption that the difference between two isotropic homogeneous 
media is a difference in the elastic constants leads to results which do not agree 
with the observed facts. 


tion of the propagation of waves of light in a crystalline medium. In 
addition to the limitation used in his previous investigations, that trans- 
verse waves can be propagated in the medium independently of normal 
waves, he introduces the further limitation in accordance with Fresnel's 
theory, that the media satisfy the condition that the directions of the 
transverse vibrations are always in the front of the wave. With these 
limitations he proves that, if the direction of a disturbance is parallel to 
the plane of polarisation and the medium is free from the action of any 
external forces, the directions of polarisation and the velocities of propaga- 
tion are the same as in Fresnel's theory. In his previous investigations 
he had proved that in order to satisfy Fresnel's relations between the 
amplitudes of the incident, transmitted, and reflected waves at the surface 
separating two isotropic homogeneous media, the direction of a disturb- 
ance is perpendicular to the plane of polarisation. He then shows that 
in order to satisfy Fresnel's results for crystalline media when the direction 
of a disturbance is perpendicular to the plane of polarisation it is necessary 
to assume the existence of extraneous forces, and that, with the appro- 
priate restrictions on these extraneous forces, the results agree with those 
of Fresnel's theory. 

It thus appears that an elastic solid medium which is self-contained 
and free from external constraints will not account for the observed facts. 
Cauchy arrived at the same result almost simultaneously. 

Various modifications of Green's elastic solid theory of light have been 
proposed, but none of them is satisfactory. Perhaps the most interesting 
is that proposed by Lord Kelvin in his Baltimore Lectures. This theory 
assumes that normal waves in the elastic medium are propagated with 
zero velocity, and to get over the difficulty, pointed out by Green, that 
such a medium is not stable, the medium is supposed to be attached to 
a boundary. Thus, although this theory gives results for the relations 
between the amplitudes of the incident, the transmitted, and the 
reflected waves at the boundary separating two isotropic media and 
also for the propagation of waves in crystalline media which agree 
with Fresnel's results, it is open to the same objection as Green's 
elastic solid theory which requires the intervention of extraneous 
forces, as the condition that the medium is attached to a boundary 
postulates the existence of some other medium which acts on and 
controls it. 

Although these different investigations did not succeed in establishing 
a satisfactory mechanical theory of light, they were instrumental in 
advancing the knowledge of the subject. One important result emerged, 
that any theory to be satisfactory must agree with Fresnel's results, and 
some writers, e.g. Lorenz, based many of their investigations on Fresnel's 

In Green's treatment of the elastic solid theory the Lagrangian function 
used by him is of the type which is expressed as the difference of a 
kinetic energy function and a potential energy function. The kinetic 
energy function is the sum of the squares of the velocities of the medium 
multiplied by the density, and, if the rate of transfer of energy due to 


a source in such a medium emitting waves of one frequency is evaluated, 
it will be found that it is oscillatory, and this is also true when the potential 
energy function is of the most general type for an elastic medium. It 
should be observed that, just as in the case of waves of sound from a 
source or of waves in water, there is an actual displacement of the 
medium itself, e.g. in the case of waves of sound air must be supposed 
to be pumped in and out at the source, and this accounts for the 
fact that the rate of transfer of energy is oscillatory. This suggests 
that it should be possible to pump out portions of such a medium, 
and raises the question whether a medium which is subject to the 
laws of dynamics and which possesses a kinetic energy of this type can 
be an ultimate medium which will account for the phenomena of 

The next important stage in the development of theories of light is the 
discovery by Faraday in 1845 that when polarised light passed through 
a transparent medium its plane of polarisation was rotated by the im- 
position of a magnetic field. In the introduction to his account of these 
experiments Faraday says : ' I have long held an opinion, almost amount- 
ing to conviction , in common I believe with many other lovers of natural 
knowledge, that the various forms under which the forces of matter are 
made manifest have one common origin ; or, in other words, are so directly 
related and mutually dependent, that they are convertible, as it were, one 
into another, and possess equivalents of power in their action. This 
strong persuasion extended to the powers of light, and led, on a former 
occasion, to many exertions, having for their object the discovery of the 
direct relation of light and electricity, and their mutual action in bodies 
subject jointly to their power ; but the results were negative. These 
ineffectual exertions, and many others which were never published, could 
not remove my strong persuasion derived from philosophical considera- 
tions ; and, therefore, I recently resumed the inquiry by experiment in 
a most strict and searching manner, and have at last succeeded in mag- 
netizing and electrifymg a ray of light .' In a footnote added subsequently 
Faraday says : ' Neither accepting nor rejecting the hypothesis of an 
aether, or the corpuscular, or any other view that may be entertained of 
the nature of light ; and, as far as I can see, nothing being really known 
of a ray of light more than of a line of magnetic or electric force, or even 
of a line of gravitating force, except as it and they are manifest in and by 
substances ; I believe that, in the experiments I describe in the paper, 
light has been magnetically affected.' 

Almost twenty years later, in 1865, Maxwell propounded a theory of 
light in his memoir, A Dynamical Theory of the Electromagnetic Field. ^ 
In the introduction Maxwell states : ' We have therefore some reason to 
believe, from the phenomena of light and heat, that there is an aethereal 
medium filling space and permeating bodies, capable of being set in 
motion and of transmitting that motion from one part to another and of 

* What might be termed an electric theory of light was propounded by 
Oersted ; in this theory light was regarded as a succession of electric sparks. 


communicating that motion to gross matter so as to heat it and affect it 

in various ways. 

' We may therefore receive, as a datum derived from a branch of science 
independent of that with which we have to deal, the existence of a per- 
vading medium, of small but real density, capable of being set in motion, 
and of transmitting motion from one part to another with great, but not 
infinite, velocity. 

* Hence the parts of this medium must be so connected that the motion 
of one part depends in some way on the motions of the rest ; and at the 
same time these connexions must be capable of a certain kind of elastic 
yielding, since the communication of motion is not instantaneous, but 
occupies time. 

' The medium is therefore capable of receiving and storing up two 
kinds of energy, the " actual " energy depending on the motions of its 
parts, and " potential " energy, consisting of the work which the 
medium will do in recovering from displacement in virtue of its 

Maxwell postulates further that the all-pervading medium possesses 
physical characteristics of the same kind as a homogeneous isotropic 
dielectric, that the effect of the action of an electric force on it is 
the production of what he terms ' electric displacement,' which is ' a kind 
of elastic yielding to the action of the force similar to that which takes 
place in structures and machines owing to the want of perfect rigidity 
of the connexions.' 

He shows that the application of the general equations of electro- 
dynamics, derived from the Ampere-Faraday laws, to the case of a magnetic 
disturbance propagated through a non-conducting field gives the result 
that the only disturbances which can be so propagated are those which 
are transverse to the direction of propagation, and that the velocity of 
propagation is the velocity v, which expresses the number of electro- 
static units of electricity which are contained in one electromagnetic 

The all-pervading medium which Maxwell postulates is a medium 
which possesses to some extent the physical characteristics of an elastic 
solid, and it is probable that his replacement of the expression for the 
electrokinetic energy which is obtained from Faraday's laws by an ex- 
pression which gives the energy in terms of the magnetic force, was 
effected to make it similar to the expression for the kinetic energy function 
of an elastic solid. This replacement is effected by an integration by 
parts and neglecting the surface integral on the ground that at an in- 
definitely great distance the surface integral tends to zero, but this over- 
looks the fact that the law of variation of magnetic force with distance is 
not the same when the magnetic field is varying as it is when the magnetic 
field is steady. This does not affect Maxwell's investigation of the 
propagation of a magnetic disturbance, as this expression for the electro- 
kinetic energy is not used in that investigation. 

As has been seen, Faraday's view, as set forth in his 1845 paper, is 
different, and he explains his views in greater detail in a letter which 


was published in the Philosophical Magazine in 1846. In this letter he 
states : ' The view which I am so bold as to put forth considers, therefore, 
radiation as a high species of vibration in the lines of force which are 
known to connect particles and also masses of matter together. It 
endeavours to dismiss the aether, but not the vibration. The kind of 
vibration which, I believe, can alone account for the wonderful, varied, 
and beautiful phenomena of polarization, is not the same as that which 
occurs on the surface of disturbed water, or the waves of sound in gases 
or liquids, for the vibrations in these cases are direct, or to and from the 
centre of action, whereas the former are lateral. It seems to me, that the 
resultant of two or more lines of force is an apt condition for that action 
which may be considered as equivalent to a lateral vibration ; whereas 
a uniform medium like the aether does not appear apt, or more apt than 
air or water. 

' The occurrence of a change at one end of a line of force easily suggests 
a consequent change at the other. The propagation of light, and there- 
fore probably of all radiant action, occupies time ; and that a vibration 
of the line of force should account for the phenomena of radiation, it 
is necessary that such vibration should occupy time also.' 

And again : ' The aether is assumed as pervading all bodies as well as 
space : in the view now set forth, it is the forces of the atomic centres 
which pervade (and make) all bodies, and also penetrate all space. As 
regards space, the difference is, that the aether presents successive parts 
or centres of action, and the present supposition only lines of action ; as 
regards matter, the difference is, that the aether lies between the particles 
and so carries on the vibrations, whilst as respects the supposition, it is 
by the lines of force between the centres of the particles that the vibration 
is continued.' 

Faraday, like Fresnel, appears to be thinking in terms of geometrical 
relations, while Maxwell is seeking to construct a mechanical model 
whose motions will resemble those which constitute light. 

Starting from Faraday's ideas, the problem of the propagation of 
a magnetic disturbance in free space can be approached in a direct manner. 
There are three vectors involved — ^the electric current at a point in the 
space, the magnetic force at the point, and the electric force at the point. 
The relation between the electric current and the magnetic force is given 
by Ampere's law,^ and the relation between the magnetic force and the 
electric force is given by Faraday's law. Assuming, with Faraday, that 
the phenomena of light and of electricity have a common origin, Fresnel 's 
law of transversality, that the vectors which specify the disturbance are 
perpendicular to the direction of propagation, will hold for the propaga- 
tion of an electric or a magnetic disturbance as well as for light. These 
three laws are sufficient to determine the circumstances of the propagation 
of a magnetic disturbance in free space. It follows that for plane waves 

' It should be noted that Ampere's law was established initially for steady 
electric currents ; its extension to the case where the electric currents are varying 
is a result of Faraday's work. 


the direction of the vector j, whose time rate of increase is the electric 
current, at a point coincides with the direction of the electric force E at 
the point, and the relation between E and; is £ = A-^V'^j, where V is the 
velocity of propagation of a magnetic disturbance in free space. Further, 
if the changes which constitute the disturbance satisfy the laws of 
dynamics, the potential energy per unit of volume is \ Ej — that is, 
E^jSnV^ in electromagnetic units — and, if E^ is the same electric force in 
electrostatic units, the potential energy is E^^ISn ; therefore E = VE-^, 
that is, the velocity of propagation is the velocity by which an electric 
force expressed in electrostatic units must be multiplied to convert it 
into electromagnetic units, or since the product of an electric charge and 
the electric force on it, being a mechanical force, is the same in both 
systems of units, the velocity of propagation is the velocity by which 
an electric charge expressed in electromagnetic units must be multiplied 
to convert it into electrostatic units. 

The Lagrangian function of the changes which belong to the propaga- 
tion of an electric or magnetic disturbance in free space is the difference 
of a kinetic energy function and a potential energy function. The 
potential energy function is the function given above — the kinetic energy 
function depends on the electromagnetic momentum and the electric 
current at a point ; the contribution from an element in the neighbour- 
hood of a point cannot be expressed in terms of one vector : it depends 
on the electric currents throughout space. On this theory the rate of 
transfer of energy from a source emitting waves of one frequency is steady 
and not oscillatory as on an elastic solid theory. 

Consistently with the foregoing, the effect of material media, so far 
as electric and magnetic phenomena are concerned, can be represented 
by a distribution of electric currents and of magnetic currents throughout 
the space occupied by the material media. These electric current and 
magnetic current distributions can be supposed to be due to electric 
charges and to magnetic particles which are in motion, and it follows 
from the electrodynamical equations, when these current distributions 
are taken account of, that the current distributions can be represented 
by a distribution of electric and magnetic oscillators throughout the space 
occupied by the material rhedia. 

Further, the magnetic field due to a distribution of electric and magnetic 
currents inside a closed surface at any point outside this closed surface 
can be expressed in terms of the components of the electric and magnetic 
forces tangential to the surface — that is, any distribution of electric and 
magnetic currents inside a closed surface produces the same magnetic 
field at points outside the surface as a distribution of electric and magnetic 
currents on the surface which is determined by the components of the 
magnetic and electric forces tangential to the surface at points on it, but 
a knowledge of the magnetic field external to a closed surface does not 
determine the distribution of electric and magnetic currents inside the 
surface which is producing the magnetic field. 

When the states of motion belonging to the electric and magnetic 
current distributions in the material medium are steady states of motion 


the material medium is in a state of relative equilibrium, but, when an 
electric or magnetic disturbance is being propagated in the material 
medium, these steady states of motion will be disturbed and, under 
certain conditions, the effect of the disturbance will be to set up small 
oscillations about the steady states of motion ; a material can be regarded 
as being perfectly transparent for a disturbance whose only effect is to 
set up small oscillations about the steady states of motion. A condition 
for this is that none of the frequencies involved in the disturbance are 
equal to or nearly equal to any of the natural frequencies belonging to 
the steady states of motion. 

Fresnel's relations between the amplitudes of the incident, the trans- 
mitted, and the reflected waves when a train of waves is incident on the 
surface separating two transparent media follow on this hypothesis, and 
also Fresnel's results for the propagation of waves in crystalline media. 
It should be noticed that on this hypothesis the electric and magnetic 
forces at a point in a material medium which appear in the equations are 
not the total electric and magnetic forces at the point, but the parts of 
them which are due to the disturbance. 

Faraday's results for the rotation of the plane of polarisation by an 
imposed magnetic field when light is being propagated in a non-magnetic 
transparent medium follow immediately from the above hypothesis 
without making any additional assumptions. 

Further, on the same hypothesis there will be ranges of frequencies for 
which a material medium is transparent, the extent of such a range will 
depend on the intensity of the disturbances, and between any two con- 
secutive ranges there will be a range of frequencies for which the medium 
is not transparent, and the mathematical treatment of the effect of disturb- 
ances involving these frequencies will require additional hypotheses. 

The theory advanced above is not a mechanical theory of light in the 
sense that it is possible to construct a machine whose motions will resemble 
the motions involved in the propagation of light. The form of the electro- 
kinetic energy function raises the question whether all the time rates of 
change involved in the propagation of a magnetic disturbance can be 
represented by moving points, and whether every time rate of change 
associated with physical phenomena involves change of position in space. 
It may be necessary to contemplate time rates of change which do not 
involve change of position in space although they satisfy the laws of 
dynamics. In this connection it is of interest to observe that a result of 
Faraday's laws is that, when there are electric currents in a system of 
circuits which are in motion, the kinetic energy function does not contain 
terms which involve the product of an electric current and a velocity, 
a result which Maxwell verified experimentally. 

A possible hypothesis is that physical phenomena are due to the inter- 
action of time rates of change which satisfy the laws of dynamics, and the 
Lagrangian function in that case would be a homogeneous quadratic 
function of all the time rates of change. In actual cases only some of the 
changes are being observed, and the Lagrangian function which is obtained 
from the experimental evidence is a modified Lagrangian function where 


the unobserved changes are supposed to be eliminated. In certain cases 
this function will be expressed as the difference of a kinetic energy and 
a potential energy function ; an important case is the case where the 
unobserved changes appear in the original Lagrangian function as 
velocities only and there are no product terms which involve a velocity 
belonging to the observed and a velocity belonging to the unobserved 
changes. There are also cases where the modified function is of this 
form approximately. 







Current Events. 

In reviewing the development of chemistry in this country during the 
past year, I must place in the forefront the political events which have 
turned so many of our most welcome visitors into residents. It is 
impossible as yet to appreciate fully the contribution thus made to the 
advancement of science in this country, and it would perhaps be invidious 
to mention any names ; but I must make an exception in order to say that 
in Cambridge we were just beginning to discover how great a chemist 
and how generous a colleague we had found in Haber, when he succumbed 
to a heart-weakness of long standing, less than a week after I had the 
privilege of presiding at his first public lecture. 

I should also like to mention the holding of the 59th and 60th General 
Discussions of the Faraday Society in Cambridge and in Oxford respec- 
tively, since it was my privilege nearly thirty years ago to initiate the first 
three of these discussions, as a means of providing an appropriate environ- 
ment for a modest paper of my own on ' Osmotic Pressure,' and for papers 
with Mr. Bousfield on the ' Hydrate Theory of lonisation,' and on 
* Liquid Water a Ternary Mixture.' 

Interpenetration of Chemistry and Physics. 

One of the most important features of scientific progress during the 
present century, and especially since the war, has been the renewal of the 
old intimate fellowship between chemistry and physics, which was 
characteristic of the earlier days, when Cavendish and Faraday were 
masters of both subjects and competent to make important discoveries 
in either. The subsequent segregation, which resulted from the growing 
specialisation of these two subjects of research, tended to produce 
chemists who were no longer competent physicists, and physicists who 
had little or no sympathy with chemical problems, to the great loss of 
both sciences. Indeed, when I was a student, the leading physical 
chemist was one who ' used to boast that he had never performed an 


exact experiment in his life ' ( i ) * ; and the physico-chemical theories which 
first attracted me to the study of chemistry were largely fallacious, since 
we now know that the concentration of ions in an aqueous solution cannot 
be deduced directly from its conductivity at different dilutions ; nor does 
the catalytic activity of an acid afford a direct measure of the concentra- 
tion of hydrogen ions which it contains, in view of the fact that the 
molecules of the acid may be even more active than the ions produced 
from them. Even more amazing evidence of inaccurate theory was the 
claim made by Ostwald in 1904 (2) that the law of multiple proportions 
(which Sommerfeld (3) cites as one of three main arguments for the atomic 
theory) could be deduced without the help of the atomic hypothesis ! At 
the present time, however, the work of Dr. Aston in the Cavendish 
Laboratory, and of Professor Lennard- Jones in the Chemical Laboratory 
at Cambridge, may be cited as a proof of interpenetration, which is as 
welcome as it is undoubtedly beneficial to both laboratories. Moreover, 
if I may be allowed to make a more personal remark, the efficiency of my 
own Laboratory of Physical Chemistry at Cambridge, and the pleasure 
that I derive from directing it, depend largely on the fact that the workers 
in the laboratory consist of chemists and physicists in approximately 
equal numbers, so that we are equally well equipped for work in the 
older Physical Chemistry and in the newer Chemical Physics. Indeed, 
our chief need at the present time is for larger numbers of organic 
chemists to undertake researches in the physical chemistry of organic 
compounds, which do not necessarily require (as is so often feared) a 
knowledge of wave mechanics and a mastery of higher mathematics. 

Atomic Numbers. 

If I were asked to indicate the principal contribution which physics 
has made to the progress of chemistry during the present century, I 
should without hesitation point to the theory of atomic numbers, and to 
the galaxy of phenomena that are associated with it. We might begin, 
for instance, by defining the atomic number of an atom as the net positive 
charge of the nucleus, on the assumption that Rutherford's ' nucleus 
atom ' is too stable to be disintegrated by any verbal bombardment to 
which it may be submitted. We then pass immediately to the epoch- 
making conclusion that nuclear charge is more important to the chemist 
than atomic mass, since the chemical properties of an element depend 
almost exclusively on the configuration of the electronic atmosphere with 
which the nucleus envelops itself in the neutral atom or in the ions derived 
from it. 

When the atomic numbers of the elements were made known, through 
the experiments of Moseley and others, a precise numerical basis was 
provided for their periodic classification. This finds its simplest ex- 
pression in the Rydberg series : 


which tells us how many electrons are required to give the configuration 

* References will be found at the end of the Address. 


of the inert gases. These gases owe their inertness to the extreme stabihty 
of the ' closed shells ' of electrons represented by the terms of the 
Rydberg series. These shells are, indeed, so stable that the elements are 
devoid of all ordinary chemical properties, although under the stress of 
great excitement pairs of atoms can be wedded into diatomic molecules. 
From the Rydberg series, the electronic theory of valency emerges at 
once, since maxima of chemical reactivity are found in those metals which 
can acquire the electronic configuration of an inert gas by parting with 
one or two surplus electrons, and in non-metals which have a like deficit 
in their electronic budget. Inorganic chemistry, which consists so largely 
of the chemistry of ions, thus finds a firm foundation in the Thomson- 
Kossell conception of ' electron transfer ' between the atoms of unlike 
elements. On the other hand, the bonds by which atoms of similar 
elements are united in diatomic gases, and in the complex molecules of 
organic compounds, can be expressed by means of the Thomson-Lewis 
conception of ' shared electrons,' for which a physical interpretation has 
now been found in the spinning electron of the older quantum mechanics, 
and the resonance energy of the later wave-theory. 

Chemical Changes in the Nucleus. 
If the study of the electronic atmosphere is of primary value to the 
chemist in his studies of chemical reactions, it is impossible to deny that 
the study of the structure of the nucleus itself is of even more funda- 
mental significance, since it is here that the atomic numbers have their 
origin ; and, if it were not for the stability of certain selected nuclear 
structures, the chemist would have no atoms from which to construct 
his molecules, except perhaps the ultimate elements (apparently once 
more four in number) from which the nuclei are built. I need not now 
describe in detail the chemical interest which attaches to the discovery of 
isotopes, since this will form the basis of a subsequent discussion ; but I 
should like to mention Oliphant's (4) separation of the isotopes of lithium, 
in sufficient quantities to test their behaviour towards high-speed protons 
and deutons, by the method of the mass-spectrograph, since this method 
is obviously capable of universal application, when developed on an ade- 
quate scale of magnitude. On the other hand, attention may be directed 
to the vast field of nuclear chemistry which has been opened up in recent 
years by the development of new projectiles for bombarding the nucleus. 
Thus the relatively clumsy a-particle, with its double positive charge, 
has been supplemented by the swift proton and deuton, with only a 
single positive charge to impede their approach to the positively charged 
target ; and a climax has been reached by using the neutron, which can 
approach the nucleus without impedance by any electric charge, like 
aircraft attacking a battleship. It can therefore score direct hits, which 
are found to have a devastating effect even on the stoutest nuclei. As a 
result of the introduction of this new projectile, no element can now be 
regarded as safe from disintegration ; and isotopes of short life promise 
in the future to become as common amongst the lighter elements as they 
are now amongst the spontaneously radioactive elements, which lie on 
the heavy side of the boundary formed by metallic lead. 


Diffraction of Molecular Rays and Electrons. 

Bombardment need not, however, be used only as an agent of 
destruction, since Dr. Fraser will tell you how gentle beams, in the form 
of molecular rays, travelling with the velocity of thermal agitation, 
instead of with velocities comparable with that of light, can be used to 
demonstrate the presence or absence of magnetic or electrostatic moments, 
to study the character of ' free radicals,' or to test the variability of 
' dipole moments ' with temperature ; and Dr. de Laszlo will describe 
some applications of the method devised by Mark and Wierl for studying 
the structure of molecules by the orderly scattering of beams of electrons. 
The results thus obtained are so similar to those given by Debye's study 
of the diffraction of X-rays as to be almost identical. 

Diffraction of X-rays. 

The applications of X-rays to chemistry are so numerous that I may 
be excused for selecting only a few examples that have interested me 
personally. The influence of Cox's X-ray analysis in vetoing an incorrect 
formula for ascorbic acid will perhaps be referred to in the joint dis- 
cussion on this vitamin ; but I may mention here that, in the case of 
another product of the same general class, Bernal was able to obtain a 
complete X-ray analysis by using a crystal weighing only 0-000015 mg., 
and was only prevented from making an exact determination of mole- 
cular weight by the Brownian movement, which prevented a precise 
determination of the density of the crystal by flotation — a difliculty which 
he suggests could be overcome with the help of a centrifuge. In a totally 
different field, I was during the war deeply interested in the polymor- 
phism of ammonium nitrate, which melts at 169°, but also has transition- 
temperatures at 125°, 84°, 32° and —16°. The heaps of nitrate from the 
driers in a shell-filling factory were therefore almost always either at 84° 
or at 32°, on account of the arrest of cooling at these transition-points. 
It is fascinating now to be told that these transitions are associated with 
the spinning of the ions in a rigid crystal lattice. As a result of this 
spinning, a tetrahedral ammonium ion and a triangular nitrate ion finally 
acquire complete spherical symmetry, and take up the same positions as 
the monatomic ions of sodium and chlorine in a crystal of rock salt, so 
that the substance crystallises in the cubic system in the range from 125° to 
169° C. 


In accordance, I believe, with well-established custom, I pass on 
now to consider those examples of ' Physical Methods of Chemistry ' 
with which I have been most closely concerned during a long period of 

Nearly forty years ago, as a student of organic chemistry under Prof. 
Armstrong, I undertook my first research, on the stereochemistry of the 
a-derivatives of camphor. The earliest experiments (5) showed that the 
bromination of a-chlorocamphor and the chlorination of a-bromo- 


camphor both gave an isomorphous mixture of stereoisomeric aa'- and 
a'a-chlorobromocamphors : 

C<( ci /CClBr Br y^( 

CsHiZ I ^Br —I CsHiZ j ^ CsHi,/ | \ci 

^C=0 ^c=o ^c=o 

Tj h ' [ Chlorobromocamphor. a-Chlorocamphor, 

(Isomorphous mixture.) 

It was then natural to extend the research to the nitro-derivatives (6). For 
this purpose it was necessary not only to nitrate bromocamphor, but to 
brominate nitrocamphor. In this way I first encountered the nitro- 
compound, which has already provided a material basis for two extensive 
series of researches, and has not yet exhausted its utility or interest. 

,H .NOa ^NOa 

Cc" .C/ C<' 

CsHiZl^Br > CgH / | \Br ^ CgH / | ^H 

^C=0 ^C=Q ^C=0 

a-Bromocamphor. aoc'-Bromonitrocamphor. a'-Nitrocamphor. 

The first of a series of happy chances (7) was a measurement of the optical 
rotatory power of a solution of nitrocamphor in the morning, followed by 
a confirmatory reading in the afternoon. During the luncheon interval 
the rotatory power of the solution had become quite different, and I was 
thus presented with a novel example of the phenomenon of change of 
rotatory power with time, which Dubrunfaut had first observed in 1846 
in a freshly prepared aqueous solution of glucose (8). This property of the 
reducing sugars had been variously described as birotation (8), multirota- 
tion, and paucirotation (9), according as the ratio of the initial to the final 
rotation was 2:1, greater than i or less than i ; but, since in certain 
solvents the sign as well as the magnitude of the rotation of nitrocamphor 
was changed, I suggested in 1899 (10) that the phenomenon should be de- 
scribed as mutarotation ; and this name has been in general use ever since. 

The chemical basis of the phenomenon was disclosed by another 
happy accident. Wishing to know whether the change of rotatory power 
could be repeated when the nitrocamphor had been recovered from solu- 
tion, I left a solution in benzene to evaporate on the water bath. Later 
in the day I examined the residue and found that it was now almost 
entirely insoluble in benzene. It had in fact been converted into a new 
compound, an anhydride formed from nitrocamphor by the loss of half 
a molecular proportion of water (11). An anhydride of this type could not 
be formed directly from nitrocamphor itself, but it could be derived 
easily enough from an isomeric hydroxylic form of the substance, such as 
that from which the salts of nitrocamphor were presumably derived. 
This conclusion was confirmed by the fact that the anhydride of 
Izevorotatory nitrocamphor was, like the salts, strongly dextrorotatory. 


The mutarotation of nitrocamphor, always from left towards right, could 
therefore be attributed to a partial conversion in solution of lasvorotatory 
nitrocamphor into a dextrorotatory isomeride, containing an acidic 
hydroxyl group, which was capable of forming an anhydride as well as a 
series of salts. 



8^ ^14"' 







B romonitrocamphor . 






Potassium salt. 


8^ ^14^ 


Anhydride of nitrocamphor. 


At this stage Prof. Kipping very generously gave me a quantity of 
the 7T-bromo-derivative of a-bromonitrocamphor, from which I was able 
to prepare a stock of 7r-bromonitrocamphor. Lapworth and Kipping (12) 
had described this compound as trimorphous, and had recorded the 
crystal-constants and published drawings of two of the forms. The 
orthorhombic form, melting at 142°, proved to be strongly dextrorotatory 
when dissolved in benzene, but it became laevorotatory after a few hours. 
The tetragonal form, melting at 108° (which is formed as a by-product, 
alongside the more stable form, by rapid evaporation of a solution in 
chloroform), was found to be laevorotatory, but like nitrocamphor it 
exhibited a relatively small mutarotation from left towards right. This 
labile form was therefore analogous with ordinary nitrocamphor, whilst 
the more stable form was analogous with the still unknown pseudo- 
nitrocamphor, the relative stability of the two isomers having been 
reversed by the introduction of a halogen. The third form, for which no 
crystal measurements had been published, was evidently a mere mixture 
of these two isomers (13). 

The mutarotation of the sugars in aqueous solutions had been 
attributed to several causes ; but, when Emil Fischer (14) observed the 
same phenomenon during the reversible hydrolysis of the sugar-lactones, 
he concluded that these changes of rotatory power were due to reversible 
hydration, and this conclusion was very widely accepted. 

CeHioOe + 



CgHijOe + 







This explanation can obviously be applied to any aqueous solution in 
which reversible hydrolysis can take place ; but it was not applicable to 


nitrocamphor, which exhibited mutarotation in a large range of an- 
hydrous solvents, but was too insoluble to be examined in aqueous 
solutions. Since interaction with the solvent was thus excluded, the 
mutarotation of nitrocamphor could only be attributed to dissociation 
or to isomeric or polymeric change. 

At that date certain sugars had already been prepared in two isomeric 
forms, which exhibited mutarotation in opposite directions (15) ; but 
these changes were attributed to the complete conversion of the two 
sugars into a third isomeride (16). In the case of 7t-bromonitrocamphor, 
however, the product of mutarotation of the normal and pseudo forms 
was obviously an equilibrium-mixture of these two substances, and not 
a third isomeride, since, on evaporation of the solution, crystals of the 
normal and pseudo forms were deposited side by side. Mutarotation 
was therefore attributed to the reversible isomeric change of two isomers ; 
and this interpretation was regarded as generally applicable to mutarota- 
tions in which interaction with the solvent could be excluded. 

Dynamic Isomerism. 

The phenomenon of reversible isomeric change had been studied, and its 
essential characteristics had been fully elucidated, twenty-two years before 
by Butlerow (17) in 1877. He had shown that two isomeric forms of the 
unsaturated hydrocarbon, zVodibutylene, CgHig, could be brought into 
equilibrium by the reversible addition of sulphuric acid, since a molecule 
of sulphuric acid could be removed from the acid sulphate in two different 
ways. Simultaneously, two wodibutyl alcohols of the formula CgHigO, 
in the form of their acid sulphates, were brought into equilibrium by the 
reversible elimination of sulphuric acid, since the resulting define could 
add on sulphuric acid in two different ways : 

CH3. .CH2.OH CHas^ ^CH^ CH3^^CH3 CHgv^ ^CHg 

CH ^ CHOH ^ 

I T H2O I ± H2O I T H2O li 

CH2 ;?=± CH2 ^=± CH2 ;^^ CH 


CMca CMe3 CMe3 CMe3 

Butlerow also recognised that, although sulphuric acid was required to 
bring the isomeric olefines and alcohols into equilibrium, the introduction 
of a catalyst might not be required in other cases. In particular he 
suggested that prussic acid might be regarded as an equilibrium-mixture 
of the two acids, HCN and HNC, from which the cyanides and iso- 
cyanides CH3.CN and CH3.NC are derived : 

CH3.CN -« HCN ;;=i: HNC ► CH3.NC 

Methyl cyanide. Prussic acid. Methyl nocyanide. 

Butlerow's paper did not receive the attention that it deserved, perhaps 
because it was published under the too modest title ' On Isodibutylene.' 
Much more interest was aroused by the publication, eight years later, by 


Laar (i8), of a speculative paper ' On the possibility of several structural 
formulas for the same chemical compound.' Laar assumed that the dual 
reactivity of certain substances, of which ethyl acetoacetate is now the 
most familiar example, might be due to the incessant wandering of a 
hydrogen atom between two alternative positions in the molecule. In 
order to make his theory more precise, he compared these internal 
migrations with the vibrations which give rise to radiation in incandescent 
gases. To this phenomenon he gave the name of taiitomerism, and in 
order to emphasise the contrast with Butlerow's phenomenon of reversible 
isomeric change, he stated categorically (19) that the substances repre- 
sented by the two alternative structural formulae were ' not isomeric but 

Since two isomeric forms of Tr-bromonitrocamphor had been isolated in 
the crystalline state and their slow progress towards equilibrium in 
solution had been followed by observations of mutarotation, it would 
have been absurd to describe them as identical, or, in terms of Laar's 
definition, as tautomeric. These well-defined compounds, however, 
provided an excellent illustration of Butlerow's phenomenon of ' equili- 
brium between isomers.' I therefore ventured to describe this pheno- 
menon in very obvious terms as dynamic isomerism (20), in contrast to the 
more usual condition of static isomerism, in which each isomer preserves 
its individuality and is not in process of conversion into any other member 
of the series. A full report on ' Dynamic Isomerism ' was presented to 
Section B of the British Association at Cambridge in 1904, and reports of 
a Committee on Dynamic Isomerism are included in the Transactions of 
Section B from 1905 to 1916. A series of twenty-eight papers on the 
same subject has also been published in the Journal of the Chemical Society . 

Arrest of Mutarotation. 
Further fortuitous observations showed that the mutarotation of 
nitrocamphor is not an independent intramolecular process, but depends 
on extramolecular circumstances, since under favourable conditions it 
may be arrested more or less completely over a period of several days (21). 
This discovery (which was made more than twenty years before Kurt 
Meyer's experiments (22) on the aseptic distillation of ethyl acetoacetate in 
alkali-free vessels of silica glass) was also the result of a fortunate accident. 
The mutarotation of a solution of nitrocamphor in chloroform had been 
followed to completion during a period of about eight days, but had been 
accompanied by some loss of solvent (and possible concentration of the 
solution) by evaporation. The remainder of the solution had been left 
in the small graduated flask in which it had been prepared, and there was 
no reason to suspect that it would behave in any respect differently from 
the sample in the polarimeter tube. It was therefore a great surprise 
when, at the end of seventeen days, on attempting to confirm the final 
reading, it was found that the residue in the flask gave a rotation almost 
identical with the initial reading recorded more than a fortnight before. 
The transfer of the solution to the polarimeter tube, however, sufficed 
to initiate the mutarotation, which then proceeded with the same velocity 
as before. 


Nearly ten years later a further series of experiments was being made 
on the catalysis of mutarotation by acids and bases (23). It was then 
observed that solutions of nitrocamphor in chloroform, to which trichlor- 
acetic acid had been added, developed an intolerable and pungent odour. 
This observation showed that the peculiar inertness of chloroform was 
due to its oxidation to carbonyl chloride or phosgene, and to the conse- 
quent elimination of traces of nitrogenous bases, in the form of inert 
carbamides (24). The same series of experiments had already shown that 
some of these laases have an amazing catalytic activity. Thus an accelera- 
tion of mutarotation was detected as a result of adding piperidine to 
benzene in the proportion of i part of the base in 10 million parts of the 
solvent ! This acceleration was also one of the earliest examples of a 
phenomenon which has since become very familiar, namely, a catalysis 
by bases, which could not be attributed to the presence of hydroxyl ions, 
and was therefore outside the scope of the conventional theories of 
catalysis by acids and bases, as developed and used by Ostwald and his 

An immediate sequel to this discovery was the arrest in silica vessels of 
the mutarotation of solutions of nitrocamphor in benzene and in ether, to 
which traces of an anticatalyst had been added (24). Subsequent experi- 
ments showed that mutarotation could also be arrested in solutions of 
tetramethylglucose in chloroform, benzene, ethyl acetate, and pyri- 
dine (25) ; and Owen (26) developed to a fine art the process of arresting, 
almost at will and with very few failures, the mutarotation of solutions of 
tetra-acetylglucose in dry ethyl acetate. 

The climax of this work was reached when Faulkner (27) found that 
the mutarotation of tetramethylglucose could be arrested both in cresol 
and in pyridine, but proceeded too rapidly for convenient observation 
in mixtures of these two solvents. Since these mixtures gave velocities 
of mutarotation which were much greater even than in water, it was 
clear that the essential factor in promoting mutarotation was not an 
oxygenated solvent (28), nor an ionising solvent (29) (as had been suspected 
at earlier periods), nor even the ionisation of the sugar by an acid or basic 
catalyst (as most other workers had assumed), but that an amphoteric 
solvent (27) must be provided to serve as a complete catalyst for the 


The migration of a hydrogen atom, in compounds such as nitrocamphor 
and the sugars, was thus shown to depend on the addition and removal of 
a proton at two opposite poles of the organic molecule. Since no satis- 
factory name had been adopted for this important group of isomeric 
changes, I proposed in 1923 to describe them by the term, prototropy (30). 
The migration of a proton was, however, regarded as only a special 
example of the more general phenomenon of ionotropy (31), in which a 
radical migrates from one part of a molecule to another either as an anion 
or as a kation. 

The addition and removal of the ion from the two poles of the organic 
molecule may be either simultaneous or consecutive, but in either case 


it leaves behind a positive or negative charge. In order that this type of 
isomeric change may proceed, it is essential that these opposite charges 
should be neutralised. The electronic theory of valency allows us to 
recognise that this is done by the rearrangement of bonds (or ' desmo- 
tropy ') (32) which accompanies prototropic change, since a valency 
electron is thereby transferred through the interior of the molecule, to 
neutralise the charge of the proton, which is transferred through the 
amphoteric solvent. 

The migration of a hydrogen atom, to which the most fertile types of 
mutarotation are due, was thus linked up to an extended definition of 
acids and bases, which I set out in 1923 (33), at a time when it must have 
been in the minds of many other workers, and which was described more 
fully by Bronsted a few months later (34). Thus, if we define an acid 
and a base as a proton donor and acceptor respectively, 

+ - 
B +HA^=^BH +A (where B is the base and HA the acid), 

the migration of a proton in a prototropic compound under the combined 
action' of a base B and an acid HA can be expressed by the equation 

B + HS + HA;^=±: BH + SH + A, 

used by Bronsted and Guggenheim (35), where HS and SH represent 
the two isomeric forms of the substrate. In an amphoteric medium such 
as water, catalysis by bases and acids can be represented by equations in 
which water plays the part either of an acid or of a base, thus : 

Catalysis by a base : B + HS + HOH :;=± BH + SH + OH 

+ - 

Catalysis by an acid : HgO + HS + HA:;=± H3O + SH + A. 

Finally, the possibility of autocatalysis must be recognised. Thus, since 
nitrocamphor is a strong acid, it may itself act as the acidic component of 
the catalyst ; mutarotation may than proceed by adding only a base, 
which in these conditions may become a complete catalyst for the 

The process of isomeric change, as set out above, can be regarded as 
an electrolysis of the organic molecule between positive and negative 
poles, provided by the acid and basic components of the amphoteric 
solvent. This mechanism has therefore been described (36) as an 
' electrolytic theory of catalysis by acids and bases.' Similar conditions, 
however, prevail in all conjugated systems, and these can now be formu- 
lated in general terms, as systems in which opposite charges at the ends 
of the system can be neutralised by a migration of valency electrons 
through the system (37). 

Rotatory Dispersion. 

At the time when the earlier measurements of mutarotation were made, 

it was customary to measure the optical rotations of organic compounds 

only for the yellow sodium line. Work on rotatory dispersion had indeed 

been suspended almost completely since the death of Biot in 1862, and 


the discovery of the Bunsen burner in 1866. It was, however, certain 
that little progress could be made in elucidating the origin of optical 
rotatory power, or in predicting its magnitude, until the values of the 
rotatory power were known over a wide spectral range, instead of for a 
single casually determined point on the curve of rotatory dispersion. 
This opinion has received abundant confirmation from the subsequent 
demonstration that the substances which had provided the favourite 
materials for studies of optical rotatory power were those whose rotatory 
dispersion was most anomalous, since these substances are in fact (and 
perhaps inevitably) most sensitive to changes of solvent, concentration, 
or temperature. 

The ignorance then prevailing in reference to this important aspect of 
the subject is shown by the fact that, when Drude wished to test his 
equation for optical rotatory dispersion, he was only able to make use of 
data for quartz (38), since the rotatory dispersion of no one of the 
hundreds of optically active compounds prepared and studied by organic 
chemists was known with sufficient accuracy to be used for this purpose ; 
and his equation for magnetic rotatory dispersion was tested on data, for 
five wave-lengths only, for carbon disulphide and for creosote ! (39) 

Experiments carried out in order to supply the data required to 
determine the form of the curves of rotatory dispersion in organic com- 
pounds soon led to definite conclusions. Thus in 1913 I was able to 
show, with T. W. Dickson (40), that the optical rotations of ten simple 
alcohols, and the magnetic rotations of thirty-four simple organic com- 
pounds for eight wave-lengths in the visible spectrum could be expressed 
by one term of Drude's equation : 

In the following year we found (41) that two terms of opposite sign: 

could be used in the same way to express the anomalous rotatory dis- 
persion of ethyl tartrate. This result confirmed the conclusion reached 
at a much earlier period by Biot (42) and by Arndtsen (43), that anomalous 
rotatory dispersion has its origin in the superposition of two partial 
rotations of opposite sign and of unequal dispersion. These partial 
rotations may be due to very diverse causes, ranging from the presence of 
two optically active absorption bands in the same molecule, to the case 
in which two liquids of opposite rotatory power and unequal dispersions 
are arranged in series in separate polarimeter tubes. This diversity has 
resulted in a certain amount of controversy as to the origin of the partial 
rotations which give rise to anomalous rotatory dispersion (44), but the 
essential facts represented by Drude's equation are established beyond 

Validity of Drude's Equation. 
Since Drude's equation is only applicable to transparent media, the 
limits of validity of the equation coincide with the conditions under which 


a maximum of experimental accuracy can be obtained, namely, by using 
long columns of concentrated solutions. Under these conditions the 
validity of the equation has been vindicated up to the limits of experi- 
mental accuracy for a single term in octyl alcohol (45) and for two terms 
in ethyl tartrate, drastically purified by crystallising to constant melting- 
point (46). 

An extreme limit has been reached in the case of quartz, where measure- 
ments to six significant figures have been made for twenty-four wave- 
lengths in the visible spectrum, on a column nearly half a metre in length. 
This column gave a rotation of 12,678-96° for the green mercury line 
Hg 5461 ; and when the ten sections of the column were dismantled and 
re-erected, the original reading was reproduced with an error of only 
0-03°, or less than three parts in a million (47). 

In the infra-red region, the rotation per millimetre falls from 25 -539° 
per mm. at 5460 -742 A. U. to2°at i8,oooA.U., 1° at 25,000 A. U., and o -74° 
at 28,000 A.U. Observations are then interrupted by an absorption 
band ; but beyond this there is a narrow windoAv through which observa- 
tions can be made before the medium again becomes opaque. Snow's 
measurements (48) have shown that the rotations in this narrow region 
of transparency (about o • 52° per mm. at 32,000 A.U.) fall on the same curve, 
and can be expressed by the same formula, as those in the infra-red, 
visible and ultra-violet regions. The infra-red absorption band is there- 
fore, as Drude supposed, without influence on the course of the curve of 
rotatory dispersion. 

In the ultra-violet the rotations increase very rapidly. Thus for a 
copper line at 2263 A.U. the observed rotation of the half-metre column 
rose to 101,332°, or 202 -328° per mm. (47). 

Throughout the whole range from 32,100 to 2263 A.U. the rotatory 
dispersion of quartz for about 1000 wave-lengths can be expressed within 
very narrow limits by two terms of Drude's equation, of opposite sign, 
together with a small constant (47) : 

9-5639 2-3113 

X-i —0-0127493 X2— 0-000974 

This equation does not express with equal accuracy the observations 
made by Duclaux (49) at still shorter wave-lengths with a much shorter 
column of quartz, but it predicts with considerable precision the existence 
of two absorption bands, with characteristic frequencies far out in the 
Schumann region at 1130 and 310 A.U. I am still waiting, however, for 
a physicist to carry out the experiments which are needed to disclose the 
presence of these two bands, the existence of which has already been 
predicted for nearly a quarter of a century. 

Normal and Anomalous Rotatory Dispersion. 

Experiments such as these have demonstrated, beyond the possibility 
of controversy, the ability of Drude's equation to express the rotatory 
dispersion of transparent media up to the extreme limits of accuracy 


which are now attainable (52). Thus normal rotatory dispersion 
(defined by the fact that a, dr/.jd'K and d^ccldl^ are of constant sign through- 
out the region of transparency (50)) can often be expressed by a single 
term of the equation, with only two constants ; but this is by no means 
universally true, since the rotatory dispersion of quartz, which requires 
a five-constant equation, is nevertheless rigidly normal throughout the 
whole region of transparency. On the other hand, anomalous rotatory 
dispersions can only be expressed by using two terms of opposite sign. 
These two terms, however, are adequate to account for the presence in 
curves of anomalous rotatory dispersion of (i) a reversal of sign, where 
a=:o, (ii) a maximum, where d'-j.jd'k = Q, and (iii) an inflexion, where 

Those normal rotations which cannot be expressed by a single term of 
Drude's equation can usually be represented by equations with two 
terms, either of similar or of opposite signs. When the two terms are of 
opposite signs, the equation becomes identical in form with that which 
is used to represent anomalous rotatory dispersion. The distinction 
between normal and anomalous dispersion is indeed often almost a matter 
of accident. Thus a wide range of dispersion-curves can be plotted for 
the tartaric esters in different solvents, and at different concentrations 
and temperatures (51). These curves all belong to one family, and can be 
expressed by the same equation, with small variations in the four arbitrary 
constants ; but some of them cross the zero axis and are therefore 
anomalous, whilst others just fail to do so and are therefore normal (52). 

Simple and Complex Rotatory Dispersion. 

An alternative method of classification is to describe as simple those 
rotatory dispersions which can be expressed by one term of Drude's 
equation, and as complex those which cannot be so expressed (53). 

This classification lends itself very easily to practical use, since, for the 
purpose of complete verification, measurements need only be extended 
to a wave-length in the ultra-violet at which absorption first begins to be 
troublesome, in view of the fact that Drude's equation is only valid in the 
region of complete transparency. On the other hand, the distinction 
between normal and anomalous rotatory dispersion depends on knowing 
whether the curve does or does not cross the zero axis in the infra-red ; 
and this cannot yet be determined with certainty with the apparatus now 
commonly used in polarimetry. 

In general, simple rotatory dispersions are only observed when the 
characteristic frequencies of all the partial rotations lie close together 
in the Schumann region, giving a dispersion-ratio a^ajg/aj^m = i -6 
approximately. Thus, in the sugar series, the partial rotations associ- 
ated with the different asymmetric carbon atoms sometimes give rise to a 
simple dispersion, as in cane-sugar (54) ; but they do not necessarily do 
so (55), since even in a sugar the characteristic frequencies of the radicals 
may cover a wide range in the Schumann region, and the foot of the 
absorption bands often extends into the ordinary ultra-violet. 

Additional partial rotations of lower frequency give rise to dispersion- 


ratios which are either higher or lower than this value, according as 
they are of the same or of opposite sign as the partial rotations associated 
with absorption bands in the Schumann region. In the remarkable case 
of tetra-acetyl-pL-arabinose, H[CH0Ac]4.CH0, however, the partial 
rotations associated with the three asymmetric carbon atoms cancel 
out (56). The whole of the rotatory power is therefore due to the partial 
rotation associated with the carbonyl group. This gives rise to a simple 
rotatory dispersion in the region of transparency. In the region of 
absorption it gives a symmetrical loop, with equal and opposite maxima 
[a] = i 1200° on either side of a zero rotation at 2909 A.U. Camphor- 
quinone is a less precise example of the same phenomenon, since its 
rotation in a narrow region of transparency in the red, yellow, and green 
is dominated by an absorption band in the blue. The influence of the 
Schumann terms is therefore so small that the rotatory dispersion can be 
expressed by a single term of Drude's equation (54). 

Simple rotatory dispersion then does not imply the existence of only 
a single partial rotation, but merely indicates that the partial rotations of 
the molecule can in practice be covered by one term of Drude's equation. 
It provides, however, the most practical way of classifying rotations, since 
no real physical meaning can be assigned to a rotation which is not 
' simple,' until the various partial rotations, which make the rotatory 
dispersion ' complex,' have been unravelled. For this purpose, however, 
a precise algebraic analysis must be made of the observed rotations for a 
large number of wave-lengths ; and no sanction can be given to the use 
of graphical methods, except for the rough preliminary tests for which 
alone they are suitable (57). 

Rotatory Dispersion in Absorbing Media. 

A formula for rotatory dispersion in a region of absorption was developed 
by Natanson (58) in 1909, by reintroducing a ' damping factor ' which 
Drude had discarded in his final simplified equation for rotatory dispersion 
in transparent media (59). No basic change has been made in the funda- 
mental relation thus developed between absorption and rotation ; but 
Kuhn and Braun (60) found that, since the form of the absorption bands 
cannot be expressed by means of a damping factor, the form of the 
corresponding curves of rotatory dispersion is also incorrect. They 
therefore introduced a new series of equations on the supposition that 
the form of the absorption band can be expressed by an exponential 
equation representing a Maxwellian probability-distribution of fre- 
quencies. Their equations are an improvement on those of Ketteler, 
Helmholtz and Natanson ; but absorption curves of the form postulated 
by them are so uncommon that, in the course of a long experience of 
absorption spectroscopy, I have not yet discovered a single example of 
this type. On the other hand, several absorption curves have been studied 
which are rigidly symmetrical on a scale of wave-lengths, and many more 
are known which shade off more slowly at higher frequencies. Hudson (61) 
has therefore developed a modified series of equations for substances 
which give rise to these symmetrical absorption curves. His equations 
express his own very exact measurements with far greater precision than 


the equations of Kuhn and Braun. Thus, in the fascinating case of 
tetra-acetyl-fx-arabinose, where the positive and negative maxima are 
equal in magnitude, the equation of Kuhn and Braun gives a difference of 
200° between the observed and calculated values ; but this was reduced 
to only 30° by using Hudson's own equation (56). 

This sugar-derivative provides ideal material for an experimental 
study of the form of the curves of rotatory dispersion in the region of 
absorption, since the partial rotation associated with the carbonyl-radical 
has been isolated automatically by a fortunate process of cancellation 
of the partial rotations of the asymmetric carbon atoms. A similar 
cancellation has been observed more recently by Baldwin in a specimen 
of penta-acetyl-fx-fructose, also supplied by Dr. Wolfrom. Although 
the simple aldehydic radical — CO.H has now been replaced by the 
radical — CO.CHg.O.CO.CHg, this compound again gives rise to equal 
maxima on either side of the axis ; but, since the configuration of the 
three asymmetric carbon atoms is reversed, these maxima are of oppo- 
site sign to those observed in the arabinose-derivative. Moreover, the 
absorption curves have not the same ideal symmetry, and the mathe- 
matical analysis of the dispersion curves has therefore not yet been 

The Origin of Optical Rotatory Power. 

Attempts to simplify the structure of an optically active molecule for 
the purpose of numerical calculations have been made by Drude (59), 
who used a model consisting of a vibrator moving in a spiral orbit, whilst 
Kuhn (62) has used a model consisting of two dissymmetrically coupled 
electrons. Each of these models includes a length, namely, the pitch of 
the spiral or the distance between the coupled electrons, and it is perhaps 
not surprising that they have led to equations which differ only in the 
meaning assigned to the arbitrary constants ; but in certain cases at least 
the length deduced from Kuhn's model appeared to bear no relation to 
the linear dimensions of the molecule. Fortunately the formulae which 
express the rotatory dispersion of a medium do not depend on the nature 
of the model used to deduce them, although new integrals are required to 
correspond with each new distribution of densities in the optically active 
absorption band. This distribution depends on the intensities of the 
sub-levels associated with a given electronic jump, and cannot yet be 
predicted. In these circumstances it is remarkable that the absorption 
curve should be symmetrical even in the few cases studied by Hudson ; 
but this result may perhaps be interpreted as the effect of some limiting 
condition, which prevents the appearance even of curves which are 
symmetrical on a scale of frequencies instead of wave-lengths. 

The real theory of optical rotatory power may be found by the 
mathematician, but is concealed from the chemist, in the papers of 
Born (63), who recognised that four coupled electrons are required to 
produce optical rotatory power. Further advances appear to depend on 
reverting to this basis, in place of Drude's single spirally controlled 
vibrator, or Kuhn's two dissymmetrically coupled electrons, since neither 
of these conceptions can be realised except in a complicated field of force, 


depending presumably on the distribution of nuclei as well as on the 
distribution of electron-densities as studied by W. L. Bragg and others. 
It is, indeed, an interesting exercise to construct a model of the molecule 
of camphor and then to inquire to which other electrons the shared valency- 
electrons of the carbonyl group must be coupled, in order to develop 
the magnificent loop which appears in the curve of rotatory dispersion in 
the region of absorption. The question answers itself by mere inspection 
of the model, since it is clear that all the electrons are involved, and 
not merely one, two or four of them. Thus, even when the carbonyl 
group has been linked to two dissimilar radicals, either in an open-chain 
ketone or in a cyclic ketone, no rotatory power at all is developed. The 
whole of the rotatory power of camphor therefore depends on the contrast 
between the two radicals — CH0.CH2 — and — C(CH3)2^ — • which lie on 
either side of the plane which contains the — CHo.CO — radical. These 
two chains are separated from the carbonyl-radical by an unbridged gap, 
since the route which leads to them through the bonds is long and tortuous. 
It therefore seems clear that we are dealing with an intramolecular field 
of force, acting across two empty spaces, which destroys the symmetry 
of the environment and thus brings out the latent possibility of dissym- 
metry in the highly-polarisable carbonyl group. 

The picture thus exhibited directs attention to the carbonyl group, 
rather than to the asymmetric carbon atoms, which in the acetate of 
[x-arabinose make no direct contribution of any importance to the rotatory 
power of the molecule. In this respect it is indeed essentially identical 
with the conception of induced asymmetry (or better induced dissymmetry) 
put forward by Lowry and Walker in 1924 (64), according to which the 
carbonyl group itself becomes dissymmetric under the influence of the 
dissymmetric internal field of force of the molecule. It therefore con- 
tributes directly to the optical activity of the molecule, whereas less 
polarisable groups, such as >CH2 or >CMe2, contribute relatively 
little to the total rotation, even when they are exposed to a similar 
dissymmetric field. 

I have had the privilege of talking over this problem with Prof. 
Born. He insists that the rotatory power thus induced in the carbonyl 
group cannot be expressed in terms of single potential-gradients along 
and across the plane of the — CH2.CO — • group, laut must be a function of 
the frequencies of the electrons with which the carbonyl group is coupled, 
since this coupling aflrects the frequencies of both components. It is, 
however, possible that in a monoketone, such as camphor, the characteristic 
frequencies of the hydrocarbon radicals on either side of the median 
plane may be summed up in a weighed mean, depending but little on the 
structure or configuration of the carbon skeleton. In that case regularities 
and simplifications may perhaps be encountered, in studying different 
cyclic ketones, which could not have been foreseen from the complexities 
of pure theory. 

Prediction of the Sign and Magnitude of Optical Rotatory Power. 

The electronic theories discussed above have not hitherto led to any 

prediction of the magnitude of the optical rotatory power of a dissym- 


metric molecule, although Hermann has calculated the rotatory power of 
crystals of sodium chlorate and Hylleraas that of P-quartz from formulas 
developed by Born. For the purpose of predicting the magnitude of the 
rotatory power of a molecule it is convenient to deal, not with single 
electrons or pairs of electrons, or even groups of four, but with the 
complete octet which constitutes the valency-shell of the atom. From 
this point of view, the four different radicals which are required to give 
rise to an asymmetric carbon atom may be considered as ellipsoids, with 
three principal axes of polarisation, arranged at a definite distance 
from the central carbon atom and with a definite orientation relatively 
to one another ; but this system is too complex for easy computation 
and some simplification is needed before numerical data can be 

This simplification was attempted nearly ten years ago by de Malle- 
mann (65), who assumed that, for the purpose of computation, single 
atoms might be treated as isotropic spheres. A further simplification 
was made by assuming that the three halogens in CHClBrI could be 
placed on the rectangular axes of x, y and z at distances depending on 
their atomic radii. On this basis he calculated (66) the rotatory power 
of the molecule in terms of the radii and refractivities of the radicals, and 
obtained a value, [aj^ = ^b 3 "2°, of the expected order of magnitude for 
a compound of this type ; but, since the compound has not yet been 
prepared, no direct comparison of observed and calculated rotations was 
possible. During the present year, however, S. F. Boys (67) has been 
able to make this comparison by extending the postulate of isotropic 
spheres from single atoms to radicals. Langmuir's theory of isosterism 
can be cited as justification for extending this postulate from the halogens 
to the isosteric radicals, OH, NHj, CH3 ; but it is certainly invalid when 
extended to radicals such as C2H5 and CH.jOH, which cannot be either 
spherical or isotropic. Nevertheless Boys has been able to deduce, for 
four of the simplest alcohols and amines, rotations which are of very 
similar magnitude to those observed experimentally. This coincidence 
is limited to dissymmetric molecules of the simplest possible type, con- 
taining only one asymmetric carbon atom and no unsaturated or chromo- 
phoric group ; but it is sufficient to show that Pasteur's model of an 
irregular tetrahedron can be used to predict the existence and the approxi- 
mate magnitude of such a molecule in terms of the linear dimensions and 
the refractive indices of the radicals. 

Detailed calculations by Mr. H. F. Willis have shown that the simple 
rotatory dispersion of ^ec-butyl alcohol, a4358/a546i = i "661, can be 
deduced exactly from the factor R^RbRcRd/X^ of Boys' formula, or 
less exactly if the factor (h-^+2) (i^^+5) is included. On the other hand, 
the dispersion-ratio of ac/-amyl alcohol, a4358/a546i = i "700, is higher 
than the maximum value which can be deduced from the formula. 
Moreover, the anomalous rotatory dispersion of aldehydes and ketones 
in the region of absorption cannot be represented even qualitatively by 
means of a formula of this kind, since the refractivity of the carbonyl- 
radical never approaches the zero axis, and cannot therefore give rise to 
a reversal of sign in the region of absorption ; but a zero value for the 


partial rotation of the carbonyl-radical might perhaps become possible 
by assuming with Lowry and Walker that an additional centre of dis- 
symmetry is developed within the chromophoric group in optically active 
aldehydes and ketones. 

From the above considerations it appears that the molecular theory of 
optical rotatory power, as de Mallemann has called it, is not capable in its 
present form of expressing the rotatory power of any but the simplest 
molecules ; and the crudeness of some of the assumptions on which it is 
based, and the importance of the secondary effects which it ignores, 
forbid any expectation of extensive developments in the near future. 
Nevertheless the theory has proved to be of real value in demonstrating 
the simplicity of the conditions which suffice to give rise to optical 
rotatory power, since this effect can be produced by four isotropic spheres 
which are near enough to pass on to one another the alternating polarisa- 
tion produced by an incident beam of light, without requiring any more 
complex form of coupling ; and chemists will always be grateful for a 
theory of optical rotatory power which makes it possible to identify the 
actual configurations of the dextro- and lasvorotatory forms of the simplest 
organic molecules, in parallel with a similar claim which has recently been 
made by Kuhn in the more complex case of the spiro-compounds (68). 
On the other hand, no theory of optical rotatory power which is limited 
to the region of transparency can be regarded as satisfactory, and further 
progress must depend on an intensive study of rotatory dispersion in the 
region of absorption. For this purpose the optically active aldehydes 
and ketones provide ideal material, since the position and intensity of the 
optically active absorption bands are both well adapted for precise 
experimental work, and two cases are already known in which the partial 
rotation of the chromophoric radical has been automatically isolated. It 
therefore only remains to determine, perhaps by the methods of wave- 
mechanics, the conditions under which the electronic cloud of the carbonyl- 
radical becomes optically active, and the factors which determine the 
magnitude of its partial rotation, in order to provide a complete solution 
for this special case, and thus to pave the way for a general solution of 
the whole problem. 


1. Walker, ' Arrhenius Memorial Lecture,' /. Chem. Soc, 1928, 1400. 

2. OsTvvALD, ' Faraday Lecture,' /., 1904, 85, 50S. 

3. SoMMERFELD, Atombuu und Spektrallinien. 

4. Oliphant, Nature, 1934, 133, 377. 

5. Lowry, /., 1898, 73, 569. 

6. /., 1898, 73,986. 

7. /., 1899, 75, 211. 

8. DuBRUNFAUT, C.R.. 1846, 23, 38. 

9. Wheeler and Tollens, Ann., 1889, 254, 310. 

10. Lowry, /., 1899, 75, 213. 

11. /., 1898,73,991. 

12. Lapworth and Kipping, /., 1896, 69, 304. 


13. LowRY, /., 1899, 75, 223. 

14. E. Fischer, Ber., 1890, 23, 2626. 

15. ScHMOGER, Be>'., 1880, 13, 1917 ; 1881,14,2121; 1892,25,1455- Tanret, 

C.R., 1895, 120, 1060. 

16. Trey, Z. physikal. Chem.. 1895, 18, i93- Lippmann, Ber., 1896, 29, 203. 

Tanret, Bull. Soc. Chim., 1896, [iii], 15, i95- 

17. BuTLEROW, Ann., 1S77, 189, 44. 

18. Laar, Ber., 1885, 18, 648. 

19. Ber., 1886, 19, 730. 

20. LowRY, /., 1899, 75, 211. 

21. ibid., p. 220. 

22. Kurt Meyer, Ber., 1920, 53, 1410 ; 1921, 54, 579- 

23. Lowry and Magson, /., 1908, 83, 107. 

24. ibid., p. 119. 

25. Lowry and Richards, /., 1925, 127, 1385- 

26. Lowry and Owen, Proc. R.S., 1928, A, 119, 5o5- 

27. Lowry and Faulkner, /., 1925, 127, 2883. 

28. Lowry, /., 1899, 75, 219. 

29. See Lowry and Magson, /., 1908, 83, 129. 

30. Lowry, /., 1923, 123, 828. 

31. Lowry, Second Solvay Conference, 1926, p. 158. 

32. Jacobsen, Ber., 1887, 20, 1732 ; 1888, 21, 2628. 

33. Lowry, Chem. and Ind., Jan. 19, 1923, 1, 43 ; compare Trans. Faraday Soc, 

1930. 26, 45- 

34. Bronsted, Rec. Trav. Chim., 1923, 42, 718 ; compare Trans. Faraday Soc, 

1929, 25, 59- 

35. Bronsted and Guggenheim, /. Amer. Chem. Soc, 1927, 49, 2554. 

36. Lowry, ' L' Activation et la Structure des Molecules,' Reunion Internationale 

de Chimie Physique, 1928, p. 219. 

37. Lowry, Nature, 1925, 115, 376. 

38. Drude, Theory of Optics, English Trans., London, 1907, p. 414. 

39. ibid., p. 439. 

40. Lowry and Dickson, /., 1913, 103, 1067. 

41. Trans. Faraday Soc, 1914, 10, 99. 

42. BiOT, C.R., 1836, 2, 543- 

43. Arndtsen, Ann. Chim. Phys., 1858, 54, 421. 

44. Hunter, /., 1924, 125, 1198. 

45. Lowry and Richards, /., 1924, 125, i593- 

46. Lowry and Cutter, /., 1922, 121, 532. 

47. Lowry and Coode-Adams, Phil. Trans., 1927, A, 226, 391 ." compare Lowry, 

ibid., 1912, A, 212, 261. 

48. Lowry and Snow, Proc. R.S.. 1930, A, 127, 271. 

49. DucLAUX and Jeantet, /. Physique, 1926, 7, 200. 

50. Lowry, /., 1915, 107, ii95- 

51. Lowry and Dickson, /., 1915, 107, ii73- 

52. Lowry, /., 1929, 2858. 

53. Lowry and Dickson, Trans. Faraday Soc, 1914, 10, 102. 

54. Lowry and Richards, /., 1924, 125, 2511. 

55. Harris, Hirst and Wood, /., 1932, 2108. 

56. Hudson, Wolfrom and Lowry, /., i933. ii79- 

57. Lowry and Abram, /., 1919. 115, 303 ; compare Hunter, ref. 44. 

58. Natanson, Bull. Akad. Sci., Krakow, 1908, No. 8, 764. 

59. Drude, Oplik, Leipzig, 1900. 

60. KuHN and Braun, Z. physikal. Chem., 193°. B. 8, 281. 

61. Lowry and Hudson, Phil. Trans., i933. A, 232, 117. 


62. W. KuHN, Trans. Faraday Soc, 1930, 26, 293. 

63. Born, Phys. Zeit., 1915, 16, 251 ; Ann. Physik, 1918, [iv], S5, 177. 

64. LowRY and Walker, Nature, 1924, 113, 565. Lowry, Nature, 1933, 131, 


65. DE Mallemann, Rev. Gen. Sci., 1927, 38, 453 ; Trans. Faraday Soc, 1930, 

26, 281. 

66. C.R., 1925, 181, 298. 

67. S. F. Boys, Proc. Roy. Soc, 1934, A, 144, 655. 

68. W. KuHN, Ber., 1933, 66, 166 ; Z. physikal. C/iem., 1934, B. 24, 335. 





PROF. W. T. GORDON, M.A., D.Sc. 


At a recent celebration ^ the President of the Royal Society, Sir Frederick 
Gowland Hopkins, said ' It has been remarked, and not without a measure 
of truth, that the scientific investigator is more readily forgotten even by 
his own world than is the author or the artist. A literary work or a picture 
is complete in itself. It is an accomplishment involving finality and it 
remains intact through the years. . . . The investigator of Nature, on the 
other hand, adds his quota to a growing structure, to the great edifice of 
science as a whole, and as knowledge grows and widens and others build 
upon his work as a foundation it may become, as it were, submerged.' 
What is true of the individual worker may be equally true of his subject, 
and the influence of research, when viewed out of its original setting, may 
be completely lost. To an extent this has happened in connexion with 
the study of fossil plants in their relation to geological science, and the 
request of the Council that the Sections, at this year's meeting, might 
explore the possibility of illustrating how far their particular science had 
added to the sum total of human advancement has afforded a chance to 
consider this matter. Geology is the science that investigates the past 
history of the earth, and, as a consequence, involves considerations of the 
past life of the earth, both animal and plant. Discussions of past life will, 
of necessity, involve investigations of life conditions, and these will react 
on ideas of inorganic nature. So far as human beings are concerned, we 
have no difficulty in appreciating the economic side of geology ; but there 
is another side — the advancement of thought — that is not quite so obvious 
to ' the man in the street.' 

Our study this morning is largely historical, and the views of the ancients 
will form a suitable beginning. We cannot accredit any real scientific 
knowledge of geology to them, but their utilisation of stone and metals 
shows that they were not unacquainted with phenomena now considered 
by the geologist as among the data of his science. Even in pre-historic 
times observation of, and inference from, natural phenomena cannot be 
denied. In a late neolithic hearth at Gullane, East Lothian, I have col- 
lected a piece of petrified wood — Pitys primceva — of Carboniferous age 

1 Unveiling of a plaque to William Hyde Wollaston on 14 Buckingham Street, 
W.C. I, on July 4, 1934. 


which certainly had deceived its collector. It is so well preserved, and 
so resembles a billet of wood, that even to-day a casual observer might 
have taken it for a piece of weathered drift-wood. While this must be 
one of the earliest known specimens actually collected and used by man, 
we can hardly say that its study led to any direct advance. Nor did the 
well-known specimen of Cycadeoidea etrusca, Capellini, found in a tomb 
twenty miles west of Bologna, signify anything more than that it had 
struck the curiosity of some ancient Etruscan. Neither the utilitarian 
outlook of the prehistoric Scot nor the curiosity of the Etruscan had any 
recorded result in further research. Other known uses of fossil plants by 
the ancients, such as the employment of logs of fossil wood by the Egyptians 
in making roads over the desert, and in fabricating ornaments, or the tools 
made out of the Rhynie chert, are likewise without any real significance 
from a geological point of view. They are all interesting, but have not 
led to further developments. 

PaLj^ontological Ideas in Classical Times. 

Among the Greek and Roman philosophers there is no doubt that 
many were acquainted with fossils, and inter alia with fossil plants, but 
again the geological import of these objects was hardly considered. They 
were accepted as of organic origin, and their presence in rocks was attributed 
variously to foriner inundations of the land or a vis plastica. That they 
v/ere remnants oi former worlds never seems to have struck them. Inun- 
dations of the land, or elevations of the land above the sea by earthquakes 
or volcanic action, they knew, and even successions of such changes,^ 
but the great past history of the earth was still an unknown volume. Yet 
the naturalness of their deductions is often very striking. This applies 
perhaps with greatest force to the Geography of Strabo. The work was 
written for the instruction of administrators, and the sanity of the dis- 
cussions and final conclusions, together with the fair-minded criticism of 
the authorities he quotes, is startling when one considers the ideas of many 
of his contemporaries, and of his predecessors. He is perhaps too generous 
to Homer, whom he seems to consider infallible, and the depository of all 
knowledge : but in this he only follows most of the Greek philosophers. 
The works of Aristotle, Theophrastus, Pliny, Herodotus and Seneca, 
that are extant, are all excellent in their way as illustrating here and there 
geological ideas prevalent before, and just after, the beginning of Christian 
times ; but Strabo excels them all. 

Yet, with all their knowledge of the processes of nature, and of the 
plants and animals that inhabitated the earth, there does not appear a 
single hint of any former phase different from theprese?it. In fact, although 
many geological processes and phenomena were known, there was no 
science of Geology. Yet the ancients have left us a legacy in their desire 
to find a natural explanation for the origin of everything. Curiosity to 
explore and explain nature seems to have been their watchword. For 
nearly i,ooo years from the beginning of the Christian era geological 

* Cf. Ovid, Metamorphoses. 


science made no progress. Doubtless many fossil plants and animals 
were discovered, but no record of them has been preserved to us. 

Mediaeval Ideas on Fossil Plants. 

In the Middle Ages fossils, both plant and animal, were regarded, for 
the most part, as produced by inorganic agencies in the earth itself. 
Mr. W. N. Edwards, in his Guide to an Exhibition illustrating the early 
history of Palaeontology, has made an interesting suggestion in regard to 
the reason for this. He considers that it may have arisen ' from a mis- 
understanding of the explanations of fossils ' given by Avicenna. The 
quotation from Albertus Magnus (1193 ?-i28o) in De Mmeralibus et rebus 
vietalltcis, describing certain stones like animals, runs : 'And the cause 
of this is, according to Avicenna, that animals themselves in their entirety 
are sometimes changed into stones, and especially into salty stones. For 
he says that just as earth and water are the material of stones, so also are 
animals, which, when they pass into places in which the stone-forming 
essence is given forth to the elements, are seized by the properties of those 
qualities which are in such places. The elements in the bodies of the 
animals are changed into the ruling element, namely, the earthy mixed 
with the aqueous, and then the mineral virtue changes that into stone, 
and they retain their figures and parts both within and without as before.' 

This might appear to be a crude description of petrification, after 
burial by natural causes in the earth, in suitable conditions, and not a 
statement that fossils were produced in the earth by some stone-forming 
essences. Yet the latter doctrine seems to have held the field. 

Leonardo da Vinci (1452-15 19) ridiculed the idea, as also did Fracastoro 
in 1 5 17, but it persisted, and we find Agricola in his De natiira fossilium 
(1548) adopting two views. He believed that some materia pingiiis or 
fatty matter produced organic shapes by fermentation, but he also thought 
that plants and animals could be turned into stone by a siicciis lapidescens. 
Andrea Mattioli two years later (1548) described fossil fishes from Monte 
Bolca, and, from his own observations, believed that bones, etc., could be 
turned into stone by absorbing such a lapidifying juice ; in modern phrase- 
ology by ground water containing mineral matter in solution. Yet not 
until the eighteenth century was the notion that these were merely lusus 
naturae, lapides figurati, or lapides siii generis finally killed by ridicule. 

Now fossil animals, rather than plants, have figured in these discus- 
sions, and Brongniart has suggested that the explanation can be found in 
the fact that coal was not in such demand because of the abundance of 
timber in Europe, and consequently the principal repositories of fossil 
plants had not been explored : but that cannot excuse workers in this 
country at all events. The earliest coal lease, for the commercial exploita- 
tion of coal, was granted between 1210 and 1219 to the monks of New- 
battle, Midlothian, by a Seyer de Quinci, as is recorded by Cochrane- 
Patrick,^ while the Newcastle coalfield was working in 1239 under a charter 
of Henry III. It is inconceivable that the miners were unacquainted with 

* Cochrane-Patrick, Records of Mining in Scotland. 


specimens of the abundant flora that is associated with the coal in these 
and other areas ; so that the paucity of references to such fossils can only 
be attributed to apathy, or interests in quite other matters. There is no 
doubt that great quantities of coal were raised and employed, among other 
uses, for evaporating sea water to produce salt. Prior to 1567, for example, 
the loth Earl of Sutherland had opened up the Brora coalfield ; and the 
coal was used by Lady Jean Gordon, not only for domestic purposes, but 
also for the salt pans working in the neighbourhood. That a goodly number 
of people were employed is shown by old records and implied by old laws 
against the ' colliers and salters ' (1606). Had there been only a small 
number of operatives employed, there would have been no need of Acts 
of Parliament to regulate their behaviour : so that everything goes to show 
an extraordinary lack of interest in the fossils they must have unearthed 
during their work. But, if fossil plants had not been mentioned very 
frequently in these ancient treatises, the time soon came when they were 
used with great eff'ect. 

The recognition, complete or partial, that these lapides figurati once were 
living organisms drove philosophers to attempt some explanation of their 
presence in rocks. In close proximity to the sea-board the presence 
of marine shells could be explained by elevation of the land, but their 
occurrence far inland, and at considerable heights and also deep down in 
mines, introduced difirculties. Men were not prepared to accept such 
wholesale drowning of the land as would be necessary. The first chapter 
of the Bible contains statements that the land was separated from the 
waters on the third day of Creation, and this was held to be the incon- 
trovertible truth. But the Church also taught the occurrence of one great 
flood — Noah's flood — and this, for the time at any rate, presented a way 
out of the philosophical impasse. Scientific discovery and what was 
thought to be Divine revelation were once more in accord. Fossils were 
real organisms that had been overwhelmed at the flood. Now, as Suess * 
has shown, there is no event of pre-historic time so well authenticated as 
an inundation that terrified the Near Eastern world. Records of such 
an event are preserved in the traditions of many races round what is now 
Mesopotamia. Although the story of this occurrence had not been so 
well examined in these days as Suess has now done, yet it appeared in ihe 
sacred books of the Old Testament, and was thoroughly implanted in the 
philosophy of the Hebrews, and, consequently, in Christian philosophy. 

Of course there were dissentients. Leonardo da Vinci (1452-1519), 
for one, could not accept the theory, for there were such obvious diffi- 
culties. We cannot estimate the eflfect of his dissent, for his writings 
were not published until long after his death ; but Fracastoro at any rate, 
who held similar beliefs, was a power in the land, and his views, set forth 
in 1517, had great influence. We have indeed to thank the Italian scien- 
tists of the fifteenth and sixteenth centuries for establishing the organic 
character of fossils, and for combating the notion of Noah's flood as an 
explanation of their presence in rocks. They were before their time, 
however, and their influence was destined to be eclipsed. 

* The Face of the Earth, introductory chapters. 


Interpretation of Fossil Plants in the Sixteenth and 
Seventeenth Centuries. 

The greatest influence in the sixteenth century in geological philosophy 
was undoubtedly exercised by Georg Bauer, [Agricola] (1494-1555). His 
personality and his scientific attainments, both in the fields of theory and 
practice, place him far above all others. He was a man entirely devoid of 
bigotry, and took up the very common-sense view that some ' fossils ' are 
inorganic, but some are remains of plants and animals. Gradually the 
organic nature of fossils was established as a principle of scientific philo- 
sophy. Palissy, whose collection contained ' more than a hundred pieces 
of wood turned into stone,' dared to assert in Paris in 1580 that fossil 
fishes had once lived, that they had not been deposited by a universal 
deluge, and that many of the fossils were different from living types. For 
his liberal views Palissy died miserably in the Bastille. Others, of the 
Italian scientists, put forward many theories, but, on the whole, defended 
the Noah's flood hypothesis. 

It is perhaps unfortunate for my general thesis that the first treatise 
on pure palaeobotany by Stelluti, in 1637, should have been one of the 
reversions to the inorganic origin of fossils. His work has many plates — 
excellent for their time — but his words are retrograde. ' The generation 
then of this wood as far as I have been able to see, and to observe carefully, 
does not proceed from seeds nor from roots of any plant, but merely from 
a species of earth which is rich in clay, which little by little must be 
changed into wood ; in this way nature works until all that remains is 
converted into wood ; it is in this way I believe with the aid of some 
subterranean fires, such as there are in some places, which go winding 
about underground and give ofl^ from time to time a fairly thick smoke, 
and at times flames, especially in rainy weather, and also with the addi- 
tional assistance of sulphurated and mineral waters.' 

Others write in what we would call a more progressive tone ; and 
Steno, the Dane, a professor in Padua, published in 1669 a work of the 
very first importance. He enunciated the law of superposition of strata ; 
the original horizontality of beds ; and that high dip of beds connoted earth 
movement. He distinguished between marine beds containing shells, 
and fluviatile beds with reeds, grasses and branches of trees. But he was 
anxious to reconcile his discoveries with Scripture, and put forward many 
ideas with that end in view ; ideas sometimes plagiarised by others at a 
later date. 

Quirini in 1676 showed that Noah's flood could not have moved heavy 
bodies to the extent that was assumed, since Boyle had shown that wave 
action did not continue to any depth. Quirini also contended that Noah's 
flood could not have been universal. The period indeed was one of great 
interest ; new observations involving new philosophical ideas that directly 
opposed doctrines, as Lyell says, ' sanctioned by the implicit faith of many 
generations, and supposed to rest on scriptural authority.' 

We now reach the time when British workers begin to take a more 
important part in the development of natural science. John Aubrey, 
Martin Lister, Robert Plot were all men of the very highest repute, but 


I can only refer to those who come within the scope of my subject, and 
Robert Hooke, Martin Lister and John Woodward must absorb my 
attention. Hooke had applied the microscope to the study of fossils ; 
and, in the first edition of Evelyn's Sylva (1664), had described a piece 
of fossil wood after a microscopical examination. The following year 
(1665) he published that epoch-making volume Micrographia, figuring 
petrified wood, showing cellular structure, for the first time. The plate 
is poor, but he claims that by the discovery of its pores he produced a 
better argument for calling it fir than Stelluti had for calling similar 
bodies merely earth. Hooke contributed greatly to other branches of 
the subject, but it was over a hundred and fifty years before his contribu- 
tion to the microscopical study of fossil plants was advanced to a greater 
degree. He believed in the extinction of species ; that volcanic action 
and earthquakes had changed the face of the earth, and that these could 
account for fossils being found in the heart of the mountains, and far 
above the level of their natural habitat ; and that it might be possible to 
' raise a chronology ' out of these records of nature — fossil shells.^ He 
considered that England must once have been in tropical latitudes, and 
speculated on shifts of the poles to explain that hypothesis. His ideas, 
indeed, involved crises in nature that appeared no less stupendous than 
those demanded by the diluvialists. These views therefore were not 
accepted, nor even given the consideration they really deserved. Lister,^ 
in 1673, published ' a description of certain stones figured like plants, 
and by some observing men esteemed to be plants petrified.' They were 
really crinoids, but Ray, commenting on them, says that the roots are a 
strong argument for their being ' pieces of vegetables ' and suggests that 
they were submarine plants. In 1692 La Hire ^ described two specimens 
of petrified palm trees from Africa. He states ' there are people who say 
fossils are stones, and have never been other than stones, that resemble 
organisms, while some say that these fossils are petrified. There is 
reason on both sides. These two stones, however (referring to the 
fossil palm trees), are so similar to two pieces of wood that it cannot be 
pure chance that has produced two bodies so similar to two other specimens 
of such a different nature. It is evident that these petrifactions are far 
other than sports of nature that have imitated tree trunks.' He also 
describes fossil wood sent by Father Duchatz from Ava near Mandalay, 
Burma, and considers that the wood was petrified by the waters of a 
nearby river as stated by that priest. This is the earliest reference to 
the famous fossil trees from the Pegu Series on the banks of the Irrawadi. 
We can see therefore the belief in the organic nature of some fossils at any 
rate (and in this case fossil plants), replacing the old view. 

But the doctrines of John Woodward as enunciated in his Essay towards 
a Natural History of the Earth (1695) so coincided with the philosophy 
of his times that they were accepted enthusiastically. It is true that, at 
this time, Burnet's Sacred History of the Earth (first published in Latin 
between 1680 and 1690) had a great vogue as a scientific textbook, although 

' Hooke, Posthumous Works — Lecture, February, 168S. 
• Lister, Phil. Trans. Roy. Soc, vol. 8, No. 100, p. 6181. 
' La Hire, Mdm. Acad, des Sciences, Paris, vol. for 1692, p. 122. 


there is practically no scientific observation in the whole work. Burnet 
studied books, not nature, but his eloquence seems to have made up, in 
the estimation of his literary friends, for his want of scientific knowledge. 
Woodward, on the contrary, was a great observer in the field, and was 
one of the figure-heads of his day, if not always a popular one. His 
methods for obtaining and recording scientific data are so thoroughly 
sound that it is difficult to believe they were formulated two hundred and 
fifty years ago. His questionnaire method of obtaining information, 
when he could not personally travel to the localities in question, is one of 
the earliest uses of an important present-day practice in scientific investi- 
gations. But his deductions from the data he received were often so 
incredibly unsound that one wonders at the enormous influence he 
attained. Accepting Noah's flood as universal, and realising that the 
fossils obtained in northern Europe, in hard limestones and shales, were 
very different from the modern-looking Tertiary specimens from the 
deposits in Mediterranean lands, and very difficult to accept as of organic 
origin when compared with them, he imagined that the flood must have 
loosened the very foundations of the earth. He considered ' the whole 
terrestrial globe to have been taken to pieces and dissolved at the flood, 
and the strata to have settled down from this promiscuous mass as any 
earthy sediment from a fluid.' ^ Gravitational segregation, to use a 
petrological phrase in a totally irrelevant connexion, collected the heavier 
fossils in the lower and more solid rocks, and the lighter forms in the 
upper beds. Woodward, therefore, did not deny like some of his con- 
temporaries, Lhuyd, Plot and others, that fossils were organic, thus 
gaining the favour of his non-scientific friends by his common sense ; 
and he did not antagonise the clerics, for he accepted as an explanation 
for the occurrence of these fossils an event about the reality of which they 
were perfectly satisfied. It is small wonder that his theory was hailed 
with acclamation on all hands. Yet he had personally some misgivings, 
for he admits that the discovery of shells ' in the most retired and inward 
parts of the most firm and solid rocks . . . almost everywhere ' is enough 
to make one believe they are ' mere minerals,' especially when found in 
places ' so deep in the earth and far from the sea, as these are commonly 
found.' Others were also sceptical of Woodward's views, and Ray,^ 
exposing some of the inaccuracies, stated that Woodward ' must have 
invented the phenomena for the sake of confirming his bold and strange 
hypothesis.' The hypothesis, however, was too excellent an escape 
from the impasse that geological philosophy had now reached to be 
relinquished readily. 

Paleobotany in the Eighteenth Century. 

Among Woodward's most enthusiastic followers was Scheuchzer of 
Geneva, who translated Woodward's work into Latin, and thus spread 
his theories through the continent of Europe. With Steno's ideas as 
well as Woodward's to choose from, it is difficult to understand why 

' Essay towards a Natural History of the Earth, 1695, Preface. 
• Ray, Consequences of the Deluge, p. 165. 


Scheuchzer should select the less scientific, but he was by no means the 
only scientist to be captivated by Woodward. Scheuchzer's chief con- 
tribution to palaeontology is an Herbarium Diluvianum (1709) in which 
there are many reproductions of fossil plants. Woodward had travelled 
widely to obtain his information, and Scheuchzer adopted a similar 
method, constantly seeking for proofs of the deluge, and, to his own 
satisfaction at any rate, discovering them. Woodward having found, 
from a study of fossil plants, that ' there is so great an uniformity and 
general consent amongst them, that from it I was enabled to discover 
what time of the year it was that the deluge began ; the whole tenour of 
these bodies thus preserved clearly pointing forth the month of May,' 
Scheuchzer set out to emulate his avowed leader. In the very first plate 
and figure of his Herbarium he illustrates what he calls an ear of corn 
(actually it is a crinoid calyx with stem and arms attached). ' Now from 
the same pit ' (in a slate quarry in Mount Plattenberg, near Matt, Canton 
of Glarus, Switzerland, from which he had obtained fossil fishes) ' I 
present an ear of corn, a great rarity of nature, a genuine witness to the 
Universal Flood, and not only a sign of the event but also of the time it 
took place.' Its plumpness, and yet its semi-mature condition, like that 
of certain filberts that were wrinkled and shrivelled, indicated that the 
flood took place about the middle of May. 

Scheuchzer, as has been noted, translated Woodward's Essay into 
Latin and spread his ideas through Europe. By drawing attention to 
collecting evidence rather than relying on the criticism of literature, he, 
like Woodward, did an immense service for Geology. It is precisely by 
assembling new evidence that criticism must come. Woodward and 
Scheuchzer were both learned and honest observers. Their evidence 
might be read differently by their contemporaries, and indeed was so 
read, but their position had been attained by sound methods, and ,the 
popularity of the views they held indicates their reasonableness in the 
eyes of the general educated world of that day. 

The stimulation given to the collection of fossils soon bore fruit, and 
among the literature dealing with fossil plants in particular we may cite 
a paper by Leigh (1700) on the Natural History of Lancashire. He 
figured numerous examples, but considered them all inorganic. Parsons, 
in 1757, described a collection of fossil fruits from Sheppey made by 
Mr. Jacob of Faversham, surgeon. He defined what he meant by petri- 
factions thus : ' By being petrified is meant being impregnated with 
stony, pyritical, or any other metalline or sparry matter.' In the course 
of his communication he recalls that Woodward thought the flood began 
in May, ' and yet this very opinion is liable to some objections ; because 
altho' fruits, capable of being petrified, from their green state, may be 
pretty well formed in May here, as well as in the same latitude elsewhere, 
(and are) in favour of this opinion ; yet there are the stones of fruits, 
found fossil, so perfect, as to make one imagine they were very ripe, when 
deposited in the places where they are discovered, which would induce 
one to think the deluge happened nearer Autumn, unless we could think 
them the productions of more southern latitudes, where perhaps their 
fruits are brought to perfection before ours are well formed.' 


In the same volume of the Philosophical Transactions (1757) Emanuel 
da Costa described the occurrence of impressions of ' herbae capillares et 
affines, the gramineous and the reed tribes ; but, however, among them 
many rare and beautiful impressions undoubtedly of vegetable origin, 
and impressed by plants hitherto unknown to botanists, are not un- 
frequently met with.' He also recorded cones in the ironstone nodules 
of Coalbrookdale. Da Costa accepted Noah's universal deluge, and, as 
evidence, cited the faults in mineral veins. These, he stated, could not 
have been the result of partial floods, for, if so, they should contain local 
plants and animals, whereas the fossils were of organisms from ' the most 
remote climes from those, where they now lie buried.' He instanced 
specimens of the Indian reeds — bamboos — from England, rhinoceros 
bones from the Hartz forest, horns of the moose-deer and elephant from 
England, and exotic shells from Harwich. Leibnitz, in 1706, thought 
that some of the fossil plants found in Germany resembled living types 
in India. 

The mystery underlying these observations was explained more naturally 
by Jussieu in 1718,^° although his ideas were not accepted. He was 
certainly one of the first to show that the floras of the Coal Measures 
and that of recent times were totally distinct, and that the supposed 
analogues of Coal Measure plants could only be found among tropical 
forms to-day. To quote his own words : ' These plants are so different 
from those of Lyons, of the neighbouring provinces, and even of the whole 
of France, that they seem to belong to a new world . . . and what is 
still more curious these plants either no longer exist, or, if they do still 
live, they occur in such distant lands that we should not have known of 
them but for the discovery of these impressions.' He considered their 
analogues, as has been stated, to occur in warmer regions in America and 
parts of India, and, since fossil shells were found along with them, he 
thought they had been floated to France by ocean currents from the south. 
Summing up in relation to the ideas current in his day, he says : ' It is 
not necessary therefore in explaining these fossil plants to have recourse 
to sports and tricks of nature, nor to palingenesis, as some recent authors 
think. . . . And when one attributes them to the Deluge one does not 
see with certainty the impressions of mature and fruiting plants deter- 
mining the month or season of the Deluge, since these plants came from 
warm countries where plants ripened before those in this country.' 
Vallisneri also, in 172 1, criticising Woodward's hypothesis, advocated 
another, namely, that the earth had been originally completely covered 
with water, the land appearing as the water gradually subsided. Moro 
in 1740 tried to apply the theory of upheaval of the classical authors to 
Vallisneri's observations. He really resuscitated Hooke's earthquake 
hypothesis. Generelli in 1748, in defending Moro's notions, stated that 
vegetable productions were found in different states of maturity, showing 
that they were embedded at different seasons, and he explained this 
by recurring volcanic outbursts. Other workers were collecting and 
describing specimens of fossils, plants, both impressions and petrifactions, 

^^ Jussieu, Antoine de, Acad. Sciences, 1718. 


as well as animals. Lehmann, for example, collected from the coal 
measure beds at Ihlfeld in the Hartz, and published a paper in 1756 on 
Aster montanus which he thought had been caught at the flood in full 
bloom. These blooms were really the nodal sheaths of Annularia spheno- 
phylloides. Gesner, in 1758, observed that some fossil animals and 
plants, like those of Oeningen, resembled the local types, while some were 
either of unknown forms or resembled those from distant parts of the 
world. One famous production of this time must be mentioned, namely, 
Knorr and Walch's descriptions of Knorr's collection (1755-1773)- 
Knorr died soon after the commencement of the work, and Walch is 
really responsible for the greater part. A resume of palaeobotany to date 
was given and figures of many plants, petrifactions and impressions. It 
would be difficult to find more beautiful plates, from an artistic point of 
view, in the whole literature of palaeobotany, but the illustrations are 
almost worthless for reference, in any endeavour to identify similar 
specimens. The classification too must be considered quite bizarre. 
None-the-less it was a classification, and, as such, deserves mention. 
Several works appeared during the latter part of the eighteenth century, 
the majority of the authors describing, with greater or less precision, the 
characters of fossil plants ; but some, like Fuchsel, were also interested 
in the geological horizons at which the plants were found, and a few 
devoted themselves to classification, and correlation of the specimens 
with living forms. 

The labours of these scientists were soon destined to bear abundant 
fruit. It is true that the whole aspect of geological studies had shifted 
from palaeontology to the wider problems of earth processes. The 
organic nature of fossils was now unquestioned, but the interest had 
swung over to the problem of rock formation and rock classification. The 
Vulcanists, Plutonists and Neptunists now held the centre of the stage ; 
but it almost seems as though the palaeontologists had been gathering 
their forces in order to launch the next attack on the philosophy of the 
new times. Again the first assault was by means of observations on fossil 
plants, and it was perhaps in view of this that Brongniart has recalled that 
the plant kingdom ought perhaps to claim the honour of having forced 
the abandonment of the ridiculous ideas that attributed these remains of 
an ancient world to sports of nature and to plastic forces. ^^ Blumenbach 
had been teaching that many fossils, plants and animals alike, must have 
existed under conditions different from the present, as indeed had been 
involved in Jussieu's writings many years before. But it was left to 
Baron von Schlotheim and James Parkinson almost simultaneously, in 
1804, and certainly unknown to one another, to draw attention to this 
aspect of palaeontology. 

The names of their respective works are practically transliterations of 
one another. Schlotheim's Flora der Vorwelt and Parkinson's first volume 
of his Organic Remains of a Former World each deal with fossil plants ; 
and each emphasise the fact that the conditions under which the fossils 
had existed were different from those now extant. Schlotheim's is 

^"^ Brongniart, Histoire des plantes fossiles, p. 2. 


certainly the better of the two productions, and deals with the flora of 
the Carboniferous rocks of the Thuringen district. Parkinson's work is 
more general and ranges through Tertiary, Mesozoic and Palajozoic 
floras. By this time fossil botany had nearly established itself as a science. 
The study of these remains during the preceding century had very 
materially assisted in forcing the acceptance of fossils as organic in origin ; 
in exposing the absurdity of the occurrence of one single Noah's flood, 
which produced all the surface rocks of the earth at one and the same time ; 
and in showing that the fossil plants obtained from rocks represented 
accumulations at diff^erent times, and under conditions different from 
the present. 

One final paper belonging to this period may be mentioned because of 
the excellence of the illustrations. The Antediluvian Phytology of Artis 
belied the ineptness of its title. The figures were well executed, and it is, 
to this day, a reference work in determining fossil plants. 

Pal;eobotany — a Science. 

But fossil botany as a science was initiated by Adolphe Brongniartwhen, 
in 1822, he published a classification of fossil plants, and when the first 
part of his Hisioire des Vegetaux fossiles appeared in 1828. The sub-title 
of the latter is illuminating. It reads : Botanical and geological researches 
on the plants sealed up in the diflferent rocks of the earth. 

William Smith's paper, Strata identified by organised Fossils (1815), and 
the works of Cuvier, Lamarck and Brongniart in fossil animal and plant 
remains, respectively, completely changed the aspect of geology. A 
knowledge of fossils, and of geology, was no longer the hobby of a few 
interested naturalists, whose main work lay in other walks of life ; but 
studies under the titles Geology and Palaeontology became recognised 
as parts of the scientific equipment of universities, either as separate 
departments or under the care of biology. 

The study of geology had been enriched, by this time, on its minera- 
logical and stratigraphical sides, and we may say that nearly every import- 
ant geological theory had been exploited, or, at any rate, envisaged, if 
only in an elementary form. Practically every one of these theories had 
its advocates. There were those who still. believed that most fossils were 
lusus naturae ; and those who considered most of them of organic origin, 
without denying that lusus naturae, in a difi^erent sense, did occur. (To-day 
we can point to specimens of beekite that will pass muster, at first sight, 
for nummulites of the type Assilina ; and others that are perhaps less 
easily confused with actual fossil genera.) Many believed in great con- 
vulsions in the earth, either one or several, and pointed to actual geological 
phenomena in proof of their contentions : others advocated continuity of 
known world conditions. Some advanced the efficacy of water, others of 
volcanic action and earthquakes, to bring about these altered conditions. 
These workers were, for the most part, ordinary reasonable people, and it 
was not a question of selecting between a right and a wrong explanation 
or observation, for like the blind men describing the elephant they were 
all partly right, and partly wrong. The question became one of proba- 
bility among all the possibilities that had been suggested. A summation 


of observations therefore was now necessary, and a systematic method of 
collating these observations was wanted. On the mineralogical side this 
had been, to an extent, accompHshed by Werner and his followers. In 
Botany and Zoology, classification had also been effected, but in Palaeo- 
botany the system of classification was still crude. In 1818 Steinhauer^^ 
described Coal Measure plants in the United States, and, for the first 
time, used the binomial nomenclature, a course that was followed two 
years later by Schlotheim in his Petrifaktenkunde. Schlotheim ^^ and 
Sternberg^* had each devised classifications, and Martius,^^ in 1822, 
published a paper giving reasoned comparisons between fossil and recent 
plants. Although Martius had an unrivalled knowledge of the Brazilian 
flora, his knowledge of fossils was not so extensive, and his classification 
was therefore defective. Artis, in his Antediluvian Phytology, 1825, Pre- 
sented a resume of these attempts at classification, and also added that of 
Brongniart (1822). His own classification, however, was a modification 
of that of Martius. 

In the introduction to the Histoire des Vegetaux fossiles, Brongniart 
discussed yet another method of classification of fossil plants. He used 
the names of living genera if the fossils could be actually identified with 
living types, modifications of these names where they were more or less 
related to living forms, and new names where no such relationship could 
be established. In other words a modification of the classification of the 
botanist. His work was a tremendous step, in advance, and although he 
made mistakes (such as classing graptolites as algae) his work is still one of 
the outstanding memoirs in fossil botany, and a book of reference for the 
stratigraphical geologist. The reason is not far to seek, for, to accurate 
descriptions, he added beautiful and meticulously drawn plates. While 
his work deals with impressions, and these chiefly of vegetative parts of 
plants, his classification is based on ' form ' similarities, and is not com- 
parable in detail with the classification of the botanist ; yet he brought 
order out of chaos, and has given a classification that is as useful to the 
geologist as to the biologist. The study of fossil plants had therefore 
attained a scientific basis, and Brongniart well deserves the title of the 
Father of Fossil Botany. 

A brief digression will not be out of place to ascertain, if possible, the 
general views of geologists at this date. The end of the eighteenth and 
beginning of the nineteenth century not only saw the publication of several 
works in fossil botany, as we have noted, but other branches of science 
were even more prolific in researches. Werner's teaching was every- 
where evident in Geology, Cuvier was probably the chief exponent of 
Natural History, and the workers in other sciences had no reason to doubt 
the catastrophic philosophy of these leaders. Hutton and Lamarck were 
both discredited in their lifetime, and, although they had shown ' the 
writing on the wall,' it was on the wall of the dungeon, or more 

^2 Steinhauer, Trans. Phil. Soc. Amer., vol. i, 1818. 
1^ Schlotheim, Petrifaktenkunde, 1S20. 

^* Sternberg, Versuch einer Geognostich-Botanischen Darstelhmg der Flora der 
Vorwelt, Leipzig, 1820-25. 

^^ Martius, De plantis nonnullis antediluvianis , Ratisbonae, 1822. 


appropriately the oubliette of the Castle of Science, and not on that of 
the banqueting-hall. As a result the guests had little opportunity of 
realising the true position. 

To change the metaphor, when everything seemed knit together in a 
stable framework, science, religion, social customs, even politics (for they 
too were more or less stable after the Napoleonic Wars), and the world 
appeared to be working like a perfect piece of machinery, can we wonder 
that the 'man with the monkey-wrench ' was unwelcome ? Poor Lamarck, 
blind as the result of overwork, but still presenting his ideas through the 
pen of his daughter, and Hutton, the discredited agriculturalist, exerted 
little influence on their fellow scientists, let alone the general body of their 
fellow men. Even Playfair's illustrations of Hutton's views had no 
large appeal. 

The belief in a ' special creation ' for each type of plant and animal, 
and catastrophic disturbances in geological science are absolutely akin. 
Uniformitarianism and evolution are equally associated. It is not un- 
natural, therefore, that Lamarck adopted uniformitarian doctrines in his 
Hydro-geologie (1802) while Cuvier rejected them in his work. The leaders 
of geology in this country belonged to the catastrophic school, save perhaps 
Macculloch, whom Lyell acclaims as his teacher.^^ 

A summary of the geological problems of that date (i 831) was the subject 
of Prof. Gregory's address to this Section at our Centenary meeting, and 
I would now only refer you to that excellent statement for further informa- 
tion. One can see, however, the difficulty Lyell found in the mental 
atmosphere into which he launched his uniformitarian hypothesis. The 
idea was contrary to all the tenets held by scientists and the general public. 
He proved, however, a better advocate than Lamarck or Hutton ; but he 
had to fight against tremendous opposition and inertia. He succeeded by 
appealing again and again to field observations and a parallel method 
was required in dealing with fossil plants. 

Subsequent to Brongniart's work, the study of impressions, or rather 
incrustations, of fossil plants was actively pursued on a stratigraphical 
basis, and the distinction between floras at different geological horizons 
became more and more evident. Tabulation of results showed the general 
truth of Brongniart's classification, and it mattered little whether the indi- 
vidual worker considered the plants as special creations or adopted an 
evolutionary viewpoint. The main object was to obtain records. Time 
and again these records were used to confute the rising tide of uniformi- 
tarian doctrines. Witham, in 1831,^^ was delighted to point out that his 
fossil trees proved the presence of high types of plants in Lower Carboni- 
ferous times ; and Hugh Miller, in 1849,^^ puts the case much more 
powerfully. From a literary point of view Hugh Miller was the most 
powerful opponent of the ' progressive development ' school of thought. 
He was also an indefatigable field worker, so that, while he made his 
opponents prove every step they took, it cannot be said that he was an 
opponent of research. His general attitude seems to be typical of the 

1' Proc. Geol. Soc, 1836, vol. ii, p. 359. 

^' Witham, Observations on Fossil Vegetables, 1S31. 

** Miller, Foot Prints of the Creator, 1849, p. 201 et alia. 


workers right up to the beginning of this century ; they took the view that 
evidence must be collected, and it mattered little whether they adopted 
the theory of evolution or not. 

The culmination of this work in Britain, for the time being, came with 
the publication of Lindley and Mutton's Fossil Flora of Great Britain in 
1837 ; but an additional series of figures, prepared under their super- 
vision, was published in 1877 under the editorship of Prof. G. A. Lebour. 
While not ranking so high as Brongniart's Histoire des vegetaux fossiles , this 
Fossil Flora is a most important publication, and is the last large work on 
incrustations published in Britain until practically recent times. 

A New Technique for studying Fossil Plants. 

But while Artis, Martius, Sternberg and, in particular, Brongniart, and 
Lindley and Hutton were establishing the classification and description 
of incrustations of plants, a new method had been devised for the investi- 
gation of the internal structure of certain specimens, by the examination 
of thin sections made from them. I have already referred to the useless- 
ness of many of Knorr and Walch's beautiful plates, because of the want 
of details of structure, and Hooke's microscopical examinations had also 
borne no fruit, but when Henry Witham published his two works ^^ the atten- 
tion of the scientific world was attracted to the possibility and importance 
of studying the internal structure of fossil plants. The history of the 
method of making thin sections of fossil plants T have already placed before 
this Section, 20 and there drew attention to the controversy that arose 
between Nicol and others, as to who originated the method. Jameson, 
writing as editor of the Edinburgh New Philosophical Journal in 1834, 
says he had long known the method, and had advocated its use to geologists . 
Nicol in the same journal claims he had used the method for fifteen years, 
and there is no doubt that Nicol introduced improvements in it ; but there 
also seems little doubt that lapidaries had used an essentially similar 
method prior to Nicol. Sprengel also had published, in 1828, a work on 
fossil plants for which he employed sections."^^ There is no doubt, how- 
ever, that it was Witham 's work that showed the importance of the method. 
(Henry Witham was one of the first members of the British Association, 
and was one of the twelve constituting the sub-committee on Geology 
and Geography at York in 1831.) ^^ 

The advent of the new technique had more than one consequence. It 
divided the study of fossil plants into two sections, one biological and the 
other stratigraphical, but it also led indirectly to what was probably the 
greatest advance ever made in Petrology. The story is too important to 
be omitted from this address, although only in a secondary sense can we 
consider it one of the influences of the study of fossil plants on geology. 

1* Observations of Fossil Vegetables, 1831. Internal Structure of Fossil Vege- 
tables, 1833. 

"" British Association, Oxford Meeting, 1926, Section C, p. 348. 

'1 Sprengel, Commentatio de Psarolithis ligni fossilis genere, 1828. 

2> Gregory, Pres. Address, Section C, British Association, Centenary Meeting, 
London, 1931- 


During the years between 1831 and 1858 many sections of fossil plants 
were made, and collections formed. One of these, including Nicol's collec- 
tion, was in the possession of Mr. Bryson, Edinburgh. Sections of 
minerals, as thin as 7,Vth inch, had also been prepared, but the possibilities 
of the method were not realised until Sorby published his paper On the 
microscopic structures of crystals}'^ In this work he says that, while on a 
visit to Edinburgh, he saw the ' excellent collection of " fluid-cavities " 
in the possession of Mr. Alexander Bryson of Edinburgh, who told me he 
had found some in the granite of Aberdeen. I immediately perceived that 
the subject could not fail to lead to valuable results when applied to 
geological enquiries.' To pursue the subject, thin sections of rock were 
required, and from this beginning sprang the study of microscopic 

A second development from the discovery of the internal structure of 
fossil plants is the biological aspect. Witham's pioneer work was followed 
by numerous monographs, and larger works like Lindley and Hutton's 
Fossil Flora of Great Britain. These generally dealt with both incrusta- 
tions and petrifactions. But there were wide differences of opinion in 
regard to the correlation of parts and of relationships. Writing in 1871, 
Williamson says of Calamites that Lindley and Hutton had given correct 
illustrations of the relation of root and stem, ' and yet for years afterwards 
some of their figures re-appeared in geological text-books in an inverted 
position, the roots doing duty as leaves ; so far was even this elementary 
point from being settled.' 2* Brongniart also believed that there were two 
distinct types of Calamites, the one cryptogamic, the other gymnospermous. 
Similar uncertainties existed in regard to other forms, and it was only 
after much patient research that the present position was established. 
One of the most important of results has been the difterentiation of the 
great group of the Pteridosperms, and the recognition of their abundance 
in Upper Palaeozoic times. The story is one of interaction of results 
obtained partly from incrustations and partly from petrifactions, while 
the later results, at any rate, have only been obtained by improvements in 
technique dealing with incrustations. In 1866 Binney described Lyginop- 
teris (Dadoxylon) oldhamium as a plant with gymnospermous affinities. 
* It evidently belonged to the genus Pinites of Witham, since changed by 
Endlicher and Brongniart into Dadoxylon.' ^^ Williamson redescribed 
the plant in 1873, and drew attention to its fern-like and lycopodiaceous 
characters, but not the gymnospermous features. Later, in 1887,^® he 
concluded that Lyginopteris [Lyginodendron) ' belongs to the group of 
ferns ' ; but, in the same paper, speaking oi Lyginopteris and Heterangium, 
he stated ' possibly they are the generalised ancestors of both Ferns and 
Cycads. . . .' Stur, in 1883, on negative evidence — the non-occurrence 
of sporangia on the fronds— excluded certain of the fern-like incrustations 
in Carboniferous rocks from the fern group, and referred them to cycads. 

" Q.J.G.S., vol. xiv, p. 454 (1858). 

^* Williamson on the Organisation of the Fossil Plants of the Coal Measures, 
Pt. I, No. I, Phil. Trans. Roy. Soc, 1871. 

*' Binney, Proc. Lit. and Phil. Soc, Manchester, vol. 56. Read, 1866. 
'* Williamson, Phil. Trans. Roy. Soc, p. 299 (1887). 


Felix, in 1885, suggested that Lyginopteris had cycadaceous affinities, and 
Count Solms-Laubach, in 1887, recognised the existence of types, includ- 
ing Lj'^z/zop^em, intermediate between ferns and gymnosperms. William- 
son even in 1890 held that the balance was towards the ferns, ' most 
probably belonging to some sphenopterid type.' In 1903 the question 
was settled definitely by Oliver and Scott ^^ when they showed that L. 
oldhamiiim bore seeds of the Lagenostoma lomaxi form. The reality of an 
intermediate group of Pteridosperms was thus proved. The position 
was attained by reference to petrified specimens, and also to incrustations, 
and the search for the male fructifications has gone on, since then, with 
marked success. Many of the male and female fructifications of these 
fern-like incrustations have been found ; and new discoveries in technique 
have materially assisted in these researches. Methods devised by the 
late Prof. Nathorst, Dr. H. Hamshaw Thomas, Prof. John Walton and 
Dr. Halle have revolutionised the study of plant incrustations and mum- 
mified specimens, so that the weapons now in the hands of the researcher 
are more numerous than ever before ; and this augurs well for the future. 
The story of the Pteridospermeae might be repeated in other groups. 
At our doors, at Rhynie, there is the chert bed which has yielded to 
Kidston and Lang plants whose structures are so distinct that they must 
be included in another special intermediate group, the Psilophy tales. 
Wieland, Florin and others have shown the existence of the Bennettitalian 
type in abundance in Mesozoic times. Hamshaw Thomas has proved 
the occurrence, in the Jurassic Caytoniales,oi characters that throw con- 
siderable light on the probable ancestors of the angiosperms. While 
it may be objected that these have more botanical implications than 
geological, there is the obvious reply that anything that has a bearing on 
the elucidation of past phases of life is, of its very essence, geological. 
I do not agree that a piece of geological research must necessarily produce 
a geological map of a piece of country. One of the most pleasant aspects 
of geological work is certainly that it takes one into the field ; but specialist 
work in the laboratory is no less geological because it is also biological 
or petrological or chemical. 

Fossil Plants as Stratigraphical Indexes. 

The outcome of the stratigraphical aspect of these researches was 
that there had occurred four distinct floras in geological times, an early 
Palaeozoic, a late Palaeozoic, a Mesozoic and a Tertiary flora ; and that 
there were florules by means of which smaller divisions could be recog- 
nised. The degree of accuracy with which these latter may be delimited 
is still, however, open to discussion. There is some evidence, also, for 
an early marine flora in pre-Cambrian and very early Palaeozoic time, but, 
though apparently extensive, the types are few and many are possibly only 
inorganic growths. 

As far back as Jussieu's time (1718) a distinction between the plants 
of the Coal Measures and the living flora had been realised, but no 

27 Pfoc. Roy. Soc, vol. 71, p. 477. 


reasonable differentiation was given until Brongniart, in 1849, suggested 
that there were three distinct floras in geological time, and named them 
after the dominant types of plants in each, namely : — 

I. Reign of Acrogens . . (Old Red Sandstone) Carboniferous, 

II. Reign of Gymnosperms . Triassic, Jurassic and Cretaceous 

III. Reign of Angiosperms or 

Flowering Plants . . Cretaceous (above Wealden) to 


We now recognise an older flora in Devonian strata, below the Upper 
Series, which has lately yielded several new and important types. The 
recent interest in this older flora was undoubtedly stirred up by Kidston 
and Lang's monographs on the plants obtained so near to us in Aberdeen, 
namely, Muir of Rhynie or Rhynie, as it has now become known through- 
out the world. As regards actual numbers of species this older Devonian 
flora is poor, but those that are known indicate considerable diversity in 
organisation. Palaeopitys is a type that Hugh Miller ^^ classed with the 
higher gymnosperms, but Kidston and Lang ^^ would incline rather to 
place it with the Pteridosperms. The Upper Devonian genus Callixylon 
has very specialised secondary xylem, and an argument might be made, 
on that account, for some ancestral form, with gymnospermous affinities, 
in the lower rocks. At any rate the higher and lower pteridophytes are 
admitted, as also the Psilophytales and the algag and fungi. In other 
words, there is a fairly representative phase of vegetation ; and a phase so 
different from the succeeding phases, that it deserves to rank as a flora of 
the first order. (May I recall that it was this flora that Hugh Miller used 
so frequently in his geological arguments combating the ' development 
hypothesis ' as the theory of Evolution was called in his day. The force 
of the argument is now gone, but it was an important feature in moulding 
geological ideas at the time.) How far down the geological scale this 
flora may extend we do not know, but it certainly carries down into the 
rocks of Lower Old Red Sandstone times. 

A yet older flora is found in the early Palseozoic and even re-Palaeozoic 
rocks. The only relics of it consist of the algze, and the so-called alga:. 
that abound at certain levels. The algal character of some of these has 
been seriously challenged ; even some of those now accepted as such may 
have to be relegated to other categories, but some at any rate can be 
accepted. Now these are all marine forms, so far as we know, and their 
very simplicity is a barrier to classification. Are they the lower terms, 
as it were, of several floras, or did one marine type persist through these 
prolonged ages ? At present we cannot say. From a geological point 
of view they are useful as indicating a type of deposit, for plants can only 
occur in shallow water ; and this affords yet another example of the 
use of plants in geological philosophy. 

*' Miller, Footprints of the Creator. 

*' Kidston and Lang, Trans. Roy. Soc. Edin., vol. liii, p. 415. 


It is well to elaborate the fact that many of these so-called algae may 
not have been correctly classified. Massive beds of limestone of Permian 
age near Denver, U.S.A., as Prof. Johnson has shown, have a nodular 
character that simulates that of algal limestones, but no trace of algal 
tubes can be found. Even the surface limestones formed as a result of 
capillary action on the borders of deserts may also show banded and 
nodular structure very similar to algal growths, as may be seen in the 
Kalahari desert to-day. 

On the other hand. Sir Douglas Mawson ^° records recent ' biscuit ' 
shapes, and nodular structure, in calcareous deposits forming on coastal 
flats, and beyond any doubt the result of the activity of blue-green algae, 
and yet no minute algae structure can be observed. 

Aside from these possibilities, algae of Cambrian, Ordovician and 
Silurian age of the Solenopora and other types have been determined ; 
and the structures in pre-Cambrian rocks are also probably true algae, 
in some cases ; so that the evidence for a pre-Devonian flora is reasonably 
good. If, and when, fossiliferous terrestrial deposits of these ages are 
discovered, we may obtain some of the higher terms in yet another floral 

But the flora that has been most thoroughly and extensively explored 
is that of Carboniferous times, and to the late Dr. Kidston of Stirling we 
owe the present accepted subdivisions ; but the work of authors in other 
lands must not be forgotten, for it has had repercussions on the position 
in this country. When I mention Grand' Eury, Zeiller, Renault, 
P. Bertrand, Potonie, Gothan, Renier, Jongmans, Zalessky, David White, 
I only select a few among the older workers whose influence has been 
felt here. Kidston recognised six divisions in this country in his latest 

Radstockian Series 
Staff'ordian Series 

Westphalian Series (Yorkian Series) 
vLanarkian Series 

T r^ -L. -c T) 1 f Carboniferous Limestone Series 

Lower Carbonirerous Rocks i -^ , -r o j ^ o • 

iCalciierous bandstone beries. 

As one of these names (Westphalian) has long been used in a wider sense. 
Prof. Watts has suggested the use of the term Yorkian, and this has met 
with general approval. In the past few years the scheme has been 
criticised, especially by mining engineers, as the zoning possible by 
using the florules was not sufficiently close for their purpose. They 
prefer to use marine bands in their work in the Coal Measures. This 
has led to a rather unjust criticism of the use of fossil plants in geological 
work. In any sequence an unusual bed will form a useful datum line, 
if it be sufficiently extensive. In a marine series an algal phase is extra- 
ordinarily important, as Prof. Garwood has shown ; ^^ and a marine phase 

'" QJG.S., vol. Ixxxv, 1929. 

'1 Fossil Plants of the Carboniferous Rocks of Great Britain, 1923-25. 

*2 Q.J.G.S., 1912 ; Geol. Mag., 1914 ; et alia. 

Upper Carboniferous Rocks 


in an estuarine or lacustrine series would be equally valuable. It happens 
that the latter types of rock may contain coal seams, and, consequently, 
marine bands have assumed a very great importance in correlating beds 
in different areas. But a widespread ash bed would have been quite as 
useful for mapping.^* For wider zoning plants have proved useful. 

But Kidston's classification is not expected to stand as the last word, 
and already research has shown it defective. Dr. Emily Dix ^* believes 
that the base of the Staffordian Series should be lower than Kidston 
suggested ; and she finds that, with the line drawn at the lower level, 
it will more or less correspond with one of the molluscan zones — that of 
Anthrocomya phillipsi. Any classification that will bring diverse groups 
into accord is of the greatest value. Dr. Dix has made another suggestion 
that might well be examined carefully. I have stated above that it is the 
accidental character of marine horizons in a non-marine series and the 
accidental occurrence of an ash bed that give them their value in strati- 
graphy. Dr. Dix states : ' . . . that more attention would have to be 
paid to the vertical ranges of various species of plants, and in particular 
lo the occurrence of rare species, which often give a clue to a particular 
horizon, before an ideal classification could be made.' This suggestion 
should be followed up, and the result might remove the odium with 
which some mining engineers regard fossil plants. 

Fossil Plants as Quantitative and Qualitative Indexes. 

Another phase of research in plant palasontology is the quantitative 
type which has been explored along two lines : (a) for correlation of strata 
in a comparatively small area with possible extension over a wider field, 
and {b) for correlation of one and the same coal seam over large or small 
areas. In 1929 ^^ the late Mr. David Davies published the results of many 
years' work in an area of some 30 square miles in East Glamorganshire. 
The most distant points were 5 miles apart. He recorded the colossal 
number of nearly 400,000 fossil plants, and, as a consequence, obtained 
a very accurate idea of the quantitative balance of plants at different 
horizons (actually 29) in the Coal Measures of that district. The strata 
searched were normally the shales immediately on top of the coal seams, 
but sometimes from 2 to 14 ft. above these seams. On the whole, there- 
fore, the flora, or microflora, is that associated with the individual seams. 
His results show that the floras ranged from wet to dry types. In the 
former lycopods {Lepidodendron, Sigillaria, etc.) predominate, and in 
the latter ferns and pteridosperms. Calamites and Cordaites were dis- 
tributed fairly evenly throughout both types. Molluscan remains 
(Lamellibranchs) occurred abundantly in association with the lycopods, 
i.e. the wet type. On the whole the dry floras were the more common, 
and so he concludes that coal, in these seams, is not so much a swampy as 
a drier boggy accumulation. I am convinced that a continuation of his 

*' Dr. Ellis has actually used an ash bed, the Frondderw Ash, in mapping the 
rocks round Bala. Q.J.G.S., vol. Ixxviii, 1922. 

** E. Dix, ' Coal Measures of North Staffordshire,' Q.J.G.S., vol. Ix.xxvii, 1931. 
** Phil. Trans. Roy. Soc, vol. cc.xvii, 1929. 


researches would yield interesting results in what we may call the study 
of micro-floras, but the work of collecting, naming and recording such 
great numbers of fossil plants will only attract a worker who has the 
appropriate opportunities for obtaining the information, and the patience 
of enthusiasm. 

Equal skill and patience was required for the second line of research 
indicated above. The tabulation and analyses of the relative abundance 
of fossil spores, in one and the same coal seam, has been used to correlate 
beds in diflFerent parts of the Yorkshire Coal Field. A considerable 
degree of success has attended the method. Diagrams have been con- 
structed representing the spore index for different types of spores from 
top to bottom of selected seams, and, as a result, Mrs. G. E. Finn ^'^ has 
been able to recognise individual seams of coal over distances of about 
40 miles, and independent of the flora or fauna of the associated rocks. 
The method was tested rigorously for the Arley, Better Bed and Silkstone 
seams with marked effect ; and it shows that the spore content and pro- 
portion of types of spore to one another can be relied upon for the identi- 
fication of seams in all parts of the Yorkshire Coal Field. 

Still thinking of single seams, the new technique of Hickling and 
Marshall ^^ opens up another avenue for the use of plants in geology. 
They find that they can identify certain bark structures in Lepidodendron, 
Sigillaria and Bothrodendron by examining the thin layers of bright coal 
that often form the surface layer of the specimens. Having identified 
the types of bark, they go on to examine the layers of the coal itself, and 
it certainly appears that we may soon know accurately the plants that 
made the actual coal, whether the bark, wood or spores, and in what 
proportions they have occurred. 

The application of the metallographic method to polished and etched 
surfaces of coal has also yielded valuable results, as has been shown by 
Seyler.^^ In these several ways the stigma of uselessness may yet be 
entirely removed from fossil plants as means of close zoning in the Coal 
Measures, and as indexes of definite conditions of accumulation of indi- 
vidual seams. The economic consequences may be equally important 
in the exploitation of special seams. 

Nor has the importance of the flora of Carboniferous age been confined 
to land and swamp plants, the marine algce have been extensively employed 
by Prof. Garwood in this country, and by other workers abroad, as 
zonal indexes. They have been employed as indicators of conditions of 
depth, and it is extraordinary the extent to which similar lagoon conditions 
had spread, for example, over the north of England and southern Scotland 
in early Carboniferous times. Sir Douglas Mawson, as already mentioned, 
has shown the wide spread of calcareous algas of the blue-green type over 
saltmarsh areas in Australia to-day ^^ ; and this forces one to remember 
that the mere presence of algae does not necessarily imply marine lagoonal 
phases. Only when they are associated with actual marine animal forms, 

*• University of Sheffield Library, M.Sc. Thesis, 1931. 
*' Trans. Inst. Mining Engineers, vol. Ixxxvi, 1933. 
*' Phil. Trans. Roy. Soc, vol. ccxvi, 1928. 
^' loc. cit. 

\ C— GEOLOGY 69 

or belong to forms that are definitely marine, can their presence be 
regarded as satisfactory evidence of such conditions. 

There is another consideration that requires investigation, and in which 
fossil plants will assist the geologist. Huge thicknesses of strata of the 
sedimentary series must have been derived from land-areas, probably of 
fair elevation to allow the necessary gradient for streams. Were these 
lands clothed in vegetation ? Examples of upland phases of plant-life 
are not always easily obtained, but, in association with volcanic action, 1 
believe we have conditions that assist in preserving some record of such 
floras. During Lower Carboniferous times in Scotland, at any rate, the 
volcanic ashes enclose abundant remains of plant life; and, while we can 
say little about the actual amount of elevation of the areas concerned, the 
plants of the Pttys type, which were so common, with their short, thick, 
hairy phyllodes, show an adaptation to a drier environment than that 
occupied by the Lepidodendrece. The proportion of wood in the axis of 
these Pitys trees also points to conditions where the individual could not 
depend as much on mechanical support from its neighbours as occurs in 
swamp growth ; while the growth rings in the wood show, when they 
occur, responses to some rhythmic influence. These characters all point 
to Pitys as an upland type. The drifted plants of the ' roof ' nodules of 
the coal seams in England, also, probably furnish examples of an upland 

There cannot be a shadow of doubt that the fossil plants of Carboni- 
ferous times have had, and still promise to have, important repercussions 
on our ideas of the geological conditions (including climatic conditions) 
of that age. 

Permo-Carboniferous Floras. 
But while the Carboniferous flora in Europe and N. America continued 
into that of Upper Carboniferous times without any marked change of 
type, though, of course, with recognisable modifications and additions, 
there were great changes developed in other parts of the world. The 
Glossopteris flora has long been knoAvn, and its association with clearly 
marked glacial phenomena has given rise to much speculation. Beneath 
the beds bearing the Glossopteris flora are rocks containing a typical 
Lower Carboniferous suite of plants, i.e., when compared with beds of 
similar age in Europe and N. America. Exact correlation of the strata 
across the Tethys sea has not been effected, and, of recent years, there 
has been some tendency to draw attention to the rarer plants in the 
Glossopteris-Gangamopteris assemblages as illustrating connecting links 
between the flora in the southern hemisphere, or rather south of the 
Tethys, and that to the north. It has been suggested also that this flora 
must have lived in a cooler environment than that in which our Coal 
Measure plants flourished ; and that a shift of the South Pole to the 
Indian Ocean would give a distribution of the known localities, where the 
floras in question occur, such that the northern flora would occupy a more 
or less equatorial belt and the^Glossopteris flora one bordering upon polar 
regions. Two considerations rather negative such an explanation : 
{a) there is no good ground for assuming that the Coal Measure flora was 


a tropical one, and (b) if the South Pole were in the Indian Ocean the North 
Pole would come out in N.W. Mexico, and no sign occurs there of Permo- 
Carboniferous glaciation. Even on the best arrangement of these locali- 
ties to suit Wegner's hypothesis of continental drift, some evidence of 
cool conditions should be found in the rocks of that area ; hot, arid 
conditions, however, are indicated rather than cold. 

The mixing of northern types in the Glossopteris floras, as shown by 
several recent papers, has some bearing upon the question of the complete 
isolation of Gondwanaland from the northern continents ; so also has the 
discovery of still other floras of Permo-Carboniferous age — the Giganto- 
pteris flora of China and Korea ; the Angaraland flora of Siberia ; and the 
Upper Permian flora of the Grand Canyon of the Colorado. But, until 
more is known of these latter, hypothetical re-arrangements of continents 
and oceans are rather premature, though, of course, they are interesting 
exercises of ingenuity. The Gigantopteris flora ^° had an admixture of 
forms more common in the Mesozoic rocks, as also had the Angaraland 
flora. The flora of the Grand Canyon deposits,*^ too, had Mesozoic 
characters. It would be interesting if the quantitative method of David 
Davies could be applied to all these floras to determine which plants 
were really abundant, and which were rarities. There is one area at least 
where this could be done, namely, at Wankie in Southern Rhodesia. 
Several of us in this room will remember the absolute preponderance of 
Glossopteris on the horizon from which we collected in the field at Wankie 
in 1929, as well as in the samples brought to us at the Mine Ofiices through 
the good graces of the manager. The ' northern forms ' were conspicu- 
ous by their rarity. It is too much, at present, to expect these intensive 
studies to be conducted in the areas in question, but such ecological 
researches will have to be attempted before we can say that these floras 
may be used as confidently for zonal, or other geological and palaeogeo- 
graphical conclusions, as we can employ the Coal Measure floras of N.W. 
Europe and Eastern America. 

Generally speaking, the Paljeozoic floras occupy the greater part of the 
attention of geologists, and the reason is not far to seek. If fossil plants 
are to be used at all in zonal work, they must be used in areas where there 
is a practical demand for such zoning, and where plants are abundant. 
Now we know that there are coal seams of Mesozoic and Tertiary age of 
very great extent, and of enormous potential value, but they have not 
been exploited so thoroughly as the late Palaeozoic coals, and consequently 
the associated floras have not yet received the attention they merit. But 
the work of du Toit, Walkom, Halle and others is gradually making us 
better acquainted with these floras. 

Mesozoic Floras. 

On the other hand, many important results, from a botanical point of 
view, have been obtained from the examination of the Triassic and 
Jurassic plants ; and the Botany School, Cambridge, has been especially 

" See Seward, Plant Life through the Ages. " D. White. 


interested in these floras, and must be congratulated for the way its workers 
have given their energies to these problems. Prof. Seward, Dr. Harris, 
Dr. H. Hamshaw Thomas, Prof. Walton and others have contributed 
noteworthy memoirs, not merely describing the plants, but discus- 
sing the geological and botanical implications of the floras they have 
studied. This has necessitated devising new methods of examination, 
and Dr. Thomas' work in that regard is most valuable. Indeed it has 
led to recent investigations of Palaeozoic fructifications, at the hands 
of Dr. Halle, that are most illuminating, and that have already been 

In general terms the Mesozoic floras contain a few survivals from 
Paleozoic times, but the special development of new forms of ferns, 
possibly some pteridosperms, cycads, conifers and rare types that may 
be the percursors, or even the ancestors, of the flowering plants, are the 
main features of the floras. On the whole, the interest of the Mesozoic 
floras is botanical rather than geological. So far as I know, no great 
amount of zoning has ever been accomplished by using these plants. 
Yet Pia has employed algas to determine zones in the Alpian Trias. 

If the Paleozoic flora has drawn attention to world climates in the past, 
that of Mesozoic times has accentuated the position. In point of fact it 
was the discovery of Mesozoic plants in Arctic regions that drew attention 
to the problem, if not in the first instance, at any rate at an early date. 
A brief consideration is therefore not only warranted, but imperative, in 
our study this morning. 

In some areas where the Gondwanaland flora has been developed, and 
particularly in India and Australia, there seems to be a gradual change from 
the late Palaeozoic Glossopteris-Gangamopteris flora into that of Mesozoic 
times and terminating in the Thinnfeldia flora. In Europe the plant 
series in similar rocks is scanty, and in America enormous numbers of 
coniferous trees, that are represented in the petrified forests of Arizona 
and Utah, are derived from one horizon — the Chinle formation of Middle 
Triassic age. In these special areas in India and Australia there are 
apparent links with the upper Paleozoic vegetation, but our knowledge 
seems like ignorance, in contrast with what has been discovered in the 
Coal Measure flora. Much more work is necessary. 

It is the Jurassic-Lower Cretaceous flora, however, that has attracted 
most attention in botanical circles ; for it is a phase that was suddenly 
replaced by one closely similar to that of the present time, and yet one 
that was itself quite distinctive. Perhaps the most striking character 
is the number and variety of plants of the cycad class. But it was a 
complete plant phase, with all the main groups represented, and even the 
flowering plants are heralded in the Caytoniales of the Yorkshire deposits. 

The Rheetic flora has been brought to our notice recently by the wonder- 
ful suite of plants of this age from Greenland. The flora in general shows 
a considerable development of ferns of the Osmimda type, numerous 
cycads and other gymnosperms, among which the Ginkgoales {Ginkgoites , 
Baiera, etc.) are specially prominent, and the genus Sagenopteris, which 
Dr. Thomas has shown probably bore fruits that are a first approximation 
to those of the flowering plants. In the later Jurassic rocks distinctions 


like those that could be detected in different areas among the older suites 
of plants, cannot be seen — the associations from widely separated places 
are very similar ; and there is decidedly less difficulty in assigning speci- 
mens to their -proper botanical group. Plants of doubtful affinities are 
fewer. Thus lines of evolution can be traced, as, for example, in the 
Osmundaceae and the Bennettitales. The last group has been of special 
interest, and the works of Dr. Wieland, Prof. Seward, Dr. Marie Stopes 
and Dr. H. H. Thomas have illustrated the wonderful variety of form 
included in it. Indeed it might be called the distinctive group of Mesozoic 
times, though the Ginkgoales also constitute another very prominent 

The physical conditions under which some forms lived can sometimes 
be detected. The swamp flora can be seen in association with coals 
like the Brora coal, Equisetites is a common type ; the estuarine series in 
Yorkshire yield a flora that has drifted probably from lowland regions ; 
and the conifers and cycads illustrate plants from a rather drier, and 
possibly upland, environment. In this connexion the Portland and 
Purbeck beds are specially interesting to the geologist. Drifted stems 
of cycads, and logs of coniferous wood, are not uncommon in the Portland 
quarries ; but the curious rings of tufa deposited round erect stems, as 
seen at Lulworth, probably point to lagoonal conditions of slow subsi- 
dence and gentle laving of the stumps by waters rich in calcareous material. 
An explanation of the well-known breccia beds of that last-mentioned 
locality, as due to deposition over thick accumulations of plants that 
subsequently rotted and caused the over-lying strata to be broken up, need 
not detain us, except to express our doubt of the suggested solution. The 
water of these lagoons was frequently evaporated to dryness, as the 
conspicuous rock salt and gypsum pseudomorphs attest. This is merely 
a local point of interest, but several of us here visited the area during the 
British Association meeting at Southampton, and it recalls to me pleasant 
memories of our discussion of the Jurassic flora on the spot. 

The Lower Cretaceous Flora. 
The plants of the upper Jurassic beds are generally similar to those that 
occur in the beds of Lower Cretaceous age, but a transition into the 
Tertiary flora is evident in the latter almost from the start. Heer com- 
pares the Greenland beds of the Kome series with the Wealden series, 
the Atane series with the Cenomanian succession. The latter view has 
been favourably accepted, the former not ; but, taking the Cretaceous 
flora in Greenland as a whole, Seward *^ regards it as representing more 
fully than elsewhere the transition between the Mesozoic and Tertiary 
floras. As a rule the comparison of late Cretaceous and Tertiary floras 
with living plants shows differences of geographical distribution and 
conditions, rather than essential differences in types. Dr. Stopes also 
has shown that the angiospermous woods from the Lower Greensand 
Series *' did not exhibit any primitive characters, nor any relationships 
with gymnospermous (cf. Bennettitales). They were ' like quite highly 

*2 Phil. Trans. Roy. Soc, vol. B., p. 215 (1926). 
" Phil. Trans. Roy. Soc, vol. B, p. 203 (1912). 


placed Angiosperms in all their details.' Thus the Upper Cretaceous- 
Tertiary flora must have been preceded by one in which highly developed 
angiosperms were not uncommon, and the suddenness of the institution 
of the later flora must have been due to some factor that allowed the 
angiosperms scope, and inhibited the other elements in the Lower Cre- 
taceous flora. What the factor was we do not know, but the suggestion 
that it was the ' Cenomanian transgression ' is one of great value. Berry ^* 
thinks it ' futile to speculate about the problem at the present time,' and 
advocates a more intense study of Mesozoic floras, especially in the 
tropics, and the upland rather then the swamp flora. There is much in 
this criticism, and I would further add that the volcanic ashes of these 
days should be searched for traces of this upland flora. 

Nevertheless the suggestion that the ' Cenomanian transgression ' was 
responsible for the alteration of conditions that gave the angiosperms the 
' boost ' which initiated their present dominance is, I think, valuable and 
worth exploring. It happens to coincide with an idea I have held since 
I first stood on the edge of the Colorado River, at the bottom of the canyon, 
and looked at the sand and mud that was being swept along. One of my 
difficulties, at the time, was to understand the conditions of deposit of the 
Greensand,Gaultand Chalk formations in England. Prof. E. B. Bailey ''^ 
had just published his suggestion of the Chalk being produced off^ a desert 
coast, and the desert conditions persisting after the beginning of Tertiary 
times. I found it difficult to reconcile the abundant plant remains of the 
upper beds of the Lower Greensand, and even of the Gault itself, with 
desert shores. But the geography of the Colorado River seemed to 
explain the situation. The river passed through areas of barren, desert 
country, and areas with abundant vegetation, carrying sand from the 
one, plants from the other, down to its estuary. Such a stream might 
be expected to produce a kind of deposit like the Greensand with smooth- 
grained, current-bedded sands, and abundant plant remains. A depres- 
sion of the drainage area up to the desert zone would widen its estuary, 
prevent sand from being swept into the areas once reached, and permit 
the accumulation of only fine clays or only pelagic deposits in these areas. 
The succession of plant-bearing, current-bedded sandstones would be 
followed by clays and calcareous oozes comparable with the succession 
of the Upper Cretaceous rocks in S.E. England ; and the shores might 
be deserts during the production of the calcareous oozes, and so permit 
the latter to accumulate close in-shore. After elevation, the desert 
conditions might still persist. 

But suppose the land prior to depression was clothed, in its non-desert 
track, with a vegetation consisting of an older flora holding in check, by 
competitive power, a younger race ; or, to put it into actual fact, a Mesozoic 
flora, similar to that found elsewhere without angiospermous associations, 
but here competing successfully or, at any rate, holding a balance with 
its angiospermous units. 

The depression of such a land would cause the flora to migrate, and 

" ' Revision of the Lower Eocene Wilcox Flora,' U.S.G.S. Prof. Paper 156, 
1930, p. ir. 
*^ Geol. Mag., 1924, p. 102. 

D 2 


the accession of water to the desert region would permit of some increase 
in rainfall over the area. The land would therefore be ready for plant 
colonisation, but each element of the flora would have more or less an 
equal chance, and the more vigorous race would prove successful. It is 
in some such way I picture the conditions to the north and west of Britain 
— in Greenland if you will — during late Cretaceous and early Tertiary 

To an extent this will also account for Greenland as one distributing 
centre for the angiosperms at a later date ; and, in addition, the depression 
would encourage the chance of ocean currents from the south rendering 
the climate rather warmer during the later stages than during the earlier. 
In fact it would explain the climatic conditions in England up to the time 
of the London Clay deposits. 

The Tertiary Floras. 

While there is some admixture of the Tertiary and the older Mesozoic 
flora to be observed in one or two localities, on the whole the change 
comes with dramatic suddenness. So sudden, indeed, that attempts at 
possible explanations appear futile, for there is no evidence of any com- 
parable change in inorganic nature. Examination of the sediments 
deposited before and after those of the zone in which the change is ob- 
served do not indicate any cause for the phenomenon, nor can the corre- 
sponding igneous rocks, if available, give us any clue. But, and this, so 
far as we are concerned, is the most important feature of all, the whole 
basis of classification of the fossil plants is also changed. This point is 
simply not appreciated by the average geologist, and, for that matter, it 
seems to have been tacitly ignored by the palasobotanist. What would 
we say to the mineralogist who classified minerals by their colour ? It 
could be done ; it has been done. That was the basis of Werner's classifi- 
cation, and we find men like Jameson defending it. Now there is no 
doubt that such a method would, now and again, be accurate — azurite, 
malachite, etc., have distinctive colours — but what faith would we have 
to-day in mineralogical conclusions based on such a scheme ? 

The classification of flowering plants is based on floral characters and 
fructifications — this is the result of the combined experience of botanists — 
and these characters depend on delicate structures produced at a particular 
season of the year, generally totally different from the vegetative parts of 
the parent plant, and developing in a very few days into a fruit that is also 
totally distinct from the other members of the plant that bears it. While 
the two end stages — the vegetative body and the seed — may be fairly 
persistent over a period of months, the flower may last only a few hours. 
Yet the floral characters are the basis of botanical classification. The 
chances of preservation of such delicate structures are very few (though 
they occasionally are found, as in the fine ashes of the Miocene Lake, 
Florissant, Colo.), and the chances of correlation with their parent plants 
are still fewer. With what are we left ? The vegetative structures, 
definitely rejected by the botanist as bases of classification of flowering 
plants 1 We cannot get away from this position, that, as a matter of 
observation, the vegetative parts of flowering plants are not safe criteria 


for classification. Here and there a plant may have characteristic vegeta- 
tive features, just as minerals may have characteristic colours, but taken 
by and large, the basis is as defective as classifying minerals by their 
colour alone. Modern methods for the determination of cuticular structure 
certainly improve matters as regards leaves and very young shoot tips, but 
they also are deficient, despite the work of many observers. I hope I 
may not be mistaken — I have said flowering plants. The case for 
gymnosperms is rather better ; we may place some confidence in their 
determination by vegetative characters, but not flowering plants. For 
this reason we have more confidence in the determination of members of 
the older floras by vegetative characters, though caution is also necessary 
in these cases. 

Unfortunately the very abundance of flowering plants, and their 
absolute preponderance numerically over other types, in the Tertiary 
floras from the very beginning is a hindrance, not a help, to their use in 
geological work. The determination and naming of the specimens is 
not easy, and the protest made by Mrs. Reid and Miss Chandler in their 
recent memoir *^ is timely in this respect, for workers are far too prone to 
give the name of a living genus to a specimen, and leave one to read down 
the description before one sees that their determination has been made 
on a few scraps that were hardly recognisable. Berry long ago protested 
against the nomifia nuda in tertiary floral lists ; Reid and Chandler's 
protest against the use of definite names for indefinite specimens is no 
less deserved ; and Sahni's statement *'' regarding the Mesozoic flora that 
' it is satisfactory to note that the hostile ranks of the species incertce sedis 
have suffered heavy losses ' cannot be taken as a matter of congratulation 
when applied to some lists of Tertiary floras. 

If workers refrain from giving the name of living types to fossils that 
merely look like them, and designate such with some name less committal, 
their floral lists would command more respect, and fewer unsafe deduc- 
tions would result, to the great benefit of geology and of our colleagues 
in other sciences who are coming more and more into the field of geological 
philosophy as we draw nearer to recent times. I refer particularly to the 
geographers, meteorologists, and archaeologists. 

Yet there are certain generalisations that may be accepted, (i) The 
earlier Tertiary floras contain angiosperms almost exclusively of arbores- 
cent type — a feature of tropical and sub-tropical vegetation to-day. 
(2) The circum-polar spread, in early Tertiary times, of so many forms 
now living in tropical and sub-tropical lands indicates that these types were 
developed in the colder regions and migrated southwards, and not the 
reverse. (3) There is evidence that some rise in temperature in the 
north temperature zone in N.W. Europe and N.E. America took place 
about middle Eocene times, and that from that ' peak ' there has been 
a progressive lowering of temperature, with oscillations during the recent 
Ice Ages. (4) The Tertiary floras of the Northern and Southern hemi- 
sphere are not quite comparable for, while there appear to be considerable 
variations in the northern hemisphere, there is a greater uniformity in 

*^ The London Clay Flora, p. 46 (1933). 

*' Proc. Asiatic Soc. Bengal, Presidential Address, 1922. 


the southern hemisphere. How far this is the result of inadequate 
collections or inaccurate determinations is difficult to ascertain. 

Fossil Plants and Special Rock- types. 

It is not my purpose to discuss the origin of coal, oil-shale, ironstone, 
limestone, etc., that are the result of the accumulation of plant debris or a 
consequence of the activity of plant life in the past, but a recent publi- 
cation by Murray Stuart makes such a direct correlation of definite fossil 
types with oil formation in Burma that some comment is merited. The 
fossil wood first described by La Hire in 1692 consists chiefly of pieces of 
Dipterocarpus stems, and the living D. turbinatus is the source of the 
Garjan oil of commerce, a single tree yielding, on occasion, 40 gallons of 
oil per annum. *^ Murray Stuart*^ suggests that the petrifaction of the 
trees now found in the Irrawaddi Series released the oil now accumulated 
in the underlying Pegu Series. The theory of the origin of oil from 
vegetable material is no new one, but such a direct relationship has never 
before, I think, been suggested, nor can it be accepted without further 

Fossil Plants and Climate. 

On account of the clearly marked zonal distribution of plants to-day, 
it has long been held that they should be good indexes of climatic zones 
in past time. The position in this regard is not so definite as was formerly 
maintained, when the continents and oceans were held to be fairly perma- 
nent in position, though not necessarily in size or shape. Migrations of 
plants were considered to be eff^ected slowly and in consonance with 
climatic changes. This was especially so in relation to the Tertiary 
flora and to the Ice Age. But the discovery of many floras in Arctic and 
Antarctic areas, and several Ice Ages, has compelled re-consideration of 
the whole position. The other discovery, that oceans and continents 
had probably not occupied the same relative position with respect to the 
poles as they do to-day, further complicated matters. 

In a recent discussion at the Royal Society ^^ Prof. Seward put the case 
from the botanical point of view and stated that plants have been over- 
estimated as indexes of climate. As regards the older floras, he stated that 
the plants were of little value, because they were extinct. One of the 
arguments that used to be advanced for a tropical climate during the 
accumulation of the Coal Measures in England was the large size of some 
of the specimens. Last autumn I had the opportunity, through the good 
offices of Prof. Fearnsides, to examine and photograph probably the 
largest Carboniferous plants ever seen. They were casts of the stems 
of members of the Lycopodiales , and their stools ranged up to 6 ft. 3 in. 
in diameter, or 20 ft. in circumference. Slightly smaller specimens in 
the same vicinity had been described by Sorby ^^ and are still protected by 
wooden huts erected round them. Now members of this relatively lowly 
plant group reaching the enormous size of forest trees must, according 

*8 Watt, Dictionary of Economic Products of India, voL iii., p. 164. 

*» Inst. Pet. Tech., 1925, p. 296: Geology of Oil, etc., 1926. 

^ ' Discussion on Geological Climates,' Proc. Roy. Soc., ser. B, vol. 106, 1930. 

" Q.J.G.S.. 1871. 


to the ideas of the time, have grown under tropical conditions. There 
is no a priori reason, however, why this should be the case. Luxuriant 
growth is not a feature exclusively tropical, it is more a question of water 
supply at the proper time. Still less can we accept the contention when 
we find that the luxuriant Glossopteris flora, co-existing with the northern 
one, was associated with glacial conditions ; the glaciers, in places, coming 
down to sea level. Tropical conditions in the northern hemisphere at 
the same time as glacial conditions in the southern, simply could not be 
brought into unison. The explanation by Wegener's hypothesis of 
continental drift is an easy way out of the impasse ; but this is only one 
case among several, and even Wegener would hardly have accepted the 
wanderings of his continents that would be required to explain all the 
known occurrences. 

Again, the presence of plants, whose living relations inhabit tropical 
lands, in the early Mesozoic rocks in Greenland is no proof of tropical con- 
ditions in Greenland at that time, for a genus of plants may have some 
species capable of enduring more rigorous conditions than others, and, 
moreover, there may be a progressive decline in the power of certain 
genera to withstand any but tropical conditions as time goes on. Prof. 
Seward further pointed out that the present diversity in floras is largely 
due to the great preponderance of flowering plants, and that the apparent 
uniformity in past floras was therefore illusionary. 

Then we must never forget that fossil plants are almost always ' form ' 
genera and ' form ' species, and that, even within a single genus to-day, 
we may have some species confined to tropical regions and others that 
tolerate a colder climate. Consequently, a specimen that cannot be 
accurately proved as identical with a living species may be little or no 
use as a climatic index. 

Of course when specimen after specimen points in one and the same 
direction, so far as probable climatic characters are concerned, then we 
cannot disregard that indication, and when such indications can be 
confirmed by collateral phenomena, such as an apparent sub-tropical 
flora and entire lack of tundra features in a region now in the tundra belt, 
the conclusion is inevitable that climatic change has taken place. 

Taking everything we know into consideration, the general consensus 
of opinion is that plants do afford an index of climatic changes, and that 
these changes have been very considerable in past times. 

Can we explain those changes, and can we obtain an explanation that 
will not conflict with other evidence ? 

In the past few years interest in the problem has been awakened by 
Wegener's theory of continental drift, or, perhaps better, the modification 
of Wegener's hypothesis suggested by the late Prof. Joly of Dublin. Yet 
it must be remembered that Lyell and Darwin ^^ were considering the 
problem seventy years ago, so that it is no new geological puzzle. 

'* Lyell's Letters. Letter to Darwin, March lo, 1866. ' I have been doing my 
best to do justice to the astronomical causes of former changes of chmate, as I 
know you will see in my new edition [Principles of Geology], but I am more 
than ever convinced that the geographical changes are, as I always maintained, 
the principal and not the subsidiary ones.' 


The most valuable contributions towards a solution are coming at 
present from the meteorologists, and Dr. Simpson and Dr. Brooks have 
each made important suggestions. There is, as Dr. Simpson says, ' no 
formulated meteorological opinion,' but he has personally come to a 
certain conclusion. ^^ Throughout geological time, he continues, there 
must have been climatic zones. The climate in a zone depends on two 
factors — the intensity of solar radiation, and the distribution of land 
and water. A study of the present climatic zones shows that the mean 
temperature in it is not affected by the distribution of land and water, 
though locally a range of 5° C. from the mean of the zone may occur. 
It is the annual range of temperature that is chiefly affected by the distri- 
bution of land and water. On these grounds he concludes that ' no 
change in the distribution of land and sea alone could have produced the 
large changes in climate shown in the geological record.' 

Increases in solar radiation will cause (a) a greater temperature gradient 
from pole to equator, (b) an increase in the general circulation of the 
atmosphere, (c) increase in cloud and rainfall, (d) an increase in the 
mean temperature of all zones. Again he concludes that there is no 
evidence of sufficiently large changes in solar radiation to account for the 
facts of geological climates. Consequently, only a theory of continental 
drift will suffice. 

Dr. Brooks thinks that Simpson has under-estimated the effects of 
ocean currents. He attacks the problem from another point of view, 
namely, the question of Ice Ages. He shows that once an ice cap com- 
mences, it spreads rapidly, for its cooling effect increases with its area ; 
but a critical point occurs beyond which the effect is not proportional to 
the area, and consequently the ice cap finally terminates. He concludes 
then that the conditions that determine the temperature of Arctic and 
Antarctic areas is not the distribution of land and water, but the distribu- 
tion if there were no tee. The most favourable distribution of land and 
water for high polar temperatures is a series of long narrow islands ex- 
tending meridionally from high to low latitudes, and separated by wide 
deep seas. The worst distribution would be lands stretching parallel 
to the lines of latitude. There are, in his opinion, only two possible 
polar climates, a mild type and a glacial type. Since the lands have 
mostly stretched from high to low latitudes, the mild type is normal and 
glacial periods exceptional. 

Wilhelm Ramsay, of Helsingfors, in 1924^* advocated an increase in 
relief to explain glaciations, as others had done in former years. Orogenic 
movements, he claims, have preceded the chief periods of glaciations. 
The Caledonian, Hercynian, and Alpine periods of orogenic disturbance 
have each resulted in glaciations in the succeeding epochs. Mountain 
chains increase radiation because the layer of air above them is thinner, 
consequently there are colder conditions developed, and snow may 
accumulate, causing a still further reduction of temperature. Again, 
the greater amount of snow involves a removal of water from the ocean, 
and the lowering of level may amount to as much as 130 metres if we 

^' ' Discussion on Geological Climates," Proc. Roy. Soc, 1930. 
s* Geol. Mag., 1924. 


accept 1 ,000 metres as the thickness of the ice sheet — a figure not incom- 
patible with known observations of former ice sheets. Ocean currents 
would be checked, and still further increase of the ice cap would result. 
Depression of the lands, however, would have the reverse effect. Beyond 
any doubt, periods of mountain building and of marine incursions have 
occurred, but Ramsay admits that there are difficulties that he cannot 
fully explain. His theory is, however, only a development of that put 
forward by Lyell in his letter to Darwin, and later published in his 
Principles of Geology. 

Now all these theories abound in conditional phrases, and the geologist 
hardly knows what to accept. Personally I favour Brooks' theory, for it 
demands far less disturbance of the conditions we are inclined to consider 
normal. The earth so far as we can see has always been solid and rotating 
at an enormous rate — a gyroscope, in fact. If we are to assume wholesale 
melting of the sub-surface rocks, then the speed of rotation would soon 
play havoc with the crust. It would no longer be a case of continental 
' drift,' there would be a continental ' surge.' I cannot accept such whole- 
sale continuous movements of continents as Wegener envisages, but I do 
accept something along the lines of Joly's periodic local softening of the 
sub-stratum, differential foundering of the continental blocks, even slow 
separation of the continents, and a rotation of the blocks round parts 
where softening had not taken place. In consequence, the continents 
are not aggregated round the equator, where they ought to be on Wegener's 
hypothesis, and there has not been any serious slip of the skin on 
the core — Wegener's definition of shifting of the poles — at any one time. 
The Atlantic I consider a young ocean, but, like Tate Regan,^^ believe that 
it was a wide ocean by Eocene times. In fine that the so-called tremen- 
dous earth storms are really very local. It is true that the * Alpine ' storm 
of Miocene date looms very large in north-west and central Europe, but 
look on a globe at the area involved and see how small it is relatively — a 
mere trifle as compared with the opening up of the Atlantic ocean. I 
feel that our maps have much to do with our defective appreciation of 
world conditions. Mercator has a deal to answer for, as a result of his 
' projection,' and until we get back to studying a globe, instead of a 
sheet of paper, our ideas will remain distorted, especially when the areas 
involved are in the temperate and northern regions — precisely those 
regions where geological research is most abundant to-day. 

Now how are we going to test these several hypotheses ? One of the 
neatest possible tests has been applied by Mrs. Reid and Miss Chandler 
in their work on the London Clay Plants.^^ This flora has puzzled people 
since Parsons' work in 1757. (We may say that the presence of Nipa 
at Sheppey and Artocarpus in Greenland are two of the most difficult 
palasobotanical facts to arrange in their proper setting.) 

These ladies set out, first of all, by establishing the principle that 
with flowering plants, at any rate, and confining their attention to living 
forms, the great bulk (70 per cent, at least) showed little power of adapta- 
bility to different climatic zones — they are tropical or extra-tropical as 

'^ ' Discussion on Geological Climates,' Proc. Roy. Soc, 1930. 
^^ London Clay Flora, British Museum, 1933. 


the case may be. The remainder show extraordinary little power of 
adaptability — a species here and there may do so, but not the bulk. They 
quote H. H. Thomas ^^ 'that there seems to be no indication in the geo- 
logical record of any gradual acclimatisation of the plants which existed 
in Eocene times in Europe as the Great Ice Age approached, and the 
climates became colder, and, presumably, also drier.' As regards the 
flora they were studying — the London Clay flora — not a single genus 
that lived in Britain survived into Upper Pliocene times. They therefore 
conclude that the bulk character of a Tertiary flora does determine its 
climatic character, and that that of the London Clay is sub-tropical. The 
presence oiNipa — the most northerly record so far- — gives them a tempera- 
ture figure, and they ask both Simpson and Brooks whether they can 
supply such conditions in Britain. The temperature is that of a wet 
tropical forest — a lower figure than the normal tropical type — a mean 
annual temperature of 70° F. 

Simpson could only supply it by the aid of some measure of continental 
drift which Mrs. Reid and Miss Chandler could not accept. Brooks 
could only give that temperature with the aid of Simpson's hypothesis 
of increased solar radiation, and increase of cloud and precipitation. But 
the plant evidence could be explained by Brooks' hypothesis ; or, expressed 
otherwise, accepting plants as good indexes of climatic zones, an appro- 
priate zone temperature could be established in Britain during London 
Clay times by the application of a theory devised to explain glacial and 
non-glacial epochs. If further tests, from the distribution of other plants, 
were applied we might obtain sufficient information to determine which 
theory is the most satisfactory. Brooks' hypothesis appeals to me because 
it does not demand increases in solar radiation over long periods. But 
increases for short periods I think are necessary to explain climatic 
rhythms that are known, and that can be traced back in the history of 
certain trees. I do not regard Brooks' and Simpson's theories as 
mutually exclusive, but as mutually complementary. 

Fossil Plants and Climatic Rhythm. 
Recent researches in archaeology in Africa and America, and also 
former discoveries in other parts of the world, have drawn attention to 
minor fluctuations in climatic character similar to those periodic cycles 
that meteorologists had also discovered from quite other considerations. 
Historical records, so far as they go, can be checked up ; but these are 
of short duration from a geological standpoint. In regions of the world 
where trees had not been destroyed, either by man or other agencies, 
certain examples have reached a great age — several thousands of years ; 
and, if plants are good indexes of former conditions, here, if an)rwhere, is 
an opportunity to obtain a cross check on historical information, and a 
possible extension into pre-historic times. The work of Antevs^^ and 
A. E. Douglas ^^ on annual rings and their variation according to climatic 

" ' Discussion on Geological Climates,' Proc. Roy. Soc, 1930. 
'' Amer. Jour. Sc, vol. ix, p. 296 et seq. (1925). 

'' Carnegie Inst., Washington, vol. xi, no. 289 (1928). Brit. Assoc. Report, 
Bristol, p. 371 (1930). 


changes, or accidents (forest fires, etc.), is most illuminating. Now 
palaeontologists had noted the possibility long ago, Witham, Lindley and 
Hutton and the earlier writers on the internal structure of fossil plants 
had noted, and discussed the implications of, the fact that in Palaeozoic 
times certain specimens of one and the same species might have rings 
in the wood, while others might not. Unger in 1847 noted that Mesozoic 
woods (Lower Triassic) had poorly developed rings, and therefore 
concluded that the equable climate of Palaeozoic times was becoming 
periodic ; but later workers, Arnold, for example, have proved that in 
Callixylon from Upper Devonian rocks, rings were quite well developed, 
and consequently the climate of Palseozoic times was not equable. 

Botanical research shows that one and the same species may or may not 
have rings, depending on the conditions in which the specimens were 
growing. This, in some cases, depended on whether the plants were 
growing in warm or cold places, but, in others, on whether the climate 
was equable or not, and quite irrespective of any particular climatic zone. 
The reaction was to environment, but not necessarily to seasonal changes. 
In other words, the rings are difficult to interpret. But some plants are 
specially sensitive to these changes, and plants in temporate regions — 
or at the higher elevation in tropical lands — nearly all have these rings. 
Conifers have the most distinct rings, in general, and even Araucaria, 
where they are not so marked, produces rings under varying conditions 
of nutrition. Now conifers have a long geological range, and so might 
possibly indicate seasonal rhythm in past times ; or even indicate, by breaks 
in the rhythm, some exceptional occurrences that might be rhythmical or 
not. Antevs ^'^ after recalling all the difficulties and the need for caution, 
has stated, 'We can say with certainty that the occurrence of very marked 
zones in Jurassic woods from Spitzbergen, and the lack of rings in Jurassic 
woods from British East Africa, indicates marked climatic zones and 
pronounced annual periodicity in Jurassic time.' Douglas made a very 
careful study of the ' Big Trees ' in the Sierra Nevada and other areas in 
America, and concludes that any ' index ' tree must be very carefully 
selected, and the results checked not merely in the immediate vicinity, 
but consistent records must occur further afield. He found that the 
best index tree is the Yellow Pine, and the next best the Scotch Pine. 
Sequoia gigantea, while more complacent to changes than the others, is 
longer lived, and the records from these trees may go back to 1,000 B.C. 
with consistent results over a considerable area. 

While geologists will not benefit much from these researches directly, 
yet meteorologists and archaeologists will, and a cross check on de Geer's 
results from Varve counts in Scandinavia, or similar results in America, 
may yet be effected. The age of ancient ruins at Gobernador Canyon, 
Aztec, and Pueblo Bonito, Chaco Canyon, Aztec, New Mexico, have 
been ascertained by examination of the ring record of logs which still 
retained their bark, and which had been used in building these dwellings. 
This was done by reference to large trees in the area, and a count back 
until the ring record of the log and that of the ' index ' tree coincided. 

•" Amer. Jour. Sc, vol. Lx, p. 300 (1925). 


Douglas has also proved rainfall records at Flagstaff, Arizona, at eleven 
year periods for 600 years, and this checks up with the known solar record. 
Though we cannot entertain extravagant hopes that this mode of 
research will help geologists, we may learn something of periodic occur- 
rences in the past. It is true that at present single trees are little use, but 
methods may yet be found for using the records of such single trees. 
The largest fossil tree I know, and I think it is the largest yet discovered, 
is a stump said to be of the Sequoia type and of Miocene age at Henderson's 
Ranch, near Florissant, Colorado. It is 17I ft. in diameter, and 10 ft. 
high, quite comparable in girth, therefore, with the Big Trees of to-day. 
A record of its rings should be made, as also of those of at least a dozen 
other stumps in that area. Then again the ' petrified forests ' of Arizona, 
Egypt, Burma, and elsewhere should also be recorded. The game 
might not be worth the candle, but it might add yet another minor link 
to the chain of ideas with which fossil plants have affected the philosophy 
of geology. 




E. S. RUSSELL, O.B.E., D.Sc, 


In his Presidential Address to this Section last year, Dr. James Gray put 
forward the view, with which I entirely agree, that the organism has 
properties and potentialities as a whole which are not reducible to the 
properties shown at the chemical level. He maintained that ' the con- 
ception of the organism as a single living entity is or should be the more 
peculiar attribute of experimental biology.' We should study not only 
the action of the parts in isolation, as does the physiologist, but also and 
more particularly the activity of the animal as a whole. Thus we should 
not rest content with a knowledge of the mechanism of muscular con- 
traction or of the propagation of the nervous impulse ; we must study 
also and before all the action of the neuro-muscular system as a whole, 
as, for example, in locomotion — and, I would add, in behaviour generally. 

I propose to continue the discussion so ably begun by Dr. Gray, and 
to deal particularly with that whole-activity of the organism which we call 
its behaviour. 

The study of animal behaviour has been somewhat neglected in this 
country, and this is all the more regrettable since first-rate pioneer work 
has been done by Prof. C. Lloyd Morgan and the late Prof. L. T. Hobhouse. 
Furthermore, it has been largely divorced from the general study of 
zoology, and handed over to the physiologist and the psychologist, 
neither of whom is, as a rule, sufficient of a naturalist to appreciate the 
full biological significance of the behaviour observed in the laboratory. 
It is of course obvious that an animal's behaviour is one of the most 
important things about it, and if the zoologist wishes to understand how 
his animal lives, maintains itself, and carries on the race, the first thing 
he should study is its behaviour in the field. It is also clear that a 
thorough knowledge of the bionomics or ecology of the animal is quite 
essential for the interpretation of its behaviour in the experimental 
conditions of the laboratory. 

We are meeting to-day in a zoological department which has always 
recognised the fundamental importance of the study of behaviour and 


ecology. Its head is Professor of Natural History, and both the present 
occupant and his predecessor, the late Sir John Arthur Thomson — to 
whom I personally owe so much— have made great contributions to the 
study of that subject which Prof. W. M. Wheeler has so aptly called ' the 
perennial root-stock or stolon of biological science.' 

Interest in natural history is — fortunately — still widespread among 
zoologists, both professional and amateur, and one of the most significant 
developments of recent years has been the vigorous growth of the 
Oxford school of animal ecologists, under the leadership of Mr. Charles 

But while excellent work in the field of scientific natural history is 
being done by the animal ecologist, the economic entomologist, the 
fishery worker and also by the amateur naturalist, they have not as a rule 
taken what one might call a professional interest in the problems of 
animal behaviour, though they have accumulated a great store of observa- 
tions which are 6i the highest value to the professional student. 

Generally speaking, as things are at present, the study of animal 
behaviour as a science has not in this country taken its rightful place as 
an essential part of zoology, either in research or in teaching ; the 
tendency has been to treat it either as a branch of physiology or as an 
adjunct to psychology, and in both cases to turn it into a laboratory 

When we inquire into the reasons for this unsatisfactory state of affairs, 
we find, I think, that one of the main causes is the influence upon biology 
of a certain metaphysical theory which we inherit from the seventeenth 
century. We owe to the great thinkers of that age, and particularly to 
Descartes, a particular view about the nature of reality which has become 
firmly rooted in our thought and is apt to bias our methods of research. 
I refer of course to the classical doctrine of materialism, with its absolute 
separation of matter and mind. 

How did this doctrine arise ? We do not find it in Aristotle. The 
dualism of matter and mind was foreign to his thought. A primitive 
form of materialism had been propounded by the lonians, and Anaxagoras 
had added to their cosmology the conception of a universal reason or 
' Nous.' But Aristotle accepted neither view. He worked out a system 
of his own, which is now somewhat difficult for us to grasp, for we have 
lost that freshness and directness of approach to the great problems 
which were his. We know that he spoke of the nutritive, the sensitive 
and the rational * souls,' which formed a hierarchy of functions, but, with 
the possible exception of the rational soul, he did not think of these as 
separate from the body. His view was not vitalistic in the modern 
sense ; it did not imply a dualism of matter and entelechy ; for Aristotle, 
' soul ' was an expression for the total functional activity of the organic 
unit, for its activity as a whole. 

We do not find the clear-cut dualism of matter as extended substance 
and mind as inextended thought fully expressed until we come to 
Descartes many centuries later. 

Descartes stands on the threshold of the modern world. No man can 


be independent of his epoch, and Descartes was in some respects a direct 
heir of the Middle Ages ; he shared their preoccupation with reason and 
the soul of man. He was primarily a mathematician and a theologian ; 
he had unlimited faith in the power of the human intellect ; he was 
concerned to demonstrate the existence of God, and to uphold the belief 
that man's soul is immortal, that he is not as the beasts that perish. At 
the same time, he was profoundly influenced by the physical and cosmo- 
logical conceptions introduced by Copernicus and Galileo, and grasped 
their enormous significance. He was acquainted with the work of his 
great contemporary, William Harvey, on the circulation of the blood, and 
made great play in his books with a somewhat crude attempt to explain 
all physiological processes mechanically. It was he who imposed 
dualistic materialism upon biology as its working method. 

Although nowadays modern physics has completely transformed the 
old conception of matter, and has little use for the notion of material 
determinism, it is not so long ago that materialism was the orthodox creed 
of science, and we are in biology still suffering from the after-effects. 
I do not think I can better describe the fundamental tenets of this creed 
than by quoting a passage from T. H. Huxley's essay on The Progress 
of Science, which appeared in 1887. ' All physical science,' he wrote, 
' starts from certain postulates. One of them is the objective existence 
of a material world. It is assumed that the phenomena which are com- 
prehended under this name have a " substratum " of extended, impene- 
trable, mobile substance, which exhibits the quality known as inertia, 
and is termed matter. Another postulate is the universality of the law 
of causation ; that nothing happens without a cause (that is, a necessary 
precedent condition), and that the state of the physical universe, at any 
given moment, is the consequence of its state at any preceding moment. 
Another is that any of the rules, or so-called " laws of Nature," by which 
the relation of phenomena is truly defined, is true for all time. The 
validity of these postulates is a problem of metaphysics ; they are neither 
self-evident nor are they, strictly speaking, demonstrable.' ^ 

As a counterpart to this abstract concept of matter as extended substance 
we have the concept of mind as inextended thought. Physical science, 
and here I include physiology, has never known quite what to do with 
mind. In practice it has ignored mind, and treated it as an ' epipheno- 
menon ' accompanying, but not influencing, certain physiological pro- 
cesses taking place in the central nervous system. ^ For the practical 
purpose of research it has treated the animal as a mechanism, and sought 
to analyse its working in detail. This theory, that the animal is to be 
regarded, from the point of view of science, as a physiological automaton, 
we find explicitly stated by Descartes nearly 300 years ago in his Discoiirs 

^ Method and Results, London, 1893, pp. 6o-6r. 

* Cf. Huxley : ' The consciousness of brutes would appear to be related to the 
mechanism of their body simply as a collateral product of its working, and to be 
as completely without any power of modifying that worlcing as the steam- 
whistle which accompanies the work of a locomotive engine is without influence 
upon its machinery.' Ibid., p. 240. 


de la Methode, and it has been for long a guiding principle of research 
in the physiological study of functions and behaviour. 

Let me give you a modern example by quoting a passage from Pavlov's 
book on Conditio7ied Reflexes, published in 1927. ' Our starting point,' 
he writes, ' has been Descartes' idea of the nervous reflex. This is a 
genuine scientific conception, since it implies necessity. It may be 
summed up as follows : an external or internal stimulus falls on some one 
or other nervous receptor and gives rise to a nervous impulse ; this 
nervous impulse is transmitted along nerve fibres to the central nervous 
system, and here, on account of existing nervous connections, it gives 
rise to a fresh impulse which passes along outgoing nerve fibres to the 
active organ, where it excites a special activity of the cellular structures. 
Thus a stimulus appears to be connected of necessity with a definite 
response as cause with effect ' (p. 7). We could not wish for a clearer 
statement of the underlying assumptions of the stimulus-response (S-R) 
theory of animal behaviour, nor for a clearer acknowledgment of. its 

It was Descartes, then, who imposed upon European thought for at 
least two centuries, and upon biology for much longer, that * bifurcation ' 
of Nature into matter and mind which has raised so many insoluble 
problems for philosophy, and diverted biology from its true method. As 
to its effect on philosophy, let me quote a great modern philosopher, 
Prof. A. N. Whitehead, who writes : ' The seventeenth century had 
finally produced a scheme of scientific thought framed by mathematicians, 
for the use of mathematicians. . . . The enormous success of the scientific 
abstractions, yielding on the one hand matter with its simple location in 
space and time, on the other hand mind, perceiving, suffering, reasoning, 
but not interfering, has foisted on to philosophy the task of accepting 
them as the most concrete rendering of fact. Thereby, modern philosophy 
has been ruined. There are the dualists, who accept matter and mind as 
on equal basis, and the two varieties of monists, those who put mind 
inside matter, and those who put matter inside mind. But this juggling 
with abstractions can never overcome the inherent confusion introduced 
by the ascription of misplaced concreteness to the scientific scheme of the 
seventeenth century.' ^ 

Actually, instead of being the most concrete of realities, both matter 
and mind are highly abstract concepts, the product of the reflective 
intelligence working upon the data of immediate experience. 

There is given in individual experience only the perceiving subject 
and his objective world. This dualism does not correspond, is not 
synonymous with, the dualism of matter and mind. Subjective experi- 
ence as we know it directly is a function of organism, not of pure mind ; 
objective experience is a relation between organism and other processes 
or events. The concept of matter is arrived at by abstracting from the 
data of sense, by leaving out the ' secondary qualities ' such as colour, 
smell and sound, and retaining the so-called ' primary qualities ' of 

* Science and the Modern World, Cambridge, 1926, p. 70. 


resistance and extension, with location in time and space. By accepting 
this abstract definition or concept of matter, we substitute for the 
objective world of perception a symbolic or conceptual world of discrete 
material particles, which we may call the ' world of matter.' This world 
of matter the materialist takes to be in some sense more real than the 
perceptual and colourful world from which he has derived it. Actually 
it is less real, less concrete. It is important to remember that the world 
which we perceive through the senses, with its shapes, colours, smells, 
tastes and so on, is not identical with the conceptual ' world of matter ' ; 
we do not perceive ' matter ' at all, any more than we perceive mind ; 
we perceive things or relations or events. 

Complementary to this abstract material universe is the concept of 
mind as an inextended, immaterial, thinking entity, and this also is 
derived by abstraction from the data of immediate experience, and 
principally from the subjective aspect of experience. 

As applied to biology, this abstract dualism has saddled us with the 
theory that the organism is a machine, with the pale ghost of a mind 
hovering over its working, but not interfering. What chance is there for 
a real science of animal behaviour if this metaphysical view is accepted ? 

Obviously from the Descartian standpoint behaviour becomes a subject 
for the physiologist to study from his analytical point of view ; he must 
regard behaviour as the causally determined outcome of the working of 
the animal machine, under the influence of external and internal stimuli, 
and he must seek to determine the elementary physico-chemical processes 
out of which behaviour is built up. The physiologist as such can have 
nothing to do with mind, and hands over its study to the psychologist, 
who finds that he can know nothing directly about the minds of animals. 
Hence we get the state of affairs I alluded to at the beginning of this 
address — the study of animal behaviour split up between physiology and 
psychology, with no possibility of a connecting bridge. The scientific 
study of behaviour thus becomes divorced from natural history and 
ceases to take its rightful place as an integral part of zoology. 

Aristotle knew better than this ; he regarded life and mind as con- 
tinuous one with another, and the basis of his zoological system was the 
form and activity of the animal as a whole. But then Aristotle was a 
first-rate field naturalist and observer. 

At this stage you may perhaps object that all this discussion of meta- 
physical notions is beside the mark and futile. You may say that as 
zoologists we are concerned only with facts and not with metaphysical 
theories. You may — quite rightly — point out that in our practical re- 
searches we deal with the objective world of perception, and not with the 
abstract ' world of matter.' 

But, unfortunately for us, these metaphysical notions which most of us 
have absorbed almost unconsciously from the older tradition of philo- 
sophical thought have influenced and continue to influence our aims and 
our methods in practical research. It is impossible to be an absolutely 
unbiased observer, an exact mirror of the flux of events ; our conscious, 
and even more our unconscious, preconceptions lead us inevitably to 


select from the panorama of objective appearance those facts which are 
of interest from our own particular point of view, and so to devise our 
researches as to obtain answers to problems which we impose upon Nature 
rather than Nature upon us. 

Thus if we are firmly convinced that all events are ruled by strict 
mechanical causality we naturally look upon the organism as a machine, 
and when we study the behaviour of an animal we seek to analyse it into 
a number of simple constituents, such as tropisms and reflexes, which are 
determined by simple and measurable external stimuli. We lean in- 
evitably towards the stimulus-response theory of behaviour — a purely 
physiological and analytical view — and our researches are based on the 
supposition that this theory is true. Hence we tend to overlook facts 
which do not fit into this scheme — we miss them simply because we are 
not looking for them. 

The point I want to get clear is that the Cartesian doctrine of the 
dualism of matter and mind is in no sense an inevitable deduction from 
experience ; one is not forced to accept it as the necessary foundation of 
biological research ; other foundations are possible, as we shall see in 
a moment. 

I have in my preceding remarks purposely exaggerated to some degree 
the contrast between the physiological and the psychological attitude 
towards the study of animal behaviour, in order to bring out clearly the 
logical consequences of accepting the metaphysical theory of the dualism 
of matter and mind. But I do not mean to assert that all work on animal 
behaviour can be definitely labelled either as physiology or as psychology 
in this limited sense. An escape from the dilemma has in practice been 
found, and this alternative method we shall now proceed to discuss. 

Let us first of all try to rid our minds of the abstract notions of matter 
and mind, and regard the activities of living things without metaphysical 
preconceptions. As zoologists our job is to study animals in action. 
Let us try to approach our task with the same directness and naiveU that 
Aristotle showed when he laid the foundations of our science. Instead 
of assuming a priori that the physico-chemical or analytical method of 
approach is the only possible and the only fruitful one, let us try the 
alternative of considering first the most general characteristics of the 
organism as a whole, and working down from the whole to the parts, 
rather than up from the parts to the whole, as is the more usual method. 

Taking this simple and direct view of living things, abandoning theory 
and accepting the obvious facts at their face value, we see first of all that 
the complete phenomena of life are shown only by individuals, or organised 
unities. Sometimes these units are combined loosely or closely in unities 
of higher order, as in social insects and in colonial animals, such as corals, 
but these cases hardly aff'ect the main thesis that life is a function of 
individuals. There is accordingly no such thing as ' living matter,' save 
as part of an organised unity. 

The second thing we note is that all living things pass through a cycle 
of activity, which normally comprises development, reproduction, and 
senescent processes leading to death. This life-cycle is in each species a 


definite one, passing through a clearly defined trajectory, admitting of 
little deviation from normality ; it takes place generally in an external en- 
vironment which must be normal for the species, and as a rule the internal 
environment also is kept constant round a particular norm. The activities 
whereby the needs of the organism are satisfied and a normal relation to 
the external and the internal environment is maintained, may be called 
the maintenance activities of the organism, and they underlie and support 
the other master-functions of development and reproduction. 

Our general definition or concept of organism is then an organised 
■unity showing the activities of maintenance, development and repro- 
duction, bound up in one continuous life-cycle. A static concept is 
inadequate ; time must enter into the definition ; the organism is essen- 
tially a spatio-temporal process, a ' dynamic pattern in time,' as Coghill 
aptly calls it. 

Now all these activities are, objectively considered, directed towards 
an end, which is the completion of the normal life-cycle. One is tempted 
to use the word * purposive ' in description of these activities, but this term 
is used in many senses and has a strong psychological flavour about it, so 
I shall use instead the neutral word directive, which I borrow from 
Myers.* It is quite immaterial from our simple objective point of view 
whether these directive activities, or any of them, are consciously pur- 
posive. The directiveness of vital processes is shown equally well in the 
development of the embryo as in our own conscious behaviour. 

It is this directive activity shown by individual organisms that dis- 
tinguishes living things from inanimate objects. The peculiar character 
of this directiveness, its orientation towards a cyclical progression of 
organisation and activity, clearly distinguishes it from the static directed- 
ness of a machine, constructed for a definite purpose. It should be noted 
too that the living thing shows a certain measure of adaptability in com- 
pleting its life-cycle, so that the end is more constant than the way of 
attaining it. 

Now from this point of view, which is, I maintain, strictly objective, 
behaviour is simply one form of the general directive activity of the 
organism ; it is that part of it which is concerned with the relations of 
the organism to its external world. Plants show behaviour in this general 
sense just as much as animals do, but they, being for the most 
part sessile and stationary creatures, respond to the exigencies of environ- 
ment, and satisfy their basic needs, mainly by processes of grovslih and 
differentiation, and only exceptionally by active movements. Thus the 
dune plant seeking water grows an enormously long root which burrows 
down through the sand till moisture is reached. Animals on the other 
hand respond to environment and satisfy their needs by means of move- 
ments, either of the body as a whole or of certain organs. But sessile 
animals, like plants, may also respond or show behaviour by means of 
morphogenetic activity. The hydroid Antennularia, for example, if 

* C. S. Myers, The Absurdity of any Mind-Body Relation. L. T. Hobhouse 
Memorial Lecture, Oxford and London, 1932. 


suspended in the water may send out ' roots ' or holdfasts to regain 
contact with the bottom. 

Behaviour, whether of plants or animals, is thus to be regarded simply 
as one form of the general directive activity which is characteristic of the 
living organism. It holds no privileged position ; it does not require 
' mind ' as an immaterial entity to explain it. 

I tried to show in the earlier part of this discourse that both ' matter ' 
and ' mind ' are abstract notions, of little real use in biology, and I main- 
tain here that the concept of ' organism ' as I have attempted to define it 
is a more concrete one, and a more useful one, for the practical purposes 
of biological research. 

If we accept this view of organism, which is to my mind a simple 
generalisation of fact, we escape or elude the difficulties of dualism ; we 
need no longer regard behaviour as either the mechanically determined 
outcome of the material organisation of the body, or the result of the 
activities of an immaterial mind or entelechy influencing in some utterly 
mysterious way the mechanical workings of the body. By taking as 
given and as fundamental the plain objective characteristics of the living 
and intact organism, by refusing to split it up into matter and mind, we 
avoid both materialism and its counterpart vitalism. 

This is, as I conceive it, the central position of the modern organismal 
theory — the substitution of the concept of organism for the concepts of 
matter and mind. The concept of organism, or more generally of 
organised system, may of course be applied right down through the in- 
organic realm, wherever organised unities are found. Thus a molecule 
is an organised system, and so also is an atom. I do not, however, agree 
with those who think that all real unities, both organic and inorganic, are 
adequately characterised as ' systems.' In certain most general character- 
istics an atom and a living organism agree, for both are systems or wholes. 
But the living organism has characteristics which are lacking in inorganic 
systems, and it can be adequately defined or characterised only by refer- 
ence to those peculiarities which we have just considered — the weaving 
together in one cyclical process of the master functions of maintenance, 
development and reproduction. These distinguish it from any inorganic 
object or construction, from any inorganic system. Underlying these 
characteristics is the general directiveness of its activities, their constant 
drive towards a normal and specific end or completion. 

It will be noted that this organismal view makes no real distinction 
between life and mind, between vital activities and those which in 
immediate experience appear as mental or psychical activities. In this 
respect we hark back to a pre-Descartian mode of thought, and call 
Aristotle our master. 

Simple observation shows us that living animals exhibit activities 
which are obviously not, on the face of them, those of a mechanism. 
Many of their behaviour actions are strictly analogous to those which in 
immediate experience we should describe as psychological. Thus we 
see animals trying hard to achieve some aim or end — a salmon struggling 
to surmount a fall, for example, or a cat using all its skill to catch a bird. 


We do not know whether these actions are consciously purposive or not, 
but we cannot dismiss the objective facts of striving merely by assuming 
that they are mechanically determined. There are the facts ; animal 
behaviour is predominantly directive, or in an objective sense purposive, 
and there is no use closing our eyes to it. 

It is well known too that many animals can learn and profit by experi- 
ence. Thus if you train a puppy to play with a ball, this becomes of 
functional significance to it ; it will go and look for its ball, which it 
remembers ; and other objects of a similar size or shape acquire for it 
the functional value of a ball, and are used in play. There is here 
definite evidence of memory, or retentiveness. 

In the same way, there is abundant evidence that animals perceive 
their surroundings, singling out those objects and those events that are 
of importance in relation to their needs. Of course we cannot know 
what the quality of these perceptions is, but we can determine by suitably 
planned experiments just what it is to which the animal responds, and 
we often find that the response is to patterns or images or relations, and 
not to a simple summation of physico-chemical stimuli. I shall give 
some examples of this later on. At this stage I merely wish to make the 
point that from the organismal standpoint there is no difficulty in assuming 
that animals perceive and react to an external world of their own ; here, 
as in our own case, perception may be regarded as a function of organism, 
not of ' mind.' 

This is essentially the attitude of ordinary common sense. In practice 
we treat our fellow men and at least the higher animals as being real 
individuals with perceptions, feelings, desires, similar to our own. And 
common sense is in principle justified, though of course it runs a great 
risk of reading human motives, human ways of thought, into the be- 
haviour of animals, and of assuming without sufficient warrant that their 
perceptual worlds are the same as ours. But because there is a danger of 
faulty interpretation, due mainly to inaccurate or inadequate observation, 
we are not thereby compelled to throw over the general conception that 
the animal organism is capable of perception, conative behaviour, and 
memory, if the facts of observation lead us to this conclusion. I do not 
mean that we should explain behaviour as being due to psychological 
functions labelled conation, perception and memory — that would be an 
empty and barren explanation. We are concerned only with behaviour, 
not with the subjective experience of the animal, which cannot be the 
subject of scientific study. But we must describe the behaviour fully 
and adequately, using if necessary terms of psychological implication, 
refusing to be bound or hampered by the metaphysical notion that the 
animal is merely a machine or can be treated as such. 

In affirming as we do that the animal organism in its behaviour shows 
a kind of activity which cannot be adequately described in terms of 
material configuration we are taking no great risk. Our own immediate 
experience is there to assure us that in one case at least the organism 
certainly does perceive, strive, feel and remember. 

One point more before we go on to consider very briefly how the 


organlsmal method is to be applied in the practical study of behaviour. 
It is sufficiently clear, I think, that behaviour is an activity of the organism 
as an intact and unitary whole. Once we begin to tamper with the 
organism we get something less than behaviour. The ' spinal ' dog still 
retains the power to carry out many and complex reflex activities — and 
it is quite unimportant whether these activities are unconscious or not — 
but it does not and cannot manifest the full range of activity which 
characterises the intact dog. Pursuing the work of analysis further, we 
can get down to the study of an isolated muscle-nerve preparation, or to 
the study of the conduction of the nervous impulse and the mechanism 
of muscular contraction. Here we shall find little or no behaviour in the 
sense of directive and adaptable activity, and we may reasonably hope to 
arrive at an adequate physico-chemical account of what goes on. There 
seems no reason to doubt that a physiological treatment of the isolated 
parts of the organism may in principle be adequate. But by taking the 
parts in isolation, we abstract from their relations to the whole, parti- 
cularly their temporal relations, and we leave out of account just 
what is fundamentally important — the working together of all the parts 
in the directive activities of self-maintenance, development and 

When we analyse a total organic event or process we break up the 
spatio-temporal unity of the action into little unconnected bits which 
are unreal in the sense that they are abstract, being deprived of their 
constitutive relations to the whole process. If for the sake of enlarging 
and deepening our knowledge we analyse organic activities in detail, we 
must correct the abstract picture so obtained by re-integrating the part 
in the whole — we cannot reconstitute the whole action by simple summa- 
tion of the actions of the parts separated out by analysis. 

While then analysis is a justifiable and useful procedure, we cannot 
hope to build up from the parts thus isolated the directive activity of the 
whole , which shows characteristics belonging to none of the parts . Accord- 
ingly, the study of behaviour is not reducible to physiology or the causal- 
analytical investigation of the parts. Physiology may profitably consider 
what are the conditions necessary for the manifestation of whole-properties, 
and we have an excellent example of this in Lashley's work ^ on the relation 
between learning and retentiveness on the one hand and the amount of 
brain substance on the other. But we must work down from the whole 
to the parts, and the study of the whole, as in behaviour, cannot be ade- 
quately replaced by the study of the parts in isolation. 

It is possible of course to abstract from the directiveness and continuity 
of organic events, and to consider the organism over a short period of 
time as being a mechanism or configuration. It is then susceptible of 
study and interpretation in physico-chemical terms, just as is an in- 
organic object, but what we get is physics and chemistry, not biology. A 
good deal of what ranks nowadays as experimental biology is not biology 
at all, but physico-chemical research carried out on organic systems 

* K. S. Lashley, Brain Mechanisms and Intelligence, Chicago, 1929. 


with complete disregard for the distinctive characteristics of such 

From our organismal point of view, the study of behaviour is neither 
comparative physiology nor comparative psychology ; it is the study of 
the directive activity of the organism as a whole, in so far as that activity 
has reference to the organism's own perceptual world. It must start 
with what Lloyd Morgan calls the ' plain tale ' of behaviour, the full and 
accurate description of what organisms do, and of what they are capable. 
Though plants also show behaviour in this general sense, and their whole- 
response to environment is a proper subject for study, it will lighten our 
discussion if we limit it to the behaviour of animals. 

The plain tale description of animal behaviour must begin with a study 
of the natural history and ecology of the animal. Most animals are 
restricted to one definite and rather specialised kind of environment ; 
they are adapted both in structure and activity to inhabit some particular 
ecological norm or ecological niche. We must discover by field observa- 
tion how the animal finds this ecological niche to begin with, and how it 
maintains itself therein. We must investigate how it counters changes in 
its environment, how it defends itself against enemies, how it finds or 
captures its food. All this is straight natural history in the old sense, 
the study of the ' habits ' of animals, and it is linked up closely with the 
modern study of ecology. It is the necessary basis for the more detailed 
study of behaviour. It is also the clue to much of the behaviour shown 
in the artificial conditions of a laboratory experiment.® 

Clearly then we must start with direct observation of the animal's 
behaviour in the field, or in experimental conditions that approximate as 
nearly as possible to the normal. We must then ask what is the animal 
trying to do, what is the objective end or aim of its action ? Sometimes 
the animal is doing nothing in particular ; it is resting or merely waiting 
for something to turn up. Usually, however, the animal is active, is 
showing behaviour ; its actions are directed to some end, are aimed at 
satisfying some need, and we can determine by observation and experi- 
ment what that end is ; the sign that the end is attained is the cessation 
of the train of action. Thus, to take a very simple example, if you remove 
a caddis larva from its tube, by the simple method of prodding it gently 
from behind with the head of a pin, it will move restlessly about until it 
finds the empty tube. Then it will enter the mouth of the tube head 
first, creep through, and perhaps widen the narrow hind opening of the 
tube, but it will finally turn right round inside the tube so that its head 
comes out at the front end, and it is then able to get about normally. 
The aim of the train of behaviour is attained — normal relations to en- 
vironment are restored. If you have removed the tube so that the larva 
cannot find it, it will achieve its end by another means, provided the 
materials are available, for it will then construct a new tube. That is 
an example of simple directive behaviour, and it also illustrates the general 
rule that the end is more constant than the method of reaching it. 

• E. S. Russell, The Behaviour of Animals, London, 1934. 


We find very often that a simple directive activity is part of a general 
directive process of long range, which may take months to reach its goal ; 
and to understand the simple action we must relate it to, or integrate it 
in, the general process of which it is a part. Take for instance the 
building of a nest by a bird. This taken by itself is a directive activity, 
aimed at the construction and completion of an adequate brooding place 
for the eggs and young. It is a fairly stereotyped and specific activity, but 
unusual materials may be pressed into service if the normal materials are 
hard to come by. But nest-building is simply one link in the long re- 
productive cycle, which may commence with migration, and its relation 
to that cycle, which includes both behavioural and phj^siological activities, 
must be studied if we are to understand it fully. 

This illustrates the general rule of biological method which we have 
just discussed — that the whole life-cycle of activity must be regarded as 
the primary thing, and that the parts of it which may be isolated for study 
must be re-integrated in the whole-activity. The human mind is prone 
to analysis, and we must be on our guard against its inveterate tendency 
to separate and distinguish parts or elements in what are, fundamentally, 
continuous processes. 

In thus relating partial events to life-cycle, we must of course consider 
above all their time-relations, not only their relations to what has gone 
before, but also and more particularly to what follows after. I should 
like to refer in this connection to a recent address by Coghill, in which 
the organismal view of development, including the development of 
behaviour, is set out with great clearness and authority. He tells us that 
' the neuro-embryologic study of behavior shows that events within a 
behavioral system can be understood scientifically only as their relation 
is known to subsequent as well as to antecedent phases of the cycle. The 
antecedent tells a part of the story about the present, but not all of it ; for 
within the present are events that have behavioral significance only in 
that which follows. . . . The purely scientific method, dealing ex- 
clusively as it does with space-time relations, can not reject the future 
from its explanation of the present in behavior, because any event in an 
organismic cyclic system is an integral part of both the future and the 
past.' 7 

We come now to the question, how is behaviour instigated or initiated, 
how is it set going ? There is one ready-made answer to this question — 
that behaviour is essentially an automatic response or reaction to stimula- 
tion, either external or internal. You will recall the passage I quoted 
from Pavlov earlier in this address, in which the stimulus-response theory 
is very clearly and explicitly set forth. According to Pavlov, stimulus is 
related to reaction as cause to effect ; the impulse generated by the 
stimulation of the receptor organ is automatically transmitted along the 
appropriate nervous pathways to set in motion the appropriate effector 
organ. Behaviour is therefore completely determined by the stimuli 

' G. E. Coghill, ' The Neuro-embryologic Study of Behavior : Principles, 
Perspective and Aim.' Science, Ixxviii, 1933, pp. 137-138. I have expressed a 
similar view in my Interpretation of Development and Heredity , 1930, pp. 170-171. 


and by the connections already existing in the nervous system or buih 
up during the formation of conditioned reflexes. 

There is no time, and no need, for me to criticise this view in detail. 
Actually the strict theory of connectionism is rapidly breaking down in 
face of the facts established by the brilliant work of Lashley on the one 
hand and the Gestalt psychologists on the other. I will merely point 
out, first, that this analytical and physiological view is a pure hypothesis, 
derivable from the Cartesian metaphysics, and second, that it does not 
harmonise well with the simplest facts of observation. 

Nothing is more striking than the apparent spontaneity of animal 
actions, their independence of the immediately present external stimulus. 
When an animal is hungry it goes and looks for food ; when a hunting 
wasp requires provisions for her future offspring she actively seeks high 
and low for the proper caterpillar or spider that she needs ; when a bird 
is building her nest she looks everywhere for the grass or feathers or moss 
she requires. As Koffka well expresses it : ' While reflexes are typically 
" passive " modes of behaviour, which depend upon the fact that some 
stimulation has taken place, instinctive behaviour is, by contrast, signifi- 
cantly " active " in its search for stimuli. The bird seeks the material 
for its nest, and the predatory animal stalks its game. In other words, 
the stimulating environment is not a sufficient cause for these activities. 
Every movement requires forces which produce it ; but the forces that 
produce instinctive activities are not in the stimulus-situation — they are 
within the organism itself. The needs of the organism are the ultimate 
causes of its action ; and when these needs have been satisfied, the 
action comes to an end.' ^ 

A very great part of the behaviour of animals is, quite simply, response 
to needs (or deviations from normal), and not to direct external stimula- 
tion. When a starfish is turned on its back it tries in various ways to 
right itself, or, more accurately, to re-establish contact with a solid surface. 
Careful study of the action by Fraenkel and others has clearly established 
that the real ' stimulus ' to the action, if one may use the word stimulus 
at all, is not something positive, but simply the lack of contact between 
the tube-feet and some solid object, the need to re-establish a normal 
functional relation to the substratum. No doubt in all cases of action 
directed towards satisfying a need introception comes into the story, 
but the broad fact remains that it is lack of normality, or the absence of 
some condition necessary for maintenance or development or repro- 
duction, that sets much of behaviour going. 

I do not, however, wish to over-emphasise the autonomy of behaviour, 
its independence of external stimulation. It is certainly true that 
behaviour is to a considerable extent influenced by events in the animal's 
environment which it perceives and to which it responds. Thus all 
animals react to danger or to signs of danger by appropriate behaviour. 
Some like the rabbit bolt for their burrows ; others like the squirrel take 
refuge up a tree ; the antelope trusts to its fleetness, and most birds to 

* K. Koffka, The Growth of the Mind, 2nd edit., London, 1928, p. 103. 


their wings. Some animals find safety in immobility, or in the protection 
aflForded by a hard shell or carapace, or an armour of spines ; the tube- 
worm retracts its tentacles like a flash and may close the tube up with 
a stopper. 

In many of these cases the animal responds not to an actually nocuous 
stimulus but to some sign of approaching danger — to a shadow, the 
cracking of a twig, or to any object looming up and drawing near. So, 
too, the feeding response is often elicited not by direct contact with the 
food itself, but by a sign of it — its smell, its movement, the disturbance' 
it makes. 

This leads us on to consider a point on which I touched before, namely, 
the nature of the perceptions, especially the visual ones, to which the 
animal gives significant responses. This is a field in which much 
interesting and important work has been done of late years. 

It has been shown in many cases that it is not the separate physico- 
chemical stimuli that are important in eliciting response, but the whole 
complex of stimuli taken together, their arrangement, their pattern, their 
relations to one another and to the visual field as a whole. A dog can 
recognise his master by sight, and it does not matter whether he sees him 
full face or in profile, standing up or sitting down, close at hand or a little 
way off. There is a general pattern or facies, with infinite variation in 
detail, to which essentially the response is made. He would be a bold 
man who would propose a connectionist or additive explanation of 
response to a varying and shifting pattern or image of this kind. 

Then there are the many examples known where response is made not 
to a particular visual datum per se but to it in its relations to other features 
in the perceptual field. The simplest cases are those of ' relative choice,' 
exemplified by Kohler's experiments with chicks. He first of all trained 
them to respond to the darker of a pair of grey colours. He then sub- 
stituted a new pair of colours, consisting of the darker of the old pair 
and one still darker. He found that his chicks now reacted, not to the 
original grey, but to the darker of the new pair. They had really been 
trained to respond not to a particular shade of grey but to the darker of 
a pair. Many similar cases are known. 

Here is an observation by Bierens de Haan * which shows in a striking 
manner how an animal may respond to an object only in its relation to 
other objects in the visual field. A young Pig-tailed Macacque was 
given the choice of two doors, one marked by a card with a red circle, 
while above the other was placed a card bearing a blue triangle. Food 
was placed behind the door with the red circle, and the monkey rapidly 
learned to choose that door. The experimenter then substituted for the 
blue triangle a blue circle or a red triangle, and he fully expected that the 
monkey would continue to choose the red circle. Instead of that the 
monkey was completely confused, and chose the red circle in only about 
fifty per cent, of the trials. When the blue triangle was restored, how- 
ever, it responded correctly and consistently. It appeared from these 

' Animal Psychology for Biologists, London, 1929, pp. 40-41. 


experiments that the monkey had learned to respond not to the red circle 
by itself but to it in combination with the blue triangle — that is, to the 
correct member of a complex comprising these two sensory data. 

The whole trend of modern work on the perceptions of animals is to 
show that they do not normally respond to simple physico-chemical 
stimuli, but to more or less complex whole-situations, and if to parts of 
the whole-situation, then to these parts in their relation to the whole. 
This is the essence of the principle of Gestalt — response to elements in 
the perceptual field as parts of the pattern of the whole. The principle 
of the whole is thus valid for the perceptual field just as it is for executive 

These few examples of modern work on the perceptions of animals 
emphasise the need for extreme care in establishing exactly what it is in 
the surrounding world to which animals respond. We must not assume 
a priori that behaviour is determined by a concatenation of simple physico- 
chemical stimuli ; we must drop all metaphysical theory and try to find 
out by careful experiment just what animals do respond to. We shall 
often find that they respond to images or patterns, or to classes of objects 
that have for the animal the same functional significance, or to bare 

Response to relations is clearly demonstrated in some very thorough 
work recently carried out by Kliiver i° on the perceptual world of monkeys. 
His general method was to train his monkey to draw in one of a pair of 
boxes differing in some particular, for instance in weight. When he had 
established a positive response to the heavier of a pair, he varied the 
difference between the boxes, using two others of quite different weights 
from the original pair. He found by this method that his monkeys 
would respond to the bare relation ' heavier than,' quite irrespective of 
the absolute weight of the boxes used, provided of course that they were 
not too heavy for the monkeys to move. Other experiments of the same 
type showed that the monkeys had a power of practical generalisation, 
that many objects differing in shape and colour yet produced the same 
response — they were, from the monkey's point of view, functionally 
equivalent. This method of studying the equivalence or non-equivalence 
of perceptual objects promises to be a very fruitful one for investigating 
the behaviour of animals. 

In the short compass of this address I have been unable to give more than 
the very slightest sketch of a method for the study of animal behaviour 
which is, I think, likely to be the method of the future. It is, I rnaintain, 
a perfectly objective method, dealing with observable fact, and it is free 
from any metaphysical preconceptions. 

I have been concerned to point out two things. One is that it is time 
biology shook itself free from the limitations imposed upon it by a blirid 
trust in the classical doctrine of materialism. This doctrine is not in 
harmony with the modern development of philosophical thought, nor 
with the modern development of physical science, and it is not well 
adapted to the study of living things. 

10 H. Kliiver, Behavior Mechanisms in Monkeys, Chicago, 1933. 


We must adopt a more concrete and more adequate concept of the 
living organism, one that will take account of its essential characteristics. 
We must think of the organism as a four-dimensional whole, or directive 
cyclical process, and no longer attempt to contain it within the static 
scheme of the classical materialism. This does not lead to any form of 
dualistic vitalism. The relation of behavioural or ' psychological ' 
activities to physiological is not the relation of mental to physical activities, 
but is, quite simply, the relation of a whole spatio-temporal directive 
process to its parts. 






Ever since our subject was re-established as an organised discipline, the 
essence of which is the study of terrestrial distributions and their inter- 
relations, geographers have been sifting and collating data of extremely 
varied character. The facts which have thus been incorporated in the 
body of geographical literature have themselves usually been established 
by workers in other fields, while geographers have drawn deductions 
from them, in many cases without having the opportunity to test their 
validity on the ground. As a result generalisation and causation in 
regard to very large sections of the continents must necessarily rest on a 
rather insecure foundation. The question therefore arises — how can this 
be remedied ? The world is large and complex, while the number of 
geographers is still small, and they are very unevenly distributed over 
the globe. In Europe, where they are numerous, the position is quite 
different. The vast geographical literature of this continent is mostly 
due to individual workers who knew their country and had at their 
disposal copious facts and abundant statistical data of all sorts, and above 
all excellent topographical maps. But consider the basis of our knowledge 
of large parts of the southern continents and of Asia. We derive much 
of our information from the accounts of primary exploration, some of the 
best of it contributed by the great pioneers, the naturalist travellers of 
the nineteenth century. Since their day the mesh of the net has become 
closer ; expeditions have been better equipped ; scientific aims have 
become more definite ; route surveys have improved. Yet the fact 
remains that comparatively few expeditions engaged in primary explora- 
tion have yielded well-balanced explanatory accounts of all the elements 
which might be the subject of observation in the regions traversed. This 
defect doubtless will be attended to more often in the future. But the 
records of exploration having the character of traverses must nearly 
always be limited, since observations are usually confined to one season 
of the year. 

I do not, however, propose to develop this aspect of the question ; 
for the suggestion which I have to offer applies rather to regions where 


pioneer exploration is regarded as finished, and especially to the colonies 
and dependencies of the more advanced nations. I submit that these 
regions offer the most fruitful field for geographical research in the nearer 
future. As the chief reason for this belief I would mention the justifiable 
hope of the rapid extension of systematic surveys in such countries ; 
and we are agreed, I think, that the basis of all sound geographical 
research is a reliable topographic map, supplemented if possible by the, 
results of geological surveys. 

Brigadier Jack, as President of this Section in South Africa, devoted 
his address to the need for extensive regular surveys and to the many 
practical advantages accruing from them ; and the Sectional Committee 
last year asked the Council of the Association to point out to our Govern- 
ment that the lack of reliable surveys and maps in the British Colonies 
and Dependencies greatly delays scientific and material progress. I am 
therefore only reiterating the firm conviction of geographers when I say 
that scientific knowledge of the continents can scarcely begin to make 
rapid progress until they have been adequately mapped. In the regions 
where this aim has already been achieved, as in India and in parts of 
Indonesia as well as in some of the African Colonies, I feel that geo- 
graphers, given at least one year in well-chosen ' key ' districts, could do 
a great deal to promote a real understanding of larger regions, especially 
in the field of human geography. We should, I think, use every means 
to make such investigation possible. But I have repeatedly asked myself 
whether there is no other way in which we can accelerate the process 
of gathering the type of information needed for the composition of 
geographical syntheses which may be at least fuller and better than those 
we now possess. And it has been borne in upon me that the right way 
lies in the direction of co-operative effort. 

The idea of extensive collaboration in geographical research is by no 
means new. An obvious method which has been employed consists in 
the concentration upon a given region of work by specialists in each of 
the earth sciences, resulting in a series of individual monographs. But 
unless there be a concluding volume in which all the results are causally 
linked, the work is not geography. An outstanding example of this 
kind is the great investigation of Lake Balaton and vicinity undertaken 
by the Hungarian Geographical Society in 1891, and involving nearly 
a hundred contributors. Most of the voluminous work was published,^ 
but unfortunately the geographical synthesis is still awaited. The same 
Society in 1905 organised a similar work upon the Alfold, but the war 
seriously interfered with this. The International Geographical Union, 
since its formation, has promoted co-operative research on various 
subjects the majority of which are of a physical character. Thus the 
creation of commissions to deal with these investigations marks the 
extension of an older and similar type of organisation well represented 
by the International Glacier Commission or by various national research 
bodies such as the late Sir John Murray's Bathymetrical Survey of 
Scottish Lochs or the Royal Geographical Society's Committee on 

^ ResuUate der Wissenschaftlichen Erforschung des Balatonsees, Budapest, 
1897 onwards. 


English Rivers. It is, however, significant that two of the new Inter- 
national Commissions are devoted to aspects of human geography. Of 
these one deals with Over-population in its Geographical Bearings. It 
has not yet had time to develop its work fully. The other, on Types of 
Rural Habitation, has accumulated a vast amount of material contributed 
by many geographers and is likely to render great service to our science. 
.Somewhat similar in aim is the separate co-ordinated study by a group of 
German geographers upon settlements in a large variety of regions 
throughout the world, and whose papers have recently appeared.^ Perhaps 
the most striking instance of an organised geographical investigation 
designed to be of definite advantage in future national planning is that 
of the American Geographical Society relating to problems of pioneer 
settlement throughout the world. The firstfruits of this, which have 
already been published,^ represent the results of regional studies by 
selected geographers and a synthesis by the organiser, Dr. Isaiah Bowman. 
Associated with this is the intensive work upon the Prairie Provinces of 
Canada, which occupied five years. Its results, now in course of publica- 
tion * under the editorship of Prof. W. A. Mackintosh, represent the 
first large undertaking of co-operative scholarship in the Dominion. 
I understand that it is a most comprehensive work in which geographical 
factors have received due consideration, although the authors are exponents 
of other subjects. 

I have mentioned these examples in order to indicate the extent to 
which we already depend upon the fruits of co-operative investigation. 
But it is clear that the collaborators in such projects have always been 
geographers or people whose life's work lies in some branch of science 
or learning that can be made to serve our purpose. But I now return 
to my original theme, the scanty nature of the data upon which our 
geographical generalisations so often rest, and the long period that must 
probably elapse before trained geographers duly equipped with maps can 
cover the immense field by personal investigation. Let us consider Africa 
as an example, with special attention to its inhabitants. 

During the past decade or so an increasing interest has been taken in 
the future of the black race in Africa, and the literature bearing upon the 
relations between Europeans and Africans has already assumed consider- 
able dimensions. But before arriving at a considered judgment regarding 
the future of the native it is evidently necessary to understand the native 
as he is, the life he leads and the beliefs he holds. These are matters 
proper to the study of anthropology ; and in fact that science has dealt 
very fully with the African races and is prepared to answer most of the 
questions that are usually asked relating to the natives. Nevertheless, in 
1926 I found it necessary to point out ^ that the geographical controls or 

* F. Klute (Ed.), Die Idndliche Siedlungen in verschiedenen Klimazonen, Breslau, 

' ' Pioneer Settlement, Comparative Studies,' Amer. Geog. Soc. Special 
Publication, No. 14, New York, 1932. Isaiah Bowman, ' The Pioneer Fringe,' 
ibid., No 13, New York, 1931. 

* By Macmillan, Toronto. 

* ' Africa as a Field for Geographical Research,' The Geographical Teacher. 
vol. xiii, pp. 462-467. 


influences affecting the material life of these peoples usually receive far 
too little attention. Indeed the physical environment as a rule is quite 
inadequately treated in the anthropological literature of the continent. 
I was interested to find soon after this that my colleagues in this Section 
agreed with me both as to the gaps in our knowledge and as to the great 
importance of attempting to fill them. A Research Committee of the 
British Association was therefore appointed after the Oxford Meeting to. 
investigate the state of knowledge of the Human Geography of Inter- 
Tropical Africa ; and this Committee has been increasing its activities 
ever since. We set ourselves to state clearly the points upon which 
information was badly needed, and then proceeded to lay plans for tapping 
a body of knowledge which we believed to exist in Africa, but which 
hitherto had scarcely been tapped in the interests of geography. Scattered 
throughout this continent are many men and women who, with long 
residence in close contact with the Africans and personal experience of 
the environmental conditions year in year out, should be able, by answering 
specific questions, to provide the essential link between the land and the 
mode of life of the natives. We had in mind chiefly the District Officers 
of Colonial Governments, and missionaries. To them we sent our 
nineteen questions, most of which might be considered to apply to any 
of the regions envisaged. We included them in a pamphlet ® that gave 
in addition a brief explanation of our aims and reprints of two model 
essays on the relation of African tribes to their environment, those of 
Pere L. Martrou on the Fang and Mr. R. U. Sayce on the Basutos. 

Human Geography of Northern Rhodesia. 

The most comprehensive response received so far has come from 
Northern Rhodesia, where the late Governor was good enough to transmit 
our request to the District Officers of the Protectorate, with the result 
that we have at our disposal a series of thirty reports covering the whole 
territory save for two Districts, in area the equivalent of France with the 
Low Countries and Switzerland, and dealing with the life conditions of 
well over one million people. 

The aggregate volume of the Northern Rhodesia reports is considerable, 
amounting to well over 200,000 words ; some are quite brief, others are 
long and generally proportionately useful. I propose presently to state 
in summary form some of the results of a synthesis derived from their 
contents. Before doing so, however, I wish to express on behalf of the 
Committee our indebtedness to the authors ' for the trouble they have 
taken in responding to our invitation. 

^ The Human Geography -of Inter-Tropical Africa: The Need for Investigation, 
1930 (reprinted 193 1). 

' The authors of reports, and the Districts, are as follows : A. W. Bonfield, 
Serenje ; H. F. Cartmel-RobLnson, Fort Jameson ; C. A. R. Charnaud, Mazabuka; 
E. H. Cooke, Feira ; T. S. L. Fox-Pitt, Kasempa ; H. A. Green, Kalabo ; D. B. 
Hall, Kalomo (plateau) ; S. S. Hillier, Luwingu ; G. Howe, Mporokoso ; R. S. 
Hudson, Balovale ; G. Hughes-Chamberlain, MwinUunga ; R. O. Ingram, 
Sesheke ; E. K. Jordan, Isoka ; S. P. L. Lloyd, Kasama ; F. B. Macrae, 
Livingstone, Kalomo (valley) and Mumbwa ; E. Munday, Chinsali ; C. P. 


There is special ground for satisfaction that the first of the British 
territories to make such full response is Northern Rhodesia, on account 
of the recent appearance of an important study of sociological and 
economic character which deals with almost the same region. This is 
the report of an inquiry into the impact of the copper mines of Central 
Africa upon Bantu society, and the work of missions, made by the 
Department of Social and Industrial Research of the International Mis- 
sionary Council.® It is to be noted that the material now in our hands 
is almost wholly supplementary to the content of this book. Yet I venture 
to think that we are in a position to compile from our reports an account 
which will facilitate the full appreciation of the vital problems dealt with 
by Mr. Merle Davis and his colleagues. 

It is a matter for regret, on the other hand, that we possess insufficient 
material from which to construct an adequate account of the physical 
geography of this region. The map is a compilation, with no real 
representation of relief, for stringent financial resources have hitherto 
prevented the undertaking of regular surveys. The presence of abundant 
reserves of copper in the central area has led, I learn, to much geological 
survey in recent years ; but, so far, few results have been published. 
There are no satisfactory general treatises either upon the soils or upon 
the natural vegetation. In regard to the climate alone are satisfactory 
data available ; for the Protectorate has some fifty rainfall stations estab- 
lished at least fifteen years and many with shorter records, while observa- 
tions of temperatures are annually reported from some fifty stations. 

Thus, with the exception noted, the physical setting, in which human 
existence is now so minutely described, still remains somewhat obscure. 
It is fortunate, however, for our purpose that over vast stretches of 
Rhodesia there is relatively little variety of natural landscape or of the 
causes which underlie it ; indeed, this is almost certainly true of the 
greater part of Central Africa. For this reason we are perhaps entitled 
to make the fullest use of accurate knowledge established in valuable 
surveys recently made across the northern border in the Katanga and 
now in course of publication by the Comite Special du Katanga. From 
the admirable sheets of this atlas ^ and the published writings of its 
creators we may gain real insight into the interrelations of structure, 
relief, soil, and vegetation cover which must be closely analogous to those 
prevailing in the Protectorate. 

From our District reports we can glean much sporadic information 
upon each of these physical elements, and there are two types of state- 
ment which are real contributions to the physical geography of Rhodesia. 
The first supplements the climatic statistics by describing the local 

Oldfield, Abercorn ; M. B. J. Otter, Kawambwa ; F. R. G. Phillips, Fort 
Rosebery ; E. H. L. Poole, Lundazi and Petauke ; C. G. Stevens, Mkushi ; 
G. R. R. Stevens, Mankoya ; G. Stokes, Mpika ; H. A. Sylvester, Namwala ; 
P. D. Thomas, Senanga ; E. F. G. Thomson, Chiengi and Lusaka ; J. Moffat 
Thomson, Broken Hill ; J. F. Warrington, Mongu. 

* J. Merle Davis, Modern Industry and the African, Macmillan & Co., 1933. 

» H. Droogmans, M. Robert et G. Maury, Atlas du Katanga, Publication du 
Comitd Special du Katanga, Bruxelles, 1928 onwards. 


weather sequence throughout the year ; and the second concerns the . 
regimen of rivers. I would draw particular attention to this matter, so 
important for the population ; we have received a statement from every 
District as to the permanence of streams and their flood character. 

Physical Environment. 

In order to have space for matter that is now available for the first time, 
I will describe the physical background in barest outline, mentioning only 
such facts as are important to the understanding of the human geography. 

The fundamental crystalline skeleton of Africa appears here in two 
broad zones extending respectively from S.W. to N.E., occupying the 
south-eastern belt, and S.E. to N.W., extending over into the Katanga. 
The structure of this latter zone is complicated by the presence of a 
geosyncline of ancient continental sediments, including dolomitic lime- 
stones, that were folded by thrusts from the S.W. Their outcrops, 
therefore, lie along an arc concave in this direction. Associated with 
these folds and with certain igneous intrusions is the mineralisation of 
the zone, by lead and zinc in Broken Hill and by copper and other ores 
farther north. The south-eastern zone is seamed by a structural depres- 
sion in which sediments of ' Karoo ' age are preserved, said to contain 
coal as well as nitrates sporadically quarried by the natives for gunpowder. 
The Luapula basin in the north is largely underlain by Palaeozoic sedi- 
ments, but with granite intrusions, while throughout the drainage area of 
the upper Zambezi the ancient rocks are almost completely masked by 
the Kalahari sands. 

The relief of Northern Rhodesia, like that of most of the Central 
African highlands, is monotonous. Planation over long periods accounts 
for this ; and consequently the hill ranges and inselbergs which form the 
chief accidents on a plateau standing mostly between i,ooo and 1,500 m. 
are chiefly residuals of stronger rock, while the more extensive elevations 
above this height, notably those dividing the Bangweolo ' saucer ' from 
Tanganyika and from the Luangwa valley, will probably be explained 
by warping. The entire plateau seems to bear traces of indeterminate 
drainage with numerous evidences of river capture on all scales and of 
varied date. By far the most pronounced relief features are the margins of 
the south-eastern structural furrow drained convergently by the Luangwa 
and the Zambezi below the Batoka gorge. This, both on account of the 
height of the escarpments — generally more than 400 metres — which are 
to be regarded as erosional fault-scarps, as well as because of their extreme 
dissection by the regressive erosion of tributaries which are rapidly 
notching the plateau rims on both sides. 

Time does not permit me to deal statistically with the climate, which is, 
of course, of inter-tropical type with markedly seasonal rainfall. In 
Rhodesia three seasons are recognised and named by the natives, the 
limiting dates varying with the locality : the cool season from March, 
April or May to July or August ; the hot, dry season from July or August 
to October or November ; and the rainy season lasting from these months 
to March or April. But in some districts, where there is a temporary 
break in the rains of from one to three weeks in December to January, a 


lesser (first) and greater (second) rainy season are recognised. Moreover, 
in Barotseland a fourth has to be added, named Mufida — the floods — for 
there the regimen of the Zambezi and tributaries is of prime importance. 

There is thus a dry period of at least six months during which the 
temperature is first dropping to its minimum in July and then rapidly 
rising to its maximum in October or November. The rains then spread 
southward and eastward, the belt of maximum precipitation being in the 
north-west in November, and in the east around Lake Bangweolo in 
December. In January rain is more evenly distributed ; in February 
the maximum is again in the east, from which it gradually withdraws 
northward again. The total rainfall is over 50 in. near the Congo frontier, 
and decreases eastward to 35 in. on the Nyasaland border and southward 
to under 30 in. in the Zambezi valley. 

The annual rhythm of vegetation, of animal life, and the seasonal activi- 
ties of the population are matters upon which we have received much 
information, especially on the latter. These phenomena can now be 
closely related to the temperature and rainfall factors and the flooding of 
the rivers and variation of swamps and lakes. 

In the absence of real knowledge of Rhodesian soils we may legitimately 
have recourse to the Belgian pedological work in Katanga, where, 
however, the rainfall is heavier. Owing to the very great extent of 
surfaces of peneplane type, it is most probable that the Rhodesian soils 
as a whole are residual and old, deficient in soluble salts and more or less 
later itic. Moreover, deforestation over large tracts has proceeded for 
long ; and the removal of this natural protective cover results in the 
lowering of the water table during the dry season, and the loss of fertility, 
especially by the removal of humus, a contributory factor in this being 
the widespread annual grass fires. It may be regarded therefore as most 
likely that prevailing plateau soils are poor. Their vegetation is savanna, 
or what Shantz has classified as dry woodland, in which the trees are mostly 
deciduous and where their stature and their density varies with available 
water. They are, of course, associated with grass which is renewed each 
rainy season, and which, like the trees, varies with the rainfall. 

Throughout the peneplanes are numerous shallow hollows known as 
dambos, filled by wash from the slopes, sandy and lateritic round their 
margins, clayey and marshy in their centres. Their soil is infertile and 
grass predominates in their vegetation. 

By far the most attractive soils are those of the alluvial areas. In the 
maps of the Katanga these are distinguished according to age — young, 
adult and old ; and the District data from Northern Rhodesia would 
seem amply to justify this classification as one that is important in 
the human geography. But of course it is impossible to do more than 
guess the distribution of such types in any locality. The first class are 
annually inundated and renewed ; the second, which may occasionally 
be flooded, are typically dotted over with termite hills. The plant cover 
of both these types is herbaceous, and their edges would seem to form the 
sites of the great majority of native villages in the Protectorate, for such 
places are close to good soil, to water, and to trees, the three main 
desiderata of the Rhodesian cultivator. The old alluvium, on the other 

E 2 


hand, has lost much of its fertility through leaching, and possibly has 
become partly lateritic. It seems to be covered by somewhat xerophytic 
bush wood. The very porous soils developed upon the thick Kalahari 
sands of Barotseland would seem to be fairly good so long as the tree 
cover is maintained, with roots reaching the ground water, but to suffer 
rapid degradation when this is cut down. 

Depredations by Man. 

The inquiry has elicited certain facts about the modification of the 
natural vegetation by the natives. The great majority of the people live 
upon their crops, and most of these are raised in partial clearings of the 
savarma. The natives are truly men of the trees, apart from which they 
cannot live. The essential feature of their system of shifting agriculture, 
a system well known throughout the forests and savanna of inter-tropical 
lands, is the annual felling or pollarding of trees and the application to the 
soil of the ash derived from burning the wood on the site of their gardens. 
The name given to the practice in north-eastern Rhodesia is chttemefie or 
vitemene, meaning ' those which have been cut.' The area of woodland 
cut for a garden of given size of course depends first upon the luxuriance 
of the trees, and secondly upon the nature of the practice- — whether 
pollarding or felling. Throughout the drainage basins of the Kafue and 
upper Zambezi, as well as east of the Luangwa, it seems to be the habit 
to fell trees and to burn all branches, leaving the trunks to rot. This is 
also the method in part of Fort Rosebery and among the Awisa of Mpika. 
But to the north of the latter Districts trees are usually only pollarded, 
and this also seems to be the case in two central Districts, Mkushi and 
Serenje. The estimates of the ratio of timber area cut to area of garden 
vary between 4 : i and 10 : i. The estimates of the period required for 
recovery of the woods are more numerous, but they are difficult to inter- 
pret in view of the inadequate accounts of the vegetation. In Mpika 
District the pollarded woods of the Awemba are left for about seven years, 
we are told, while the felled timber of the Awisa would require a genera- 
tion to recover. Yet several District reports mention rest periods as 
short as four or five years ; in others these are between ten and twenty, 
and in Barotse thirty to thirty-five years. 

The degree in which the savanna has degenerated under this system of 
agriculture depends largely upon the density of the population. Many 
writers point out that tracts of the natural vegetation still exist simply 
because the population is small — as, for instance, in Chinsali with three per 
square mile. But such figures are misleading, for the actual densities on 
land desirable from soil and water qualities are very much greater. More- 
over, the native cuts wood for many purposes besides that of manuring 
his garden. He needs timber for a new hut every few years, for heavy 
garden fences, and for canoes. He fells trees to obtain honey, he strips 
trees of their bark. ' Bark,' writes the author of the report on Mongu,^" 
' comes more frequently into daily life than anything else ; every piece of 
rope used by natives and most of that used by Europeans is made of it, 

^° J. F. Warrington. 


consumption is enormous and must be responsible for the destruction of 
thousands of trees and saplings every year.' Finally, there is the damage 
to seedlings and young trees caused by the annual grass fires which sweep 
the territory. These are started for various reasons. Fire may be 
allowed unintentionally to spread from the garden burning. Hunters 
use fire for two purposes : first, to promote rapid growth of young grass 
to attract game, and, secondly, in the case of organised hunts, to drive the 
animals in required directions. Stock-keepers also start fires to accelerate 
the appearance of fresh pasture, and, furthermore, long grass is disliked 
near villages for various reasons. 


While no information was asked for regarding the physical or other 
characteristics of the inhabitants of Northern Rhodesia, yet a consider- 
able amount of data of this kind has been received, and it will be placed 
at the disposal of the anthropologists. Nevertheless it is pertinent 
here to mention some of the geographical effects upon the migrations 
into and within the territory as revealed by tribal tradition and reported 
in the present documents. Most of the migrations referred to have taken 
place within the last two centuries, and the dominant direction appears 
to have been south-easterly from the southern part of the Congo basin. 
Thus the way seems to have been easy for tribes from the Congo-Zambezi 
watershed, either south-eastward through the upper Zambezi area or 
southward, over the peneplane drained by the Kafue, as far as the escarp- 
ment. The north-eastern plateau also seems to have been peopled by the 
present Bantu tribes chiefly from this same Katanga region of Congo, but 
here approach had to be either to north or to south of the Bangweolo 
swamps. The Awemba, who are now dominant in the centre, took the 
northern route, but have pressed south across the Chambezi, driving a 
wedge in the Awisa folk. Other tribes like the Lungu and Mambwe have 
penetrated south-westward from east of Lake Tanganyika. The most 
notable invasion from the south is that of the Makololo from Basutoland 
in the mid-nineteenth century to the country of the Aluyi, whom they 
conquered ; their men were later massacred, yet Sikololo in a modified 
form remains the language of the region. 

British rule has, of course, gradually brought these mass movements to 
an end ; but there is one outstanding exception in the Barotse plateau, 
where there has been a steady infiltration of people from Angola from 
1 91 7 onwards, which represents a resuscitation of the older south-eastward 
drift. These immigrants, known collectively as the Mawiko or ' People of 
the West,' and now numbering 100,000 or more, have left Portuguese 
territory when discontented with its administration, and they have now 
penetrated Barotse Province to a depth of nearly two hundred miles. 

A striking feature of human geography throughout Central Africa is 
the relegation of the weaker or more primitive peoples to the least desirable 
areas. In Northern Rhodesia these areas were the swamps of the plateau, 
and the hot lowlands of the Luangwa and the Zambezi below the Falls. 
In the former we find the backward Batwa or marsh folk, whose culture, 
however, has greatly advanced in recent years ; in the Luangwa, the Senga 


and others, who appear to have been forced thither by the Awemba or 
others from the west and the Ngoni raiders, of Zulu stock, from the east ; 
while the low Zambezi valley is peopled by numerous debilitated tribal 

External Influences. 

The effect of European influence upon the economic and social structure 
of native society in Northern Rhodesia has recently been very thoroughly 
dealt with by Mr. Merle Davis in the work already referred to. It is, of 
course, not a geographical work, though geographical factors are recognised 
by the author. I have therefore attempted to make an estimate, based 
upon our District reports, of the nature and degree of external influence 
upon the material life of the natives. These influences differ widely in 
date and in potency. The acquisition of the chief cultivated plants and 
domestic animals reaches far back, and I do not propose to deal with this. 
Direct contact with the earlier Portuguese traders has been of little account, 
save possibly in the Feira District, but in the west their indirect influence 
has been considerable in view of the migration of tribes whose ancestors 
had been in touch with the Portuguese on the Atlantic seaboard. The 
use of manioc ^^ bears witness to this, and the square or oblong type of 
house which to-day prevails in the two north-western districts probably 
derives ultimately from this source. In Balovale it replaced a beehive 
grass hut, and its superiority over the circular pole and thatch hut of the 
other Rhodesian areas is being recognised, as is the skill of its builders, 
who are often paid to build houses for neighbouring tribes. Since 191 7, 
the new wave of immigrants from Angola has led to the spread of this 
house type throughout the upper Zambezi basin. 

About the southern end of Lake Tanganyika there are evidences of 
various effects of the incursions of Arab slave raiders. Here again a 
square house is found mingled with the circular huts (Abercorn), while 
the small groups of Swahili people have groves of date palms and other 
cultivated fruit trees. 

But these aspects are all insigniflcant in comparison with the potent 
influences due to the British rule and partial settlement by European 
farmers, the rapid exploitation of minerals in the Belgian Katanga and 
the Ndola and Broken Hill Districts of the Protectorate ; while the estab- 
lishment of missions throughout Rhodesia has had widespread material 
as well as moral effect. As indexes of the outward evidence of this 
permeation, which really amounts almost to revolution, I select data of 
three types : first, the distribution of houses built on the European 
pattern ; secondly, the continuance or otherwise of the old-established 
native iron industry ; thirdly, the direction and volume of movement of 
native labour to work for Europeans. 

Houses built on the European model, either of wood or of sun-dried 
brick, are most numerous along the southern half of the railway ; in Kalomo 
they are estimated at 10 per cent. Here also native iron-working is either 
not mentioned or is stated to have died out, or else the smiths have turned 
their attention from axes, hoes and spears to the repairing of ploughs and 

" Cf. Fig. 3. 



bicycles. These latter, which are rapidly multiplying, are a good index 
of prosperity, since their price is £$, and the possession of cycles gives 
special inducement to the people to keep the inter-village paths clear and 
encourages the habit of paying visits at a distance, the native's chief 
recreation even w^hen he had to walk. This southern railway belt is, of 

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Fig. I. — Cartogram of Northern Rhodesia to illustrate effects of 
External Influences, 
(i) Rhodesian circular house ; (2) Rectangular house of Bantu or Swahili origin ; 
(3) Rectangular house on European model ; {4) Native iron industry 
reported as still in operation ; (5) Annual migration to European mines ; 
(6) to other European employment ; (7) to market produce ; (8) Surplus 
produce sold locally. 

course, the centre of European population, the effect of which is seen in 
the nature of money-earning employment. The poll tax of from 7.?. ^d. 
to 125. 6J., according to the region, is in Rhodesia the initial cause of 
the widespread annual migration of the younger men, but the desire 
for change and excitement and for luxuries increasingly influences it. 
Throughout most of the country natives have to travel far to earn money. 
But here in the south employment on farms, on the railway or in domestic 
service may be had at a distance usually much under one hundred miles. 
Moreover, surplus crops or stock may be sold for local use or for transport 


by rail to the northern mines. Thus the annual movement in the south 
is for the most part convergent upon the railway strip for service or for 
trade ; from Feira some agricultural labour moves to Southern Rhodesia, 
and such men as prefer the mines may go by train either north or south. 

Over the great north-eastern region European settlers are very few, 
and in East Luangwa they are concentrated about Fort Jameson. 
European influence, therefore, is either spread by the Administration, 
the missions, of which there are nearly forty, or by the migrating natives 
themselves. Copies of European houses occur in significant proportions 
throughout the Luapula drainage area, as well as in Isoka District. Only 
four of the thirteen Districts report native iron industries, the rest relying 
mainly on imported implements. The annual movement to the labour 
market is directed almost everywhere westward to the mines of Broken 
Hill, Ndola and the Katanga, the only important exodus for farm work 
being from Isoka to the coffee plantations of Mbezi in Tanganyika 
Territory. The distance travelled by the natives going to the mines 
frequently amounts to four hundred miles, and the average periods of 
absence from these northern districts are given as from six to nine months. 
The consequences of these long absences of the able-bodied men, whether 
accompanied by their wives or not, are fully discussed by Mr. Davis ^^ ; 
I will mention only one result — the serious reduction of land in crops 
and the consequent increase of famine risk. From the Mweru Luapula 
Province there is a further movement into and across the Katanga. This 
marks the export of the surplus produce of the Province, consisting of 
dried fish and manioc meal for sale at the mines. Natives may make 
three or four such journeys a year, but some of this commerce is now in 
the hands of European traders, mostly Greeks and Italians. These also 
buy skins, notably those of the otters killed around Lake Bangweolo. 

The western plateau, drained by the Zambezi, lies off all main routes. 
Moreover, the greater part of it is Barotseland, where limited self-govern- 
ment exists and missions are fewer than elsewhere. Consequently the 
region has less contact with the white man. European houses are 
mentioned only in Mongu (probably mission influence) ; and all the 
Districts either mine their own iron or at least manufacture many of their 
implements. Yet the whole basin sends its quota annually to the mines 
when labour is in demand there. From the southern half of the country 
the majority probably go to the Wankie or other Southern Rhodesian 
fields, and Mankoya also sends agricultural labour southwards. But from 
the northern districts natives walk, up to four hundred miles, to the 
copper belt. 

Such are some of the regional effects of European contacts. But 
I must not omit to mention one which applies equally everywhere. Before 
British rule the Rhodesian natives lived dangerously. Because of inter- 
tribal wars and the risk of attack by slave raiders the people lived in large 
villages surrounded by stockades. With the new security their groups 
have been steadily growing smaller and tending to approach the natural 
unit which is the family, albeit a larger unit than that to which we apply 
the name. Government, however, has imposed its veto upon further 

12 op. cit. 


subdivision. Therefore it may be stated in general that the population 
is everywhere contained in villages varying in size according to local 
geographical conditions. 

Population Density. 

I have had to spend much time in studying the distribution of native 
population, since the responses to the Committee's request for informa- 
tion under this head varied greatly in value. The average density for the 
whole Protectorate is a little over four per square mile. The official 
figures of average density by Sub-Districts in 193 1, however, at once draw 
attention to the uneven distribution of the people. Thus, two Districts 
in Barotse Province, Kalabo and Mongu, have densities of 11 -6 and 16-3 
respectively; Chienji on Lake Mweru has 13, while Fort Jameson has 
20-8. On the other hand, in a beh from the Katanga border southward 
to Sesheke the District densities vary from 1-3 to 2-5, while in the 
railway belt to the east of this, figures are between 3 and 4. A cartogram 
made from these data, however, gives but a crude representation. In 
the first place, wherever there is a nucleus of European farmers the natives 
of the vicinity have been or are being moved into reserves, thus greatly 
increasing their density per square mile in these Districts. But it is the 
examination of life conditions which brings realisation of the real 
distribution. We have seen that agricultural village sites must of 
necessity be close to water, to reasonably good soil, and to trees. In the 
central District of Mkushi the actual distribution, almost entirely along 
the river valleys, was shown on a map by Mr. C. G. Stevens, from which 
I calculate densities of from 50 to 60 per square mile instead of 2-77 for 
the District, the interfluves apparently being inhabited. The evidence 
is insufficient and the map too vague to allow of such refinement being 
made for the whole territory, but I have had no great difficulty in plotting 
approximately the more outstanding variations in density. The following 
are some of the more interesting results of the operation. 

The type of locality which carries the greatest population is that which 
provides a means of livelihood apart from agriculture ; and fishing is 
by far the most usual supplement of this kind. Indeed it becomes the 
dominant occupation around Lake Bangweolo, where the islands have 
about 80 persons per square mile, and many shore areas must be nearly 
as densely peopled. Similarly, high densities occur along the shore of 
Lake Mweru and the banks of the lower Luapula. Such areas of good 
fishing which are also excellent land for producing manioc have received 
access of population in recent years on account of the encouragement to 
market fish and meal in the mining areas to the west. 

Fishing, again, is the cause of the most concentrated population on the 
River Kafue below Namwala and round several small lakes in Kalabo. 
Here indeed, near the western border, the appearance of ground water 
from the sands seems always to draw people in an otherwise dry region. 
The great alluvial plains of the Barotse, the Kafue Flats, and the reserves 
east of the Luangwa are all relatively populous districts in which cattle 
are held by cultivators. Apart from the areas mentioned and a few 
others less notable, the population densities, calculated on the assumption 



of stream-bank arrangement, would seem to vary from, say, 5 to 10 per square 
mile in Districts of small population to 40 to 50 in the more populous. 

Tsetse Fly. 

No element of the huRian environment is more important than the 

distribution of the tsetse flies (Glossina). G. palpalis, the carrier of 

sleeping sickness, appears happily to be either absent or innocuous over 

nearly all the country, the only districts where the disease has been 

Fig. 2. — Sketch-map of Northern Rhodesia, showing Distribution of (i) Tsetse 
Fly and (2) Native-owned Cattle. 

reported in recent years being the Luapula and Luangwa valleys, the 
shore of Lake Tanganyika, and a small part of the upper Kafue valley. 
But with the bearers of Nagana it is quite otherwise. The presence of 
these flies is a menace to cattle owners, European and native, and un- 
fortunately they infest the greater part of the territory. Their distribution, 
as plotted from the reports and certain local maps, reveals three large 
tracts that are free of fly. The first includes the greater part of Barotseland. 
East of this lies a broad fly belt ; within this the flies seem to be spreading, 
and at the southern end the belt is extending both eastward and westward 
toward the native and European cattle land of the lower Kafue and the 


railway zone. This latter, with its greater amount of cultivated land, is 
still free of fly to the edge of the great escarpment, and the same is gener- 
ally true of its continuation north-eastward along the divide between the 
Chambezi and Luangwa ; Broken Hill and Mkushi even report a re- 
duction in fly. The Luangwa fly belt shuts oflt the clear area of the 
Nyasaland border, and at the head of the valley the pest is encroaching on 
the plateau land. The tsetse distribution is more patchy in the northern 
areas. Generally speaking, the higher lands are the freer. In Fort 
Rosebery the fly is local, and Kasama records a reduction ; but evidently 
there are few areas which can safely be reached by cattle. 

The map indicates clearly the prevalence of tsetse in the hot lowlands, 
but the controlling factor on the plateaus, which is doubtless the character 
of the vegetation, cannot be examined until a survey of that element has 
been made. The nature of the wild fauna is a contributory factor ; and 
while the reports contain useful information regarding the wild animals 
which are hunted or cause depredations to crops, it is insufficient to allow 
of any important deduction. 


While cattle are restricted to the areas free of fly, they are by no means 
evenly distributed throughout these parts. Nor are they of equal 
significance in the life of their owners, chiefly on account of varying tribal 
tradition in regard to cattle, but also from the incidence of European 
influence. In Barotse it is the Maroze chiefs and indunas who are the 
chief cattle owners, and the herds vary according to the available pasture, 
being greatest on the Zambezi plain (in Mongu c. 50,000 head) and 
decreasing north and south. Cattle in general are regarded merely as 
wealth, chiefly in relation to the marriage security, sometimes as a source 
of meat and of hides, more rarely of milk. But in contact with Europeans 
and a market, the tribesman tends to devote his animals to work, notably 
with the acquisition of the plough in the alluvial plains, of two-wheeled 
carts on suitable ground and of sledges elsewhere. It is chiefly in the 
vicinity of the railway that the natives are following European guidance 
in the matter of breeding and of dipping. Elsewhere the herds receive 
little attention, and consequently the stock is poor. Furthermore, the 
Barotse cattle were stricken with pleuro-pneumonia in 1915 and their 
numbers reduced by perhaps 50 per cent. In the central Districts, on the 
other hand, stock is increasing, owing to the natives' contact with Europeans. 
This feature is most pronounced in Mazabuka, where the Tonga and 
Lundwi have over 108,000 head, and as these have recently been driven 
into the reserves, there is a risk of overstocking. This reacts not merely 
directly on the animals, but indirectly and permanently upon the land, 
which is much more serious. It results in rapid erosion of the soil 
wherever there are slopes. 

Cattle, of small size and few in number, are kept in the Zambezi lowland 
along the river banks and partly shut off from the plateau by a fly belt. 
Similarly a few animals only remain in the hot Luano valley of Mkushi, 
though formerly the herds there were sufficient to attract the Ngoni 
raiders from the east. The Ngoni and other tribes of the Nyasaland 


border form the remaining native group which keeps large numbers of 
cattle ; for the tribes of the northern plateau, in spite of considerable 
available land, are not pastoralists to any extent, the chief exception 
being the Isoka District with 7,000, where, however, tsetse, extending up 
from the head of the Luangwa valley, has been causing destruction. 

Small stock in Northern Rhodesia are widely spread : they are in almost 
every village and receive very little attention. Goats are a universal 
possession, far outnumbering cattle in most parts, and the same may be 
said of poultry ; sheep are more local in distribution, and pigs, which 
become crossed with the wild variety, seem to have an uneven distribution. 

Transhumance is practised by the cattle owners of the Barotse Plain 
and the Kafue Flats, in each case in response to the flooding of the alluvial 
belt. The Maroze possess two sets of villages, on the plain and in the 
savanna respectively. They occupy the former from May to January, 
cultivating their maize and grazing their cattle ; then, when the Zambezi 
rises in February, they move to their woodland villages, where the cattle 
manure their manioc and millet land. The inundated villages have, of 
course, to be repaired regularly before reoccupation. The Baila of the 
Kafue, on the other hand, live in large permanent villages, above the 
floods and far from the river, where they grow maize. The river is at its 
highest in March and, when the floods have receded in June, the migra- 
tion to the flats takes place, grass being burned for hunting and grazing ; 
temporary villages are occupied, where fishing can also be had. The 
Baila are exceptional in the variety of their -diet of maize, fish, milk, and 
game meat. 

Food Staples. 

The distributions of four of the leading food crops of Africa meet and 
overlap in Northern Rhodesia ; the three cereals, comprising the great 
millet — sorghum, the lesser millets of which eleusine is the most important, 
and maize. These, with manioc (cassava), form the food staples of the 
native population. Allowing for some uncertainty as to the identity of 
the millets mentioned by the authors of reports, it has been possible to 
plot the crop distribution with general accuracy. It is thus evident that 
the small millets, especially eleusine, prevail in the north-eastern plateau 
while sorghum is more cultivated in the central Districts. This crop, 
however, has yielded the first place over most of its area to maize, most 
probably introduced from the south and certainly increasing where the 
contact with European farming is close. The most outstanding fact 
elicited is the penetration of the territory by manioc as a staple crop. 
The lower Congo region is generally held to have been the centre of 
dispersion of this American plant, and it will be interesting to learn 
whether its area is now unbroken to the Rhodesian border. It is clear 
that manioc is still being carried south-eastward by the Angolan immi- 
grants in Barotse, and, for reasons to be mentioned, its cultivation is being 
encouraged elsewhere by the Administration. Its appearance along the 
railway belt and its dominance in Lusaka are perhaps due to this. But 
manioc is also the staple along the Luapula valley and thence eastward 
to Lake Tanganyika. Where the small millet appears as secondary crop 



it is often grown solely for the beer that is brewed from it. Such * beer 
crops ' are those secondary to manioc in Chiengi and Fort Rosebery, and 
that of Kasempa, subsidiary to sorghum. 

To understand the geographical significance of these crops it is necessary 
to examine the manner of their cultivation. The preparations for millet- 
growing appear to vary but little. The lopping of trees and heaping of 

Fig. 3. — Cartogram of Northern Rhodesia, showing Distribution of 
leading Food Staples. 
(i) Small Millet, generally Eleusine ; (2) Sorghum ; (3) Maize ; (4) Manioc 
(Cassava). For sake of visibility, rulings have been drawn over European 
as well as Native areas. 

the branches on the cleared garden site are completed by the end of the 
dry season and the burning takes place, usually on the chief's signal, 
just before the first rains ; if this is done too early there is a risk of the 
precious ash blowing away. The seeds are then planted in the ash- 
covered soil during the early rains ; and the millet crop is directly 
dependent upon rainfall for its water and upon wood ash for its nourish- 
ment. Hence it is the only cereal which flourishes on poor, lateritic soils. 
It is therefore the characteristic grain of the savanna away from the alluvial 
strips of rivers, which are devoted in general to sorghum or maize. The 
same conditions govern the cultivation of ground nuts, which are generally 


associated with tlie smaller millets. In many Districts the main part of 
the garden is devoted to millet for only one year, a new garden being 
prepared for the staple crop each year, and the old garden used for mixed 
subsidiary ' relish ' crops. The number of successive years in which a 
garden grows millet must, of course, depend upon soil fertility, and as 
we have little information about the plateau soils, no deduction can be 
drawn from the facts recorded. But three years appears to be the 
maximum, save for special reasons. Thus the Amambwe of the north-east, 
who are industrious hoe cultivators, have a four-year rotation system, 
consisting in millet, fallow, a leguminous crop or maize, and again millet, 
by which they use the same garden for eight years or more. Again, the 
Maroze cattle owners of the upper Zambezi systematically manure the 
ground by moving their kraals at intervals, when the cattle are in the 
savanna during the Zambezi flood season. These, however, are exceptions, 
and it is abundantly clear that dependence upon a millet crop results in 
the maximum destruction of timber, with the attendant impoverishment 
of the soil. Moreover, this reliance upon the chitemene system accounts 
for the temporary character of settlements, which is characteristic of all 
but a few areas of the Protectorate. 

Gardens must repeatedly be moved to avoid carrying wood for long 
distances. Soon the gardens are found to be inconveniently far from the 
village, and so this is moved. There are many social and economic con- 
sequences of such an unstable form of existence. Soil exhaustion is by 
no means the only cause of the movement of villages ; among the others 
are various superstitions and the insanitary condition of huts. But it is 
only for agricultural reasons that the displacement amounts to several 
miles. At the same time it must be remembered that the people usually 
return to the original site after a lapse of time sufficient for the recovery 
of the woodland ; they are deeply attached to their own special piece of 
country. Each District Officer was asked to state the average period during 
which villages remain in one site, and in general the life of the savanna 
village appears to be from three to four years. Where it is shorter there 
is probably exceptional poverty either in soil or in trees, and, conversely, 
longer periods are to be accounted for by abnormally good conditions. 

The small millets are grown nearly everywhere to some extent for the 
purpose of brewing beer, and in Districts where they also form the staple 
food there is grave risk of the native's improvidence leading to famine 
during the months, generally February to April, before the new crop is 
ready, as in Luwingu, north of Lake Bangweolo, for example, where 
about one-half of the eleusine is devoted to beer. 

Manioc as a Rhodesian crop offers several contrasts to millet. In the 
first place the natives, after planting the shoots on the mounds they have 
prepared, must wait for at least one year before the tubers mature ; and 
this period may be eighteen months, as in Chienji, two years, as in Mankoya, 
or even three, as in Mongu. This implies a greater amount of foresight 
than is the case with other crops and also more stability of the population, 
for since two crops may be taken successively from the same patch, a 
garden will last five or six years (e.g. Mwinilunga). Secondly, the 
cultivator does not have to spend time in scaring birds from his field or 


in constructing heavy fences round it to keep off graminivorous animals, 
as he has to do if he grows cereals ; nor does he risk loss from plagues of 
locusts. On the other hand, the manioc suffers much in every District 
from depredations of bush pigs and from elephants where these are 
numerous. Thirdly, this plant is less susceptible than the cereals to 
rainfall deficiency. For all these reasons the inhabitants of manioc 
Districts rarely suffer from hunger — indeed there are several which have a 
regular export of cassava meal ; ' meal in Mankoya is almost a currency.' 
The Government is obviously fully justified in its efforts to induce extended 
cultivation of this valuable and reliable plant. 

The other two common staples are sorghum and maize. Both are 
more characteristic of relatively treeless land, and the former is the more 
resistant to drought. At their best they are the crops of the open alluvial 
plains, and we find them characteristically in the river bank gardens of 
the Zambezi and Luangwa and many of their tributaries, where two crops 
are often taken — especially of maize — the first from the wet silt of the 
receding river flood, and the second from the summer rains. We also 
find them on the older alluvium abounding in termite hills, which form 
the very best soil when levelled. But these cereals are by no means re- 
stricted to alluvial soils, as witness their wide distribution on the central 
plateau on both sides of the railway. Maize in outlying Districts is 
commonly eaten green, but here there is a market for surplus grain which 
may be sold for transport to the mines. Herein lies the importance of 
the freedom of this area from tsetse fly ; for the cultivator is also a cattle 
owner and he has readily taken to the plough. 

Ploughing gives great advantage in maize cultivation, and some also in 
the case of sorghum. Moreover, the acquisition of carts enables the native 
to market his produce. Yet even from this central region it is interesting 
to note that in the Broken Hill District, sorghum and eleusine are both 
commoner than maize, which is disliked because harder to grind. Again, 
in the plateau section of Kalomo, while maize predominates in the east 
where ploughing prevails, this is not true of the fly belt to the west, for 
here ground must be hoed, and the hoe is the woman's tool. But the 
women cannot be induced to raise a surplus for export. 

This account of the distribution of staple crops must suffice to illustrate 
the kind of contribution which co-operative inquiry has made to our 
knowledge of the native agriculture. 

I have now given a fair sample of the kind of information which we 
have gained by this piece of co-operative research in human geography. 
There are many other matters that I have had to omit. For instance, 
the inquiries as to animal pests and to the amount and nature of hunting 
have led to replies which give a good general idea of the distribution 
of the principal mammalian fauna. Again, we have learned much of 
fishing in relation to the rise and fall of rivers ; we have data relating to 
the seasonal migrations in search of fish and various food relishes such 
as caterpillars. Most important of all is the whole subject of seasonal 
rhythm of occupation and its regional variations, a matter upon which 
the reports are of great service. 



I have devoted most of this address to Northern Rhodesia for four 
reasons : First, because it is now possible for the first time to give to 
this Section some idea of the real results of an inquiry set on foot within 
the Section. Secondly, because these resuhs themselves represent new 
material contributed to the geographical synthesis of a region still very 
imperfectly known — material, moreover, which is really geographical in 
nature. It relates to specific localities and it records both the human 
actions in these and the explanations in so far as they are traceable to 
special environmental factors. My third reason lies in the importance 
that I attach to directing the attention of all interested in Africa to a close 
understanding of the conditions of the natives' material life, which, 
simple though it is, yet varies considerably throughout the continent. 
Finally, I have in mind the wider implications of the success of this 

Our Committee hope that the other African territories will do for us 
what Northern Rhodesia has done, and answer our nineteen points, or 
such of these as are applicable, district by district. But I am looking 
beyond Africa to countries where many Europeans reside, people who 
may never have thought of geography as we regard it, but who might 
well be sufficiently interested in the land of their choice to be wiUing to 
take part in the kind of team work which I have outlined. 

Take India as an example. In spite of voluminous official and other 
literature, we have still a great deal to learn of the geography of man in the 
sub-continent. Although the task of gathering the information there would 
be much more complex than in the case of Africa, there would be certain 
offsetting advantages. Among these are : the accuracy of the map of 
India, the existence of a great body of data created by the various scientific 
services, and a wonderful census organisation. In addition, there is the 
likelihood that men of science could be found on the spot who would be 
able to fill in the gaps in the picture of the physical environment. These 
might be asked to deal with the numerous connecting links which are 
not usually required for official departmental reports but are nevertheless 
essential to the geographer. 






One hundred years ago the * calamity of railways,' as Sir James McAdam 
termed it, fell on the existing means of transport. Though the Stockton 
and Darlington Railway had been opened fortrafficin September 1825, and 
the locomotive had been known since 1804, it was still doubtful whether 
locomotives could be used on lines with heavy gradients. It was the 
success of Stephenson's ' Rapid ' and Hawthorn's ' Comet ' on a section 
of the Newcastle and Carlisle railway in March 1835 which set the seal 
on their success, and led railway promoters to think no longer of horse's 
and stationary engines as the tractive power on the new roads. Three 
years later locomotives were working the whole length of the line from 
Newcastle to Carlisle, and an era of rapid railway development began. 

The effect of railway competition on the canal companies, the stage 
coaches, and the road carriers of that time is well known. At first slowly, 
yet in the end surely, and in spite of severe reductions in their tolls, the 
canals lost all but the slow and bulky traffic. The effect on the turn-pike 
roads was no less severe. Horse-drawn traffic, it is true, not only survived 
the early days of railways, but actually increased, though long-distance 
journeys by road, whether of passengers or goods, practically ceased. 
As Prof. Clapham says, ' Carts and cabs increased, but coaches and 
posting-horses decayed. Journeys behind horses multiplied ; but long 
journeys behind horses stopped. . . . The tragedy was repeated on each 
trunk route as the sleepers and metals were laid along it. . . . The effect 
in every case was instantaneous and inevitable.' 

To-day it is the railways whose established position is assailed. Compe- 
tition by road has taken on a new form ; coastwise traffic has increased ; 
the reliability and efficiency of the internal combustion engine has 
opened up the air for a third competitor. 

In view of these developments in transport, what is the future position 
of the railways likely to be ? Are they to be displaced from their position 
as the chief mode of transport, to which the rest are supplementary, and 
to be relegated to a position of secondary importance in the transport 
system of the twentieth century ? It is a question of far-reaching import- 
ance. I agree with Sir Josiah Stamp that of the country's domestic 
problems at the present time none presses more gravely on the nation 
than the position and future outlook of the railway system. The number 
of workpeople it employs, the amount of capital invested in it, the 
increasing difficulty of providing for and controlling the traffic on the 
roads, the vital importance of securing for the community the most 






















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economic and efficient system of transport that our present means and 
knowledge permit, combine to make it one of the most pressing problems 
that we have to face. Nor is it a situation confronting this country alone. 
A similar position has arisen in practically every country in the world. 

In view of these considerations, and quite apart from the fact that my 
own studies have mainly been in the subject of transport, I felt that 
I could not choose a subject more appropriate for a presidential address 
to this Section, and for a city so dependent on transport as Aberdeen than 
the future of rail transport. 

If justification for my choice were needed, I think I could find it in the 
Presidential Address of my predecessor, Henry Sidgwick, when the 
British Association last met in Aberdeen forty-nine years ago. The 
subject of that Address was the ' Scope and Method of Economic Science,' 
and I venture to think that my own paper comes well within the field 
which he there mapped out for economic thought. 

It will be well at the outset to examine briefly the position of the rail- 
ways of this country in the post-war years. For this purpose some 
statistics are essential, though I will endeavour to reduce them to the 

The table opposite gives the revenue earned by the four grouped 
railway companies and the percentage change for the chief of the post-war 
years. The corresponding figures for 191 3 are given, though in comparing 
the later years with 19 13 it is, of course, necessary to bear in mind the 
change which has taken place in the value of money. 

The form of railway accounts was amended in 1928, and though the 
figures for 1927 have been recompiled on the new method, it has been 
possible only to make approximate adjustments for the earlier years. 
Nevertheless, if not pressed too far they may be used for comparative 

Railway revenue has, it will be seen, fallen by no less than 26 per cent, 
since 1923, and the fall has been most marked since 1929. Owing to the 
general strike and the coal dispute, 1926 was, of course, an exceptional 
year. The fall has been more severe in the case of passenger traffic and 
merchandise than in that of coal and minerals, though the revenue from 
the carriage of live stock also shows a big decline. The revenue from 
mails, parcels, and goods by passenger train has been surprisingly well 

Compared with pre-war years the expenditure of the railways shows 
a considerable increase, due in part to the increase in the cost of materials, 
but chiefly to the rise in the level of railway wages, which in 1932 were 
117 per cent, higher than in 19 14 ; or allowing for the rise in the cost of 
living, 51 per cent, above the pre-war level. But since 1924 the expendi- 
ture shows a considerable reduction, partly owing to the lower cost of 
materials, partly owing to the numerous economies effected by the 
companies in their mode of working since 1923, and partly, of course, due 
to diminished traffic. 

The changes in expenditure and the net revenue of the companies, 
both from railways proper and from their ancillary undertakings, such 
as canals, hotels, and docks, are shown in the table on the next page. 



























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It will be seen that railway expenditure has been reduced almost in 
proportion to railway receipts. The net railway revenue of the four 
grouped railway companies has fallen to 67 per cent, of the amount in 
1923, whilst the net revenue from all sources has fallen to 63 per cent, 
of the 1923 amount. 

Similar declines in receipts and expenditure are to be observed in most 
of the European railways, as in those of the United States of America, 
as the table on p. 123 shows. 

The railways selected have been chosen to show how the serious fall in 
receipts has affected countries with widely differing characteristics. It 
will be noticed that the fall in receipts on the British railways, serious as it 
is, is not so great as in most of the European countries ; but it should be 
remembered that in Great Britain railway receipts had not, as in these 
countries, been rising fairly steadily up to 1929. 

The effect of the changes in receipts and expenditure on British rail- 
ways has been very marked. First in the numbers of staff employed. 
In 1921 the number of staff on the railways comprised by the four grouped 
companies, including the Railway Clearing House, was 735,870. This 
had fallen to 681,778 in 1923, to 642,137 in 1929, and to 615,592 in 1931. 

The effect on railway dividends has, of course, been even more marked. 
In 1913 the net revenue earned by the companies within the groups 
represented 4-41 per cent, on all capital. The return was 4*40 per cent, 
in 1923, 3-96 per cent, in 1927, 4- 17 per cent, in 1929, 3-48 per cent, in 
193 1, 2-30 per cent, in 1932, and 2-68 per cent, in 1933. 

The stocks chiefly affected are, of course, the ordinary stocks. The 
average earnings on ordinary stocks were in 1913, 5 • 55 per cent. ; in 1929, 
3 • 27 per cent. ; in 193 1, 0-95 per cent. ; in 1932, 0-57 per cent. ; in 1933, 
0-77 per cent. 

The causes of this decline in railway traffic and railway revenue are 
not far to seek. They are industrial depression, the contraction of 
international trade, and the competition of roads, and to a lesser extent 
of coastwise and air transport. 

In the case of passenger traffic it is probable that a relatively small part 
of the decrease is due to economic depression, and that the bulk of it is 
due to road competition, including that of the private motor-car. Thus 
if we compare 1929, a year of relatively good trade, with 1923, in which 
trade was definitely not as good, we find a marked diminution both in 
the total number of ordinary passengers and in the total receipts from 
them. The figures are shown in the next table. 

Four grouped companies. ^^ 

1923. 1929. percentage 

of 1923. 
Total number of ordinary 

passengers . . . 633 •4 m. 589-8 m. 93 

Total receipts from ordinary 

passengers . . . jTsS'^^- £i^-3^- 87 

Thus there was a decrease of 43-6 million in the number of such 
passengers, and oi £^-1 million in the receipts from them. 



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Since 1929 road competition has become increasingly severe. It 
would seem fair to estimate, therefore, that in 1933 at least 15 or 16 per 
cent, of the total decline of 28 per cent, since 1923 is due to road competi- 
tion, giving a loss of at least ^(^ii millions due to this cause. 

It is much more difficult to assess the loss of railway goods traffic due 
respectively to bad trade and road competition. Some indication may be 
obtained from a comparison with the Index of Production and the 
Quantitative Index of Imports compiled by the Board of Trade. These 
figures have been available since 1924, and between that date and 1930 
the Index of Production of manufacturing industries rose from 100 to 
106-3, while during the same period the Quantitative Index of Imports 
rose from 100 to 11 1 -4. If we make the assumption that in the absence 
of road competition the merchandise and live-stock traffic receipts of the 
railways would have increased in approximately the same proportion, 
say by 6 per cent, between 1924 and 1930, these receipts would have 
increased from £51-6 millions to 3^55 millions in 1930. In 1930, however, 
they actually amounted to no more than £^7-2 niillions, representing, if 
this argument is valid, a diversion of ^^7-7 millions. In 1927 there was a 
general increase in freight rates of 7 per cent., and assuming that this did 
not cause a diminution in aggregate revenue, this would mean that the 
loss was the more significant. Since then, however, many rates have 
had to be reduced. 

Taking passenger and merchandise traffic together, the total loss of net 
revenue to the railways due to road competition between 1923 and 1930 
may be estimated at not less than ;(^i6 millions. 

In order to view the position in true perspective, it is necessary to 
disgress a little at this point and consider the growth of road transport and 
the causes of its development from the side of the motor transport industry. 

Since the war the development of motor transport has been remarkable. 
Though there were some 307,000 motor vehicles in use in Great Britain 
in 1914, the number had fallen to 189,000 in 1918, owing to the restric- 
tions of the war period. The railway strike of 1919, however, greatly 
stimulated the use of motor vehicles and by 1920 the number in use had 
grown to 551,000. By 1923 it had soared to 1,131,000. In 1928 it was 
just over 2 millions, and it reached 2^ millions in 1933. 

Up to 1925 the most numerous category of vehicles was the motor- 
cycle, but since that year the number of private motor-cars has exceeded 
the number of motor-cycles. Motor-cycles increased in number con- 
tinuously from 373,000 in 1921 to 705,025 in 1929, but in 1933 they had 
decreased to 540,594. 

The growth in the number of private motor-cars as at August 31 in 
each year is shown in the following table : 



























The reduced horse-power tax on private cars, which comes into force 
in 1935, will no doubt serve further to stimulate the use of such vehicles. 

There has been a similar continuous increase in the number of goods- 
carrying vehicles, despite the ups and downs in national prosperity. In 
spite of the trade depression after 1929 and the uncertainties caused by 
the publication of the Salter Report, the number of goods vehicles has 
continued to increase. The next table gives in each year the number of 
such vehicles in use in Great Britain as at November 30, the number 
licensed being greatest in this quarter of the year. 



































The last category of vehicle to which it is necessary to direct attention 
is that of Hackney Carriages, comprising taxi-cabs, motor-buses, and 
motor-coaches. In this class a noticeable feature has been the decline 
between 1930 and 1932. This is to be explained by the operation of the 
Road Traffic Act, 1930, which imposed restrictions on the use of motor 
buses and coaches. The number of hackney vehicles in use in each year 
in Great Britain as at August 31 is given in the next table. 

1921 82,800 

1922 77,614 

1923 85,965 

1924 94,153 

1925 98,833 

1926 99,077 

1927 95,676 

According to statistics contained in the Reports of the Traffic Com- 
missioners the number of passengers carried in public service vehicles was 
5,269! millions in 1931 and 5,4185 millions in 1933, or approximately 
more than six times the number of passenger journeys by rail including 
season ticket holders. The average receipt per passenger journey by 
road was, however, only 2-66d. in 193 1, and 2- 5yd. in 1933. The total 
passrenger receipts were £s^'4- millions in 1931, and £S7'9 n^iHions in 


Apart from such factors as the exhaustion of the railways after the war, 
and the industrial disputes of 1919 and 1926, the striking growth of road 
transport has been due to a variety of factors, such as its mobility, flexi- 
bility, and convenience ; a succession of technical improvements ; the 
fall in the price of fuel and other costs (petrol cost 2s. 11 ^d. in May 1921, 
but in 1934 it cost only i^. ^d. despite the addition of a tax of 8d. a gallon) ; 
and its lower charges for certain traffics. 

The great convenience of motor transport has been a most important 
factor in the case of the private car. The advantages of having a vehicle 
which can be used when, where, and as the owner desires are obvious. 


To commercial travellers, salesmen, etc., the motor-car is a most valuable 
help. Naturally this development has robbed the railways of much 
traffic which would otherwise have come to them, but which they are 
unlikely to regain. The effect is most obvious in the case of first-class 
traffic. There must also be a considerable loss of traffic to the railways 
during holiday times. On the other hand, there is no doubt that a big 
proportion of road traffic is new traffic which would not have developed 
without the motor-car. 

The competition of the motor-bus and motor-coach has been most 
severe on local journeys, short distance travel, and cross-country routes, 
where the railway station is not so near, or the services less frequent, or 
the timings not so good. In these circumstances, partly through greater 
convenience, partly owing to lower fares, the motor-bus has established 
a definite ascendency and it will be no easy task for the railways to regain 
much of this traffic. 

On the goods side the competition of road transport with rail has become 
intensified during recent years. Again, this competition is partly a matter 
of the convenience of road transport ; but it is chiefly a question of 
charges, especially in the case of goods placed in the higher classes of the 
general railway classification. Road hauliers have been able to quote low 
rates for the higher grades of traffic without any statutory obligation to 
carry commodities in the lower grades, such as ores, iron, coal, limestone, 
or road metal. Knowing both the standard and the exceptional rates of 
the railways from any station to any other, they can undercut the railways 
with a lower rate, and frequently base their charges on the existing railway 

Mr. W. V. Wood, a vice-president of the London, Midland, and 
Scottish Railway, has recently emphasised the probable eff"ects of such 
competition. ' It is clear that the two systems cannot live together, 
and ordinary commercial considerations will force a levelling downwards 
of the higher railway rates and a levelling upwards of the lower railway 
rates, if the conditions governing the use of the public roads continue as 

The Road and Rail Traffic Act, 1 933, which is now coming into operation, 
will no doubt tend to restrict increased competition from road hauliers, 
since before new licences to operate goods vehicles may be granted it has 
to be shown that there is a need for them, and the railways have a right 
to lodge objections. But it must be remembered that the Act permits 
what is called ' claimed tonnage ' to all existing operators. There can, 
therefore, be no immediate reduction in competition. Moreover the issue 
of ' C ' licences, that is, licences to those traders using road transport in 
connection with their own business and not carrying for others, may not 
be refused for either new or old tonnage, except on grounds of former 
bad conduct or failure to observe conditions. But, as stated in the 
Report of the Royal Commission on Transport, 80 per cent, of goods- 
carrying vehicles are owned by traders and manufacturers for providing 
their own collections and deliveries, and one effect of the 1933 Act may 
be to increase the number of traders who provide their own transport. 
There is here, therefore, a wide margin of goods traffic which may be still 


further lost by the railways, or a similar margin that may be won back 
by them under favourable conditions. 

Before the coming of the railways coastwise shipping used to be of 
the greatest importance to British trade, and during the nineteenth century 
it remained a formidable competitor to the railways. War-time con- 
ditions, however, transferred much of the traffic to the railways, and even 
yet coastwise shipping has not fully recovered from this set-back. 

Nevertheless coastal shipping is by no means a negligible competitor 
with the railways since it is a very cheap form of transport. It has 
indeed been described as the British equivalent of the inland waterways 
of the Continent. It is particularly well suited to the carriage of coal 
(indeed 60 per cent, of the commodities carried coastwise consist of coal), 
and for the distribution of foodstuffs from ocean-going vessels. 

Coastwise passenger services operate between London and Newcastle, 
Liverpool and Scotland, while goods services are very numerous. From 
Manchester, for example, cargo liners sail weekly to Aberdeen, Dundee, 
Leith, Kirkcaldy, Newcastle ; and twice weekly to London, Glasgow, 
and Greenock. The coastal liner services are now utilising road transport 
to effect collections and deliveries, and in this way are able to give direct 
door-to-door services, for which through rates are charged. Containers 
are also being employed. 

During recent years it would seem that the railways have lost some of 
their traffic to the coasting trade. In evidence before the National Wages 
Board a year or two ago. Sir Ralph Wedgwood stated that the railways 
had lost the carriage of two million tons of coal from the Midlands to the 
South in consequence of the competition of coal shipped coastwise from 
Northumberland and Fife. Coastal shipping rates, he stated, are now 
16 per cent, below their pre-war level owing to the severe depression in 
the freight market. 

A recent important development in the coasting trade has been the evolu- 
tion of Diesel-engined shallow-draught vessels capable of working into the 
smaller ports of the country. Such ships are now regularly penetrating to 
such places as Norwich, Colchester, York, Selby, Lancaster, Bridgwater, 
Gainsborough, Truro, Penryn, Exeter, and Totnes. The total number 
of ships engaged in navigating shallow channels has of recent years tended 
to diminish owing to the ' scrapping ' of obsolete sailing vessels, but, 
owing to the substitution of power-driven vessels of larger size, the volume 
of trade has tended to increase. The use of such craft has, for example, 
transformed Norwich as a port, and no less than 30,000 to 40,000 tons of 
sea-borne coal a year are now being carried into Norwich, whereas a few 
years ago the port was little used. 

Some of the latest coasting vessels, though of 1,400 tons dead weight, 
have a draught under full load of somewhat under 14 ft., and can therefore 
enter ports formerly used by only the smallest coastal liners. The ships 
are fitted with the most modern equipment for the handling and stowage 
of cargo, and are therefore independent of the dock facilities — -formerly 
a question of considerable difficulty. It is indeed true to say that the 
British shallow- draught coasting trade is being rapidly revolutionised. 
Air transport is the third, and most recent, competitor with rail transport. 


Its great advantages are speed and independence of the nature of the route 
traversed, since direct journeys over both land and sea are possible. In 
other countries, notably Germany and the U.S. A., air transport competi- 
tion has been severely felt by the railways ; but in Great Britain the 
comparatively short distances have prevented any rapid development of 
internal air transport lines up to the present year. The advantage of speed 
is somewhat reduced by the time taken to travel from the centre of towns 
to the adjacent aerodromes. In the table on p. 130 statistics are given 
relating to air transport in this country for the years 1929-33. It will be 
seen that the total mileage flown, even for 1933, amounted only to a little 
more than three million miles. 

During the present year, however, great activity has been shown in the 
inauguration of internal air routes. In March 1934 a total mileage of 
approximately 5,000 route miles, or roughly a quarter of the railway route 
mileage, was contemplated by various undertakings taken together. Not 
all these schemes may come to fruition. Last year the mileage operated 
over regular routes was under 600 route miles. In previous years, there- 
fore, the railway companies in this country had no occasion to take air 
competition very seriously, but profiting by their experience of road trans- 
port competition, and to be prepared, they obtained air transport powers 
in 1929. This year they have formed a new company — Railway Air 
Services, Ltd., in conjunction with Imperial Airways, Ltd. — for the 
operation of internal air transport routes. 

Experiments made in the past have not been very encouraging, and last 
year, for example, the G.W.R. lost over ;^6,ooo on its air service between 
Birmingham, Cardiff, and Torquay ; while in 1930 the City Councils of 
Liverpool, Manchester, and Birmingham had to subsidise the internal 
experimental routes of Imperial Airways, Ltd. 

In the past the best results have been shown where air transport could 
take shorter routes than the rail, or routes involving a sea passage — e.g. 
the air ferries between Bristol and Cardifi:", Hull and Grimsby, Glasgow 
and Belfast, London and Cowes, Thurso and the Orkneys. 

In August of this year Railway Air Services introduced a route between 
London, Birmingham, the Isle of Man, Belfast, and Glasgow, whereby 
it is possible to leave Glasgow at 9.15 a.m. and reach London (Croydon) 
by 1.30 P.M. Leaving London again at 3.10 p.m. one could be back in 
Glasgow at 7.30 p.m. 

The importance of this year's developments are due to the employment 
of faster aircraft. The machines used in 1930 on the Manchester-London 
route had a cruising speed of 90 miles per hour, but to-day the machines 
which are being employed are capable of over 140 miles per hour. Another 
important development is the utilisation of these services by the Post 
Office for the carriage of mails. 

If the new services commenced this year can survive as a commercial 
undertaking, a new era in British transport will have been inaugurated. 
But when full account is taken of all the costs of operation this is extremely 
doubtful, unless a subsidy in some form is granted them. 

The decline in railway traffic which has taken place during the post- 
war years has been due, as I have said, to a variety of causes, including 


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economic depression, the shrinkage in world trade, and competition from 
other modes of transport. It is a very difficult matter to disentangle the 
effects of the various causes, and no very definite conclusions can be 
reached on this point. The effects of road competition are, however, 
incontestable, and the abstraction of traffic by this competitor is reflected 
in the general trends in traffic statistics for general merchandise and 
passenger services during the post-war period. 

Fluctuations in national prosperity are clearly indicated by variations 
in the volume of traffic (e.g. the peaks of 1920 and 1929 stand out clearly, 
as does the trough of the great depression), and these have affected traffic 
of all kinds. The improvement in the internal economic position of the 
country is definitely indicated in the monthly traffic statistics of the past 
year, but it cannot be expected that the prosperity of 1929 can be attained 
until the international trading position improves. 

The chronic depression in the old pre-war export industries has 
naturally led to a fall in the traffic provided by them ; thus even in the 
comparatively good year 1929 the tonnage of coal, coke, and patent fuel 
carried by rail was only 91-8 per cent, of that in 1913. By 193 1 this 
traffic had fallen off by a further 33I million tons. Now coal traffic is 
practically immune from road competition, and it is only during the past 
few years that coastwise competition has become somewhat more severe. 
A considerable fall in other mineral traffic since 19 13 is obviously due to 
a similar cause. 

General merchandise traffic shows a fall of more than 10 million tons 
comparing 1929 with 1913, despite the fact that the industrialisation and 
population of the country has increased since 1913. In this case, there is 
no doubt but that road competition has been the prime cause of the loss 
of traffic. The considerable expansion in the lighter industries of Great 
Britain hardly appears to be reflected at all in railway traffic. These 
industries are well suited to road transport, and in fact many new factories 
are now built not at rail-side, but on the main roads and utilise road 
transport for all their requirements. 

As regards passenger transport, the very marked decline in First Class 
travel from 23^ million journeys in 1913 and 34I million journeys in 
1920 to only 17I million journeys in 1929 is no doubt in large part — though 
by no means altogether— due to the increased use of motor-cars. The 
fall in Third Class travel (756 million journeys in 1913, 823 million 
in 1920, and only 657 million in 1929) is due to the competition of the 
motor-bus and motor-coach. In estimating the effects of road com- 
petition it must be remembered that it is not sufficient to measure the 
figures of to-day against those of 191 3. The railways have failed to 
obtain their share of the new traffic which has arisen since 19 13 owing to 
increase of population or from the tendency of journeys per capita to 
increase as the years go by. 

The only direction in which rail traffic has definitely held its own is in 
parcels traffic. Season ticket travel by train, it is true, has increased since 
1913, but the railways have not gained a proportionate part of the new 
traffic which must be very considerable bearing in mind the trend of 
population away from the centres of towns to outlying districts. 


Turning next to consider the reasons why traffic hitherto rail-borne has 
been captured by other forms of transport, it is obvious that the effects of 
the war, though they gave the railways an advantage over canals and coast- 
wise shipping, were responsible for a setback to railway efficiency, and 
thus gave road transport an opportunity to develop in its initial stages. 
Next the strikes of 19 19 and 1926 resulted in the loss of much traffic to 
the roads and it is certain that much of this was never regained. The 
question of relative cost to the user has naturally been an important factor 
in determining the distribution of traffic as between road and rail, though 
it has not been the only factor. For many kinds of traffic, especially those 
placed in the higher classes of the railway classification, road transport 
except over long distances has been cheaper. Here we are faced with a 
fundamental difference in principle. The railways base their classifica- 
tion in the main on the value of the commodity, while road transport 
bases its classification on the cost of the service. 

Relative costs to the user as between road and rail are affected by a 
variety of considerations such as transhipment, the degree of packing 
required, loading and unloading, the possibility of return loads, the 
volume of the traffic offering, distance, frequency of journeys, wage rates, 
and labour costs. 

Road transport generally has the advantage where the haul is for short 
or medium distances, where return loads are available, where the articles 
require careful handling, or where the traffic passes in quantities sufficient 
for a van or lorry load. The advantages of road transport in regard to cost 
are, for example, well illustrated in the case of furniture removal, where road 
quotations in the past have often been very much below rail. The railways 
are now, however, trying to regain this traffic by means of containers. 

Road transport has definite advantages for local deliveries and collec- 
tions and for transit up to a certain distance, which varies with the nature 
of the traffic. On the other hand, beyond a certain distance for most kinds 
of traffic, for transport in bulk, and where certain ancillary services have 
to be performed, the rail has a definite superiority. 

Cost, however, has not been the only factor in determining the relative 
economic spheres of the two forms of transport. As already indicated, 
speed, convenience, and incidental advantages have also to be taken into 
account. The motor vehicle is at the direct command of the user ; it 
can readily be adapted to suit special requirements ; there is a lessened 
liability to damage and pilferage ; prompt service can be given ; the goods 
can be loaded and unloaded by men conversant with the special require- 
ments of the business. The location of the consignor's or consignee's 
premises may be a further factor affecting the choice of transport methods. 
Again, the motor vehicle has a considerable publicity value for certain 

On the other hand, the dependability, reliability, and speed of the 
railway, especially on long distances, gives it an advantage. The relative 
advantages are well illustrated in the case of perishable commodities. 
Fish traffic, for instance, which often goes long distances, and which must 
arrive in time for the market, goes by rail ; fresh fruit, which can be sent 
direct by road from the grower to nearby towns, goes by road. Again, 


long-distance milk traffic in bulk, generally, though not always, goes by 
rail ; short-distance collections from farms or deliveries to neighbouring 
towns go by road. 

In the case of passenger traffic, the road has gained most on the short 
haul. Motor-buses can be operated so as to give a more frequent service ; 
they can go right into the centre of the towns, and they may pass by the 
door of the traveller. They do not require a very heavy traffic in order 
to prove remunerative. But on the long journey, the motor-bus is slow — 
even the long-distance express services in operation just prior to 1930 
were generally competing with the railways in price only. Costs were 
low because of the user obtained from the vehicles and the cheap ' summer ' 
tickets had not then been introduced. Road transport cannot deal so 
successfully with intensive passenger traffic as can the rail. 

In the case of air transport competition depends almost entirely on 
speed. Air transport in this country shows to the greatest advantage 
where rail transport is slow because of roundabout routes or where transfer 
between rail and sea is involved. 

It must, I think, be admitted that until the last few years the railways 
either did not realise the extent to which road transport was likely to 
develop or, at least, were slow to take steps to meet the competition which 
was arising. Prior to the advent of road transport the railways relied 
too much on their established position. They were inclined to wait for 
traffic to come to them, since in most cases no other mode of transport of 
equal efficiency was available. It is true they employed canvassers, but 
canvassing for traffic was not undertaken to the same extent or with the 
same zeal as it is to-day. The needs of their customers were not made a 
special subject of study. There was a tendency to wait for complaint 
to arise before altering an existing mode of operation or the kind of service 
offered, except in those cases where an operating economy to the benefit 
of the company was likely to be effected. Examples are not far to seek. 
On the passenger side they failed to see the latent demand for a more 
frequent service of trains at more regular intervals, especially on branch 
lines. On the goods side they took insufficient notice of the changes in 
the needs of traders. Owing to the more rapid changes of fashion, to the 
necessity of holding a greater variety of goods and at the same time 
keeping working capital low, traders to-day keep smaller stocks of each 
commodity. Frequently they need to replenish stocks at short notice, 
and consequently demand a more expeditious delivery of small consign- 
ments. In consequence of these changes, merchandise traffic by goods 
train has definitely tended to go in smaller lots, and in many depots the 
increase in the number of consignments per ton of goods handled has been 

These demands of the passenger and the trader are admittedly ex- 
pensive to meet. The costs of providing such services with the existing 
equipment or mode of operation are higher than for the kind of service 
hitherto rendered by the railways. A monopoly holder under such 
conditions may refuse to supply the public with what it wants, but where 
competition exists a firm can only do so at the risk of being driven out of 


It is true that the Railways Act, 1921, no less than the economic de- 
pression, made it incumbent on the railways to effect economies both in 
their organisation and in their mode of working ; and, as we have seen, 
in spite of the high level of their wage and certain other costs, they have 
succeeded in doing so to a marked degree. Yet I cannot help but feel 
that in certain directions economies have been effected at the expense of 
efficiency, though not, as the statistics show, at the expense of safety. 

Within the last few years this policy has, however, been reconsidered. 
A considerable programme of re-equipment has been entered upon. 
Lines are being widened, new locomotives and rolling stock are being 
built, and smaller trains at more frequent intervals are being run on 
branch lines. There is every indication that this policy is to be actively 
pursued in the near future. The extension of electrification of lines is a 
special case in point. 

Even more noteworthy are the attempts now being made to recover 
the goods traffic the railways had lost to road transport. Braked goods 
trains have considerably increased since 1928, giving a far quicker service 
from station to station. Containers for perishable goods, for furniture, 
and for special consignments of various kinds are now being increasingly 
provided, and suitable wagons built for their conveyance. Collection and 
delivery services at terminal stations have also been entirely overhauled 
and improved. The delivery areas have been extended. Feeder services 
for the collection of goods by road vehicles have been established in many 
centres, enabling the delivery of goods at their destination to be effected 
on the day following that of collection. The delivery of goods has also 
been expedited by the establishment of railhead or radial distribution 
centres from which goods are delivered over wide areas by fleets of motors, 
which thus save the delays of transhipment and quicken delivery. 

Naturally, these new services have taken time to develop, and though it 
is still true that in certain cases consignments of less than wagon-load 
amounts are several days on the journey from sender to consignee, the 
average journey time of consignments on the railways has been greatly 

A considerable change in the methods which the railways might adopt 
in dealing with road competition was brought about by the Railway 
(Road Transport) Acts, 1928, which.conferred road powers on the railway 
companies. Under these Acts, each of the four grouped railways was 
permitted to own and operate road vehicles in any district to which 
access is afforded by the system of the company. The railway companies 
were also allowed to invest in any established road transport concern or to 
enter into agreements with any municipality, company, or other concern. 
Rates and charges, however, are subject to review by the Rates Tribunal 
on application by interested parties, and notice of any agreement must be 
given to the Minister of Transport. 

Until these Acts came into operation the railways were fighting with 
one arm tied. The road arm is now free, and the railways have already 
shown that they intend to use it freely, not only where it is actually 
remunerative, but wherever it is felt desirable to improve efficiency and 
effect quicker delivery of goods. The liberty conferred on the railway 


companies by the Acts is very wide, and except in the matter of charges 
for regular services — which will, it is likely, be always a minority of the 
services required — puts the railways companies in a position to compete 
with the road haulier with absolute freedom. 

An ' ideal distribution ' of traffic would provide for an economically 
sound division of function between road, rail, and other forms of trans- 
port, and would take into account, not only the price to the consumer and 
the cost to the operator, but also the ultimate real cost to the community. 
Such an ' ideal ' division of function would provide that every passenger 
and every ton of goods would pass by that mode of transport or com- 
bination of modes which would provide the most efficient service at the 
least cost to the community. In this way overlapping, redundant, or un- 
necessary services would disappear, and each form of transport would 
convey just those passengers and goods for which it was best suited. 
Such a division of traffic between the different modes of transport would 
be determined by the demand of those who required it and the facilities 
offered by those who provided it, while the incidence of cost to the com- 
munity should be such as not to involve the subsidisation of any one form 
at the expense of the others. 

Sir Josiah Stamp, in his Presidential Address to the Institute of 
Transport, examined this particular problem from the point of view of 
expenditure of capital. He argued that if all forms of transport were 
subject to one authority, such a body would be failing in its duty if it 
extended one form of transport — other things being equal in the matter 
of service — instead of another which would have involved less expenditure 
or given better results for the same outlay. But, as he pointed out, 
under present conditions there is no guarantee that any one section of 
transport, in ignorance of the true costs or scientific position of the other, 
may not embark capital on projects which may be quickly rendered 
obsolescent by imminent advances elsewhere, or alternatively it may fail 
to embark capital for fear of obsolescence which in fact does not occur. 
We have, as he pointed out, not yet reached the stage where rival forms 
come together and agree that a particular piece of transport development 
should be undertaken by that form of transport which can do the work 
for least cost taking into account any public expenditure involved. He 
added that ' Even governmental application of capital to transport itself 
is quite empirical, especially if it has responsibility for one form and not 
for another. How much more is the application of capital by a hundred 
different agencies ? ' 

The difficulties of distributing traffic on any ' ideal basis ' has been 
strongly emphasised in the Final Report of the Royal Commission on 
Transport. ' But as things are to-day,' they ask, ' is such a state of affairs, 
or even any approach to it practicable ? Who is to decide, for example, 
what rail services are desirable in the public interest and what amount 
of coastwise shipping ? Or what goods should in the national interest 
be sent by rail, road, canal, or ship ? To propound the question is 
sufficient to bring home the immense difficulty which it involves.' 

They suggested, however, a rough approximation to this position in 
one particular, since they were of the opinion that it is not in the national 


interest to encourage further diversion of heavy-goods traffic from the 
railvi^ays to the roads. ' Such further diversions would add greatly to the' 
expenditure on highways and tend to make the railways unremunerative, 
without conferring any commensurate advantage.' 

The Salter Committee endorsed this view, and recommended that the 
Minister of Transport should be given power to prohibit by regulation 
(after consulting the Advisory Committee which they recommended 
should be set up) certain classes of traffic which are unsuitable for road 
haulage from being transferred in the future to the road. They added 
that there is room for a scientific inquiry as to the most economic form 
of transport for each class of goods, having regard to distance and other 

The ideal distribution of traffic could only be brought about if it were 
possible to secure that each piece of transport service, by whatever mode 
of transport it was effected, was charged for at a rate sufficient to cover 
its true cost of production. But the difficulties of determining such 
true costs are very great indeed, and especially so in the case of both rail 
and road transport. On the railways it is impossible unless one makes 
large and arbitrary assumptions in the division of costs between different 
categories of traffic, yet requiring the same permanent way, much 
common equipment, and many common services. It is equally difficult 
in the case of road transport — as the Royal Commission on Transport 
and the Salter Conference realised — if one is to take into account a proper 
share, according to user, of the cost of construction and maintenance of 
roads, the cost of signalling road junctions, the cost of street widenings 
in cities, and the construction and maintenance of terminal and junction 
stations. It would appear that in both cases we can only approach the 
problem by empirical methods. The real cost of production eludes us. 

To what extent is it possible for the railways to find some solution of 
their problem by an alteration of their present (statutory) system of 
charging } Such a step is advocated by many railway critics at the present 
time. The proposals range from a general lowering of rates and fares — 
based on the assumption that the elasticity of demand for rail transport 
is such that a higher aggregate net revenue would thereby be obtained — 
to schemes involving a revolutionary change in the general structure of 
railways charges. 

Prof. Pigou, in his Economics of We/fare, makes a careful analytical 
examination of the contrasted methods of charging according to value of 
service and cost of service, and comes to the conclusion that the latter mode 
of charging would bring about a better distribution of national resources 
and thereby increase national welfare. But his argument is by no means 
clear, nor does he indicate how the system could be carried out in practice. 
He admits that to apply the system would involve a number of delicate 
adjustments, since rates would have to vary with the incidental costs 
attaching to each service, and with the time at which it is provided in 
relation to the peak of the load. To provide for these adjustments 
would often be, as he again admits, a very difficult matter, involving 
costly technique and account-keeping. Eventually, he compromises by 
stating that it is a matter of how near to the ideal of cost of service it is 


desirable to approach, and of determining at what point the advantage 
of getting closer to cost of service is outweighed by the complications, 
inconveniences, and expense involved in doing so. Moreover, there is the 
point that any change-over to a system of charging based essentially on 
cost of service would cause a very considerable disturbance in the present 
distribution of economic resources and activities. Various economic 
equilibria have been established on the basis of the present system of 
charges — e.g. location of plants, organisation of the heavy industries, etc., 
all of which would be disturbed by such a fundamental change. The 
matter is, for example, linked up with our present export industries, 
since in the past the mainstays of our export trade have been the coal, 
iron, steel, heavy chemical, and heavy engineering industries', all of which 
obtain the advantage, under the present system of differential charging, 
of low railway rates. Obviously, a change of such magnitude would 
create great opposition from many people who would fear that their 
position would be adversely affected. There is, indeed, little doubt 
that public opinion would strongly resent any sweeping changes. On 
the other hand, should the nature of our export trade change in character 
in the future or should we develop our home markets at the expense of 
our exports, there would probably be less opposition to the change. 
Nevertheless, as Mr. Wood has indicated, some change in the structure 
of railway charges must be made, unless the competition between rail 
and road transport is put on a more equitable basis, or their competitive 
superiority in given cases can be more clearly established. 

Prof. Pigou has emphasised the importance of the time factor in relation 
to peak loads ; but it is also necessary to consider the load factor itself. 
Some advocates of railway reform, such as Mr. M. F. Farrar, have based 
their proposals on a consideration of this factor. It must, I think, be 
admitted that the load factor, both in relation to time and volume of 
traffic passing in a given consignment or on a given section of line is of 
considerable importance. The influence of this factor is already seen 
at work in current railway practice. For though railway rates are based 
in the main on the value of the service, other factors are also taken into 
account. An example of the influence of the time factor is that of reduced 
fares on certain suburban routes for traffic outside the peak hours. The 
load factor is also taken into account in ' minimum consignment ' rates, 
the rate for small consignments, and in those special or exceptional rates 
which are granted in consideration of the traffic passing in bulk — e.g. full 
wagon or full train loads. 

The question is how far could the practice of charging according to 
the load factor be extended with advantage. Costs to a railway are at a 
minimum when its capacity is fully employed. It could, I think, be argued 
that charges should be varied according as the particular demand for 
transport services increases or diminishes the load factor. If certain 
traffics involve only the partial utilisation of equipment which nevertheless 
has to be provided — e.g. traffic passing in less than full wagon or full train 
loads, provision of additional terminal facilities, etc. — then it might be 
said that the charges should be higher than for traffic which gives a better 
utilisation of equipment. 

F 2 


In the somewhat analogous case of electricity supply, it is of interest 
to note that charges are more and more being based on considerations 
relating to the load factor. Electricity cannot be stored economically. 
Hence any demand that comes on at a peak hour has, so to speak, to have 
part of the capital of the generating machinery allocated to it. But if a 
new demand came on only between peak hours, this allocation would not 
be necessary. 

It is conceivable that the system of railway charging according to the 
load factor may be taken more into account in the future ; but it is diffi- 
cult to see how it could be applied as a universal method. It is still more 
difficult to see how it could prove a solution of the problems to-day 
confronting the railways. Road competition alone, and perhaps that of 
air transport in the future, not to mention the increasingly retail character 
of trade, would wreck any attempt to enforce a rigid adherence to this 

I see, therefore, no real solution of the problem along either of these lines. 
Meanwhile, there is considerable diversion of traffic from a more economic 
to a less economic mode of transport. How is this to be prevented ? 

In a noteworthy article in the Economic Journal , June, 1922, on ' Com- 
munication Costs and their Inter-dependence,' the late Sir William 
Acworth drew attention to the uneconomic diversion of traffic which may 
occur when one form of traffic is subsidised by the State. ' There is,' 
he said, ' a real distinction between the cost of providing a means of 
communication which is of general — or at least of wide — public benefit, 
and the cost of its use, which normally benefits only the particular user.' 
If, however, in one case the user, whether passenger or trader, has to pay 
the whole cost of his use, including the cost of providing and maintaining 
the specialised road as well as the actual conveyance cost, whilst in another 
use he is called upon to pay either a conveyance cost only, or the cost of 
conveyance plus some of the cost of maintenance of the roadway, un- 
economic diversion of traffic from one mode of transport to another is 
likely to occur. He quotes numerous instances of such diversions of 
traffic, not merely from railways to roads, but also from railways to canals 
or coastwise shipping. 

' If it be reasonable to charge upon the user of a macadam road the cost 
of use only, there seems no a priori reason why a similar policy should 
not be adopted in the case of a rail-road.' He foresaw, however, the very 
great difficulty there would be in apportioning the cost of construction 
and maintenance to the users of the roads or other mode of transport. 
In the case of the roads, even if the capital cost incurred up to a given 
point were ignored — as in fact the Salter Committee later proposed that 
it should be — it would be a task of well-nigh insuperable difficulty to work 
out a new scheme of tolls or licences which would apportion the remaining 
costs even approximately and with only rough justice as between the 
many different classes of users. 

His plea, therefore, is that the cost of construction of communications — 
using the term in a broad sense — together with the annual cost of their 
maintenance should be a State charge, undertaken in the economic interests 
of the whole community. 


The adoption of such a policy would mean not only a drastic revision 
of the present system of road taxation, but also the handing over of the 
permanent way of the railways at a fair valuation to the State, which would 
then become responsible for its maintenance. 

The difficulties of getting public opinion to approve such a scheme are 
obvious, and were fully recognised by Acworth himself. The railways 
are private enterprises, and the suggestion that the tax-payer or rate-payer 
should be called upon to pay any part of the cost of construction and 
maintenance even of new lines, much more of lines constructed in the 
past, ' would come as a shock ' to the average Englishman, though both 
in Paris and New York, this has in fact been done in the case of urban 
lines. This would be the first difficulty. Nor is it likely that public 
opinion would be won over by the fact that both in this country and in 
the U.S.A. laws have been passed limiting the profits which railways 
may earn to a reasonable return on their invested capital. 

But there is a further difficulty. It is obvious that if the railway 
companies were relieved of this part of their cost of operation, railway 
charges could be very greatly reduced. The capital expenditure of the 
four grouped companies to December 31, 1933, on the lines open for 
traffic or under construction amounts to ;^795 millions. Interest on this 
sum at 4 per cent, would amount to ;^3i-8 millions. Maintenance of 
way and works amounts to £i6-8 millions. Though a considerable 
reduction would have to be made from both these items in respect of 
works which are not part of the permanent way, it is clear that the rail- 
ways would be able to make sweeping reductions in their charges and yet 
earn their full standard revenue, as fixed by the Railways Act, 1921. 

But would this in itself secure that economic distribution of traffic, 
both of passengers and goods, as between competing modes of transport, 
which is the distribution desired ? Though it would remove some 
glaring inequalities, as between road and rail, it would not really effect 
the object Acworth had in mind. The cost to the State in providing and 
maintaining the communications for each mode of transport might easily 
prove to be heavier for a unit of transport work undertaken by one mode 
of transport than by another. Nor is it easy to see how the State might 
so adjust the scales that traffic — having regard to the kind of service 
required — would pass by the most economic method. In the absence of such 
adjustment the economic loss to the community would be considerable. 

Whilst, therefore, we can agree with Acworth that ' it is incumbent 
on the Government so to shape its policy as to encourage that means of 
communication which in each case is on the whole the most economical 
to the community at large ' and that ' to permit individual users to employ 
a means of communication which, though the total cost is greater, is 
cheaper to them because they can impose on the tax-payer or rate-payer 
a portion of the cost is economically unsound,' yet we cannot but feel that 
a solution of the problem is not to be found along the lines he indicates. 

Nor do I think a solution is to be found in an attempt to bring about 
some rational and economic division of traffic as between rail and road, 
as was advocated by Mr. G. Walker in his paper to this Section at Leicester 
last year. Under his scheme the railways would be considered not as a 


whole but by sections, distinguishing those sections which could and those 
which could not be worked profitably under a revised scheme of charges 
dictated not by adherence to the general railway classification, but by 
the exigencies of the situation, the charges being higher where the traffic 
is light than where it is heavy. The profitable lines would thus, he 
claimed, be able to earn a reasonable net revenue. The unprofitable 
lines would be closed down and their capital cost written off. The areas 
of the latter would then become entirely dependent on road or other 
modes of transport. It is even asserted that, of the 20,000 route miles, 
as much as 10,000 miles might have to be closed, and that, in fact, the only 
lines to be kept open might be the main lines between large towns. 

The adjustment required from the road transport industry would be 
equally drastic. Under such a scheme it would be required to serve only 
those routes, or areas, where traffic is both light and irregular, and where 
return loads are not by any means certain. Each mode of transport 
would have a virtual monopoly in its own area. 

It is hardly necessary to dwell on the opposition which such a division 
of traffic would call forth not only from the railways, but from the road 
hauliers, and, more important still, from the traders. It is sufficient 
criticism of such schemes to say that they fail to take account of the great 
diversity in transport needs, and in the most economic methods of meeting 
them. As modern practice is increasingly showing, a combination of rail 
and road transport is often the most efficient and economic method of meet- 
ing a given demand, particularly in the case of small consignments the 
delivery of which is urgently required. Moreover, it would entail carry- 
ing by road in certain areas, traffic for which road haulage is unsuitable 
and uneconomic ; or in other areas sending goods by rail for which rail 
transport cannot give the kind of service required. 

It is not, therefore, by division into areas or spheres that the problem 
can be solved. Both rail and road transport are necessary in all areas, 
except those of very sparse population. The decision as to which shall 
be employed for a given piece of transport must be decided by relative 
efficiency and relative cost in meeting the demand. The two modes of 
transport must necessarily be in constant competition with each other ; 
and it is desirable that they should be so. The real problem is whether 
those costs can be sufficiently nearly determined in any case to decide 
which is the more economic. 

A new phase in the competition between rail and road transport has 
arisen as a result of the Road and Rail Traffic Act, 1 933 . Under section 37 
of Part II of this Act, a railway company may, subject to the approval of 
the Railway Rates Tribunal, make such charge or charges for the carriage 
of the merchandise of any trader, as may be agreed upon by the Company 
and the trader. Such ' agreed charges ' must, however, not be approved 
by the Tribunal if the object may, in its opinion, be secured, having 
regard to all the circumstances, by the grant of appropriate ' exceptional 
rates ' as provided for in the Railways Act, 1921. Moreover, it is import- 
ant to note that a railway company in respect of an ' agreed charge ' is 
exempt from the obligation to make equal charges to all persons under 
like circumstances, and from the obligation to accord no undue preference 


to any person or firm. The consequences of this to traders will be con- 
sidered later. 

Already over 100 applications for ' agreed charges ' have been made, 
and a large number have been sanctioned by the Tribunal. Judging from 
the number of inquiries received by the railways, this system of ' agreed 
charges,' which may take the form of a flat rate on all the traffic of a firm, 
irrespective of distance or the diverse nature of the goods, would seem to 
off'er definite advantages to a number of traders. The agreements so far 
made include a provision that the trader should hand to the railway the 
whole of his traffic to which the ' agreed charges ' are applicable. In 
one case — one of the greatest interest — the charge is based not ' per 
package ' or ' per ton ' but on an ad valorem basis of 4J per cent, of the total 
value of the goods purchased by the trader. Such a basis of charge, 
whilst not unknown in the case of road haulage, is a distinct innovation 
in the case of railways. It is obvious that these ' agreed charges ' may help 
to reduce accounting and clerical costs both to the trader and the railway 
company. But to the railways the main advantages are that they will 
secure additional traffic and eliminate the risk of further diversion to road 
transport. The provision in the Act of 1933, which made these charges 
legal, was inserted as a result of an adverse judgment by the Railway 
Rates Tribunal in 1932, in the celebrated ' Robinson Case ' when an 
agreed charge in the form of special exceptional rates proposed by the 
Great Western Railway was refused on the ground that these were not 
new exceptional rates within the meaning of the Railways Act, 1921. 
The Act of 1933, therefore, relieved the railways of a statutory limitation 
which did not apply to their road transport competitors. 

If the number of successful applications for ' agreed charges ' is any 
indication, it would seem that this new system of charging is likely to be 
considerably extended, especially in the case of the larger traders. It is a 
development of the utmost significance in the history of rail and road 
competition. The system of differential charging prescribed by Parlia- 
ment in the earliest Railway Acts, and continued in successive Acts, had 
already been seriously undermined by the great extension of ' exceptional 
rates,' despite the attempt in the Railways Act, 1921, to reduce their 
number by the device of increasing the number of classes in the general 
railway classification from 8 to 2 1 . ' Agreed charges ' are a still greater 
departure from the principles of that classification. 

The result of a large extension of the system of ' agreed charges ' will 
undoubtedly be still greater competition with road hauliers, and much of 
this cannot fail to be extremely wasteful to the community. But the effect 
on traders generally is even more serious. If the railways make individual 
contracts with particular traders, others in the same line of business will 
no longer be able to rely, as they have been able in the past, on non- 
preferential treatment. The appropriate ffat rate to one trader may, 
owing to the different nature or scale of his business, be higher than the 
flat rates to one or more of his competitors. Hitherto he has been able 
to rely on the fact that one of his costs — his costs of transport — is identical 
with that of the others in the same place in competition with him. This 
may no longer be the case in rail rates, just as it has not necessarily been 


the case with road transport charges. That the traders reaHse the conse- 
quences of this is clearly seen in the evidence given by them and various 
trade organisations in the course of the hearing of the Robinson and 
Woolworth applications for agreed charges. 

The traders are, in reality, on the horns of a dilemma. They cannot 
ask that the railways should be tied to their former methods of charging 
while they themselves are free to choose road transport when it suits 
them to do so, and at the same time to fall back on rail transport when it does 
not suit them, or when it is more expensive to use the roads. In the past 
the traders have had the best of two worlds by utilising road transport for 
the delivery of their high-valued manufactured products and rail trans- 
port for their coal, raw materials, and even returned empties. 

What then is the solution of the problem ? How can the trader's 
position be best safeguarded and at the same time wasteful competition 
between road and rail be minimised — a competition which will become 
more intense with the extended use of agreed charges ? How can the real 
needs of the country in the way of transport be best and most economically 
met ? 

It would be a foolish and retrograde solution to suggest — though this 
has secured approval in certain countries where state railways have been 
protected by the governments — that the great advantages accruing from 
the development of road transport should be forfeited in the interests of 
the railways. These advantages should be secured to the community 
except where they are clearly uneconomic in character. The railway 
companies in effect admit this, as is shown by their own increasing use 
of road transport either alone or in conjunction with the rail, not only in 
those cases where they have to meet road competition, but in cases where 
this method gives a better or more economic service. 

The best solution that I can see is that the railways should cease to be 
regarded as merely railway companies — which as a matter of fact they 
have long ceased to be, as witness their numerous and well-developed 
ancillary undertakings such as hotels, docks, canals, housing estates, 
associated air and road transport services, and numerous other under- 
takings. They should come to be regarded as transport companies, 
undertaking a given piece of transport by that means or combination of 
means which appears to them (however impossible it is to ascertain real 
relative costs) to be the most economic and, at the same time, most suited 
to meet the real demand of the traveller or trader. 

But this solution would mean the absorption of road passenger and 
goods services — where undertaken for hire or as public services and not 
performed by a firm for the transport of its own commodities — by the 
new ' transport companies.' There would naturally be much opposition 
to this solution, and public opinion would have to be educated. 

This, however, is the solution of the problem which has been adopted 
by the Irish Free State. The Transport Act, 1933, of the Irish Free 
State provides, subject to the approval of the Minister of Transport, for 
the compulsory acquisition of all road transport agencies by railway or 
shipping companies. 

It is significant, too, that a similar solution has been recommended by 


Sir Felix Pole in his Report of July 2 1 , 1 934, to the government of Northern 
Ireland, who had requested him to submit recommendations for co- 
ordinating road and rail transport in that country. He advises the 
formation of a Road Transport Board to include all road transport services, 
both passenger and goods. Further, he recommends that the Board 
should be compelled to pool its revenues with the railway companies. 
He was deterred from recommending a single Transport Board, com- 
bining both rail and road transport, only because this would involve 
special difficulties due to the fact that six of the railway companies operate 
both in Northern Ireland and in the Irish Free State. Sir Dawson Bates, 
the Minister for Home Affairs, has since anounced that the Government 
have decided to adopt the main principles of Sir Felix Pole's report. 
' The Government,' he said, ' have come to the conclusion that the only 
practicable method of achieving the object we have in view is to bring 
the two systems of transport into partnership with a common financial 
interest, and to get them to work together instead of against one another, 
so that the best features of both may be used in one system.' It is under- 
stood that the necessary legislation will be introduced in the spring session 
of Parliament. The formation of the London Passenger Transport 
Board was also a step in the same direction, though, as its name implies, 
it is limited for the most part to the carriage of passengers only. 

If the scheme proposed as a solution, namely, the formation of ' Trans- 
port Companies,' were adopted, it might also be necessary to include air 
transport operating on internal routes. But this should not be difficult 
since the railways, as we have seen, already have an interest in some of 
these services. 

In this way all the means of land transport would come under unified 
management, leaving competition only between land transport and canal 
or coastwise traffic. This is capable of being distributed on a more 
economic basis under competition than in the case of road and rail, and 
it could therefore be left to the forces of competition. It would thus be 
left to the transport company to decide whether a given piece of trans- 
port should be effected by rail or by road, or by a combination of the 
two, but with due regard to the service required by the community. 
Obviously it would be to its own interests to effect it by the most economic 
method. Its own net revenue will be diminished by mistaken methods. 
And though, as we have seen, it will still be impossible for it to work out 
exact costs of operation, either for rail or road, it should be able to do so 
approximately on certain general assumptions based on experience, and 
in this it will be appreciably helped by the fact that both methods of 
operation are within its own control. 

This solution involves, of course, a considerable degree of monopoly. 
The fact has to be recognised. But it should be remembered that in this 
matter transport would only be adopting in its own special way the 
method of rationalisation that has had to be applied in different ways and 
in different degrees to other industries. 

The interests of the community could be safeguarded. The principle 
of limitation of profits could be applied to the new transport companies 
as it was applied to the railways in the Railways Act, 1921, and as it is 


applied to other public utility undertakings. Provision would have to be 
made so that the companies would share in increased profits or reduced 
costs due to greater efficiency of operation. 

The main difficulty would, of course, be to ensure that the monopoly 
companies should be kept to a high degree of efficiency, and that they 
should continue to meet in a satisfactory way the real and ever-changing 
transport requirements of the community. This might be effected by a 
transformation of the Railway Rates Tribunal , which no longer performs 
any vital function, into a statutory body charged with the express duty of 
seeing that the transport companies are working with due economy and 
efficiency and at the same time meeting the reasonable and legitimate 
demands of the travelling public and those engaged in industry and trade. 
Such a body should have power, with certain safeguards, to compel a 
reluctant company to institute a change in its services or methods of 
operation. There would remain, too, a certain check on efficiency, 
since it is not proposed to restrict the use of private motor-cars or traders 
in the use of their own road vehicles for the purposes of their own 

Despite the development of the new forms of transport, railways still 
remain the backbone of the transport services of the country. They are 
likely to remain so for many years to come. They are still the most 
economic mode of transport for many purposes. But to meet modern 
requirements, they need to be supplemented by other modes of transport. 
This, I venture to think, can be done most effectively and economically 
when the different modes of transport are under one management. 






For many years the extravagant waste of our coal has been the subject 
of criticism. The steam engine, the blast furnace, and the domestic 
fire consumed it recklessly, and thermal efficiency was formerly dis- 
regarded. To-day we are more careful of our fuel, except perhaps in 
the domestic fire, but there is still a considerable and unnecessary waste 
at the very beginning. The amount of combustible material left in the 
mine, dumped at the surface as useless, or burnt at the pit-head to get 
rid of it, has often been pointed out, but its poor quality and large 
proportion of dirt make its transport to a consumer unprofitable, or render 
it unsuitable for use. The latter disability has been largely overcome by 
various devices in the boiler-house, and to-day we see steam raised by stuff 
that would have been scorned by our predecessors. But the material must 
be used on the spot, and the Commission called together by Mr. Lloyd 
George ten years ago advocated a comprehensive if rather shadowy scheme 
for generating electric power at the pit-head. The saving in coal was 
clearly demonstrated, but the financial advantage was not so convincing. 

The last ten years have brought about great changes in the conditions, 
some favourable to the scheme, some diminishing the financial advantage, 
and the question requires reconsideration under present-day conditions, 
with, if possible, a forecast of future developments. 

The general idea of the scheme of production of electric energy here 
proposed takes as its basis the complete linking up of all parts of the 
country by the grid and the subsidiary lines fed from it or from the 
stations directly. All stations are connected to the grid, and as well as 
supplying their local consumers, put the additional power into the grid 
as required. This is the well-known main function of the grid. It is 
here submitted that this leads to a different scheme of generation from that 
now followed, and that sources of cheap power are rendered available that 
previously could not be utilised economically. 

The questions to be considered are : 

(i) The proportion of consumers who are within economic distance 
of a pit-head station. 

(2) The quantity of very cheap coal that is available. 

(3) The relative advantages of widely spaced large stations and more 
numerous small stations. 

(4) The opportunity offered by the grid to bring into economical 
use pit-head stations at small isolated mines, power from factories 
using industrial steam, power from coke-oven and blast-furnace 
gas, and hydro-electric stations. 


(5) The cost of transmission of electric power as compared with the 
carriage of the equivalent coal by rail or ship. 

(6) The effect of a substantial reduction in the cost of generation on 
the cost of distribution and the selling price of electric energy. 

The first question to be considered is whether pit-head production will 
so much limit the position of the sources of supply as to involve a great 
distance of transmission to a large part of the population. 

If a distance of forty miles be regarded as still in the neighbourhood 
of the coalfields, a map of the coalfields shows that most of Great Britain 
is within this distance. A line across Scotland from Montrose to 
Arrochar on Loch Long is the northern boundary, and a line from Hull 
to Bournemouth, and up to Taunton in Devon, marks the southern and 
eastern limits. A small part of Wales is also outside. Two-thirds of 
the population live in the area, and if London be omitted as a special 
case, only one-fifth of the rest are outside. There is also a probable 
coalfield in Lincolnshire, which if it materialises will bring in a good 
part of this fifth. To a large extent, the population has gathered round 
the coal pits, and there are practically no large towns, except seaports, 
that do not lie within easy reach. A scheme depending on nearness to 
coal pits will have a large field for its operations, and it will in no way 
act prejudicially on parts which it may not be able to benefit. 

It is proposed to use the lowest grade and waste coal, and the proportion 
required may be up to 10 per cent, of the total coal raised. If the outputs 
of the different areas be examined, it is found that this proportion will 
in all cases be adequate for the population of the area. In some areas — 
Durham, S. Wales, and part of Yorkshire — where there is much less waste 
coal, the quantity of coal raised is so large that not more than 2 per cent, 
will be required, which is easily provided from waste. 

The belt of coalfields which lie about 120 miles from London can 
provide enough for their own people and still have an excess of some 
three million tons per annum of cheap coal, which will suffice for London 
at present, but is not enough for the future. Hence London and the 
south may require a proportion of sea-borne coal. There is ample 
Midlands coal, but its use will entail the consumption of qualities for 
which a good price can be obtained for other purposes, and it will be a 
question of relative cost of sea-borne coal and electrical transmission. 
The prospective Lincolnshire field may solve the question in favour of 
direct supply from the pits. 

Inside the area the pit-head station will be more economical than the 
present stations. There are seventy or eighty selected large stations within 
the area, some with no river, many with rivers that will not suffice for a 
largely increased station, so that the sites have little to recommend them 
except nearness to large towns. They were advantageous in early years, 
when their cooling water was adequate and distance of transmission was 
an important matter ; but their future will be without these advantages, 
and their huge consumption of coal will make them undesirable neighbours 
in cities. Railway and canal facilities for coal transport were also 
attractive factors, but these disappear if it is cheaper to convey power 
electrically than to carry the equivalent coal over the distance. 

Any wholesale sudden change of the existing state of things would 


certainly involve more loss of central station capital than the economies 
would repay, but in view of future expansion there seems a need for an 
examination of the present policy, which is only the old isolated station 
plan with interconnection by the grid superimposed. The opportunities 
afforded by the grid permit of a great change in the general plan, and a 
change, moreover, that can be introduced by gradual steps, if the final 
scheme is outlined at the beginning. The present rate of expansion 
indicates that in ten years' time the station power will be at least double 
its present figure, and while the utilisation of spare plant which the 
grid permits will slow down the increase of plant for two or three years, 
after that the normal growth will give opportunity for a new policy. 
There may be some waste of capital, where stations have been designed 
with a view to large expansion, in that certain permanent parts are now 
unnecessarily large ; but the proportion of such parts, taken all over, 
is only a small item, which the saving in fuel costs will quickly repay. 
No scrapping of existing plant need be done unless there will be a gain 
by so doing. 

Waste Coal. 

The term ' waste coal ' will here be used to include all coal in the seam 
that is not at present sold, but is or can be brought to the surface, and 
coal of poor quality that will be profitably used in the pit-head station, 
instead of being extensively cleaned for sale. This quantity varies with 
the kind of seam and with the purpose for which the coal is used. In 
Durham and S. Wales, where much of the coal is converted into coke, 
there is little waste, as even small fragments can be coked, and the coal 
is won with small admixture of dirt. But in most other parts the dross 
has a larger ash content and is less saleable. Machine cutting produces 
a larger proportion of dirt than hand winning, some of the mixed coal and 
dirt being left in the pit as not worth raising, but the actual cost of working 
is much less. If a use is found for the waste, this disadvantage of machine 
cutting will be removed, and the full advantage of the reduced cost of 
cutting will be gained, while no coal need be lost. 

The use of dry-cleaning processes results in a rather larger proportion 
of waste than does the wet process, and if this waste has no value, the 
cheapness of the process is neutralised by the loss of coal ; but again 
a use and a market for the waste will be in favour of dry-cleaning. Wet 
processes are from one aspect a wrong action. The water that is 
unavoidably left in the coal and often ignored is quite as detrimental 
to the calorific value as an equal percentage of ash. It is just as useless 
as fuel, and it has further to be evaporated, in which process it absorbs 
I IOC B.Th.U. per pound, whereas one pound of ash would require to 
be heated to a temperature of about 2000° F. to absorb that amount 
of heat. There is, of course, the additional trouble of removing the ash, 
but the avoidance of water in the dross and small coal is a definite 
advantage. Hence dry-cleaning will be more widely adopted if (he 
waste can be used. The waste from dry-cleaning is often cleaned again 
and some saleable coal recovered, but if the whole waste has a value and 
is used, the cost of additional cleaning will be saved. 

Of the dirty coal that is at present raised and remains as the residue 
of cleaning operations, some is dumped on to waste land and some into 


the sea, but the greater part is burnt in the furnaces of the mine power 
station. The consumption is wasteful in the extreme, for burning is 
the cheapest way of getting rid of the otherwise useless material. About 
6 per cent, of the coal raised is used to produce steam for power to work 
the mines, whereas in a colliery where the coal is scrupulously saved 
and there is little waste, it is found that the fuel required is only i -25 per 
cent, of the coal raised, and the quality of it is exceedingly low. Hence 
some 5 per cent, is immediately available for other purposes if it is used 
economically, to which can be added what is actually thrown away. 

Summing up all these actual and prospective sources of low-grade 
coal, it may be estimated that if an overall price of 5^. per ton at 
the cleaning floors were oifered, in most districts a quantity equal to 
10 per cent, of the coal raised would be readily obtained, with a smaller 
proportion in the rest, and that this would yield some 18,000,000 tons 
per annum, with a calorific value averaging 10,000 B.Th.U. per lb. This 
is 50 per cent, more than is used to produce the present output of all the 
generating stations. 

Any arrangement by which a waste product from one industry is used 
in another requires some plan to prevent an excess or deficit in the 
product. In the present case an adequate supply of fuel is essential, as 
the sales of electricity cannot be controlled. There is, however, an 
elastic amount of product, for the coal on the boundary line may be either 
used in the station or given a cleaning process, and a greater quantity 
will be available at a small increase in the price. The figure of five 
shillings will include much coal that now has almost no value, so it will 
also cover a fair proportion of coal of a higher value. 

The daily variation in the load curve requires no great storage, but 
the Saturday and Sunday demand must draw from a store, if the colliery 
raises coal on five days a week, as is usual. The seasonal variations 
will, to some extent, balance, for though the domestic load is less, the 
domestic coal demand is also less, and the waste coal corresponding to 
this will be reduced. But seasonal and trade fluctuations can be adjusted 
by altering the amount of boundary line coal. 

The general scheme should permit of using the waste coal from as 
many pits as possible, including even small isolated mines, for they 
assist in supplying the grid at points otherwise unprovided for, and 
reduce the distance of transmission. What the lower limit of economical 
pit station will be need not be elaborately discussed, for the isolated pits 
provide only a small part of the total coal, and their exclusion does not 
materially affect the available supply. As their small stations will have 
a larger cost of interest on plant, they will be advantageously allowed 
to run at full load, putting all their excess power into the grid. The 
wages costs will be little more than their present figure for boiler and 
steam engine attendants. In each case it will not be difficult to determine 
whether to include them as supplying stations, or to supply them from the 
grid and discard all coal that is quite unsaleable, or finally to leave them 
to use their waste coal as at present. The quantity and quality of the 
available coal, and the position of the pit, as regards other pits and as 
regards neighbouring consumers, will be the deciding factors. 

The greater part of the coal raised comes from pits which can be 


grouped together, and it is becoming more the custom to bring the coal to 
a central point for cleaning, which will facilitate the use of the waste coal. 
If the figure of 10 per cent, is taken as a working hypothesis, then a 
station of 100,000 kw., working on a load factor of 0-4, will use per 
day some 700 tons of waste coal, and will require a total output from the 
cleaning plant of 9,000 tons per day over the working week. This is 
not an exceptional quantity, and any additional advantage in grouping 
will tend to increase the custom. 

The scheme will evidently provide an important amount of cheap fuel, 
and will permit of power stations of a size that ensures a low figure for 
cost of plant and running costs, so that the low price of the fuel is not 
offset by any increase in cost in other directions. It is true that the 
stations will not be placed in the towns, and to that extent distribution costs 
are increased ; but, on the other hand, land is cheaper, and it is being 
found that a station consuming many hundred tons of coal a day will 
compel the use of expensive remedies against sulphur and dust, so the 
advantages of an urban site will be sensibly diminished. Moreover, 
most of the large towns are not far from coal mines, and the cost of 
transmission will be very small. With pit-head stations of the 100,000 kw. 
size the economy is easily determined, for all working costs other than fuel 
will be practically the same as those of existing stations, if the latter 
were designed and built to-day. 

There will be doubtless a good many stations of smaller size, in which 
there will be some increase in the capital cost per kilowatt and in wages. 
But down to a size of 30,000 or even 20,000 kw. the influence will 
be slight. Coupled by the grid or other lines to neighbouring stations, 
they will not resemble the existing stations of this size, but will contain 
perhaps two generating sets of 10,000 kw. and boilers to correspond, 
so that the present figures of increase of cost per kw. with decreasing 
size will not apply. It will be economical to put all necessary spare plant 
into the large stations, and the equipment of these smaller stations can 
be simplified. Their cost of production will therefore be little different 
from that of the larger stations, and will be substantially lower than 
the best of present-day large stations. 

An actual example will show what can be done in a pit-head station 
equipped with efficient modern plant and run with economy on very 
low-grade fuel. It is only 4,000 kw. in two sets, working at a load factor 
of 0-7. The coal used contains 40 per cent, of ash and moisture, a 
very remnant of fuel, and is given in the colliery accounts a rather 
exaggerated value of 35. per ton, corresponding in calorific value to a good 
steam coal at 4^. 6d. The consumption corresponds to i -5 lb. of steam 
coal per unit delivered, notwithstanding the small size of the sets and 
the absence of a supply of water for condensing purposes, and the whole 
cost of fuel, wages, maintenance, and supervision, with interest and 
depreciation at 9-5 per cent., is not more than 0-137 pence per unit 
delivered. It will be shown below that the usual cost for the largest 
stations to-day, on the same charge for interest and depreciation but with 
normal coal, is at this load factor • 185 pence, so that even small stations, 
suitably designed, can be usefully brought into the scheme. This 
particular station corresponds closely to what is proposed for isolated 


pits, for it works in conjunction with the supply company of the area, 
deUvering its excess power into the mains, and relying on the mains for 
unusual overloads or possible breakdowns. 

Condensing Water. 
An argument that has frequently been brought against the pit-head 
station is that there is little likelihood of a sufficiency of cooling water 
for the condensation of exhaust steam, in order to produce the high 
vacuum that the turbine can make use of. The cooling tower provides 
water that is still a little warm, and the condenser pressure is i -5 lb. 
instead of 0-5 lb. But the gain in efficiency due to the high vacuum 
is often exaggerated by failure to apply comparable conditions and to 
take recent improvements into account. For a given turbine taking 
a given amount of steam and suitably modified in the final stage, a 
reduction in back pressure adds a definite amount of power. Also a 
rise in the initial pressure, again with suitable design, gives a definite 
increase of power for the same steam. Hence the effect of the improved 
vacuum is large if the initial pressure is low, but it becomes less and 
less as the boiler pressure is raised, and with 350 lb. initial pressure the 
actual loss of power due to a back pressure of i -5 lb. instead of o -5 lb. 
is theoretically only 5 per cent., and in practice the full expansion of the 
whole of the steam to o -5 lb. is not economical, so that the actual saving 
in fuel is barely 4 per cent. This is certainly not sufficient to condemn 
a plan which can offer other advantages. The case of Hams Hall station, 
in Birmingham, is of interest on this point. It has 30,000 kw. generating 
sets, working at a load factor of 0-32, and consumes the equivalent of 
I • 35 lb. of good steam coal per unit delivered, attaining an overall thermal 
efficiency of 23-34 P^^ cent, on the units generated. Though it works 
entirely on cooling towers, and the turbines are not of the largest size, 
its economy can hardly be improved upon. It may be claimed that 
the absence of cooling water can be definite^ disregarded as a disability 
in the use of pit-head stations. 

Industrial Steam. 

Another source of cheap power may be found in the proper utilisation 
of industrial steam. Many industries need low-pressure steam in their 
processes, and use boilers working at a pressure of 50 lb. or less. There 
is no difficulty in producing steam at 350 lb., superheating it, and passing 
it through steam turbines, to exhaust at the required low pressure, and 
the steam so delivered is in all respects as good as that produced directly 
from boilers, as it does not come into contact with lubricating oil. The 
thermal efficiency of the turbine is 100 per cent., less the small radiation 
losses and bearing friction, for the rejected heat of the exhaust steam is 
used for the other purposes, and all steam friction loss is retained as heat 
in the steam. As compared with the coal used in the boilers to produce 
the low-pressure steam, taking into account the cooling and running 
losses of the turbine set, the extra boiler losses due to the higher 
temperature, and the higher pressure of the feed pumps, the additional 
coal works out at 0-4 lb. per unit delivered. The additional capital 
charges are also low, for there is no condensing plant, the turbines are 


cheaper, the boiler plant requires a different and rather more expensive 
type of boiler, but not a larger output of steam, much of the subsidiary 
plant is the same as before the change, coal-handling plant being larger, 
water supply and handling are unchanged, boiler-house staff is little 
increased, and engine-room staff and plant are the only complete additions. 
The result is that capital costs for the additional plant are, overall, not 
more than half of those for the complete plant in a corresponding supply 
station, additional repairs, wages, and management also one-half, and 
coal not more than one-third of that in the best supply station. Hence 
even a small station of this kind can operate at a very low figure, little 
more than o • i pence per unit, and the works in question will obtain 
their own mechanical power at this very favourable price. The only 
difficulty in the plan at present is in the utilisation of the surplus power. 
The works require a supply of steam depending on their processes, and 
if this is to pass through the turbines, the electrical output is fixed not 
by the consumers but by the process steam. An isolated plant cannot 
cope with two independent and variable loads, except by complex by-pass 
contrivances, steam accumulators, additional plant for evenings and 
Sundays and so forth, entailing so much extra cost and loss that the 
advantages are dissipated. On a large scale the method is highly 
economical, and is well exhibited in the Billingham works of Imperial 
Chemical Industries. If, however, the factory electric station is con- 
nected to the grid, even a small one may put in all its spare output, no 
matter how irregular that may be, provided that consumers are not too 
far away, and that it can supply the energy at a price which will benefit 
all parties. 

How much power can be obtained from this source it would be 
laborious to ascertain. Each factory would require separate consideration, 
and the cost of altering existing boiler plants would be important. But 
the change can be introduced gradually, new factories or renewal of 
plant affording opportunities, until all suitable factories are absorbed 
into the scheme. By that time the increased demand will easily take up 
all the power without disturbing the other sources. 

Other possible sources of cheap electric energy are coke ovens and blast 
furnaces, both of which produce combustible gas. The coke-oven gas 
has a high calorific value, and will command a better price if distributed 
as town gas. The proposal to transmit town gas at high pressure to 
considerable distances, if it prove successful, will allow of the direct use 
of very large quantities of gas, if of high calorific value. It is not worth 
while to transmit the low-grade gas from blast furnaces, just as it does 
not pay to carry low-grade coal, and the gas may therefore drive electric 
plant, and all power in excess of works requirements can be put into the 
electric mains. This has been in operation at the North-Eastern Supply 
Company for many years, and while no great amount of power can be 
expected from this source, all cheap electricity at distributed points is 
helpful. The stations would operate like the small pit-head and the 
process steam stations, the output being controlled by the supply of 
gas and not by the consumer, so as to avoid the storage of gas. 

Two large consumers of coal are probable in the near future, the 
one being the proposed petrol factory, the other the low-temperature 



carbonisation process. But neither is likely to provide low-grade coal. 
While only high-grade coal is used for actual hydrogenation, there is 
consumed a large quantity for heating purposes, and this may be of 
very low grade, if the works are near the pits, so at present there does 
not seem likelihood of the new industry providing power for the grid. 
The production of low-temperature carbonisation fuel provides a good 
gas as an additional product, which should be distributed as suggested 
above. While a fairly good coal with low sulphur and ash content is 

FIG. 1 

















B. £40 



C. £30 

D. £20 





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\ \ 



— v-v — 

i \\ 
\\ \\ 

\\ V 











**•— -^ 














required for actual conversion, there is here also an additional amount used 
for heating, which can be low grade, and if the works are near to the 
pits, they will absorb all the refuse coal belonging to the coal that is 
coked. While this industry should have an important future, if properly 
organised, it does not seem likely to come into the electric supply scheme. 
The items in the cost of a unit have of recent years been codified 
and separated into parts dependent on the load factor and those that are 
independent, together with the influence of the size of the station. The 
costs for a normal station of 100,000 kw. and for a pit-head station of the 
same size are here given, assuming certain conditions. The capital 


expended on the plant is, one quarter 4I per cent, debentures, one quarter 
5^ per cent, preference shares, and one half ordinary shares expected to 
pay 7 per cent., or 6 per cent, all over. Depreciation and reserve are 
3J per cent. The cost per kw. of the normal station is £,1^ per kw., 
and of the pit-head station ^^15. Coal is 135. per ton at 11,500 B.Th.U., 
and waste coal is 5^. at 10,000 B.Th.U. Salaries, wages, repairs, main- 
tenance, and stores are the same for both, and are at the average rates for 
this size of station. All charges for rates and taxes, office expenses, and 
other general expenses are omitted. 

The curves are shown in Fig. i. At all load factors the reduction in 
cost at the pit-head station is about one-twentieth of a penny per unit. 
While this reduction does not look impressive when compared to the 
usual charges for lighting, it makes a substantial difference to the cost of 
the unit for domestic heating, w^hich is now down to 0-5 pence in some 
places ; and it will be shown that any lowering of cost of production is 
followed by a decrease in cost of distribution, so that there will be a 
beneficial improvement on the first economy. 

[More recent figures of steam station costs show reductions in wages 
and repairs amounting to some o-oi pence per unit, varying very little 
with the load factor. This correction lowers the curves for both normal 
and pit-head stations equally, so the saving due to the pit-head station 
is not altered.] 

Water Power. 

In England there is at present no question of electric supply of any 
magnitude from water power. The Severn scheme is receding into the 
background, as the cost of generation from coal goes steadily down. 
When the Association met in Edinburgh in 1921, this Section devoted 
some attention to water power, and no one ventured to prophesy so great 
a change in every item in the cost of production from coal as has actually 
taken place. 

The chief part of the cost of water power lies in the civil engineering work, 
for the water turbines, now reduced in cost and improved in efficiency, 
are financially an unimportant part. There is a dead weight of capital 
expended on permanent works, and their very permanence is against 
them. Repayment charges may be put low, but they remain while the 
rival steam stations are installing cheaper, larger, and more efficient 
machines, and reducing fuel, wages, and capital charges. In Scotland 
these years have seen the planning of several ambitious schemes, some of 
which have been undertaken and are nearing completion. As engineering 
work they are well conceived and in every way excellent, but already their 
expected production costs are being hard pressed by their rivals, and the 
end is not yet. This paper shows that substantial reductions are quite 
feasible, in addition to the gradual reductions that have gone on steadily 
and show no signs of ceasing. In the Highlands and everywhere north 
of the industrial belt from Glasgow to Fife, excepting the large towns on 
the east coast, the hydro-electric station is in a strong position, for its 
foot is on its native heath. But in the Lowlands and in coast towns 
obtaining sea-borne coal, in the author's opinion it is fighting a losing 

The cost of a hydro-electric scheme cannot be given a single figure 


per kw., depending only on the size. Even the actual station plant 
varies in cost according to the head of water, while the pipe lines, lades, 
and reservoirs may have a wide range, so that each proposed scheme 
must be considered individually for capital expenditure. Station wages 
are small, as the machinery is simple, but the upkeep of the hydraulic 
works is usually a substantial item, and one which depends largely on the 
results of natural phenomena, which cannot be foretold. The load 
factor introduces complications, differing with different types of layout. 

For comparison with steam stations, all wages, salaries, and main- 
tenance, i.e. all running costs, are taken at 145. 6d. per kw. per annum, 
the load factor having very little effect. The corresponding figure for 
the steam stations described above is 18^. at a load factor of 0-7, and 
155. M. at load factor 0-4. Or the cost per unit for the hydro-electric 
station at load factor 0-4 is 0-05 pence. Capital charges are 6 per cent, 
as before, and depreciation and reserve are put at 2-5 per cent., instead 
of 3-5. All rates, taxes, etc., are omitted as before. The curves for 
varying load factor, worked out for a range of capital costs per kw. 
from £60 to ;^20, are shown in Fig. i. The power is taken as that which 
the station has normally sufficient water to supply continuously, and the 
actual annual output falls below this if the load factor is less than unity, 
due to variable demand or to shortage of water. 

At the usual load factor of 0-4, the scheme is limited to ^^32 per kw., 
if it is to equal the normal steam station, and to ^25, if it is to compete 
with the pit-head station, disregarding all question of transmission. 
A cheap design is one in which the river is diverted into a channel or 
tunnel, and after some distance sufficient head is obtained above the 
river bed. No storage is attempted, and during periods of low water 
the output falls off and must be supplemented from a neighbouring 
steam station. Its use corresponds to what has been suggested for small 
pit-head stations. The Clyde Valley stations are of this character, and 
at their cost of £2^] per kw. they compare favourably with the normal 
steam station if the load factor exceeds 0-3, but they require a load factor 
of nearly o-6 to reach the pit-head station cost. The load factor in this 
case is really the river factor, which varies between a wet and a dry year, 
but they are certainly more economical than the normal steam station. 

For stations with reservoirs the cost usually rises considerably, 
although that at Kinlochleven has exceptionally low cost and large 
storage. But such stations may be used in a different way. The daily 
fluctuations in load make no appreciable difference to a reservoir, and 
if the pipe line to the turbines is short, the extra cost of increasing the 
power of the station is small, for it only means larger pipes and larger 
turbine sets, which are cheap machines, so the cost per kw. of station 
power may be much reduced. The annual output is not increased, as 
that is limited by the water supply, but the station can operate more 
economically at low load factors, and it becomes a good peak load station. 
The cost curve is much altered in character, and an arbitrary example 
is given for comparison. The cost is divided into two parts, ^{^36 being 
constant for all load factors as representing the reservoirs and collecting 
lades, and being calculated on the power at unity load factor, as determined 
by the annual quantity of water. Station and pipe cost at this power is 


^14 per kw., and this is recalculated for each load factor, the station 
wages and maintenance also being adjusted. The curve is much flatter, 
and from 0-5 downwards its costs are lower than the pit-head station. 
Although at unity load factor the cost per kw. is £$0, this reduces to 
£22 at 0-3 and to £18 -5 at o -31 load factor. 

The stations of the Galloway scheme are to be mostly of this type, 
but the costs, when analysed in this way, are considerably larger, in 
fact 50 per cent, larger. The estimates given by the promoters in the 
parliamentary inquiry bring out the cost per kw. at £2J at a load 
factor of 0-2I, at which it was proposed the stations should work, and 
the cost per unit on the above basis of calculation comes up to • 34 pence, 
which is also the figure estimated by the promoters. The pit-head 
figure is 0-32 pence, so that in its own area and for peak loads there is 
little difi^erence, though with higher load factors the pit-head station 
rapidly gains. The neighbourhood is, however, quite unable to absorb 
the 100,000 kw., which it is proposed to develop, on peak load or even 
as a complete load. It has been suggested that power can be transmitted 
to Carlisle, which is 50 miles away, and this, as will be shown below, 
will add o -022 pence to the cost, if the load factor is o -21. This brings 
the total to 0-36 pence, nearly the cost for a normal steam station. As 
Carlisle has a coalfield on each side of it, the advantage of the trans- 
mitted power becomes rather illusory, and the grid will not be greatly 
helped by the scheme, except in Galloway and Wigtownshire. 

It might be imagined that with cost curves of different shape a happy 
apportionment of loads would yield a lower combined cost. It will be 
found, however, that little difference is made if the average load factor 
is not below 0-4, for the steam station curves are becoming flatter, and 
the reduction in their cost is absorbed by the higher cost of the peak 
load station. Each case must be worked out for itself, as no general 
rule can be given, and there are too many variables to allow of a 
mathematical determination of the conditions for a minumum cost, but 
in most cases the efltect is disappointing, and the more so the higher the 
load factor of the system. 

Cost of Transmission. 

The position of generating stations brings in the cost of transmission. 
In the coal areas the numerous sources of supply will on the whole reduce 
transmission costs, but the supply of power to outside areas depends 
chiefly on the cost of electric transmission, as compared with other 

The cost of long-distance transmission of electric energy has been 
much reduced by increased voltage, and by reduced cost of transformers 
and transforming substations. It is considerably influenced by load 
factor, for capital charges and wages are constant, while line losses are 
much reduced on low load factors. For any distance of importance the 
grid at 132,000 volts will be the usual means, and the cost of transmission 
over 100 miles is shown in Fig. 2 for the various generating stations, the 
difference being caused by the respective costs of the power wasted in 
the line. The conditions assumed are — interest at 3I per cent., repayment 
in thirty years, and annual upkeep at ;^2o per mile, which makes a total 



capital and maintenance charge of 6 -75 per cent. There is 10 per cent, 
drop on full load at power factor o • 8 in the line and transformer windings 
at each end, and core losses are 1-25 per cent. At unity load factor 
the energy loss is directly subtracted from the station output, and must 
be charged at the cost of production, as given in Fig. i. For lower 
load factors the exact figure to be allowed is not more than this, and is 
probably slightly less, but as the loss is small, the unity load factor value 
for the units loss has been taken all through for the coal stations and for 







- 001 





^ A 









. — ■ 














0-2 0-4 0-6 




the ^40 hydro-electric station without reservoir. But the station working 
on a reservoir has only a certain amount of energy per annum to sell, 
and the wasted energy is charged at the value for the load factor, which 
increases the cost at low load factors. Below o -6 there is little difference 
between them. There is a definite minimum at about o -6, which can be 
shifted to a lower load factor by increasing the load and line loss, if this 
does not cause regulation troubles. There is also shown the cost of 
transmission over 50 miles from the Galloway stations, and the cost over 
40 miles from a pit-head station, which was the distance taken above 
as in the neighbourhood. 

These costs may be compared with the cost of rail and of sea carriage 
of raw coal. Rail transport is in general one penny per ton mile plus 


sixpence for end charges and waggons, or 8^. lod. for 100 miles. Allowing 
1-3 lb. per unit the cost is -061 pence, which is three times the cost of 
electrical transmission at a load factor of o -4, so the coal waggon cannot 
compete with the grid. For shorter distances the proportion is slightly 
different, but always much larger. Carriage by sea is cheaper for long 
distances, if both pits and generating stations are conveniently situated. 
From Newcastle or Fife to London, for favourably placed pits, the 
cost is at present about 4^. per ton, so that electrical transmission from 
the nearest existing pits to London, 120 miles, will cost very nearly as 
much as carriage by sea to stations on the Thames banks, and only the 
cheapness of waste coal will give an advantage. Shipping freight charges 
are low at present, and a rise will make electric transmission economical 
to London, apart from the use of cheaper coal. Hence transmission 
from the pit-head stations may be safely undertaken, even if the amount 
of waste coal available should not suffice for the whole load, and if the 
Lincolnshire coal materialises, there will be plenty, some of it at a shorter 

Rates and Taxes. 

In the foregoing calculations of costs, the item of local rates has been 
omitted, for rates vary in different districts, and a general figure is not 
possible. The present charge for rates on electric supply stations is very 
high, and they have not come under the recent reduction of rates on 
machinery. Roughly, the item of rates on the generating plant alone 
amounts to about o -06 pence per unit, considerably more than wages and 
salaries, and more than half the cost of coal. It is a tax or contribution 
towards local expenditure, which has grown to dimensions far greater 
than the early years of its operation seemed to indicate. While generating 
costs have gone down, taxes have gone up, and this charge is not generally 
realised, except by the engineer who is trying to reduce costs, but it 
amounts to nearly /^ioo,ooo per annum for a 100,000 kw. station. Now 
and again a few thousand pounds of credit balance in the year's working 
of a station belonging to a town council is handed over ' for the relief of 
the rates,' and often there is much protest that this is obtained at the expense 
of the consumer. The far larger sum quietly extracted as rates is not 
called in question. While the theory and practice of rating, as applied 
to factories and public utility companies and services, cannot be discussed 
here, it may be permissible to claim that the position of electricity and gas 
supply and railways has become anomalous. The supply mains are also 
assessed for rates, so that the total rate charge to the consumer is often as 
much as o • I pence, while the selling price for domestic heating is o • 5 pence 
or little more. Without demanding the complete abolition of rates on these 
public industries, we may reasonably claim some substantial reduction, 
such as one-half, amounting in our case to 0-05 pence per unit. If to 
this is added the equal sum which the cheap fuel of the pit-head station 
can achieve, a total reduction of o • i pence is obtained. The importance 
of this will now be discussed. 

Future Consumption. 
The cost given in Fig. i for generation in large steam stations is 0-25 
pence per unit at the usual load factor of o -4, while the selling price is at 


least o*5 for domestic heating, power being 0-75 to i -o, and lighting 
threepence to sixpence. Local rates account for some of this difference, 
but distribution and office expenses are the chief part. Both are nearly 
constant expenses for a given maximum demand, and are directly reduced 
by a high load factor. The mains do not wear out faster if they carry 
current for more hours a day, nor does it cost more to read a larger 
number of units on the meter, nor to make out a larger bill. Also the 
cost is decreased by a greater density of load over an area. More con- 
sumers per mile of low-tension cable merely mean more feeding points 
and larger high-tension mains or a higher tension, and to obtain a more 
nearly universal demand and a larger demand per house is simply a matter 
of reduction of selling price, while they will themselves help greatly to 
reduce the cost further, if the process can once be started. 

The historically first use of electric energy — electric lighting — is now 
so general where a supply is available, that no great increase will be 
obtained by a reduction in price, and enlargement of areas of supply 
means country districts with sparse population. Motive power in factories 
is now supplied to the extent of one-half from electric mains, and a con- 
siderable part of the other half is electric drive from private plant, where 
industrial steam is required and a steam generator is easily added. These 
may come into the general scheme, but will not greatly increase the 
public demand. The old shop engine is rapidly disappearing, and the 
process will not be much accelerated by cheaper electricity, as in the great 
majority of cases the electric drive from a public supply already costs less 
than the shop engine. 

There remain as comparatively little developed directions for new 
demand the fields of domestic heating of all kinds and electrification of 
railways. In these a successful competition with other methods depends 
largely on cost. Electric cooking, hot water supply, and house warming 
must be brought down to a figure not greatly exceeding that involved in 
the consumption of raw coal, if anything like a general adoption is to be 
brought about. A figure of one halfpenny begins to be persuasive, but 
above that the added convenience does not outweigh the cost in the view 
of most people, and even that figure only meets the competition of gas 
on equal terms, if the price of gas is eightpence per therm, and there are 
signs that this may be reduced. The possible demand is enormous, for 
the present consumption of domestic fuel is some forty million tons per 
annum, more than three times the whole of the coal used in electric 
supply for all purposes. Owing to the large losses of energy in the steam 
engine, with boiler losses and transmission, at the best only 20 per cent, 
of the total heat in the coal burnt is delivered to the consumer. The 
domestic fireplace has a rather better efficiency, but it is not used so 
economically, so on the whole the amount of coal used will be much the 
same. The station uses a cheaper fuel, but loses on the cost of distribu- 
tion. As domestic heating yields a high load factor, and offers scope for 
a high density factor, it will help greatly in lowering distribution costs. 

The railways ofl^er a large, though not so large a field. This was 
explored by Lord Weir's committee of 193 1, and the finding was 
favourable. But it was not universally accepted in its entirety, and the 
margin of advantage claimed was obtained by economies of doubtful 


character. The price of electric energy was taken at o • 5 pence per unit, 
and at that figure the electric power came out at little less than the cost 
of present methods. Since then locomotive designers have not been 
idle, and coal consumption has been reduced in the latest patterns, so that 
a substantial reduction on the halfpenny will be required. This should 
be quite possible, for the price that was assumed was on the safe side and 
could be reduced to-day, since distribution costs in bulk to the railway 
line will be less than to individual householders, and the further reduc- 
tions indicated in this paper will bring the question to a practical proposi- 
tion. The complete electrification was estimated to require a consump- 
tion of 5,400 million units, but probably a good many branch lines would 
not be electrified, and a total of 4,000 million may suffice. It is not a great 
addition to the total load, which was close on 16,000 millions last year, 
but it is a desirable increase, as it will have a good load factor and can be 
easily provided, for railways and population go together. 

There are signs that a low price will bring in large consumers in the 
metallurgical industries. The use of electric furnaces is rapidly increasing, 
and below o • 5 pence the private plant has little chance of competing, if 
complete reliability is to be ensured. The possible magnitude of this 
load it would be futile to estimate, but it will be considerable and will 
have an excellent load factor. 

From the foregoing it is evident that the electric supply industry can 
be put on the road to a substantial and even to a great increase, and that 
the new business will materially improve the load factor and reduce costs 
of distribution. The use of cheap fuel and an alleviation of the burden 
of rates will give the initial stimulus that is needed, and the great increase 
will automatically recoup the apparent loss to the rate fund of the local 

These prospective new consumers will reduce the amount of waste 
coal that will be available, for house coal and railway coal are high-grade 
fuel, from which a good supply of low-grade coal has been screened oflF. 
If they are taken out of the class of raw coal consumers, and put into the 
class which uses electricity, the effect will be twofold. But there is little 
chance of a wholesale complete electrification of dwelling-houses, and a 
complete cessation of the use of raw coal for any purpose. And under 
most circumstances it will be cheaper to use the coal at the pits than to 
carry it to supply stations at a distance, even though some of the coal is 
of good quality. There are many possibilities in the future, such as 
petrol and tar extraction and gas production, but for all of them it is 
preferable to avoid carriage of raw coal, so the pit-head electric station 
will always be in the right place, able to work in with the other processes, 
so long as coal continues to be our main source of power, and that is a 
long time. 

To sum up the main theme, the grid and the branch lines should 
operate not only as distributors of power to the consumer, wherever he 
may live, but also as collectors of power wherever it may be obtained, 
and like all successful middlemen, it should buy in the cheapest market 
and put the consumer into connection with the nearest producer, whether 


small or large. The small producer, in other goods as well as electricity, 
may show very low costs of production, but fail to find a steady market. 
The grid can offer such a market, and while it has no warehouse or other 
means of storage, it can harmonise the consumer and producer by varying 
the output of the large stations, which will work on the principle of 
keeping up the pressure at distribution centres, and the current will flow 
naturally to where it is demanded. The stations will gradually be placed 
where their costs are lowest, and the pit-heads and coal-cleaning floors 
will be their natural sites for the greater part of this country. The 
economies thus made possible will attract consumers that are at present 
in doubt, and a great increase will ensue. 

The process of introducing these new supplies need not be sudden or 
simultaneous at all parts, nor need the existing stations be hastily dis- 
carded. What is required is a policy of making all extensions of power 
at pit-head stations, and allowing a natural development of this policy 
as is found good. The closing down of the present small stations, and 
the normal rate of growth, will give opportunity for a large-scale trial in 
a few years, and commencing with the most suitable places, the process 
can be steadily continued. Every improvement in methods of trans- 
mission will place the pit-head station in a stronger position for the supply 
to large towns. 

The question of the ownership of these large pit-head stations will 
require consideration. Several solutions are possible, but for all of 
them it is essential that there shall be co-operation between the producers 
of coal and the producers of electricity. The one party must be assured 
of a steady sale of their cheap fuel, that they may be willing to remodel 
their business to suit the new outlet ; the other party must be assured of 
a steady low price, that they may not be exploited after they have given 
hostages by large expenditure on the new stations. It seems a suitable 
case for a central control, as without guarantees neither party would be 
wise to commit themselves, though the advantages to both seem fairly 
certain and considerable. A proposal of such wholesale common action 
would have seemed impracticable ten years ago ; but we are becoming 
used to Central Boards, and the Coal Board and the Electricity Board 
are already in being for the purpose. 

To the owners of large generating stations these proposals may appear 
rather alarming. The supply companies in whose areas are coal-pits 
will be able to put their new stations at the pits and reap the full advantage, 
and they constitute the majority. The others will have the choice of 
importing a bulk supply, if it is cheaper than their own product. The 
case of the large cities in the coal areas, which have their own stations 
but no pits in the city area, presents some difficulty. Sooner or later 
their stations may be outclassed by foreign imports. But it must be 
recognised that there is nothing permanent in engineering, least of all in 
electrical engineering, and a fitting motto for the supply industry may be 
taken from In Memoriam : 

' Our little systems have their day ; 

They have their day and cease to be.' 







Infusions from vegetable products are common throughout the world, 
but the particular infusion with which this paper deals is that procured 
from the leaves and shoots of the Ilex paraguayensis, a shrub indigenous 
to Paraguay and to southern Brazil. After a process of drying, aided by 
fire, hot water is poured on the broken or powdered leaf, and the infusion 
is imbibed through a tube of silver or of native bambu. From the 
centre of its origin it spread rapidly, like all valuable food products, to 
Argentina, Chile and Peru, and, especially since the war, when many 
South American contingents were engaged, it has become more familiar 
in Europe than formerly. 

The particular virtue of the drink is that it contains little or no tannin, 
combines favourably with a meat diet, and can be repeatedly refreshed 
by hot water without deleterious effects. In South America, especially 
amongst the Gaucho class, it used to take the place of fruit and vegetables, 
for it is an antiscorbutic of considerable value. Thousands of tons are 
used in South America annually. 

Mixed with cold water, it provides a very refreshing beverage, but the 
normal method of taking the drink is in the hot infusion. When lukewarm 
it is regarded as a violent aperient. Two appliances are used, the mate, 
a gourd or silver cup in which the decoction is prepared, and a tube, the 
bombilla, through which the infusion is drunk. 

The word for the receptacle {mate) became transferred to the leaf and 
the drink ; both are now generally known under that name, especially 
in Europe. 

The first mention of the drink in published literature occurs in a book 
by Nicolas Duran, a Jesuit missionary in Paraguay in the early seventeenth 
century. Duran travelled through the province of Guaira and visited 
the Jesuit missions at Villa Rica, San Xavier, Loreto and San Ignacio ; 
all these regions were, at that time, centres oi yerba wa^e preparation and 
of distribution. 

Translated from the Latin, Duran writes as follows : 

' The most severe labour to which the Indians are put consists in being 
sent by their masters to Maracaiu, to collect the foliage of certain trees 
growing in the mountains and forests. These trees, not unlike laurels, but 


of a brighter green, flourish especially in moist and swampy woods. The 
leaves, after being parched in a fire, are pounded in mortars, and, when 
reduced to dust, are packed in cases, and carried many miles on the backs 
of the Indians. On account of the unhealthiness of the climate, and 
the scarcity of food, which their poverty-stricken masters cannot provide, 
these unhappy Indians are forced to subsist on snakes, grubs and spiders. 
And so, worn out by contagious diseases and famine, they die. It is a 
pitiable picture, for, in return for their labour, all they receive when 
they return from this slavery is a beggarly two yards of cloth. Some 
even go home empty-handed, because the Spaniards themselves are 
extremely poor. The Spaniards sell the powder of this herb (which they 
call " Herb " par excellence) to traders who come hither (Guaira), or 
rather exchange it for necessaries. And it often happens that 2,000 lbs. 
of this powder is given for a suit of common cloth, or 500 lbs. for a hat. 
Spaniards and Indians of both sexes drink this powder, mixed with hot 
water, once or twice daily, which proves a most efficacious emetic. So 
much are they slaves of this habit, that they will barter shirt, trousers or 
bedding for it. An instance is known where a woman stripped her hut 
of its roofing in order to buy this herb. They say too that their strength 
fails, and that they cannot live, if they are deprived of its use. The 
Indians take it at daybreak and at frequent intervals during the day. It 
has come to be such a vice in these provinces that all the inhabitants of 
the River Plate, Tucuman and Chile make use of it. So that in Potosi, 
and throughout Peru, i lb. of this herb is sold for four golden crowns. 
This herb makes men gluttons, slaves to their bellies, and renders them 
averse to work of any kind. And its efficacy appears to lie more in the 
imagination of him who uses it than its own inherent virtue.' 

By the middle of the seventeenth century, Nicolas del Techo (du Toict), 
who became Superior of the Province of Paraguay, as a Jesuit missionary, 
writes of the use of the drink as follows : 

' In Paraguay, for a long time, sugar and cotton, both produced in 
small quantities, were the chief wealth, till the leaves of a certain tree, 
growing in marshy grounds, commonly called the Herb of Paraguay, 
began to be in esteem. These leaves they dry in the fire and reduce to 
powder ; then, mixing with hot water, the Spaniards and Indians, both 
men and women, drink of it several times a day ; and, vomiting it up 
with all they have eaten, they find it creates an appetite. Many things 
are reported concerning this powder or herb ; for they say if you cannot 
sleep, it will compose you to it ; if you are lethargick, it drives away 
sleep ; if you are hungry it satisfies ; if your meat does not digest, it 
causes an appetite ; it refreshes after weariness and drives away melancholy 
and several diseases. Those who once use themselves to it cannot easily 
leave it, for they affirm, their strength leaves them when they want it and 
can't live long : and so great slaves are they to this slender diet, that they 
will almost sell themselves rather than want wherewithal to purchase it. 
The wiser sort (tho', moderately used, it strengthens and brings other 
advantages) will hardly ever make use of it ; and, if immoderately used, 
it causes drunkenness and breeds distempers, as too much wine does. 
Yet this vice has not only overrun Paraguay, but Tucuman, Chile and 


Peru. And is near coming over into Europe ; this Herb of Paraguay 
being valued amongst the precious commodities of America. At first 
the Spaniards were well pleas'd with their cotton garments and liquor 
made of honey. But afterwards, trade enhancing the value of this herb, 
covetousness and luxury encreas'd, to feed both which the Indians began 
to be enslav'd to make this powder. Labour made their numbers 
decrease, and that made the Spaniards poor again ; to show us that very 
often the same methods we take to gather wealth serve to impoverish us.' 

The two quotations given above are couched in rather harsh terms in 
regard to the excessive use of the ilex ; but the same could be written 
of tea, or any infusion, or of alcoholic drinks if taken in excess. However, 
Southey, writing in 1817, avers that over-indulgence has been known to 
result in almost total mental aberration, lasting over many days ; and 
the danger of serious infection, owing to the use of a common bombilla, 
which passes from lip to lip, is emphasised by many writers. Demersay 
adds that the constant imbibing of hot mate, alternating with draughts of 
cold water, is bad for the teeth, and suggests that the use of a silver 
bombilla, which can become unbearably hot, may cause cancer in the lip. 

As regards the properties of the ilex, which have won for it so wide- 
spread a popularity, authorities are not quite in accord. Christy (1880) 
states that the leaf contains ' the same active property as tea or coffee, in 
a proportion (nearly 2 per cent.) intermediate between the two; a volatile 
oil ; 16 per cent, of an astringent principle ; and about 10 per cent, of a 
nutritious gluten, only a portion of which is dissolved in the infusion. 
He states further that the full benefit of the leaf is only obtained when 
it is chewed. 

The Handbook of Paraguay (1894) gives the analysis as 0-45 caffeine, 
20 -88 caffeo-tannic acid, an aromatic oil, gluten, and a proportion of 
theine. However, we may conclude that the action of the infusion 
would be that of a cardiac and a nutritive, while the relatively small 
proportion of tannin would render it more digestible than tea. It is, 
perhaps, a little strange that the earliest authors who record its use, 
Duran (1626-27), Leon Pinelo (1636) and del Techo (1649-72), quote 
it primarily as an emetic. 

To leave aside for the moment the question of the actual discovery 
of the properties of yerba mate, the initial exploitation of the ' tea ' was 
undoubtedly due to the Jesuit missionaries. The first Jesuit reservation 
was founded in 1609, the last in 1760, and the Jesuits were expelled in 
1774. The missionaries encouraged the use of the leaf among their 
Indians, to whom it was served out with other rations ; and Endlicher 
and Martins state that this was done to wean the natives from over- 
indulgence in fermented drinks. But there is no doubt that the revenues 
derived from the trade in the leaf became indispensable to these self- 
supporting communities, whose establishment is one of the most remark- 
able developments in the world's history. On the expulsion of the 
Jesuits their mission houses and lands became Crown property, and the 
mate industry had become so prosperous that, in 1807, the profits derived 
from it were reckoned at 3(^100,000 annually. 

Long before this, in the seventeenth and eighteenth centuries, the leaf 


had become an article of trade to the western provinces of Argentina, 
to Uruguay, Chile, Peru, Bolivia and Ecuador. The chief collecting 
region was the Maracayu district. Asuncion was the outlying depot, 
whence the produce was sent by river to Santa Fe, on the Parana, the 
chief depot for external trade. Frezier (1712-14) writes that the ordinary 
route was from Santa Fe to Jujuy in the Argentine by wagon and thence 
to Potosi in Bolivia by mule-back. Chile, according to Juan and Ulloa 
(1740-44), was supplied direct from Buenos Aires, and passed supplies 
on to Peru. 

The most vivid and detailed account of what had developed into a well- 
organised industry was given by the Robertsons in the first half of the 
nineteenth century. Then, the chief collecting regions, the monies, 
or woods where the ilex flourished, were near Villa Real, about one 
hundred and fifty miles up river from Asuncion. The work of collecting 
was lucrative, but so arduous that it was usually performed by newcomers 
and men in debt. These concessionaires were financed or ' grub-staked ' 
by merchants of Asuncion, who expected repayment in the form oiyerba. 

Each concessionaire hired twenty to fifty workers, and the difficult 
journey through untracked forest to the ilex groves (yer bales) ended when 
a promising locality was reached ; here camping-ground was prepared for 
a stay of six months or so, with huts for the personnel and corrals for the 
mules and oxen. The tataciia, z space some six feet square of hard-beaten 
earth, with a post at each corner, was made ready for the preliminary 
curing of the leaf, a simple process of scorching the masses of verdure 
over burning logs. 

Nearby the barbacua was prepared, an arch of boughs supported on 
trestles ; upon this arch the ilex leaves, now readily separated from 
large twigs and boughs, were placed for the secondary drying. The fire 
built below the arch was carefully tended to prevent the leaves from 
burning, and to ensure complete drying ; and when the process was 
complete the barbacua and the ashes of the fire were removed, the ground 
swept and beaten smooth, and the dried ilex leaves placed on it, and 
pounded with wooden mallets. 

The powdered or broken leaf was then packed tightly into sacks made 
from freshly flayed bulls' hides (serones), sewn up and left to dry. Each 
seron weighed 200 to 220 lbs. when dry. A similar process is employed 

The origin of the practice of infusing the leaves of the ilex is very 
obscure. The earliest mention of the drink I have quoted above from 
Nicholas Duran (1626-27). By that time, as the extract shows, the 
beverage had spread far and wide through South America. But there 
is no account of its discovery. Pinelo, writing in 1636, refers to an 
author, Robles Cornejo, where he says a full account of the herb is given. 
Cornejo's work, Examen de los Simples Medicinales, dated 1617, must 
contain the first reference to the drink. But the book existed only in 
manuscript and, though mentioned in Cejador y Franca's Historia de la 
Lengua y Literatura Castellana, has absolutely disappeared. 

So far, evidence would seem to show that the drink was a native discovery, 
developed by the Jesuits ; but a study of the early history of the country 


provides another aspect. The Rio de la Plata was discovered by Juan 
Diaz de Solis in 1516. In 1534 an expedition was sent from Spain 
under Pedro de Mendoza to make permanent occupation of the country 
to the north. With him sailed one Ulrich Schmidt, or Schmiedel, as 
he was called by the Spaniards, a Bavarian agent of merchants in Seville. 
He ascended the Parand and Paraguay with the pioneer expeditions and 
made many journeys of exploration through the heart of the Guarani 
country, finally making a cross-country journey of some hundred and thirty 
miles from the upper Parana to Sao Vicente ; after this he returned to 
Europe after an absence of nearly twenty years. His reminiscences are 
remarkable from several points of view, and perhaps especially for the 
accuracy of his memory and the almost incredible vileness of his ortho- 
graphy in dealing with Spanish and Indian words. His narrative is of 
great importance to anthropology, because it is the report of a pioneer 
and an observer. Whatever he may have forgotten, his mind is extra- 
ordinarily clear on the food question. He writes in detail what he had to 
drink and eat and where, day by day. Naturally, food was very impor- 
tant, and these European expeditions, living on the country, were often on 
the verge of starvation. For days they had to pass through unoccupied 
country, and their minds were naturally focussed on the food quest. 
Schmidt tells how the Carios make ' wine ' of Mandepore (manioc) and 
of honey ; the Mbaia and Payagua, of ' fenugreek ' ; the Guyacuni, of 
the algarroba bean. But in none of his copious food notes does he ever 
make mention in his twenty years' experience of the use of the ilex leaf, 
either chewed or infused. 

During the period of Schmidt's residence in Paraguay, Cabeza de Vaca 
was sent to the country as Adelantado. From Sao Francisco, in the far 
south of Brazil, where he landed, he made a remarkable overland journey 
to the newly founded settlement of Asuncion, passing through the heart 
of the country where the ilex grew naturally. In the course of his three 
years' residence he made several journeys northward. His narrative 
(1555) is full of details of considerable ethnographical importance and, 
though he pays less attention to local foodstuffs than Schmidt, the 
precarious nature of his supplies led him to record much useful informa- 
tion on this subject. Yet in his account there is no mention of the ilex. 

Between 1569 and 1574 Nicolas Monardes published a work entitled 
Las cosas que se traen de nuestras Indias occidentales, translated into English 
in 1580 under the far more attractive title Joyfidl Newes of the New-found 
World. He gives an extended and delightful description of the properties 
of coca, tobacco and many other American products, but there is no 
mention oi yerba mate. 

Diaz de Guzman (161 2) gives a descriptive account of practically the 
whole region occupied by the Spanish east of the Andes in his Historia 
Argentina (Paraguay did not become a separate province until 1620), but 
there is no mention in his pages of the ' Herb of Paraguay.' Thus the 
first reference to the use of the ilex leaf does not occur in literature until 
more than ninety years after Schmidt entered the country, eighty-five 
years after Cabeza de Vaca passed through the forests which later became 
the principal source of supply, and more than half a century after 


Monardes had published his series of monographs on the economic 
contribution made by the newly discovered Americas to the Old World. 
The lost MS. of Cornejo might supply the information as to the origin 
of the commercial use of the ' herb.' But the inference is, on the 
evidence, that the leaf was not in general use by the natives prior to the 
establishment of the Jesuit missions, except, perhaps, for chewing. 

The native name of the dried leaf gives little help. In the Guarani 
dialect the principal varieties were known as Caamini and Caaguazu 
(in Brazil, Congonha). 

The tree itself was known as Caa, which simply means a tree, a generic 
term, and it is easy to produce parallels from other native dialects that 
no plant of importance is mentioned except by a specific name. The 
implication is that, as far as the natives were concerned, the ilex was 
merely a tree. 

It has been suggested that the word Caa bears some relation to the 
Chinese C'ha, meaning tea in the Pekinese, Mandarin and Cantonese 
dialects. Tea was first brought to Europe by the Dutch in the early 
seventeenth century from Bantam, whither it had been imported by 
Chinese merchants from Amoy, where it was called Te. The Portuguese 
found it in Macao, under the name C'ha, a little later. The first mention 
of tea in Western literature is in Maffei's Historica Indtca, published in 
1558. It is not inconceivable that the Jesuits of the period, looking for 
a substitute for tea, by then introduced into southern Europe, also 
introduced the Chinese word, which was mis.-pronounced by the natives. 

The subsequent development of the Yerbales, or ilex plantations, is 
a matter of history. The economic importance of the leaf, combined 
with the fact that it grew in the less accessible regions (swampy mountain 
valleys), soon led to the inception of attempts to bring it under cultivation. 
Rodero gives the account of the first attempt. 

Young trees were brought from Maracayu to the mission communities 
along the Parana river, but did not flourish. Experiments in raising 
seedhngs were also a failure. The eventual success is recorded by 
Dobrizhofter (1749), who reports that the seed of the ilex is covered with 
a thick coating of gluten which prevents germination. In the wild state, 
this gluten is removed by passage through the bodies of certain birds, 
principally the South American pheasant (Jacu). This gluten was 
eventually removed by careful washing and the seed sown deep in ground 
drenched with water. The young seedlings were planted out in deep 
trenches under thatched shelters. Yet, even after these precautions, the 
cultivated plants never attained the size of those growing under natural 
conditions. However, the Handbook of Paraguay (1894) states that the 
Jesuit attempts were so successful that at Santiago (Paraguay) there once 
existed a grove of 20,000 trees. On the expulsion of the Jesuits these 
plantations disappeared, and only in recent years have successful yerbales 
been established in the Misiones territory of North-eastern Argentina. 

The ilex tree remained without any name assigned by international 
botanists until the nineteenth century ; and it was by a curious piece of 
bad luck that the famous French botanist. Dr. Bonpland, was prevented 
from having the honour of classifying yerba mate. Bonpland went, in 



the year 1820, up-river from Buenos Aires to Paraguay, with the object 
of obtaining specinnens of the plant ; but Paraguay, always isolated, was 
under the dictatorship of that extraordinary individual Jose Caspar 
Francia, whose policy put a fence round the little country. Bonpland 
was placed under a kind of arrest, detained for many years, and while he 
was still practically a prisoner of Francia's, yerba mate had been seen 
by Saint Hilaire in South Brazil, in the Curityba region, identified as a 
member of the ilex family, and named by him Ilex paraguariensis. 
Saint Hilaire afterwards changed the name to Ilex mate ; but meanwhile, 
in 1824, A. B. Lambert, the distinguished English botanist, described 
the tree, illustrated it, and gave it the name Ilex paragiiayensis, by which 
it is now usually known. 

The subject with which I have been dealing may seem, at first sight, 
to be a little removed from the activities of the Section. But I would 
suggest that the study of Ethno-botany is of the highest importance. 
The rapid spread of stimulants, narcotics and food plants throughout the 
world has a direct bearing on culture-diffusion. 

But trouble arises from the fact that valuable food plants spread so 
rapidly that their origin becomes obscured. Especially cereals. Maize, 
to give one instance, indigenous to America and unknown in the Old 
World before Columbus, became the staple food of half Africa within a 
century of the discovery, spreading from tribe to tribe, far beyond 
European exploration. In Europe it penetrated to the Levant, and became 
known in France as ble de Turquie. In Cermany it was called turkische 
Weisen. In England it was called guinea corn, because it came to us 
from West Africa. 

I suggest that there is a splendid opportunity for a young man, trained 
in botany, to undertake the revision of that fine work The Origin of 
Cultivated Plants, written by Alphonse de CandoUe. The last edition 
of this was published in 1909, but the Preface, written in 1882, is a model 
of sympathetic guidance to those who follow. Much has been dis- 
covered since de Candolle's day, and a new edition is badly needed. 
It is in the hope that some of the younger men may take up the task that 
I have chosen this subject for my address. 


1535-53- Ulrich Schmidt (Schmiedel), A True and Agreeable Description of 

some Indian Lands. (Hakluyt Society, vol. Ixxxj, The Conquest of La Plata, 

ed. by L. L. Dominguez, London, iSgi.) 
1541-44. Alvar Nunez Cabeza de Vaca, Commentaries, in the same volume as 

the preceding, 
ijgg-y^. Nicolas Monardes, Joy full Newes out of the New-found World 

(London, 1580) ; a translation by John Frampton of Las cosas que se traen 

de nuestras Indias Occidentales. (Seville, 1569-74.) 
1612. Rui Diaz de Guzman, ' Historia Argentina, in P. de Angelis' Collection 

de Obras y Documentos, vol. i. (Buenos Aires, 1S36.) 
? 1617. Antonio de Robles Cornejo, Examen le los simples Medicinales 

1626-27. NicoLAUs DuRAN, Litterae Annuae Provinciae Paraquariae Societatts 

Jesu. (.\ntwerp, 1636.) 


1636. Antonio de Leon Pinelo, Question Moral si el Chocolate qucbranta el 

ayuno Eclesiastico. (Madrid, 1636.) 
1649-80. NicoLAUS DEL Techo (du Toit), HistoHa Provinciae Paraquariae 
Societatis Jesu. (Liege, 1637.) (English translation in Churchill's Co//ec/iow 
of Voyages, vol. iv. London, 1732.) 
1692. Anthony Sepp, ' Account of a Voyage from Spain to Paraquaria.' 

(Churchnrs Collection of Voyages, vol. iv. London, 1732.) 
1711-14. Florentin de Bourges (quoted by Bouchet) in Lettres edifiantes ei 

curieuses. Tome viij. (Paris, 1781.) 
1712-14. M. Fr^zier, Relation du Voyage de la Mer du Sud. (Paris, 1732.) 
1720. Captain Betagh, ' A Voyage round the World. (London, 1728.) 

(Reprinted in Pinkerton's Voyages, vol. xiv.) 
1729. Vat, in Lettres edifiantes et curienses, Tome ix. (Paris, 1781.) 
C. 1734. Gaspard Rodero, ' Memoire apologetique,' in Lettres edifiantes et 

curieuses. Tome ix. (Paris, 1781.) 
1740-44. Jorje Juan and Antonio de Ulloa, Voyage to South America. 

Translated by J. Adams. (London, 1807.) 
1740-46. John Byron, Narrative. (London, 1785.) 
1749-67. Martin Dobrizhoffer, Historia de Abiponibus. (Vienna, 1783.) 

(English translation by Sara Coleridge. London, 1822.) 
1757- F- Xavier de Charlevoix, Histoire du Paraguay. (Paris, 1757.) 
1772-76. CosMi; Bueno, El Conocimiento de los Tiempos. (Lima, 1772-76.) 
1781-1801. Felix de Azara, Voyages dans rAniSrique meridionale. (Paris, 

1807. S. H. Wilcocke, History of the Vice-royalty of Buenos Aires. (London, 

1811-30. J. P. and W. P. Robertson, Letters on Paraguay. (London, 1838.) 
1817. 'RoB-E-RT SoVT-R-EY, History of Brazil. (London, 1817.) 
1816-22. A. DE St. Hilaire, ' Aper9u d'un Voyage dans ITnt^rieur du Bresil." 

(Memoires du Mus. d'Hist. Nat., Tome ix. Paris, 1822.) 
1817-20. Endlicher and Martius, Flora Braziliensis. (Vienna, 1840-1906.) 
1820-21. Peter Schmidtmeyer, Travels into Chile. (London, 1824.) 
1824. A. B. Lambert, A Description of the Genus Pinus. (London, 1824.) 
1842. Sir W. J. Hooker, ' Some Account of the Paraguay Tea.' {London Journal 

of Botany, vol. i, 1842.) 
1857. D. P. Kidder and J. C. Fletcher, Brazil and the Brazilians. (Phila- 
delphia, 1857.) 
i860. L. A. Demersay, Histoire physique, economique et politique du Paraguay. 
(Paris, i860.) 

1878. T. P. Bigg-Wither, Pioneering in South Brazil. (London, 1878.) 

1879. A. T. de Rochebrune, ' Recherches d'ethnographie botanique sur la 
fiore des sepultures peruviennes d'Ancon. [Actes Soc. Linneenne de Bordeaux, 
Tome x.xxiij, 1879.) 

1880. Thomas Christy, Netv Commercial Plants. (London, i88c-) 
1886. H. Semler, Die Tropische Agrikultur. (Wismar, 1886.) 

1894. Handbook to Paraguay (Bureau of the American Republics, Bulletin 

No. 54, 1892, revised to October 15, 1894), including Appendix B, Report 

of Consul Baker. (Washington, 1894.) 
1901. R. V. Fischer-Truenfeld, ' Paraguay thee.' [Deutsch Rundschau f. 

Geographie u. Statistik, xxiij 15. Wien, 1901.) 
1911. A. Hale, Bulletin of the Panamerican Union, vol. xxxij. (1911.) 
1913. Pablo Hernandez, Organisacion Social de las Doctruias Guaranies. 

(Barcelona, 1913.) 





PROF. H. E. ROAF, M.D., D.Sc, 


The choice of a subject for a Presidential Address is a difficult matter. 
In this case, however, the following consideration seemed of importance 
in making the crucial choice. 

Recently attention has been drawn to the number of accidents caused 
by mechanically propelled vehicles. The use of coloured signals may 
lead to difficulties for drivers with defective colour vision. History 
seems to be repeating itself with reference to the use of coloured lights. 
At one time it was claimed that no railway or marine disaster had been 
shown to be due to defective colour vision — which is not surprising, as 
the individuals concerned were never examined after the accident to see 
if they had normal colour vision. 

One person with defective colour vision (hypochromat) has advised 
me not to say that coloured traffic lights cause any difficulty, as he can 
recognise them quite easily. On the other hand, I have heard that some 
drivers with defective colour vision do experience difficulty. Until the 
colour vision of persons who seem to disregard the coloured lights is 
tested, we do not know to what extent coloured lights constitute a difficulty 
to motor drivers with defective colour vision. In any case the remedy 
is simple, as a difference in shape of the coloured lights would be sufficient 
to prevent mistakes. It is true that the relative positions of the lights and 
other data may help in the recognition of the colour, so that the problem 
is not so serious as in the case of railway and marine services. 

It is not my intention to give a detailed documentary description of 
recent work, as those interested will find references to many papers in 
some of the reviews of the subject.^ 

The aim of this address is to discuss three aspects of the Physiology of 
Colour Vision. The first aspect is the validity of the trichromatic 
hypothesis. There may not be many new things to be said, but a 
restatement of the arguments is useful as showing to what extent the 

^ H. Pieron, Bull. Soc. d'Ophthal. de Paris, p. i (1930). H. E. Roaf, Physiol. 
Rev.. 13, p. 43 (1933)- 

G 2 


hypothesis can be reUed upon. The second aspect is the nature of the 
departures from normal colour vision of those with defective colour 
vision. The third aspect is a brief consideration of some theoretical 
views on the nature of colour-perceiving mechanisms. 

Why is Colour Vision of importance in Physiology ? 

All measurements depend upon perceptions ; many are concerned with 
visual perceptions, and some are based upon the perception of colour. 
Therefore the study of special sense physiology should be of interest to 
all branches of science. Colour is an attribute of vision ; therefore any 
views as to the perception of light by the eye must involve a consideration 
of the phenomena of colour. As colour sensation is interpreted in the 
brain, the study of colour vision involves not only the action of light on 
the retina, but also the transmission of impulses through the various 
layers of the retina and through the optic nerve, and the interpretation of 
the impulses in the brain. Some of these problems are common to other 
parts of the nervous system : therefore a thorough knowledge of colour 
vision may illuminate other sensory processes. 

As the retina is merely an outgrowth from the brain, and the optic 
nerve a tract of the central nervous system, the function of the layers of 
the retina and of the optic nerve should correspond with other parts of 
the nervous system. Therefore, the distinctive problem in the physiology 
of colour vision is to discover how light affects the retina and produces 
nerve impulses. On the other hand, it is difficult to separate experi- 
mentally those activities due to stimulation of the retina from the activities 
of the various layers of the retina or the central nervous system. 

Statement of the- problem involved in the consideration of 

Colour Vision. 

The real problem that one has to consider in special sense physiology is 
how the threshold of stimulation can be lowered for certain stimuli, but 
left high for others. The nature and action of the receptors determine 
what stimuli will most easily give rise to nerve impulses in certain nerve 
fibres. The number of varieties of receptors depends upon the data 
which must be presented to the cerebrum for the proper perception of 
sensory stimuli. 

The first difficulty is to decide whether a single nerve fibre can convey 
impulses corresponding to more than one sensory datum. This problem 
was mentioned by Prof. Adrian in his address last year, and although the 
thesis cannot be definitely proved, the evidence seems to indicate that a 
single nerve fibre cannot convey more than one kind of impulse.^ The 
velocity of transmission and other characteristics may vary from fibre to 
fibre, but it has not been shown that one fibre can convey different types 
of impulse. 

If the above assumption is a legitimate one, we must endeavour to 

^ E. D. Adrian, British Association Report, p. 163 (1933). 


reduce the sensory data to the lowest possible number, as the simplest 
mechanism is that requiring the fewest possible components. 

All perceptions can be analysed into qualities of sensation — i.e. we can 
distinguish between sensations of light, sensations of sound, etc. These 
qualities can each be subdivided into different attributes of sensation, or 
subqualities. Some of these subqualities are common to all exteroceptive 

The subqualities of vision are perception of form or shape, perception 
of movement, recognition of differences in intensity, and discrimination 
of colour. Before we can attempt to distinguish the minimal data which 
must be presented to the cerebrum, an analysis of colour must be made. 

What is meant in this address by Colour ? 

We can define colour as one of the psychological accompaniments of 
vision. The physicist defines radiation in terms of wave-lengths, but he 
should speak of colour only as a means of avoiding circumlocution. 
When we say ' red ' light we use the term ' red ' in quotation marks to 
stand for light which gives rise to the sensation of red in the normal 
person. In many cases no difficulty results from the use of such terms, 
but in a description such as this one we must be clear that there is a 
difference between the two uses of the words red, green, etc. — namely, the 
stimulating radiation and the sensation. 

Colours are visible in the spectrum, and we can recognise certain colours, 
which seem unitary and distinct from all others, namely, red, yellow, 
green, and blue. There are, however, other unitary sensations which 
must be considered, namely, white and black : these cannot be produced 
by stimulation with any one region of the spectrum. These two sensa- 
tions are sometimes described as belonging to the colourless sensations, 
but psychologically one cannot separate them from a discussion on 

Thus we find that certain colours are related to definite regions of the 
spectrum, but there are other sensations which do not correspond to any 
single group of wave-lengths : the latter are the purples, white, and black. 
All colours can be represented by fusion of lights from several regions 
of the spectrum, and the minimum number of regions is three. This 
physical relation is generally considered of paramount importance in the 
discussion of colour vision. 

In 1802 Young postulated that there were three sensory mechanisms, 
because all colours could be reproduced by a combination of three regions 
of the spectrum.^ There has always seemed some difficulty in recon- 
ciling this view with the psychological standpoint that there are six distinct 
kinds of visual colour sensation, namely, red, yellow, green, blue, white, 
and black. In the discussion of this problem some of these simple 
psychological effects can be shown to be built up from other sensory 
processes. The discussion of the sensation of yellow occupies an 
important place, but before we deal with the sensation of yellow it is 
simpler to consider the sensations of white and of black. 

3 T. Young, Phil. Trans., 92, p. 12 (1802). 


Sensation of white cannot be produced by any single unitary physical 
stimulation. It requires the simultaneous action of light from more than 
one region of the spectrum. This seems to me a fundamental considera- 
tion, because if a simple sensation like white can be produced only by a 
heterogeneous stimulation, it is possible for a simple sensation like yellow 
to be the result of a heterogeneous stimulation. The sensation of white 
can be produced by stimulation by light from the whole of the spectrum, 
or from three or from two selected regions. There is no fixed standard 
of white. A white surface is one that reflects all visible wave-lengths 
well and equally. In order to define a ' white ' light a standard is taken 
of the radiation of a perfect radiator at 4800° K. or other specified tempera- 
ture.* When a white sensation is produced by light from two regions of 
the spectrum, the separate sensations produced by these radiations are 
said to be complementary, and this phenomenon will be referred to later. 

Black sensation cannot be produced by any combination of radiations. 
It is always the result of a relative deficiency of stimulation. A black 
surface is one that does not reflect any visible wave-length to an appre- 
ciable extent. To produce a black effect with spectral lights a brighter 
light must shine, alongside them. Thus, a red produced by wave-length 
of about 6500 A. looks brown when a bright yellow produced by wave- 
length of about 5900 A. shines alongside of it. 

The transition between white and black through grey depends upon 
the relative amount of illumination. There must, however, be the right 
mixture of wave-lengths, otherwise the grey will be tinted with the 
colour sensation produced by those wave-lengths which are in excess. 

We are now in a position to consider the phenomenon of yellow. 
Yellow is a unitary sensation which can be produced by a single group of 
wave-lengths or by two groups, one each on the 'red ' and ' green ' sides 
of the ' yellow ' region. If we are to believe that three types of sensory 
mechanism are sufficient to account for colour vision, one of the four 
colours red, yellow, green, and blue must be due to a stimulation of at 
least two of the other ones. For several reasons, yellow has been chosen 
as the heterogeneous one. 

To my mind there is no more difficulty in considering yellow as due 
to stimulation of two types of receptors than to consider white as due to 
stimulation of more than one type. Experimental evidence supports this 
view. Macdougall,^ Rochat,^ and others have shown that a ' red ' 
stimulus to one eye and a ' green ' to the other will give a sensation of 
yellow. This result is obtained even with lights from the spectrum. 
The fact has been demonstrated by Hecht,' but his method is not such a 
satisfactory proof as that obtained by other methods — e.g. a ' red ' glass 
over one eye and a ' green ' one over the other, or two definite wave- 
lengths of the spectrum each presented to one eye. 

Central summation of this type shows that the sensation is built up in 
the nervous system beyond the optic chiasma, as neither eye need be 

« W. D. Wright, Proc. Roy. Soc, B, 115, p. 49 (1934). 
s W. Macdougall, Mind. X.N.S., pp. 52, 210 and 347 (1901). 
" G. F. Rochat, Arch. nSerl. de Physiol., 10, p. 448 (1925). 
' S. Hecht, Proc. Nat. Acad. Sci. Wash., 14, p. 237 (1928). 


stimulated by the ' yellow ' of the spectrum. The red and green sensa- 
tions are lost, but their disappearance cannot be due to processes in the 
layers of the retina. As Macdougall points out, the alternative suggested 
by Hering that his four-dimensional system is cerebral rather than retinal 
deprives his hypothesis of its special value as a theory of colour vision. 
Hering's theory then becomes part of a general problem of how afferent 
stimuli are combined to produce perceptions, which is too complex a 
matter to be discussed here.^ 

As the unitary sensations yellow, white, and black can be built up from 
stimuli associated with other sensations, it is possible to reduce the number 
of data for colour perception to three. 

The object of the above discussion is to show that there is no real 
objection to the trichromatic explanation of colour vision proposed by 
Thomas Young. 

Colour Contrast. 

In many observations on colour, contrast phenomena occur. These 
effects are always related to complementary colours. When, for example, 
one looks at a grey surface surrounded by a colour, the grey is tinted with 
the colour complementary to that used. This phenomenon is called 
simultaneous contrast or spatial induction. There does not seem to be 
any reasonable explanation of this effect except on a psychological basis. 

To say that the inducing colour lowers the threshold of surrounding 
areas is purely hypothetical, and the evidence is in favour of the threshold 
being raised in surrounding areas. This effect of one area of the retina 
on another is part of the problem of adaptation to light. ^ 

When a grey surface is viewed alongside a coloured surface, the light 
coming from the grey surface contains less of the dominant wave-length 
characteristic of the coloured surface than that coming from the coloured 
surface itself. 

The grey surface is less coloured with the inducing colour, and as there 
is no fixed standard for white (or grey), it appears tinged with the com- 
plementary colour. Objectively it has a greater proportion of the com- 
plementary colour than the other surface.^" 

Successive contrast or temporal induction is produced by looking at a 
coloured surface and then at a grey one. The grey surface under appro- 
priate conditions appears tinged with the colour complementary to the 
inducing one. This is easily explained by the process of adaptation 
whereby the frequency of impulses falls off rapidly during stimulation of 
the receptors. On looking at a neutral surface the impulses initiated in 
those end-organs which were stimulated by the inducing colour will be 

* J. H. Parsons, Introduction to the Theory of Perception., Camb. Univ. Press 

» H. E. Roaf, Proc. Roy. Soc, B, 110, p. 448 (1932). W. D. Stiles and B. H. 
Crawford, Proc. Roy. Soc, B, 113, p. 496 (1933). W. D. Wright, Proc. Roy. Soc, 
B, 115, p. 49 (1934)- 

" F. W. Edridge-Green, Physiology of Vision (G. Bell & Son), pp. 232-234 


fewer than those from the end-organs which were not previously stimu- 
lated ; hence the more frequent impulses from the previously less 
stimulated receptors will produce the sensation of the colour comple- 
mentary to the inducing one. 

Defective Colour Vision. 

Abnormal colour vision may be congenital or acquired. It is not my 
intention to discuss certain defects in colour vision due to disease — e.g. 
tobacco amblyopia. 

Defective colour vision is a condition in which the persons affected 
make mistakes in matching colours. Any explanation of the nature of 
colour vision must be able to explain how certain colours are mistaken. 
The usual form of defective colour vision is congenital, and does not alter 
during life. This is what is generally understood when speaking of 
defective colour vision. The defect seems to consist in a decrease in the 
ability to distinguish ' red ' from ' green,' and the subjects distinguish 
fewer colours than the normal (euchromat) ; hence they may be spoken 
of as hypochromats. It is very difficult to compare the sensations of such 
cases with those of a normal person, but they are frequently described 
as having blue-yellow vision. Another way of expressing the fact is to 
say that in the spectrum they distinguish blue from not blue, whereas the 
normal person subdivides the not blue into red and green. As ' yellow ' 
occupies the region between ' red ' and ' green,' the defect is most notice- 
able in the ' yellow ' region of the spectrum, especially in the milder 
degrees of the defect. 

Part of the evidence for these statements is that analysis of the mistakes 
made by hypochromats are all explained by a failure to distinguish red 
from green .1^ Further evidence is furnished by observations on colour 

By measuring the difference in wave-length necessary to cause a differ- 
ence in colour, it is found that normal people have two main maxima of 
discrimination where a difference in colour is recognised for a minimal 
change in wave-length. These maxima of discrimination probably 
indicate where there is a most rapid change in the ratio of stimulation of 
two different types of receptor organs. The hypochromat shows only 
one maximum of discrimination, thus suggesting that he has only two 
types of receptor organs. 

In extreme degrees of this defect the whole range of colours can be 
reproduced for these people by fusion of light from two regions of the 

The normal maxima are in the ' yellow ' and ' blue-green ' of the 
spectrum, whilst the hypochromat has only one maximum, that in the 
' blue-green.' It appears as if the distinction on each side of the yellow 
had been diminished or lost : hence the failure to distinguish ' red ' from 
' green,' and the whole not blue portion of the spectrum appears more or 
less of one colour. The bearing of this on any theory of vision is that 

" H. E. Roaf, Quart. Journ. Exp. Physiol., 14, p. 151 (1924). A. B. Follows, 
in the press (1934) • H. E. Roaf, in the press (i934)- 


we must be able to explain how the distinction between red and green can 
disappear, yet without marked decrease in the visibiUty of any portion of 
the spectrum. The threshold for light is not necessarily altered, and it is 
possible for hypochromats to see clearly through a filter which allows 
only the red end of the spectrum to pass through. In fact a hypochromat 
who cannot see red geraniums amongst the green leaves can distinguish 
the flowers as light objects against a dark background when looking through 
a red glass filter. 

Anomalous Trichromatism. 

In 1 88 1 Lord Rayleigh described a condition known as anomalous 
trichromatism, which is characterised by the fact that various people 
require different proportions of ' red ' and ' green ' to match a fixed 
' yellow ' but there seems to be no defect in the recognition of colours. 
This condition has been considered by some people to be the basis of a 
division of hypochromats into two groups, and that there are a series of 
cases ranging from normal vision to complete red-green confusion. 1- 

Up to the present there has been no satisfactory explanation of the 
condition of anomalous trichromatism, and I am now investigating this 
condition. The explanation may be that the radiation corresponding to 
the sodium flame (5896 A.) looks orange to some and greenish to others. 
If the fixed ' yellow ' looks orange, the appearance suggests that the red 
sensation is relatively more stimulated by the ' yellow ' light, and more 
' red ' would be required in the mixture to make the match, whilst if the 
fixed ' yellow ' looks greenish, more ' green ' would be required. It is 
not yet known whether a similar phenomenon is shown in matching a 
fixed ' blue-green ' with a mixture of ' blue ' and ' green.' That some 
such explanation is possible is shown by Gothlin,i^who finds that different 
people do not mark out the same region of the spectrum as yellow. The 
maxima of discrimination mentioned previously are also found to be at 
different wave-lengths for various individuals.^* 

The sensation of yellow seems to be a crucial problem, as it may be 
recognised at different wave-lengths of radiation, and if it is seen over a 
wide range of wave-lengths the subject has defective colour vision. 

Means of Stimulation by Light. 

Stimulation of the retina is due to a photochemical action. That is, the 
radiant energy is absorbed and converted into some other form of energy. 
Joly has ascribed the eflFect to a photoelectric process, meaning that 
electrons are given off as the result of the radiation. It is difficult to see 
in what way this differs from a photochemical action, as electronic changes 
in organic material accompany chemical change. One cannot compare 

" A. Guttmann, Zeit. f. Psychol, d. Zimiesorgane, Abt. 2, 42, pp. 24 and 250 
(1908) ; ibid., Abt. 2, 43, pp. 146, 199 and 255 (igog). 

" G. Fr. Gothlin, Journ. Physiol., 57, p. 181 (1923)- 

i« O. Steindler, Sitzungsber. d. Akad. Wiss. Wien, 115, 2a, p. 39 (1906). H. 
Laurens and F. W. Hamilton, Amev. Journ. Physiol., 65, p. 547 (1923). 


these changes with those produced in photoelectric cells. Furthermore, 
it is known that there is a chemical substance in the retina which is 
bleached by light. It would be a remarkable circumstance if this photo- 
chemical change were entirely divorced from the function of vision. 
Hecht has published a series of papers on the photochemical action of 
light on living organisms, and it has been shown that the data for dark 
adaptation are best explained on the basis of a bimolecular chemical 
change. The analytical factors in sensation are generally considered to 
be specialised receptor organs which receive the stimuli and cause nerve 
impulses. These receptors act by having a low threshold to some mani- 
festations of energy while maintaining a high threshold to others. It 
is for this reason that receptors are of such importance in the physiology 
of the nervous system. 

Theories of Colour Vision. 

If it is legitimate to regard all colour perceptions as being synthesised 
from three sensory mechanisms, we can return to the consideration of 
visual perceptions (p. 170.) 

Perceptions of form may be regarded as related to the optical patterns 
produced in both uniocular and binocular vision ; therefore they are 
related to the anatomical connections between areas of the retina and of 
the cerebrum. 

Perceptions of movement depend upon the presentation of successive 
patterns, such, for example, as shown by the cinematograph. 

Recognition of intensity differences is ascribed to the frequency with 
which impulses reach the central nervous system .^^ Therefore we have 
to consider how the three subqualities underlying colour vision can be 
conveyed by the optic nerves. If we could prove that different types of 
nerve impulse could pass up the same nerve, we could say that a single 
nerve fibre could serve for all colour perceptions, but if we must limit 
each nerve fibre to one type of impulse, then we must look for separate 
nerve fibres for each of the three colour sensation processes. In other 
words, of the six properties of vision we can relate three of them — form, 
movement, and intensity — to anatomical, temporal, and frequency relations 
respectively. The other three, namely colours, must be related to different 
groups of nerve fibres. It is possible to imagine frequency relations 
giving rise to colour sensations, but we would then have to abandon the 
experimental relation between frequency and intensity. 

The maximum frequency at which nerve impulses can pass up a nerve 
fibre is of the order 400 per second, whilst the frequency of light waves 
is from 400 to 750 billions per second. It seems difficult to imagine a 
relationship between such disproportionate frequencies. 

The relation between receptor organs in the retina and nerve fibres in 
the optic nerve is complicated by the synapses in the layers of the retina 
(Granit has been investigating these problems ^®). If vision depends 

" E. D. Adrian, British Association Report, p. 163 (1933). 
" R. Granit, Arch, of Ophthal., 6, p. 104 (1931). 


upon the presence of three types of receptors, it is difficult to see how the 
nerve fibres corresponding to the different sensations can be reduced to 
less than three groups, nor can one imagine how fewer than three types 
of receptors can give rise to three groups of nerve impulses. This is a 
general problem as to what extent simplification or complexity can be 
introduced between receptor organs and the interpreting mechanism in 
the brain. It seems to me that the trichromatic hypothesis implies, as 
stated by Young, the presence of three types of receptors linked with 
three groups of nerve fibres in the optic nerves. 

The tentative conclusion is that, in order to explain the phenomena of 
colour vision, it is necessary to have three groups of nerve fibres passing 
to the brain — one group giving rise to sensation A, a second to sensation 
B, and a third to sensation C. We must discover what wave-lengths 
stimulate A, B, and C respectively, what sensations are produced by 
stimulation of one of these alone, and what is the effect of stimulating 
more than one of these, either to the same degree for each or to different 
ratios of response. Stimulation of the receptors may correspond to 
definite wave-length groups, but there may be a certain amount of 
rearrangement in the retinal synapses. It does not seem probable that 
the number of types of receptors or groups of nerve fibres can be reduced 
below three if frequency of the impulses is to be related to intensity of 
stimulation and if only one kind of impulse can pass up each fibre. It is 
like the solution of simultaneous equations : the number of equations 
must be at least equal to the number of unknowns to be found. That 
seems to be the essence of the trichromatic hypothesis as suggested by 

Helmholtz introduced the view that the differentiation is due to the 
presence of three photo-active substances which are acted on by the long, 
medium, and short wave-lengths of the visible spectrum respectively. 
The range of radiation which affects these three substances overlaps so 
that, for example, some rays affect all three of these substances. Up 
to the present there is no definite evidence for the presence of three 
photo-active substances, only one photo-active substance, rhodopsin or 
visual purple, has been found. Apart from this fact the view of three 
photochemical substances such as postulated by Helmholtz does not agree 
with the experimental evidence. For instance, in order to explain 
hypochromatism, it is not assumed that one photo-active substance is 
absent but that the range of activity has shifted so that the one substance 
is activated by the range which was formerly active on the two separate 
substances. It does not seem likely that such a chemical transformation 
would occur. 

Hecht has attempted to modify the Helmholtz view by assuming the 
presence of three substances activated by practically the same range of 
radiant energy. The dissimilarities in Hecht's curves seem to me to be 
too small to explain the differences in colour sensations. Such views as 
those of Hering are untenable so long as we cling to the idea that a single 
nerve fibre can conduct only one type of impulse. Further, the sensation 
of yellow can be produced by the fusion of impulses from the two eyes : 
hence it is not due to the neutralisation of ' red ' and ' green ' in the 


retina with a residual yellow effect due to both these ranges of radiation 
stimulating a yellow sensation-producing mechanism. Burridge's state- 
ment that there is an increase or decrease in rhythmical activity does not 
indicate how colour sensations are produced. 

Edridge-Green describes a theory which is quite different from all 
others. He says that the rods do not cause visual sensations, their only 
activity being to produce visual purple. Visual purple is passed into 
solution and, when decomposed by light, acts upon and produces stimula- 
tion of the cones. He seems to regard each cone and each nerve fibre as 
capable of giving rise to a number of different colour sensations ; this 
suggestion requires a modification of the view that a single nerve fibre 
can conduct only one type of impulse. 

Another suggestion is that put forward by Schultz (i866),i'' namely, 
that there is one photochemical substance but different coloured filters to 
distinguish the various regions of the visible spectrum. Such filters have 
been found in amphibia, reptiles, birds and marsupials, but have not been 
found in other mammals. The coloured filters in the birds' retinas 
would explain the type of colour vision found in man. For instance, by 
reducing the intensity of red pigment in the red filters the various degrees 
of hypochromatic vision would be produced, but in a single human eye 
examined by me no such filters could be seen. 

My own work leads me to suppose that the types of receptors which 
are stimulated by visible radiation are as follow : — 

The first type of receptor is one which is stimulated by all parts of the 
visible spectrum and gives rise to a sensation of violet ^^ when stimulated 
strongly by itself.^® 

The evidence for the first part of the above statement is the same 
as that which caused Hering to speak of a white-black substance and 
von Kries to describe a bluish-white sensation as due to stimulation 
of the receptors for achromatic scotopic vision : these usually being 
regarded as the rods. 

The evidence for the second part of the above statement is first of all that 
a narrow beamof any wave-length when shining slightly eccentrically gives 
rise to a violet sensation. This has been called secondary excitation, 
implying that the sensation is due to stimulation of receptors by nerve 
impulses passing along fibres of the optic nerve. It is unlikely that such 
stimulation would occur, and if so, why should the sensation produced be 

" M. Schultz, Arch.f. Mikr. Anat.. 2, p. 255 (1866). 

1' It is with some hesitation that one states that violet is due to stimulation of 
a single receptor, as psychologically it suggests a mixture of blue with a little 
red. If violet is the sensation corresponding to stimulation of one type of 
receptor, we must regard the unitary sensation of blue as due to stimulation of 
the receptors for green and violet. It may be that blue is the sensation due to 
stimulation of the single receptor, and that violet is the result of stimulation of 
the receptors which give rise to blue and to red sensations. This matter must be 
left in abeyance, but the use of the term ' violet receptor ' is to be understood to 
mean either the receptor for violet or blue, owing to the fact that fatigue to ' red ' 
causes violet to appear more blue. Wright believes that the single receptor gives 
rise to a sensation of blue. 

1' W. O. Siv6n, Shand. Arch.f. Physiol., 17, p. 306 (1905). 


violet ? On the whole, it seems simpler to interpret it as stimulation of 
rods by any wave-length. Furthermore, diseases involving the rods lead 
to night blindness or raising the threshold of achromatic scotopic vision. 
If this threshold is sufficiently raised then there is loss of vision for violet, 
so that the distinction between green and blue is lost.^" This defect is 
a true violet blindness, because it is accompanied by a raised threshold 
for the short wave-length end of the spectrum. Finally, adaptation to 
light conditions is accompanied by a special raising of the threshold to 
the short wave-length end of the spectrum. Therefore, although the 
point is not proved, there is much evidence in favour of violet vision being 
a function of the rods. 

The second type of receptor is one which is concerned with the not 
blue aspect of vision of the hypochromat. These may be cones of which 
there need be only one variety for the hypochromat. 

The third type of receptor would be functional in normal vision, and 
it seems as if this second variety of cone were one that distinguishes red 
from not red, and according to the activity of this variety the stages 
between normal vision and complete red-green confusion can be 

Therefore, normal vision may be due to a receptor which gives rise to 
a red sensation, one which gives rise to a blue sensation and one which 
gives rise to a not blue, not red sensation which, of course, corresponds 
to green sensation. The actual wave-lengths of radiation that stimulate 
the several receptors are not known. The real difference between various 
hypotheses is the extent and region of the spectrum which stimulates the 

In the Young-Helmholtz hypothesis the type of receptor responsible 
for the sensation of red is stimulated by almost the whole of the spectrum, 
but most strongly by the long wave-length end. The receptors for green 
are stimulated by almost the whole spectrum, but most strongly by the 
mid -region. And those for blue are stimulated by a large extent of 
the spectrum, but most strongly by the short wave-length end. 

' Red ' light of longer wave-length than 6200 A. is supposed to stimulate 
the red receptor only, whilst shorter wave-lengths will stimulate the red 
receptor to decreasing degrees, but the other receptors to increasing 
extent, hence the change of colour with wave-length. 

Relation of Wave-length Differences to Colour Discrimination. 

The change of colour is probably most noticeable when the change in 
ratio of stimulation of the receptors is most marked — e.g. yellow sensation 
might correspond to a sudden decrease in frequency of impulses from 
the receptors for red, a sudden increase in impulses from the receptors 
for green, or a rapid decrease of the former and rapid increase of the latter. 
This assumption is one reason for the great interest in the maxima of 
discrimination in the spectrum. 

2° H. Kollner, Die Storungen des Farhensinnes (S. Karger, Berlin, 1912). 


Interpretation of the relations between receptors and incident light is 
not yet attained. Sensation curves merely express the results of matching 
regions of the spectrum with three groups of wave-lengths. As Wright 
remarks,^^ ' The physiological mechanism by which such an effect could 
be produced cannot be visualised very readily, but it would apparently 
necessitate the assumption that all three fundamental responses have 
some quality in common, so that one response could produce a sub- 
tractive effect on another. This quality must probably be in the nature 
of an inherent " whiteness," and it is on an assumption of this sort that 
saturation differences might be explained.' 

This view has much in common with the belief of Hering and von 
Kries that there is an underlying white sensation to all stimuli. 

It is possible that monochromatic regions of the spectrum may stimulate 
all three types of receptors to constant ratios — e.g. the extreme ' red ' 
end of the spectrum may stimulate all three types to equal degrees or any 
ratio such as 3:2:1. Therefore, the monochromatic ' red ' at the end 
of the spectrum may correspond to stimulation of the three types of 
receptors, and not only of one, as represented in Wright's curve. A 
high degree of discrimination, as in the ' yellow,' would correspond to a 
rapid change in the ratio of stimulation. Therefore, (a) the red sensation 
is rapidly falling off, (b) the green sensation is rapidly increasing, or 
(c) the red is decreasing and green increasing rapidly about 5800 A. 
Similarly a change in the ratio of stimulation is taking place rapidly 
about 4900 A. 

It is difficult to know how to test these assumptions. The phenomena 
of binocular rivalry, etc., indicate that nerve impulses may be suppressed 
before they produce consciousness : hence sensations may not always 
correspond to the algebraical sum of nerve impulses — e.g. an object seems 
darker when a semi-transparent screen is placed in front of one eye than 
if the one eye is entirely obscured. 

Conditions necessary for the Investigation of the Specific Stimuli 

FOR Visual Receptors. 

For the purpose of finding out what range of wave-lengths is effective on 
the different receptors, weak stimuli must be employed. The eye must be 
in a condition of dark adaptation, because any other state is accompanied 
by stimuli which make the results more difficult to interpret. ' White ' 
light should never be used, as it stimulates all receptors ; therefore 
specific relations between receptors and stimulus are upset. 

With stronger stimuli a wider range of radiation will become effective 
in stimulating the end-organs ; in fact, with strong illumination it is known 
that the purity of the sensation diminishes, thus showing that weak 
illumination is better for the purpose of differentiating the relation of 
receptors to different wave-lengths of radiation. 

The effect of one group of wave-lengths on the sensitivity of the same 

" W. D. Wright, Proc. Roy. Soc. B, 115, pp. 69-70 (1934). 


area of the retina to another group, is probably the only method of com- 
paring the stimulating actions of these groups on the same receptors. 
If different receptors are acted upon, one light should not affect the 
sensitivity to another, but if the same receptors are concerned, 
then interference will take place according to the Weber-Fechner 

Experiments of the above nature suggest that long wave-lengths of 
visible radiation stimulate all receptors to an appreciable degree, whilst 
the shorter ones act mainly on one only. 

As a result of my own experiments I am led to believe that the ranges of 
wave-length which stimulate the various receptors correspond to the 
effects to be expected from the coloured globules found in the birds' 
retinae. No such colour filters have been found in the eyes of mammals 
higher than the group of marsupials. It may be that photo-active 
substances are the means of selection. 

The three types of receptors would be : (i) Those corresponding to the 
red globules which would be stimulated by the long wave-length end of 
the spectrum, with a marked falling off in effect about 5800 A. As no 
filter is absolutely opaque, it is probable, especially with bright lights, 
that some stimulation of these occurs by wave-lengths to the extreme 
short wave-length end of the spectrum. These receptors would be 
absent or the pigment in the filter reduced in the various degrees of 
hypochromatism. (2) Those corresponding to the yellow globules which 
would be stimulated by long and intermediate wave-lengths, with a 
marked falling off in effect about 4900 A. Some stimulation might also 
be produced by shorter wave-lengths. (3) Those corresponding to the 
pale greenish globules which could be stimulated by the whole of the 
visible spectrum. ' Red ' light would thus stimulate all three receptors. 
' Green ' light would stimulate mainly two. ' Violet ' light would 
stimulate mainly one. 


Colour vision is probably dependent upon three types of receptor 
organs. In some persons the activity of one of these types is reduced or 
absent, giving rise to varying degrees of defective colour vision. 

Discrimination curves suggest that the change in ratio of stimulation 
occurs rapidly at wave-lengths about 5800 A. and 4900 A. Hypochromats 
do not possess the maximum near 5800 A. ; hence their dichromatic 
vision depends upon two types of receptors with marked change in ratio 
of stimulation by wave-lengths about 4900 A . 

The normal person differs, therefore, from the hypochromat in that 
the former is better able to distinguish wave-lengths of radiation longer 
than 5800 A. from shorter ones. The defect does not appear to be a mere 
absence of one type of receptor leaving a portion of the spectrum unrepre- 
sented, but it seems as if the red discrimination of the euchromat were 
superimposed on a background of something else. In the absence of 
discrimination of ' red ' the background might be classed as yellow, but 


when discrimination of ' red ' is present the sensation of yellow is 
aroused by a region of the spectrum which separates that giving a red 
sensation from that which gives another colour, namely, green. 

The deficiency is always characterised by a spreading out of the 
portion of the spectrum which gives rise to a sensation of yellow until, 
in severe cases, the whole of the spectrum from 4900 A. to the extreme 
' red ' end is distinguished only by characters such as brightness or 
decrease in blueness. 






Social problems are partly material and partly mental. Every society 
consists of interdependent personalities whose harmonious co-operation 
is necessary for the general well-being, and the really serious problems of 
life concern this co-operation. Very great progress has been made in 
the solution of the material problems : the physical and biological sciences 
have given increased control over material resources ; the energy values 
of foods have been determined, the amounts required for different kinds 
of work have been calculated, and preventive and remedial measures have 
been devised by medical science which are improving national health 
and lengthening life. 

Very much less attention has been given to the study of the mental 
aspects of social welfare, perhaps because every man finds it difficult to 
persuade himself that his conduct and thought can be studied as physical 
and biological phenomena are studied, resenting the suggestion that 
anyone but himself can know what he is going to do or what he is able to 
do, and yet with a strange inconsistency not hesitating to claim for himself 
such knowledge regarding others, or perhaps it is because the conditions 
that affect human thought and behaviour are so extremely complex that 
they make the understanding of a chemical reaction a trivial matter as 
compared with that of a bit of human behaviour. Nevertheless, for a 
proper understanding of the numerous problems that arise from life in a 
community, such as those of supply and demand, labour and capital, law 
and order, hygiene, housing, transport, education, the conflict of traditions 
and ideals, and local and international rivalries, the study of mind is just 
as important as is that of matter. The solutions to these problems are 
to be found ultimately in the forces that move men to action, in their 
inherited tendencies, in their acquired habits, in the mentality of the 
groups to which they belong, and in their relationships to those groups. 

Most men with any experience of the world know this, but it rarely 
occurs to them that these matters are amenable to scientific treatment : 
they rely on their own intuitions, seldom doubting their truth, preferring 
persuasion to proof. If opinion is to give place to knowledge, scientific 
method is just as necessary here as it is in chemistry, physics or biology, 
for it is just a deliberate effort to get a clear understanding of things by 


making systematic observations under conditions which others can repeat, 
by inventing explanations, and by testing these explanations thoroughly 
and impersonally. 

An appreciation of this need for objectivity was doubtless in Fechner's 
mind when he dreamed of measuring sensory experiences and making 
psychology as mathematical as the physical sciences : it certainly underlies 
the activities of the experimental and statistical psychologists. Fechner's 
hopes have not been realised. Psychology has had to develop methods 
suitable to the solution of its own problems, and these have not been the 
classical methods of the physical sciences : they are more like those of 
the biological sciences. They are essentially systematic methods of 
describing and analysing the experiences and bodily activities of representa- 
tive samples of the population under specified conditions. This is the 
logic of psychological inquiry : it is a slow, laborious business, not nearly 
so exhilarating nor so impressive as the invention of sweeping generalisa- 
tions supported only by rhetoric and casual observation ; but it is necessary, 
and, in the end, satisfying. 

Though the need for objectivity is recognised in the experimental 
laboratory, where information is laboriously collected and analysed, and 
where theories are thoroughly tested, it has not been so clearly recognised 
in the treatment of the psychological aspects of social problems. The 
social psychologist seems to be drawn to those branches of his subject 
which are the most obscure and the least amenable to objective co-opera- 
tive testing and to those methods of inquiry which are the least exact : 
he maintains, for example, that the department of psychology that is of 
first importance for the social sciences is that which deals with instinctive 
impulses, and for his knowledge of these impulses he relies largely on 
casual observation. There has been much speculation regarding the 
number and nature of the innate human tendencies and their operation 
in social life, and there are fascinating theories regarding the ways in 
which individual personal experience affects behaviour. Unfortunately, 
much of this lacks the precision and objectivity which science demands ; 
it is in the old philosophical tradition, being characterised by wide 
generalisations based on casual observation, subtle analyses and fine dis- 
tinctions that are often merely verbal ; it is not based on that controlled 
and repeatable observation which makes science. It is none the less useful, 
for it provides working hypotheses and it is perhaps inevitable ; but it has 
to be tested : so long as its main support is general impression and opinion, 
no matter how respectable, it is not science. 

Much of the text-book psychology of behaviour falls into this category. 
Casual observation suggests that there are forms of behaviour which are 
common to all the members of a species, unlearned and grounded in 
inherited structure and disposition, and, as McDougall, Drever, Bartlett 
and others have shown so clearly, such innate dispositions explain much 
of human behaviour ; but we still lack methods of assessing the strengths 
of these tendencies : few people doubt that there is an innate tendency 
to remove more or less violently obstacles to one's activities and that it 
varies in strength from one person to another and from one race to another, 
but until satisfactory objective methods of assessing it have been devised, 


comparisons between individuals and between peoples as to the strengths 
of these tendencies will remain difficult and unreliable. 

Such methods will probably be devised in the course of time : as 
regards the temperamental traits, which are believed to be important for 
social life, some crude beginnings have already been made with the so- 
called rating scales. Certain qualities of mind, such as impulsiveness, 
steadiness, and cheerfulness, are selected and each person under investiga- 
tion is rated in respect of each trait on, say, a five-point scale, that is, he is 
put into the first, second, third, fourth, or fifth class, the classes being 
chosen so that in a representative sample of the population the numbers in 
them will form a distribution that is approximately normal. The success 
of this method obviously depends on the sagacity and experience of the 
examiner : it gives a partially controlled subjective estimate which is 
probably accurate enough for some purposes and very much better than 
a haphazard uncontrolled judgment, but is somewhat unreliable when 
estimates by different people are pooled or compared, as anyone can dis- 
cover for himself by getting estimates made in this way by different 
observers on the same group of people. The method is promising : it 
would be completely successful if the estimates were based on adequate 
descriptions of systematic direct observations of behaviour. 

While it is true that racial inborn tendencies to activity, such as aggres- 
siveness and curiosity, are of great social importance, it is equally true, 
and perhaps more important for practical life, that these tendencies, as 
they appear in man, are ill-defined as regards both the stimuli which excite 
them and the actions in which they issue, and that they are easily directed : 
this is important for social life because it is an essential condition of 
educability. It is in this respect that human innate tendencies differ 
from those of the lower animals. After all, a human community is different 
from a mere animal herd ; even an undisciplined, brutal and stupid mob 
is not quite so stupid as a herd of animals. With rare exceptions all the 
members of an animal herd appear to feel and act in the same way : they 
hunt or browse together, apparently enjoying one another's society and 
protection, but there appears to be very little co-operation between them : 
for this there is needed diversity of ability as well as a common purpose, 
and it is just this which distinguishes a human group from most non- 
human groups, with the possible exception of such groups as those of ants 
and bees, which, however, are physiologically so far removed from us 
that it is futile to attempt to compare their mentality with our own. A 
typical human group is not the squad on the parade ground where every 
man is expected to make the same movement at exactly the same time, 
but rather an army in action where each man's work is different from that 
of his neighbour, but all are interdependent and working for a common 
purpose. A human community, in fact, implies variety of ability and 
effort, organisation, and an appreciation, more or less clear, of relationship 
to the group, and its success depends very largely on its intelligent use of 
its resources. 

Social problems can be approached either from the point of view of the 
individual or from that of the group to which he belongs. Neither approach 
can be consistently maintained to the exclusion of the other, for the 


problems of the individual are the problems of society and vice versa : 
a man is not independent of his fellows ; his social environment is part of 
himself ; his thoughts, feelings and desires vary with his environment ; 
he is socially a chameleon, and any account of him which fails to consider 
his environment is as distorted as is an account of society itself which fails 
to consider the variety of aptitudes, motives, knowledge, manners and 
customs of its members. A social group is a complex structure which 
contains within itself other groups and sub-groups, professional, economic, 
linguistic, etc., whose harmonious co-operation is necessary for the welfare 
of the whole. The big social problem is the dual one of fitting the 
individual into the group and fitting the group to the individual. This is 
essentially an educational problem, one for education in the widest sense 
of the word ; it concerns the home, the school, the university, the press, 
and the broadcasting and other publicity agencies. Its solution demands 
some knowledge of the natural endowment of the individual, his impulses 
and intellectual capacities, and of methods of making the most of them ; 
and this in its turn implies the need for and the use of methods of assessing 
human endowment and achievement. 

I wish to consider especially the scientific assessment of natural capacity 
and some of the problems connected with it, therefore, it is necessary to 
keep clearly in mind the distinction between ability and capacity. Ability is 
actual, capacity is potential. Ability is measured by what can be done here 
and now ; capacity can usually be estimated by what can be done after a 
course of training. Knowledge and skill at games are forms of ability ; 
they depend on certain natural capacities and on upbringing. All 
examinations are tests of ability. 

The satisfactory measurement of ability is always difficult on account 
of the adaptability of the human organism. The measurement of the 
efficiency of an engine is by comparison a very trivial affair. Even the 
best of examinations gives a somewhat blurred estimate of human mental 

The measurement of ability is difficult enough, but the estimation of the 
parts played by native capacity and upbringing respectively in determining 
such ability is very much more so. Innate qualities do not exist in vacuo : 
they exist with reference to certain external conditions and they must be 
diagnosed and measured in relation to these conditions. Every test is 
directly a test of ability, and can be a test of capacity only indirectly. 
Where training has no effect on the expression of a capacity, then a test 
of ability is a test of capacity ; but few, if any, capacities are unaffected 
by training. If opportunities and incentives are so widely scattered that 
they are available for everybody, or if similar training has been given to 
all, then differences in performance indicate differences in capacity ; but 
where the essential training and environmental conditions vary, inferences 
regarding capacity can be made with much less certainty. It is difficult 
to convince oneself regarding the uniformity of external conditions and easy 
to blunder : for example, it is sometimes supposed that mental differences 
between children of the same parents are due solely to genetic differences, 
but some of them are certainly due to variations in the family environment : 
the health and age of the mother are not the same at the birth of each child 


(unless they be twins) ; families move from easy to difficult circumstances 
and vice versa ; parents become more experienced, or more indulgent, in 
the management of their children ; school-fellows vary ; and the children 
themselves vary in their relationships to one another and to the rest of the 
world. The conditions of the experimental chemical laboratory cannot 
be exactly reproduced in the study of human and social phenomena ; we 
have to be content with approximations to these conditions. 

It is necessary to stress these considerations of method, for psychologists 
have hitherto been more concerned to distinguish and measure different 
kinds of ability which seem to be dependent on native capacity than to 
prove their innate basis. An example may make this clear. It is a common 
belief that people differ in respect of mechanical ability, that some have 
little difficulty in understanding the working of a motor car, a dynamo, 
a clock or other piece of mechanism, and that others find these things 
unintelligible ; it is also commonly believed that these differences are 
due to differences in natural capacity. Now, the first thing that must 
be done is to find whether there is actually a positive correlation between 
ability to solve one kind of mechanical problem and ability to solve 
other kinds, for until such a correlation has been established, it is 
futile to talk about mechanical ability. This is the kind of problem on 
which much effort has been spent, especially in this country : but after 
a correlation has been established, it is still necessary to find to what extent 
this ability is the expression of a specific inborn capacity. This more 
difficult problem is usually attacked by using test situations so novel that 
there is little probability of one examinee having any advantage over 
another through familiarity wdth the situation, or by using problems such 
as occur so often that it can be presumed that inability to solve them is due 
ultimately to innate incapacity. In practice, the difficulty, once it has 
been recognised, is probably not so great as may appear, for the opportuni- 
ties of and the need for exercising most of one's native capacities are in 
fact numerous ; a person who fails to pass a properly designed and pro- 
perly conducted test of colour blindness is almost certainly colour-blind. 

All kinds of capacities are being investigated with varying success, and 
it may be possible some day to evaluate mental characters with some 
approximation to the accuracy with which physical characters can be 
assessed. What is needed is more extensive and more co-operative work. 
Most progress has been made in the evaluation of intellect by the so-called 
intelligence tests, largely under the pressure of educational needs. 

Intelligence tests, as developed by Binet, were simply tests of educabi- 
lity, methods of picking out those children who are incapable of profiting 
from the education provided in the ordinary primary school. They have 
done more than this, for they have provided a method of distinguishing 
all degrees of general capacity. In principle they are just a refinement of 
a very common method of estimating native brightness. Binet put to 
children questions about topics which were likely to come within their 
everyday experience ; he found what average children of different ages 
could do and was able to arrange his questions in a scale of increasing 
difficulty ; then he assumed that those who picked up the necessary 
information or acquired the necessary skill or showed the necessary 


intellectual grasp of a problem at an earlier age than the average child 
were bright or intelligent, and that those who were slow in doing so were 
dull ; and subsequent inquiry has shown that his assumption was well 
grounded. The danger here lies in variations of opportunity and training. 
Obviously, a child who has not had the opportunity of using the current 
coinage, or of buying and selling (or playing at buying and selling), or of 
learning to read and write, is at a disadvantage when he is put through 
certain of the Binet tests. This danger, however, is not so serious as it 
appears at first sight, for the social environment of children living in 
civilised communities differs very little in so far as it affects the results of 
the tests, and most of the tests have been chosen so as to minimise the 
influence of the environmental factor. These tests have been analysed 
and improved, and Spearman claims to have shown that they measure a 
central common factor which is intellectual in nature and which, to be 
non-committal and to avoid the ambiguities of everyday speech, he calls, 
not intelligence, but ' g.' 

Mental tests have been used so extensively and in connection with so 
many problems that they have yielded information of social significance. 
They have been been applied more or less carefully, and in forms more or 
less satisfactory, to children of all ages, races and grades of society, and 
the results obtained raise some hope of getting reliable information 
regarding the distribution of intellect in the population as a whole and in 
the various professional, social and economic strata, and regarding its 
connection with fertility, disease, environment, and other conditions : 
they suggest too that at last we may have here a method of getting reliable 
information which will throw light on the puzzling problems of mental 

Repeated application of these tests to the same children suggests that 
mental development, as measured by the tests, proceeds along lines 
analogous to those of physical development and that it reaches its maturity 
about the age of adolescence, as do stature and other physical characters. 
The rate of development is expressed by the ratio of the level reached by 
the individual to that reached by the average of his age — for example, a boy 
of age ten years who has reached only the level of the average nine-year-old 
is said to have an intelligence-ratio (mental-ratio or intelligence-quotient) 
of nine-tenths or 90 per cent. This figure seems to measure some innate 
capacity or capacities, for, though it varies from one person to another, yet it 
remains fairly constant for each individual and appears to be little affected 
by external circumstances. Even serious and long-continued spells of 
illness appear to affect it very little : it is only ailments producing pro- 
gressive deterioration of the central nervous system, especially of the 
brain, such as encephalitis lethargica and some forms of epilepsy, that 
reduce it. Absence from school may interfere with a child's education 
and so promote social inefficiency without affecting his intelligence-ratio. 

Changes in social and physical environment have very little effect in 
modifying this ratio unless they be very great. Residence in an institution 
does not appear to make the ratios more alike than they were on admission, 
and children who have never seen their parents, but have been reared 
in the same homes, show the same differences of intellect as do their 


parents. It is very hard to find the necessary data to decide this question 
of the effect of environment. In Glasgow about 300 children were tested 
at the time of their removal from slum houses to a rehousing area, 
and again about eighteen months later. It had been intended to allow 
an interval of two or three years to elapse between the examinations, 
but so many of the children — about 20 per cent. — left their new homes, 
that the interval had to be shortened. The ages of the children varied 
from five to nine years, an age at which they might be expected to react 
quickly to the new and improved environment. At the second test they 
did on the whole show a just appreciable improvement, their average ratio 
was raised from 90 • 6 to 92 • i . A control group that did not move from 
their slum homes showed no such improvement. The result of this 
investigation is cheering for those who are trying to improve the external 
amenities of life ; but the improvement is so small that it suggests that 
any improvement in the social virtues that is to attend the initiation of 
social welfare schemes may have to rely on the formation of new habits 
of thought, feeling and action, habits that will have to be learned, rather 
than on any improvement in intelligence. 

Here, in the interest of scientific accuracy, a word of caution is necessary. 
While the constancy of the intelligence-ratio raises a presumption that 
this ratio is determined by genetic constitution, it may, however, to some 
extent be partly determined by other conditions, ante-natal, natal, or 
post-natal : birth accidents are certainly responsible for some cases of 
dullness and defect. There are, however, several considerations which 
suggest that in most cases the ratio does measure something that is innate, 
for example, this theory gives the readiest explanation of the fact that 
the correlation between the ratios of identical twins is higher than that 
between fraternal twins. 

As might have been expected, the average intelligence of the children 
of men engaged in professional and skilled occupations is higher than that 
of the children of unskilled workers ; but more interesting and more 
significant for social problems is the fact that the variability within the 
different occupations is so great that there is much overlapping, in other 
words, high-grade intellect is not the exclusive property of any social class 
or professional grade. When more extensive inquiries have been made, 
it should be possible to estimate with fair accuracy the actual distribution 
of intellect in the different social and professional groups. 

Perhaps more important still is the information regarding the distribu- 
tion of intellect through the whole population. Various estimates have 
been made, but the most interesting for Scotsmen is one based on an 
investigation conducted in June 1932, by the Scottish Council for Research 
in Education with the assistance of education officers, teachers and others, 
in which a group test was given to practically the whole of the school 
population in Scotland born in the year 1921 and so of age loh to ii| 
years, 87,498 in all. 

A group test such as had to be used in this inquiry suffers from certain 
obvious disadvantages, the chief of which is that those who are tested 
must be able to read with understanding, and any weakness in this direc- 
tion must affect their replies, but, as all parents are by law compelled to 


make provision for the education of their children at age five, and most 
children begin to go to school at or about that age, any serious backward- 
ness in this direction probably indicates some intellectual deficiency. 
If we assume that the average child can read sufficiently well at age nine, 
then this test, so far as the reading difficulty goes, was suitable for about 
90 per cent, of the age-group that was examined. Another difficulty 
arises from the fact that one set of questions must be given to suit all levels 
of mental development from mental age nine upwards. A few of out- 
standing ability may not have taken the test, others may not have been 
examined fully enough to show all their ability, and none of those so 
markedly defective as to be certified for institutional care were examined : 
the findings regarding those at the extreme ends of the intellectual scale 
are, therefore, somewhat uncertain. Still, the general significance of the 
inquiry is quite clear. 

The average agreed with previous estimates, but the dispersion proved 
to be greater than had previously been supposed — in other words, there 
were more who were dull and more who were bright : about half the 
population examined had mental ratios between 89 and iii (instead of 
between 91 and 99, as was previously supposed), and it was estimated 
that in the whole population between i| and 3 per cent, fell below the 
70 line, that is, below the line which is commonly supposed to mark the 
boundary between mental defect and normality. The average of the boys 
was the same as that of the girls, but their dispersion was greater, that is, 
there were amongst them more who were very bright and more who were 
dull. This distribution has important implications, of which I shall con- 
sider only one, and that very briefly — namely, its bearing on the rate at 
which boys and girls leave school after completing the work of the primary 
school. " 

In Scotland about 44 per cent, of the children of age twelve embark 
on a secondary school course ; of these 70 per cent, begin the second year 
work, 43 per cent, the third, 22 per cent, the fourth, 15 per cent, the fifth, 
and 9 per cent, the sixth. Of those who pass to the ' Advanced Divisions ' 
only 14 per cent, enter on a third-year course. These educational casual- 
ties are due to many causes ; some fall out for economic reasons, others 
find — or think they find — a better preparation for the serious business of 
life elsewhere (and these include some of the brightest), but probably 
most drop out because school seems to be a testing-ground rather than a 
training-ground, a means of picking out the brightest. This suggestion 
finds some support in the fact that it is the duller pupils who drop out 
first, the very pupils who are most in need of training. It has been 
estimated that a boy or girl must have an intelligence-ratio of 115 or over to 
profit without undue strain from a secondary school education ; this may 
be an over-estimate, but there can be little doubt that the average secondary 
school curriculum is unsuitable for the boys and girls whose ratios fall 
below the mean, that is, for half the school population. The bulk of the 
population are of average or nearly average intelligence — about 68 per 
cent, have mental ratios between 84 and 116 — and it seems reasonable to 
ask whether a national system of post-primary education should not give 
first consideration to these rather than to the 16 per cent, at the upper end 


of the scale who have the intellect and temperament that fit them for 
professional and administrative work. 

There is no ground for suggesting that the enormous casualty list of 
the post-primary schools is due to poor teaching : indeed, there is distinct 
evidence that teachers are often attempting the impossible and coming 
very near to achieving it. The fault seems to lie rather in the nature of the 
curriculum, which, though suitable for the upper 20 per cent., is obviously 
quite unsuitable for the middle 60 per cent. It would be interesting to 
know what proportion of the men who sit on Education Committees, men 
who have earned the confidence and respect of their fellow-citizens, can 
pass, or have ever been able to pass, the ordinary School Leaving Certificate 

It may be suggested that the mental development of the duller elements 
of the population ceases at the age of twelve or thirteen and that, therefore, 
they have learned all they can learn by that age, whereas the mental develop- 
ment of their more brilliant fellows continues for several years longer. 
This suggestion is probably incorrect. We know that intellect develops 
more slowly in the dull, so that they fall farther and farther behind, but there 
is some ground for thinking that it reaches its maturity at about the same 
age. Further, the suggestion that the dull child has learned all he can 
learn by the age of twelve or thirteen implies a certain confusion of thought. 
Whatever may be the age at which maturity of intellect is reached, and 
whatever may be the level of development reached, it is certain that learn- 
ing does not cease at that age : it can continue until senile decay sets in. 
The age at which maturity is reached has little or nothing to do with the 
age at which training must cease. 

The open school door is a well-established tradition in Scotland : here 
the gifted child has ample opportunities of developing his talents ; but 
the practice of pushing all children along the same scholastic course 
studded with hurdles which must be jumped, under penalty of being left 
behind, is one which could be improved upon. As the intelligence-ratio 
seems largely to determine scholastic success, and as it remains approxi- 
mately constant, at any rate during school life, and can be determined early, 
it should be possible to organise education on a basis of natural capacity. 
The early ascertainment of capacity and the provision of courses suitable 
for different grades of intellect would do something towards solving the 
problem of the backward child, who is often backward because he has not 
those aptitudes which are needed for success under the existing scholastic 
regime : he struggles to keep up, but ultimately, finding this too much 
for him, he gives up the race, sits by the wayside, and does not use even 
those gifts which he has. It would also make for health and peace of 
mind, for we have sooner or later to learn our limitations, and much 
mischief can be done by assuming that a boy has aptitudes which he does 
not possess. Experience in psychological clinics has brought this out all 
too clearly, for it has shown that many perversities of conduct are due 
solely to social misfits : the dull child of able parents who cannot live up 
to the expectations of his family may run wild, and one who cannot find 
a place in society to suit his talents and training is a potential source of 
mischief. A good deal of distress could be avoided by discovering a 


boy's capacities, general and specific, during his school career, and 
especially when he is about to undertake the serious business of choosing 
a profession. 

Mental tests offer an objective nmethod of approach to the investigation 
of similarities and differences between races and between one generation 
and another, and perhaps also to the very difficult problems of mental 
inheritance. Racial differences have been investigated in countries like 
America and South Africa, where racial problems occupy men's minds. 
In Great Britain, where these problems are not so acute, little attention 
has been given to the subject : there have been some comparisons of Jews 
and Gentiles, of urban and rural populations, and of bilingual and uni- 
lingual communities. In America the testing of a whole army has been 
followed by numerous studies of the mentality of the races, white, black, 
yellow and brown, that constitute the American population. The general 
finding is that the Nordic races are superior to the Mediterranean in test 
performances, and the white to the coloured ; but it should be remembered 
that it is very doubtful whether the mentality of the European races can 
be estimated at all correctly from the samples, some of them very small, 
of their representatives in the U.S.A. Racial psychology will begin to 
stand on a firm basis when the scope of these inquiries has been extended 
and observations have been made on thoroughly representative samples. 
It is a pity that the lead given by Rivers, McDougall and Myers in their 
investigation into the sensitivity of the Murray Islanders and their suscep- 
tibility to illusions has not been followed more energetically. 

These objective methods of investigating mental traits will also provide 
reliable information regarding the problem of the differential birth-rate. 
It has been shown repeatedly that the least efficient members of the com- 
munity have on the whole the biggest families, and this has caused some 
concern, for it suggests a dilution of our intellectual stock-in-trade. 
What is needed is exact information about the intellect of parents, the 
number of births per family, the number of children who survive to 
establish families of their own, and their mental status, but there is very 
little of this. What little there is points to the need for further investiga- 
tion, for it suggests that the casualties are higher among dull children, but 
that the losses are more than made good by the greater number of births, 
and that the problem is not so serious as some have maintained, but 
sufficiently serious to make this and other problems of mental inheritance 
worthy of investigation. 

The study of mental inheritance has suffered sadly from a readiness to 
take over the crude concepts of everyday life : it has been concerned 
mainly with marked abnormalities — mental defect and insanity — and this, 
too, has hampered the study of the subject, for there is widespread 
opinion that these deficiencies and ailments are morally reprehensible— 
an opinion which is rarely expressed openly, but is enshrined in everyday 
speech and conduct. We have outgrown the practice of jeering at physical 
ailments and deficiencies, we care for the maimed, the sick, the deaf and the 
blind ; but dullness of intellect and mental disease are looked at askance, 
though the dullard has no more reason to be ashamed of his dullness than 
the genius has to be vain about his brilliance, both being apparently 


matters of inheritance : moral judgments should concern only the use 
that is made of one's talents. 

One serious difficulty in the study of mental inheritance has been that 
of defining and measuring accurately the characters under investigation : 
for example, mental defect can be, and is, defined in several ways, legally, 
clinically, psychologically, etc. In the legal sense it is a social concept, 
for according to the law the feeble-minded are ' persons in whose case 
there exists from birth or from an early age mental defectiveness so pro- 
nounced that they require care, supervision, and control for their own 
protection or for the protection of others ; or, in the case of children, 
that they, by reason of such defectiveness, appear to be permanently 
incapable of receiving proper benefit from the instruction in ordinary 
schools.' However satisfactory this may be as a legal definition, it is 
useless both biologically and psychologically, for in the absence of any 
definition of mental defectiveness or arrested mental development, it 
means just inability to look after oneself and one's affairs without proper 
supervision. Obviously, inability to look after one's affairs depends 
very largely on the nature of those affairs, and so on one's social and 
physical environment, and since life is easier in some circumstances than 
in others, a man may be feeble-minded in one environment and not in 
another. If social environment becomes more complex and makes higher 
and higher demands on natural capacity, then, unless that capacity 
improves, the proportion of feeble-minded must increase. Some think 
that feeble-mindedness is increasing, and that this is due to differential 
birth-rate, but it is equally possible that the cause lies in the increasing 
coniplexity of civilised life : intellects that could live happily in a simpler 
environment may be finding the complexities of modern civilisation too 
much for them : there can be little doubt that to-day bigger demands 
are being made on children in the ' ordinary schools ' than were made on 
them fifty years ago. 

The influence on this social attitude is reflected also in the way in which 
mental defect, mental disease, criminality, pauperism, infantile mortality, 
and all kinds of organic disease are thrown together in serious investiga- 
tions which purport to be investigations into mental defect, but actually 
are nothing more than inquiries into social inefficiency. It is possible 
that various traits that make for social inefficiency are associated in the 
same stock and may be the result of some common inherent weakness, 
but in the interests of clear thinking they should be kept apart until their 
causal relationships have been determined : a mind diseased may yet be 
capable of brilliant thought, and not all criminals are mentally defective. 

The clinical varieties of mental deficiency which medical men meet, 
mongolism, cretinism, microcephaly, hydrocephaly, etc., are distinguished 
by anatomical rather than by either social or psychological characters. 
Psychologically, mental deficiency is usually defined in relation to per- 
formance at intelligence tests : the legally mental defective usually has 
an intelligence-ratio below seventy, so this figure is often taken as marking 
the line that separates the mental defective from the normal. This is an 
arbitrary method of defining mental deficiency ; it has the merit of pre- 
cision, but it is a precision which may be misleading when we begin to 


investigate its genetic basis, for it is possible that feeble-mindedness may 
be due to one or more of a large number of genetic factors ; there may be 
different forms of feeble-mindedness which are not distinguishable by 
means of intelligence-ratios. 

In investigations into the inheritance of intellect much reliance has been 
placed on rough-and-ready estimates based largely on social and professional 
success. In so far as such estimates are sound, these inquiries show that 
there is a correlation between the intelligence of parent and that of child, 
that bright parents have a higher proportion of bright children and that 
defective parents have a bigger proportion of defective children than do 
normal parents, but they have also shown that normal, even brilliant 
parents sometimes have defective children, that defective parents some- 
times have normal children, and they suggest that the mental deficiency 
of children of either bright or dull parents may be due either to external 
causes or to defective inheritance. The main facts have probably been 
made out, but the details are lacking, and will not be available until exact 
measurements have been made of the mental traits of parents and their 
children under conditions in which social opportunities and encourage- 
ments are equal for all. 

The theories of genetic inheritance which have proved so fruitful in 
the investigation of the physical characters of plants and the lower animals 
have been shown to apply also to human anatomical and physiological 
characters, such as the colour of the skin, stature, and susceptibility to 
disease, and it is probable that they apply also to mental characters ; if 
they do, then it is important that the characters should be distinguished 
and the manner of their inheritance traced out. The difficulties are great 
and for the most part obvious ; one is the difficulty of controlling environ- 
mental factors (the most humane method of overcoming this difficulty is 
to improve the conditions of life so as to give all a chance) ; another 
difficulty is that of finding really satisfactory tests for adults ; but perhaps 
the greatest of all is that of isolating and defining simple mental characters. 
Fortunately the last of these is a difficulty which we can hope soon to 
overcome, for the search for unitary mental traits has been proceeding 
vigorously, and there is now some prospect of diagnosing and measuring 
them, and so putting the study of genetic basis of mental traits on a sound 
footing. This will demand the co-operation on a big scale, not only of 
psychologists, but also of biologists, statisticians, teachers, medical men, 
and others, in which respect the study of mental inheritance resembles 
that of most other social problems. 






The forest with its associated flora and fauna is a highly complex and 
delicately balanced community. In it we find an abundance of material 
upon which much of our prosperity depends. Perhaps the best proof 
of this statement is that the consumption of forest products and the 
destruction of forests is increasing at a rate which, in well-informed 
quarters, gives rise to serious apprehension as to the ability of the forests 
to withstand increasing and continued unscientific exploitation. 

The first users of the forest cared little for its timber. It was used 
principally for shelter and the chase. Later on, as population and settle- 
ment increased, wood was required for housing and fuel. In those early 
times whatever wood was handy and whatever trees seemed suitable to 
supply any requirement were utilised without any thought as to reproduc- 
tion and maintenance of supplies. Thus began the system of forestry 
which at the present day, under more organised methods, is known as the 
selection forest. In the selection forest only trees of a certain diameter 
may be removed, the number and volume of the trees to be felled annually 
or periodically being regulated by measurements of rate of growth in the 
forest. The regeneration is a natural one. Seedlings in due course take 
possession of the spots from which the mature trees have been removed. 
We have thus all ages and kinds of trees in irregular mixture singly, or in 
very small groups , scattered throughout the forest . This system preserves , 
more closely than any other, the conditions which prevail in and characterise 
the primeval forest, T\ has many advantages, but the main disadvantage 
is that the volume, and perhaps the quality of the timber as a whole, is 
not so high as that which can be obtained under more artificial systems 
of forestry. It is here that the main problems in regard to success or 
failure arise. When man interferes too much with Nature, she inevitably 
replies by countering his efforts, unless they comply within certain limits 
to natural laws. The endeavour to grow pure forests of trees on wide 
areas, in dense, uniform, even-aged masses, irrespective of changes in soil 
conditions and climate, is not in accordance with natural laws. In 
coriverting the virgin forest or the selection forest into the modern 
artificial forest, the principal aim was to secure uniformity, and that branch 
of forestry known as forest management came into existence. The 
principal aim in forest management was to obtain the highest yield in the 
shortest time. For the sake of ease in regularity of yield or utilisation, 


the forest was subdivided into working units called compartments, and 
for the sake of uniformity in working, these compartments were made 
as large as possible, with little or no regard to local variations in soil, 
climate and exposure. To a large extent the laws which govern tree 
growth and the possibilities of silviculture were ignored in favour of 
artificial formulae. This trend in forest management naturally led to a 
preference for pure stands — that is, large timber stands of the same species. 
The variation in species and age differences which characterise the 
primeval forest disappeared on its conversion into artificial forest, and 
much of the naturally associated flora and fauna was destroyed. It was 
easy enough to get so far, but difficulties arose when the questions of 
sustained permanent yield, conservation of soil fertility, and the repro- 
duction of this kind of artificial forest came to be faced. It is here that 
the inseparable connection between botany and forestry becomes all- 
important, and I hope to be able to show, by a brief reference to certain 
factors which govern tree growth, how important is the study of botany, 
especially plant physiology, ecology, anatomy, and plant geography, to the 
forester. In the northern hemisphere, from the subtropics to the Arctic 
and alpine limits of forest growth, certain well-defined climatic forest 
zones can be recognised. I here adopt Prof. Mayr's subdivisions : 
the tropical forest zone, the Palmetum ; the subtropical zone of the 
evergreen oaks and the laurels, the Lauretum ; the temperate warm zone 
of the deciduous broad-leaved forest, warmer half, the Castanetum ; the 
temperate warm zone of the deciduous broad-leaved forest, cooler half, 
the Fagetum ; the temperate cool region of the spruces, silver firs and 
larches, the Picetum, the Abietum or the Laricetum ; finally, the cold 
region of dwarf trees and scrub, the Alpinetum or the Polaretum. Each 
tree has a certain natural range of geographical distribution. By ' tree ' is 
meant anything not less than 25 to 30 ft. in height. It has a cold limit, 
a warm limit, and between these an intermediate or optimum region of dis- 
tribution. The factors which make up climate — e.g. such as temperature, 
aqueous precipitations, relative moisture of the atmosphere, and light 
intensity — vary from the optimum to the'cold-and-warm-range limits of 
each species, and the trees react accordingly. The optimum region is 
where the general balance in climatic factors is the most favourable, but 
deficiency in any one growth factor may be made' good or compensated 
for by the more favourable condition of other growth factors. It happens, 
however, that as a general rule, ultimate height growth, diameter incre- 
ment, volume production, form of bole, crown balance and development, 
seed production, and ease and certainty in establishment and after care 
are less troublesome and less costly in the optimum than elsewhere. In 
the southern or warmer climate, rate of growth is, to begin with, quicker 
than in the optimum, but it falls off sooner and, about middle age, rate of 
growth falls behind that of the optimum. Hence to obtain the best 
results in the cultivation of any species we must study its growth and 
habit and form throughout its entire range of natural distribution. This 
brings us now to the question : Is there such a thing as acclimatisation, 
or do trees possess the property of adapting themselves to climatic con- 
ditions which are new or different from any climate within their natural 

K.— BOTANY 197 

geographical limits ? This is a question of considerable scientific and 
economic importance, and concerns both the botanist and the forester. 
A complete survey of the form, habit, and growth of a tree within the 
limits of its natural range shows undoubtedly that each species can 
and does react to different environmental conditions, but opinion is by 
no means unanimous that these external conditions can bring about 
permanent change of an hereditary character. Late and early frosts are 
very troublesome and do much damage in the nursery, young regenera- 
tions and newly planted areas. Attempts have been made to obtain frost- 
resistant trees by collecting seed from the higher and colder elevations 
in the mountains, or from the northern and colder limits, but all such 
attempts have not yet solved the problem as far as frost-hardiness is 
concerned. A short consideration of the behaviour of young plants 
transferred from a colder to a warmer climate, and vice versa, may serve 
to bring out some points of interest in this connection. The four seasons 
vary in relative duration and climatic character according to latitude and 
elevation. This determines the length of the active period of vegetation. 
The critical seasons are spring and autumn. A certain amount of heat 
acting for a certain time is required to awaken the plant into vegetative 
activity, while the fall in temperature at the end of the vegetative season 
controls the rapidity and completeness of ripening and preparation for 
the resting season in winter. As regards the length of the active period 
of vegetation, the controlling factor seems to be the average temperature 
during that period. Further investigation concerning the commencement 
of vegetation and meteorological data are required, but as far as available 
information exists it would seem that each species of tree has an average 
temperature-constant which is necessary during its seasonal vegetative 
period. This period of average temperature is longer or shorter according 
as the tree is on its southern or northern limit . The effect of climate merely 
lengthens or shortens the period of vegetative activity, but the specific 
average constant of the tree is in no way altered. This has been called 
the vegetation therm by Prof. H. Mayr, who states that 14° C. is the 
constant for the larch, and probably also for the spruce. If such a figure 
could be fixed for all trees its value would be great, but this investigation 
necessitates further meteorological data and phenological observation. 
To return now to the question of the transference of a living tree from a 
warmer to a colder climate, or from a sheltered nursery to bare exposed 
planting ground. The chances are that if the transference takes place in 
autumn, the plant will suffer from early and winter frost. The plant 
has ripened off and prepared or attuned itself during the previous summer 
for the approaching winter conditions in general balance with the warmer 
climate, and it is not prepared for the earlier and more rigorous winter of 
the colder climate. On the other hand, if the transference takes place in 
spring after the winter resting period in its accustomed warnier climate, 
it has all the growing period in front of it, in which to adjust itself to the 
new conditions of the changed colder climate. This cannot be called 
acclimatisation, since the changes in the plant itself are not constitutional 
and hereditary. The tree will react to changed climatic conditions 
within its natural limits of distribution, but that is all. If a tree could be 


got to grow normally up to full maturity, and to produce fertile seed, in 
a climate warmer or colder than that of any climate in which it is found 
within its natural range of distribution, then and then only it would seem 
that we could speak of acclimatisation. Trees have a certain amount 
of plasticity and can alter their form, rate of growth, and stature to a 
surprising extent in response to external growth factors, but such reaction 
changes are not permanent and hereditary. Trees vary in their demands 
for light : some are more tolerant of shade than others ; nevertheless, all 
trees will show definite symptoms of want of light if grown in too dense 
shade. Small scanty leaves and needles, thin attenuated twigs, small 
buds, a gradual flattening and broadening of the crown, as well as certain 
internal anatomical changes, are some of the symptoms. In a dense 
forest, trees may pass their lives in varying degrees of overshading and yet 
we find that individuals, or their seedlings if any, are always ready to 
respond by normal growth to increased light intensity. There is no trace 
here of reaction changes to light becoming permanent and hereditary. 
Again trees, some at least, can grow in a fairly wide range of soils, but in 
no case, however gradual the transition, can we induce the deep-sinking 
tap-rooted oak to grow normally in shallow soil. Nor by the reverse 
process can we get the shallow-rooting spruce to form a deeper root 
system by cultivating it on deep soils. In these and other cases, the 
results would be very valuable, but all the tree does is to temporarily 
react in growth and habit according to variations in the soil. 

In forestry the long period which must elapse between the establish- 
ment of a crop and its final harvesting at maturity makes it imperative 
that we should use every endeavour to secure the best types of trees 
suitable for the concrete conditions of the localities in which they are to 
be grown. If a wrong species is chosen at the start — that is, a species 
unsuited to the soil or climate — and in mixed woods, if a wrong combina- 
tion of species is adopted in their formation, then no amount of skill, care, 
and attention on the part of the forester can remedy the defect or make 
full use of the productivity or growth factors of the locality. In cultivating 
his crops the forester must always keep in mind that the ultimate success 
of his eflf'orts is determined by rate of growth combined with the useful- 
ness and volume of the timber produced. This again brings him into 
close contact with the botanist. Among species of trees, apart from 
varieties and sports or mutations, no two individuals are absolutely 
identical, in spite of all outward resemblance. There are differences in 
rate of growth ; commencement and duration and finish up of seasonal 
vegetation ; flower, fruit and seed production. All these may vary in 
time from a few days up to as much as one or two weeks. These differences 
may occur in all soils and in all climates. In both the artificial and the 
primeval forest it can be detected among trees of the same species, growing 
side by side on the same soil and sprung from seed of the same parent 
tree. Individuals from the same seed may show differences in stem 
quality, branch formation and crown balance, due to some internal 
impulse, which is independent of soil or climate. Some individuals 
produce straight cylindrical stems, others bent, twisted and crooked 
stems ; some have an inherent tendency to fork and produce double 

K— BOTANY 199 

leaders — accident to the end bud of a leading shoot may cause double 
leaders, but that is a different thing ; in some the branches ascend at an 
acute angle, in others they tend to spread horizontally at right angles. 
Forking leaders and spreading branches result in defective crown forma- 
tion. Another individual defect is the tendency to produce water shoots 
or epicormic twigs. Unfortunately this individuality does not seem to 
be hereditary, otherwise we could with greater certainty avoid such in 
selecting our growing stocks, but even if this were possible we would 
still have to face the fact that defect in stem, branch and crown and rate 
of growth is not due to individuality alone. Although the characteristic 
individuality remains constant throughout the life of each single tree, it 
does not follow that its seedlings will all possess the same characteristics : 
each seedling will have inherited an individuality, but not necessarily the 
same as that of the parent tree. Nevertheless, rate of growth and 
tendency to late or early vegetation become apparent early in the life of 
the seedling. It is then that the first choice can be made in the selection 
of growing stock. But no matter how perfect the young tree may be, it 
is still subject to the influence of external growth factors, and climate, 
soil and silvicultural treatment can influence its form and growth. A plant 
with individual tendency to slow growth in the colder limits of its dis- 
tribution will be stimulated to more rapid growth in the warmer climate ; 
and, on the other hand, a rapid-growing individual of the warmer climate, 
if transferred to the colder climate, will suffer check to its rate of growth, 
and individuals of normal growth will show the same tendency. Keeping 
these facts in mind, it is easy to see how readily false conclusions may be 
drawn in regard to the actual and relative rate of growth of different 
species. In a community of trees of different species growing on the 
same soil and in the same climate, some may be in their optimum, while 
others may be on the colder or warmer limits of their natural habitats, 
and the soil may suit some species better than others. If such an experi- 
mental plot were established by planting, allowance would have to be 
made for the time taken by different species to get over the check stage 
and to become completely established in their new quarters. Some 
species are quicker to re-establish themselves than others. That is, they 
are more easy to transplant. Then again, trees are not uniform in their 
rate of growth at all ages. We must, therefore, be careful in coming to 
conclusions regarding the growth behaviour of trees. We must seek the 
aid of plant physiology and plant geography if we wish to arrive at reliable 
and useful conclusions. CHmate is after all the main controlling factor, 
and each country must collect its own data. Hitherto, in forestry, we 
have had to rely too much on data applicable to the continent of Europe. 
But with a well-selected series of representative sample plots established 
throughout Britain by the Forestry Commission, the arrears of our 
knowledge in this respect are being made good rapidly. 

Let us now consider the importance of these fundamental biological 
facts to silviculture. For convenience let us divide the life of the forest 
into three stages : the juvenile stage, the pole or stage of most rapid 
height growth, and the adult or tree stage ; and, in order not to obscure 
the main points by unnecessary detail, let us assume that the trees have 


been artificially planted. In all recent plantations there is bound to be 
competition by weed and grass growth ; it may be also woody scrub, stool 
shoots, or interloping and unwanted light-seeded invaders. Cleaning and 
weeding must not be delayed. Careful tending of the young trees should 
begin early. Too often plantations are left to look after themselves 
until they are supposed to have arrived at the thinning stage, when they 
may yield something in the way of returns for the cost of thinning. But 
by this time irreparable damage may have been already done to the grow- 
ing crops. Not only is weeding and cleaning necessary during this period, 
but now is the time to remove and replace trees of inferior growth habit, 
which they begin to show at this early stage. Trees which naturally tend 
to fork cannot be improved by pruning off one of the leaders : forking will 
be repeated later on, as this natural individual tendency persists throughout 
the life of the tree. The same thing applies to all trees with faulty stem 
and crown formation. Among all species, but more especially among 
broad-leaved trees and in particular the beech, it is these heavy-branched, 
spreading-crowned, short-stemmed trees which may forge ahead and 
become predominant in the mature stand at the cost, it may be, of smaller 
but better-formed and more valuable trees. Therefore by the timely 
removal of such individuals, so-called wolf trees, much future trouble, 
cost and loss will be avoided. A certain amount of thinning may be 
advisable before the pole stage is reached, but such operations should be 
confined to completely suppressed, back-going and dead trees and aggres- 
sive, malformed wolf trees. For various species under average conditions 
the period of the pole stage falls between the twentieth and the fortieth 
year. This should be the time of greatest density in the life of the stand. 
The trees have reached the stage of their most rapid annual growth in 
height, and this is further stimulated by the density of the stand, which 
also leads to lateral branch suppression and the cleaning of the stems. 
The density must not be too great, otherwise the trees are liable to become 
too long and attenuated to carry their own weight. It is here the skill of 
the forester is put to the test. Now is the time, and indeed the best 
opportunity, during the whole life of the stand to encourage length, form 
and cleanness of stem. Growth in height is dependent upon crown 
room and light ; and cleanness of stem is dependent upon crown density 
and shade. These two opposing conditions must be so balanced that 
the one will not defeat the object of the other. The thinnings during this 
period will depend upon the planting distance originally adopted and the 
amount of care and attention which has been given to the young growth 
until the branches meet and establish cover or canopy when the thickest 
stage is reached. The maintenance of pole stage density is prolonged 
until the side branches have been killed off, by side shade, up to the 
desired height on the stem. Subsequent drying, decay and fall is merely 
a matter of time. Up to this stage, which will occupy as a general rule 
the first half of the rotation, the main endeavour is to secure a good 
growing stock of tall, straight, clean-stemmed trees. In the second half 
of the rotation, which we have called the tree stage or adult stage, the 
problem in tending should resolve itself into obtaining the greatest 
volume production and quality of timber by encouragement and control 

K— BOTANY aoi 

of diameter increment. The quality of timber depends to a large extent 
upon uniformity in breadth of the year rings and the texture and fibre of 
the wood. This can only be obtained if the growth of the tree itself is 
uniform and sustained. Hence in this latter half of the rotation attention 
must be directed to the crowns and roots of the trees. A gradual removal 
of certain trees and opening up of the canopy gives the crowns of the 
remaining trees more light and room to expand, and this means increased 
food production. These cuttings may be called ' light increment cut- 
tings,' in contradistinction to ' thinnings,' from which they differ in regard 
to their influence on the biology of the stand. The more open growth 
under light increment treatment means fewer trees at maturity, say 
1 60 per acre, but individually they are of greater volume and collectively 
of not less volume than would have been produced by a larger number 
of trees in closely crowded crown competition. The more open stand 
necessitates the retention of some kind of undergrowth or, more commonly, 
underplanting for soil cover and preservation. This method has been suc- 
cessfully practised in Denmark in the case of beech, oak, pine and spruce. 
Under the old system of dense canopy preservation, the intermediate 
yield in thinnings was about 25 per cent, of the final yield. Under the 
light increment treatment the thinnings may amount to 20 per cent, and 
the light increment cuttings to 50 per cent, of the final yield. That means 
in the latter case we have 75 per cent, against 25 per cent, in the former ; 
and if we assume, as we are entitled to, that the value of the material 
removed in light increment cuttings is greater per unit of measurement 
than that of thinnings, and at the same time if we keep in mind the fact 
that the volume of the final yield is the same in both cases, with the 
balance in favour of quality in the case of light increment treatment, it 
will be seen that the treatment increases the yield per acre by well over 
50 per cent. The material removed by the light increment cuttings, from 
the fiftieth year onwards, would be clean grown and straight, and would 
yield all sizes required for telegraph poles, for which the demand has 
always been high. The trees of the final crop would easily be of sleeper 
size — that is the most all-round useful and valuable size for mature timber. 
If this can be done in Denmark, why should it not be possible in our 
equally favourable if not more favourable climatic and soil conditions ? 

All the problems which arise in regard to the care and treatment of 
young, middle-aged and maturing stands of trees, are subjects of the 
study of stand biology, and that system of silviculture which makes the 
fullest use of the external factors of growth, in combination and individ- 
ually, will achieve the best results in the end. The old system of preserving 
dense, uniform, unbroken canopy was unnatural and made it impossible 
to utilise to its full advantage the important growth factor, light. 

In the primeval forest, loss and replacement is constantly going on. As 
each veteran disappears it is replaced by hundreds of seedlings which 
strive and struggle among themselves and against surrounding hindrances 
to reach the light. The struggle is a prolonged one, and many seedlings 
and saplings are killed off in the process. Still, Nature works cheaply if 
slowly, and if we can make use of the free gift she offers in the way of 
natural regeneration, it would be an obvious gain. Nature has produced 

H 2 


and maintains the forest for her own purposes. On the other hand, man 
exploits the forest for his comfort and wellbeing, but if he oversteps 
certain Umits in his treatment of the forest for the sake of extra gain or 
profit to himself, Nature revolts, with the result that man defeats his 
own ends. 

If we are to make use of Nature's free gifts, in the natural regeneration 
of the forest, we must study the natural biological laws under which the 
process can take place. As we have seen. Nature works slowly but surely 
in her conservation of the primeval forest, irrespective of what the utility 
and value of the species may be to man. Man's idea is to grow certain 
species only in massed, even-aged assemblages, in order to obtain the 
maximum amount of timber of the kind, size and quality he wants, and 
if he expects Nature to help in the quick and certain regeneration of these 
artificial woods, at the end of what he considers the most advantageous 
age or rotation, he must make certain provisions in accordance with 
natural laws. This can be done by appropriate silvicultural treatment. 
The trees must be of a suitable seed-producing age, the forest floor must 
be in a suitable condition for the reception and germination of the seed, 
and the conditions of light, moisture and temperature must be suitable 
for the future growth and development of the seedlings. These three 
things are of fundamental importance. In most of the mature and 
maturing woods which have been treated under the strict artificial rules 
of so-called forest management, the question of quick and certain natural 
regeneration often presents insurmountable difficulties. At the time 
required by the working plan the trees may not be in a suitable condition 
for flowering and seeding ; the forest floor, under light demanders, may 
be long past the best conditions for the reception and germination of seed, 
owing to weed growth, and under shade bearers an over-abundance of 
humus, especially raw humus, is equally unfavourable. Many years are 
required to bring the trees and the forest floor into a suitable condition 
for natural regeneration, and if this is attempted over a whole compartment 
simultaneously, the result is seldom satisfactory. In dense-canopied, 
even-aged stands a series of preliminary fellings, called preparatory 
fellings, must be gradually carried out to allow more light and room for 
the selected seed trees, in as even distribution throughout the stand as 
possible, and also gradually to prepare those trees for their more isolated 
conditions and resistance to wind. Under shade bearers this opening 
up of the canopy leads to the disintegration of over-abundant humus by 
allowing more direct access of precipitations and light, and also by increased 
aeration due to the freer circulation of the air. Under light demanders 
it means costly artificial surface and soil preparation. In either case, 
when the soil is in its most suitable condition a further felling is made 
either immediately before or during a seed year, if one should happen to 
occur at the right time ; if not, it means delay and the soil gets past its 
best condition for seed germination. Even if a seed year should occur at 
the right time, there are many climatic and weather conditions which may 
prevent complete and uniform regeneration over the whole area : only 
patches of seedlings may occur here and there. This means waiting for 
a second seed year, which may be five or ten years hence, meantime 

K.— BOTANY 203 

further deterioration in soil conditions and risk of storm damage to the 
seed trees which were isolated so late in life. The only alternative in 
such cases is to complete the process by clear cutting and artificial planting, 
and this is what generally occurs. If, as sometimes happens, by good 
luck the regeneration is sufficiently complete to provide a new crop, 
then the old trees are gradually removed in a series of falls, called the 
final fellings. But the whole process known as the uniform or compart- 
mental system is slow, uncertain and risky. To lessen the risks of failure 
and loss by opening up large areas at one time, numerous modifications 
have been introduced into the practice of forestry. The underlying idea 
was to confine natural regeneration to smaller areas, in the shape of groups 
or strips, with peripheral extensions of these as they became regenerated. 
By selecting the shape, breadth, line and direction and sequence in time 
of the strips, a considerable amount of success has been achieved. Strips 
or groups may be clear felled or a certain number of trees may be left 
to provide seed and to protect the young seedlings. In the former case, 
protection is supplied by the adjacent stand of mature trees, and seeding 
takes place from the side. Various and numerous combinations of the 
uniform, group and strip methods have been tried, with more or less 
success, under certain favourable locality conditions. 

The main trouble is that in the past the woods have not been managed 
with a view to natural regeneration ; under light increment treatment, 
the more open canopy and crown room enables the trees to respond almost 
immediately to the influence of the seed felling. The under planting 
which has kept the soil in a favourable condition for seed reception can 
be dealt with easily, and after the seedlings have appeared, the old trees 
may be removed at one felling instead of gradual removal over a protracted 
series of years, as a certain amount of undergrowth can be left to provide 
shelter and protection to the young trees. 

The biology of the large pure stands of timber must obviously diflfer 
from that of large mixed stands, consisting of two or more species, as 
generally prevail in the primeval forest. To establish artificially or to 
regenerate naturally a mixed stand of timber which will have the desired 
ratio of species at maturity, involves much labour and cost, and the attempt 
is not always certain of success, except perhaps under the selection method 
of treatment. To get over the difficulties associated with single stem 
mixture, other forms have been tried, such as planting the different species 
in alternate rows, bands, strips, clumps and groups, but still this does not 
quite solve the problem. It is all right for the trees in the centre of the 
group or strip, but those on either side at the contact margins are apt to 
become bent and branchy ; further, each of these numerous units requires 
individual attention, and this is not compatible with economic manage- 
ment. It is possible with certain light-demanding and shade-bearing trees 
to form mixtures in which the crowns of the light demanders form a kind 
of upper storey, with those of the shade bearers beneath ; but such 
mixtures are very difficult to bring through the pole stage of growth 
unless the light demander happens to find itself in its optimum conditions. 

The problem may now be stated : How are we to manage and develop 
our woods so that the demands for different species of timber, sorts and 


sizes of the highest quaUty possible, may be met, and adequate provision 
made for the regeneration of these woods, without loss of time and with- 
out deterioration to the productive capacity of the soil, and at the same 
time make as full use as possible of all growth factors, without interfering 
too much with the natural laws of forest growth ? This is a big and im- 
portant question, and in my humble opinion the solution suggested by 
Prof. Heinrich Mayr of Munich seems to fulfil all these requirements. 
His suggestion was to compromise between the economic objects of man, 
the user, and the natural laws which govern the designs of Nature, the 
producer. He suggested that the forest should be made up of small 
compartments, i to 8 acres, each compartment to consist of one species. 
These small pure compartments would be scattered as much as possible, 
so that adjacent compartments would differ in age and species. We 
would thus have a forest of mixed small compartments differing in age 
and species. Due attention would be given to assigning each species 
to its most suitable soil and exposure. Where conditions were such 
that only one species would grow satisfactorily, owing to physiographical 
conditions, such as in the mountains, pure sand, wet soils, cold climate, 
the compartments may be larger, about 14 acres, if desired, and the 
same species may adjoin each other, but the age difference between 
adjoining compartments should be varied. The present division of the 
forest into large compartments need not be done away with, but each 
large compartment should be subdivided into sub-compartments — small 
compartments — which would become permanent units of management. 
Each small compartment treated from its earliest stages with a view to 
natural regeneration would, under later light increment treatment, always 
be in such a condition that natural regeneration could be imitated without 
long and costly preparation. The process could be completed within 
five years, and the risks of failure would be small compared with those of 
large contiguous areas, where ecological and biological conditions vary. 
In the small stand, the more open stand of the trees under the light 
increment treatment and the shelter afforded by adjacent stands would 
eliminate the necessity of the risky and lengthy preparatory fellings — 
a seeding felling and one final felling would suffice. Thus, as Prof. Mayr 
claims, natural regeneration could be made easier, speedier, and safer. 
The danger and risks from wind, fire, insect and fungus epidemics would 
be lessened ; the varied demands for different kinds, sorts and sizes of 
timber could be more easily met. The forest community as a whole 
would approximate that of the primeval or natural forest, and the 
productivity of the soil would at least be preserved, if not improved. 

To turn now to another aspect of the forest as a living community of 
plants and animals. The forest is perennial, and less subject to seasonal 
changes than other forms of massed vegetation. The tree stems raise 
their crowns of branches, twigs and leafy canopy high above the forest 
floor, and this has a marked influence on the light, temperature and moisture 
conditions within the forest. Light is subdued, but temperature and 
moisture are both increased, and this, combined with a relatively still 
atmosphere, render the conditions within and under the crowns of the 
trees quite different from those of open country. Under the leafy canopy 

K.— BOTANY 205 

the soil surface vegetation consists mainly of shade-loving shrubs, herbs, 
ferns and mosses. The leaf fall from the trees and the general organic 
remains, along with that of the undergrowth, produce a soil covering of 
disintegrating organic matter, generally referred to as the humus layer. 
This layer acts like a mulch and ameliorates and conserves soil moisture 
and temperature. The tree roots penetrate more deeply into the sub- 
stratum than most forms of other vegetation, this increasing its aeration, 
permeability, and water-holding capacity. Although it has not been 
definitely decided whether forests increase the rainfall or not, it can be 
claimed with every justification that the forest is of great importance as 
a conservator of water and as an equaliser in the drainage of the land. 
Where no forests exist in the upland or collecting regions of watersheds, 
the rain falls unhindered, beating the surface hard or eroding it down to 
the bare rock. There is nothing to check the downward rush of water, 
which collects into mountain torrents which gush unbridled into the 
main rivers and streams, causing them to become swollen and flooded. 
These in turn race through the fertile valleys to their outlets, tearing down 
and overflowing theiir banks. The damage done by severe and sudden 
floods to roads, bridges, agricultural crops and stock, including human 
habitations, is well-nigh incalculable. Nor does the matter end there : 
millions of tons of valuable soil is washed away in these turbulent floods, 
and deposited as barriers in the river beds or in the sea at the river bar. 
Harbours and docks at the outlet of our main rivers become silted up 
with mud and debris : this in turn — apart from the loss of soil — involves 
costly dredging operations to keep the navigation channels clear. 

Where forest exists in the upland districts or collecting ground of the 
water, rivers are more uniform in their flow, year in year out, and carry 
much less silt and debris. The crowns of the trees break the force of the 
falling rain ; the humus layer on the forest floor has an enormous water- 
absorbing capacity, and when saturated it allows the water to percolate 
slowly into the deeper loosened layers of mineral soil, from which in turn 
it gradually finds its way into springs and watercourses. Further, the 
influence of the forest is such that the melting of snow is more gradual 
and water is slowly absorbed and held, thus again avoiding floods. The 
forest regulates the off -flow of water after heavy rains or melting snow. 
This water is fed into springs and watercourses more gradually throughout 
the year, thus preventing floods at one season and equally serious drought 
at another. As regards the influence of the forest in lessening the 
destructive effects of cloudbursts, we have it on the authority of Fernow 
that : ' The Forest litter, the moss-covered leaf-strewn ground, is capable 
of absorbing water at the rate of 40,000,000 to 50,000,000 cubic feet per 
square mile in 10 minutes, water whose progress is delayed by some 
12-15 hours after the first effects of a heavy freshet have passed.' I do 
not claim that afforestation or forest conservation in the high ground and 
valley slopes will entirely prevent floods and drought, but what the 
forester is doing or leaves undone in the remote hinterland will go a long 
way to check or ameliorate the evil effects of both. I have referred to 
these facts because the biological influence of the forest is so important 
and widespread in regard to drainage and water supplies. 


As a form of vegetation which rises high above the surface of the ground, 
the value of the forest in breaking and tempering the effects of the cold 
winds has long been recognised and appreciated by the agriculturist. 
An adjacent sheltering strip or even clump of trees exercises a marked 
influence on farm crops and pasture lands ; stock also thrive better in the 
shelter afforded. The trees afford shelter and at the same time exercise 
a very marked influence on the rate of evaporation of moisture from the 
surrounding area ; this influence, in lessening the surface velocity of the 
wind and rendering it more moist, may be noted up to between 300 and 
400 ft. from the trees, but the distance varies with the height of the 
trees. In spring the pasture is earlier and more abundant, while in the 
autumn it remains longer green. The question of a reasonable balance 
between forest and grazing land is one of considerable biological and 
economic importance. 

In the time available it is obviously only possible to refer to a few 
aspects of forest biology. I would have liked to say more about the 
importance of plant geography, but probably enough has been said to 
indicate how important this branch of botany is to forestry. Plant 
physiology and ecology are also of the highest service in the applied 
science of forestry. Plant anatomy is likewise of great value in wood 
technology, timber identification, seasoning, testing and preservation, 
which are all very materially helped by a knowledge of wood anatomy. 
It is needless to say that without the help of the botanical systematist 
the forester would frequently find himself in serious difficulties, while 
the mycologist is equally indispensable. 

Many biological problems of first-class importance in silviculture 
have still to be tackled, and it is to botany that the forester must look for 
their ultimate successful solution. 





H. T. TIZARD, C.B., F.R.S., 


This section of the British Association for the Advancement of Science 
rejoices in the impressive title of ' Educational Science.' To judge from 
its past proceedings the range of its interests is so prodigious as to 
daunt one like myself, who neither pretends to be an educational expert 
nor belongs to the large body of enthusiastic amateurs who hold such 
pronounced and varied views on the education of other people's children. 
The only way in which I can hope to justify my selection this year as 
President of the Section, an honour that I deeply appreciate, is to devote 
most of my address to matters of which I have first-hand knowledge and 
experience. If I occasionally appear to be too didactic, please attribute 
this only to my desire not to be long-winded ; while if, in speaking of 
Universities that I know best, I make remarks that are not applicable to 
Scottish Universities, please forgive the ignorance of a Sassenach. 

We have lived, and are living, in times of absorbing interest. I was 
at a public school at a time when to take an interest in science was held to 
be a sign that you were not quite a gentleman. At my school there were 
' close ' scholarships to Oxford and Cambridge, but I was soon given to 
understand that these were not available for boys on the science side. 
They were made so available soon after I left, at about the time when 
baths were first installed in college — an interesting coincidence of sanity and 
sanitation. It does not seem so very long ago to me ; yet the changes that 
have taken place since then are so profound that it is now considered quite 
respectable to be a scientist, even at a public school. I wonder if any 
generation will ever see such far-reaching changes as we have seen in so 
short a space of time ! When I reflect that our better conditions of life, 
better health, greater opportunities for interesting and useful work and 
recreation, have been mainly brought about directly or indirectly as the 
result of scientific education and research, I wonder that some distinguished 
men have fallen into a gentle melancholy with advancing years, and tend to 
dwell in public and in private rather on the mistakes than on the achieve- 
ments of this brilliant age. Mistakes there must be when progress is 
rapid. One difference between these and other times within living 
memory is that a few years of madness have revealed weak spots in the 
structure of civilisation that would otherwise have been discovered only 


after many years of slower progress ; just as a motor race shows up in a 
few hours unsuspected defects in the inechanism of a car. The economic 
foundations of industry and trade have not suddenly become unstable and 
weak : they always were so, but we did not observe it. The gold standard 
has not suddenly become imperfect ; its imperfections have been made 
obvious. Human nature has not changed for the worse ; but we are all 
more conscious of the deficiencies of others than we are in placid times. 
I think we should do well to emulate the robust spirit of the practical 
engineer, who after a partial failure spends little time in wondering whether 
his work is really worth while, but uses his experience to make a better 

The great practical achievements of science have naturally brought 
about a change of attitude on the part of the general public towards 
scientific education and research. Everyone believes in scientific research, 
without knowing quite what it means. Thirty years ago a member of 
Parliament advocating the need for scientific research would as likely as 
not have emptied the House : to-day I should be inclined to say of the 
House of Commons that it is not sufficiently critical of expenditure on 
research, because its faith is greater than its understanding. A scientific 
man need no longer spend tedious hours in advocating the value of a 
general scientific education, because he has many convinced and influential 
supporters who themselves never had any scientific education. The chief 
problem now is to define what we mean by * a general scientific education,' 
and on that there is little agreement. Should it include biology, and if so, 
of what kind, and to what extent ? How rnuch laboratory work should 
be done ? How is it possible, in a few years, to give a boy some insight 
into the beauties and wonders of the physical and biological sciences, 
some real conception of law and order in the universe, some true apprecia- 
tion of scientific method, without running the risk of leaving him with a 
mere smattering of uninspiring knowledge ? I do not propose to offer 
any advice on these important matters to schoolmasters, because I 
honestly believe it would be of little value to them. Further, I do not 
think the questions can be finally answered by discussion, but by 
experiment ; and I am content with the thought that the experiment is 
being tried in different ways in a number of schools, by enthusiastic 
science masters, who meet every year to exchange views and experiences 
and to keep their own knowledge up to date. After all we must remember 
that the teaching of science at schools has not centuries of experience 
behind it, and we must expect imperfections. Classical education has a 
much longer history. The value of the Classics lies not so much in the 
intrinsic merits of Latin and Greek, nor in the importance of the opinions 
and work of people who lived in a primitive state of society thousands of 
years ago, and who, in the words of an old friend of mine, ' had access to 
so little information,' as in the way it is taught ; and the way it is taught 
is the result of hundreds of years of ruthless experiment on unhappy boys ! 
Science masters, who are intensely self-critical, so much so that they 
invite, and get, the criticism of others, must often envy the calm con- 
fidence of their classical colleagues, who teach admirably a subject that is, 
to all intents and purposes, a closed book, while they, on the other hand. 


have constantly to be adapting their instruction to the advance of know- 
ledge. They can take heart from the thought that theirs is a living sub- 
ject, which will assuredly become the basis of all good education as time 
goes on. I cannot imagine the Classics being widely taught in 500 years' 
time, and I cannot imagine a time when science will not be taught. A 
young child is naturally scientifically minded : he makes experiments ; 
he wants to know ' why ' ; it is only as he grows older that he gradually 
loses his eager curiosity, because his parents, in their ignorance, are 
unable to satisfy him. But the inability of parents to provide reasonable 
answers to the simplest questions of children is gradually disappearing 
as the result of better education and the provision of better and more 
accessible scientific and technical literature ; every year the chance 
becomes greater that the inquiring minds of children will be stimulated 
and not stifled. No scientific man desires to see scientific education 
pushed to the neglect of literary studies ; all of us recognise that a properly 
balanced diet for the mind is as important as for the body : what we do 
think is that science, well taught, can supply all that is best in the classical 
tradition ; can ' teach accuracy and exactness ; can give a discipline in 
clear thinking ; can teach boys to recognise differences in things which 
seem alike ; can brace with its difficulties minds that are not afraid of 
difficulties ; can inspire with its beauty minds not insensitive to beauty ' — 
to quote the recent words of the Headmaster of Rugby in praise of 

The general growth in the teaching of science at secondary schools has 
naturally been accompanied by a great increase in the number of students 
of science at universities. There are now about 50,000 students in the 
universities of Great Britain, half of whom are studying some form of 
natural science. This growth has been only made possible by the pro- 
vision of public money ; all universities in this country are now dependent 
on the taxpayer and ratepayer. The State alone provides annually for 
university education a sum nearly ten times as great as was provided 
before the war ; and local government bodies, in addition to their direct 
contributions, find large sums for maintenance allowances to students. 
The student of science has to be provided with laboratories, where he 
consumes power, heat, light, and expensive material. He is in conse- 
quence the most costly of university students : I estimate that the public 
expend, in one way or another, nearly ;£200 a year on each student of science, 
with the possible exception of students at Oxford and Cambridge, who 
are more richly endowed from private sources. 

This public expenditure has laid additional responsibilities on the 
teaching and administrative staffs of universities. Most of us are now in 
the position of Public Trustees ; we have to examine our expenditure 
more scrupulously than we should if we were not (indirectly) responsible 
to the public, and we have continually to ask ourselves whether additional 
expenditure can be justified. There was a time when it was feared that 
the autonomy of universities would disappear if the State provided a large 
measure of financial support ; that this fear no longer exists is due to 
the work of the University Grants Committee. I shall have reason to 
base some of my subsequent remarks on extracts from the reports of the 


University Grants Committee ; at this point, however, I should like to 
say a few words about its general influence. 

There will be general agreement that the establishment of the Univer- 
sity Grants Committee was an event of first-class importance. So far as 
I know, it has no counterpart in any country. By a stroke of administra- 
tive genius, most of the fears with which universities naturally regard any 
suspicion of interference by Government departments were dissipated. 
Everything that has happened since has strengthened the relations between 
the Committee and the universities. We read the reports of the Com- 
mittee with profit, look forward to the visits of its members with pleasure, 
and welcome their criticisms and advice. We find ourselves masters in our 
own houses ; untrammelled by political influence ; trusted guardians of 
public money. We are so used to this happy state of affairs that it needs a 
convulsion in a foreign country to make us realise our good fortune. 
Universities owe a great debt to all the distinguished members of the Com- 
mittee, and especially to the two Chairmen and to the late Secretary, Mr. 
A. H. Kidd. The sudden death this year of Sir Walter Buchanan Riddell 
came as a great shock to many of us. That deeply loved and trusted man. 
Sir William McCormick, set a standard difficult for others to live up to ; 
but when Sir Walter Buchanan Riddell, who was the first Secretary to 
the Committee, was appointed to succeed him, everyone felt that the 
happiest choice had been made. The few years that have passed since 
his appointment have been all too short for the full exercise of his con- 
structive influence, though long enough for universities to realise that in 
him they had a worthy successor to Sir Williarn McCormick. Mr. A. H. 
Kidd, who died a year ago, was an old friend and contemporary of mine 
at Oxford. He was a man of rare distinction of mind and charm of 
character, who was prevented only by continuous ill-health from reaching 
one of the highest positions in the Civil Service. He used his great powers, 
quietly and unostentatiously, to promote university education. I feel 
sure that I shall be forgiven for digressing a little from my subject in 
order to express, very briefly, our gratitude for the work of these men. 

I have already referred to the high cost of teaching science at universi- 
ties. I find it useful to look at problems of education from a financial 
point of view : it clears my mind, without, I hope, clearing it altogether 
or destroying my ideals. Take the position of the public schools as an 
example. There is much criticism of the public schools. We hear that 
they do not win a fair proportion of scholarships at the universities in 
comparison with grant-aided secondary schools ; that their hold over the 
higher division of the Civil Service is disappearing ; that altogether they 
are behind the times. Consider, however, their financial position. Most 
of them get no grant from public funds : they have to rely on endowment 
income (often small) and on the fees paid by parents. Many of them 
doubtless have their financial anxieties ; but at least they are solvent. It 
is indeed remarkable that through these years of serious industrial de- 
pression the public schools have remained full to overflowing ; tens of 
thousands of parents have thought it worth while to sacrifice a large part 
of their income, or to diminish their capital, in order to give their boys the 
benefit of a public school education. It may be said that their action is 


partly dictated by snobbery, and partly by the feeling that the market 
value of a man is increased if he is known to have been educated at a 
public school. Snobbery doubtless has some influence, but surely very 
little ; and if the market value of a public school boy is on the average 
higher than that of boys educated at grant-aided secondary schools, 
it is not merely because of the reputation of his school, but because he 
learnt something there that he could not get elsewhere. The obvious 
answer of the public schools to all general criticism is that it is not com- 
pulsory for anyone to send their boys to them. So long as they perform 
a useful function they will continue to exist and to be solvent ; when they 
cease to provide a better all-round education than other schools they will 
die a natural death. 

There was a time when some universities were in the same happy posi- 
tion as the public schools. As self-supporting institutions they could go 
their own autocratic way, impervious to outside criticism. They took 
special measures to encourage the influx of students of outstanding 
ability ; and as for the rest, the chief conditions of entry to a college were 
that they should be capable of paying highly for the privilege, and of 
passing a very elementary examination — often waived for men of noble 
birth or athletic renown. Those were the days when a headmaster is 
reported to have advised parents to send their sons to Oxford or Cam- 
bridge on the grounds that they would there make a number of very 
desirable acquaintances, and be kept out of mischief during a dangerous 
period of their lives. 

The chief advantage of this complete independence was that it en- 
couraged individuality in teachers and students ; the chief disadvantage 
of the many reforms that have taken place since then, resulting finally in 
financial dependence, is that they tend to discourage individuality. Is any 
university school of physics or chemistry, for instance, noticeably different 
from any other ? In London we do our best to encourage individuality 
by having different final examinations for certain degrees in different 
colleges ; at the Imperial College the B.Sc. degree of London is awarded on 
the results of college examinations in which outside examiners take part. 
The advantage of this is that it is not necessary to bring our syllabuses 
and methods of teaching exactly into line with those of other London 
colleges. There is, however, a strong but fortunately not a majority 
body of opinion in the university in favour of common examinations, 
chiefly on the grounds that they are easier and cheaper to organise. I hope 
it will be long before our measure of independence disappears. I would 
go so far as to say that individuality, which should be a natural growth 
in universities, needs to be deliberately encouraged in these days of 
committee rule. Any step taken to discourage it is a step downwards. 

Oxford and Cambridge still have considerable freedom of action, partly 
because of their old traditions, but mainly, I think, because of the financial 
independence of the colleges. I do not know how far the ancient univer- 
sities of Scotland preserve their own complete independence, but, in spite 
of apparent autonomy, the newer universities of England have not quite 
the same measure of freedom as Oxford and Cambridge. Their income 
can normally only just cover their expenditure, for if the margin were 


great, it would mean that they were receiving too much from the pubhc. 
The close budgeting that is necessary inevitably restricts freedom of 
action. For instance, if the number of students be reduced, the loss in 
fee income may convert a slight surplus into a deficit for some years, as it 
is impossible to reduce expenditure on staff and equipment correspond- 
ingly quickly. On the other hand, the immediate effect of increasing the 
number is to make the balance sheet look healthier : until a strong case 
can be made for more expenditure on staff and buildings, which eventually 
results in increased cost to the public. It is unfortunate that there is 
quite a strong financial incentive to increase the number of students at 
universities ; it looks so well on paper. Yet I feel that the time has come 
when we ought seriously to consider whether a further increase can really 
be justified. The public, I take it, is not interested in the individual ; if 
the taxpayer thinks at all about his contribution to university education — 
and I do not suppose he does, as it is so trifling compared with other 
public calls upon his income — he must come to the conclusion that the 
object of his contribution is to help students who will subsequently be of 
more value to the nation if they spend three or more years of a sheltered 
existence at a university, than if they were obliged to earn their living on 
leaving school. Where shall we draw the line ? 

There are many students who occasion no misgiving. They are those 
who are capable of teaching themselves, given the opportunity. To them, 
and ideally to all, the attitude of the university should be this : We give 
you here the opportunity of learning, if you wish to, from masters of their 
subjects ; we give -you access to well-equipped libraries and laboratories ; 
and opportunities for learning from each other. We help you to help 
yourselves. What use you make of these opportunities depends upon 
yourselves. If we find you do not, or cannot, make good use of them, 
you shall go, and make room for others. Broadly speaking, I believe that 
is the right attitude. In such an atmosphere, learning, individuality, and 
self-reliance flourish ; and public expenditure is worth while. Judged 
from this standpoint, I have little hesitation in saying that universities are 
too full. As a result the tendency is towards over-organisation, too little 
latitude, and too much spoon-feeding. The more distinguished the 
teacher, the more he is tempted away from teaching and research : his 
presence is required on committees. In London we elderly gentlemen 
even organise students' athletics ; and official debates take place on such 
important questions as the site and finance of a university boat club for 
women. The wider we fling open the doors to a university, the more 
will such organisation be necessary, and the worse will be the conditions 
for the best teachers and students. 

There is another, more practical, way of looking at this question of 
numbers. Do graduates find any difficulty in getting suitable employment 
at the end of their university career ? Perhaps it is hardly fair to attempt 
to draw a definite conclusion from experience during the last few years ; 
but it does form some guide to policy. The majority of students of the 
Imperial College enter some branch of industry ; and most of them, even 
in these difficult times, have succeeded in finding posts within six months 
of leaving the college. Whether they are all suitable posts for university 


graduates, I doubt ; many of them could equally well and perhaps better 
be filled by students from technical schools. I do not think this is an 
experience confined to the Imperial College ; indeed, to judge from in- 
formation I have had from other sources, I should say that we had been 
on the whole more fortunate than other similar institutions. 

Different branches of industry seem to hold different views about the 
value of a university education in science. Compare, for example, the 
present position of the university chemist with that of the engineer. The 
chemical industry calls out for university graduates ; every year you will 
find leading representatives of the prominent firms in the universities, 
looking for recruits. It is not demanded of the recruit that he should 
possess a large stock of practical knowledge ; it is expected of him that he 
should have high scientific qualifications, and that he should have shown 
aptitude for independent work.^ The attitude of the engineering industry 
seems different. In some branches of the engineering industry the 
university graduate is as welcome as he is in most branches of the chemical 
industry ; but in many he seems to be regarded as a misfit. One pro- 
minent manufacturer, the creator of a great industry, who has lived most 
of his life near a university, has been known to boast that he employs no 
university graduates. Many employers seem to expect of an engineering 
graduate a degree of acquaintance with practice that they have no right 
to expect ; for we do not pretend to teach at universities what can be 
better learned at the works. Finally my experience is that too many 
engineering graduates find themselves in blind alleys from which they 
have little opportunity to escape. 

Where does the fault lie ? With the employers or with the universities ? 
I think there are faults on both sides : let me leave the faults of the em- 
ployers for others to discuss, and for time to correct, and deal with some 
of the problems of university schools of engineering. 

Engineering is a branch of technology. The object of a university 
school of technology is to seek to advance and apply scientific knowledge 
for practical purposes. Many people at universities still think there is 
something derogatory about this ; they would prefer that instruction 
and research had no relation to the practical needs of mankind, forgetting 
perhaps that most if not all university education started with a practical 
aim in view, or we should have had no schools of law or medicine. 

Let me quote from the report of the University Grants Committee for 
1921 : ' There is nothing in the nature of technology which makes it 
necessarily unsuited to the methods and spirit of university work. . . . 
The very fact that this alliance [between science and industry] is intimate, 
and the border line between pure and applied science difficult to define, 
involves serious difficulties for the universities. We cannot ignore a certain 
tendency to lay an exaggerated emphasis on utilitarian applications in 

* In his Presidential Address to Section B in 191 3 Prof. W. P. Wynne said : — 
' Once again the cry has been raised in the press that chemists trained in our 
Universities are of little value in industrial pursuits ; they are too academic ; 
they are not worth their wage — little as that often is, whether judged by a 
labourer's hire or the cost of a University training.' Evidently some progress 
has been made ! 


some technological departments. ... It would be in the worst interests 
of industry itself if the study of scientific problems were to be approached 
by the universities from the point of view of immediate material advantage. 
. . . We believe it to be urgently necessary, therefore, to define more 
closely the aim of university courses in engineering and technology, and to 
difi"erentiate such courses from work properly assignable to technical 

With these views and criticisms, I heartily agree : what is more to the 
point, perhaps, is that they have, I feel sure, the approval of many univer- 
sity professors of engineering, who would say that their aim is to teach 
principles, not practice ; to train the mind without neglecting the training 
of the hand ; and to send out ultimately from the university resourceful 
men whose education and outlook enable them to attack with confidence 
the new problems that are perpetually arising in the engineering world. 
A university school of engineering should be primarily a school of what is 
now called classical physics, the principles of which are illustrated in 
lecture room and laboratory by examples and problems which have a 
special bearing on engineering. To a less extent it should be a school of 
mathematics and chemistry. I think we are inclined, at universities, to 
value too highly mathematical ability in an engineer. Many students 
have obtained first-class engineering degrees mainly through their mathe- 
matical ability ; but such students do not necessarily become first-class 
engineers, and some of the most original and distinguished engineers are 
poor mathematicians : one of whom I can think had to be content with 
a pass degree at his university. 

I am inclined to think that there are too many students of engineering 
at universities. There are many young men who have a practical flair, 
but who cannot respond to the kind of teaching that I believe to be appro- 
priate to the university. Their presence at the university, where everyone 
wishes to do their best for them, inevitably encourages the introduction 
of practical instruction of a kind more suited to technical schools. The 
university school is then trying to fulfil two functions, and runs the risk 
of failing to fulfil either well. Such men often have qualities which will 
carry them far in the engineering profession, which is large and varied 
enough to provide opportunities for men of very different types, but they 
are really out of place at universities, and would be well advised to take 
advantage of some of the excellent schemes now in operation for combined 
training at works and technical schools. 

The same is true, T suggest, of other branches of technology. The chief 
aim of a university department of technology should be to produce the 
leaders of the profession. The best education for potential leaders is not 
the same as the best education for the rank and file. It cannot be expected 
that all university graduates will become leaders ; but at least we ought 
to look for, and develop, the qualities of leadership. This we cannot do 
if we fall into the temptation of mass production. 

Highly specialised schools of science at universities present somewhat 
different problems. How many students, for example, should one 
encourage to study subjects such as mining geology, biochemistry, plant 
biology, entomology, when the demand for such specialists may be small 


and fluctuating ? Take the biological subjects as typical. Two years 
ago there was published the report of a strong committee appointed by 
the Government to advise on the education and supply of biologists. 
Their first two conclusions were : 

(i) There is a substantial and growing demand from Government 
Departments for biologists for service in this country and in the colonies, 
and there is a small but probably growing demand for biologists from con- 
cerns engaged in agricultural production overseas and in industry in this 

(2) It is not possible to state this demand in precise arithmetical terms, 
but the supply of candidates for biological posts is not equal to the present 
demand, and even in those branches where the supply is sufficient in 
quantity it is deficient in quality. 

Whatever evidence in support of these conclusions existed when the 
Committee started its inquiry in 1930, I think it safe to say that even 
before the report was published these conclusions were falsified by events. 
The fact is that some ten to fifteen years ago there was a sudden demand 
for biologists to meet the needs of new and of rapidly expanding research 
organisations at home and in other parts of the Empire. Highly trained 
biologists of all kinds were sought for, and naturally could not be found 
in sufficient numbers, for universities cannot suddenly increase the rate 
of production of first-class specialists. Some of the new organisations 
made the mistake, therefore, of accepting less able and less highly trained 
men, which is bad for the individuals concerned and for the organisations ; 
for, if a first-class man is really needed, it is better to wait until one is 
available than to make shift with a second-class man, who runs the serious 
risk of having his livelihood taken away from him later on. 

Then came the world depression, and far from there being an increased 
demand for ' industrial ' biologists in recent years, there has been a con- 
traction. This is a serious state of affairs for universities. It would be a 
fatal policy to encourage young men of good ability to spend long years in 
specialised study, only to find at the end that there was no demand for 
their services, or that what little demand there was offered inadequate 
prospects for the future. It is a far better policy deliberately to keep the 
supply somewhat short of the demand ; the world will not appreciably 
suffer if any particular application of science to industry and agriculture 
develops rather more slowly than the enthusiast could wish, and there are 
few spectacles more distressing than that of the highly educated specialist 
who is unemployed through no fault of his own, and whose training and 
interests do not fit him for other work. At the Imperial College we have 
ample room and equipment for more students of plant biology, plant 
biochemistry, industrial entomology and similar subjects ; but we do not 
intend to fill the room until we can be more certain of the future. The 
lessons of the last few years teach us that public statements about the 
shortage of specialists in any branch of science and technology are apt to 
have an unfortunate effect in schools and in universities ; for they may 
be out of date before a normal period of advanced training is finished. 

It is of interest to examine a little further the Committee's belief that 
the supply of biologists at universities is lacking in quality as well as in 


quantity, which they attribute to the neglect of biology as a subject of 
study in schools. While sympathising with their views, which are shared 
by many people, I think it cannot be denied that whereas a biologist must 
have an adequate knowledge of physics and chemistry, it is not necessary 
for a physicist or chemist to have a knowledge of biology ; and if one con- 
siders the position from a cultural rather than from a practical point of 
view, it would be fair to say that the boys who need least to study 
biology as a cultural subject at schools are those who are going to study 
it at a university. The only point that remains, then, is that if biology 
were taught more widely in schools it is possible that here and there a boy 
* may experience from biology a pull which he had hitherto failed to secure 
from his special subject.' For my part I feel confident that directly there 
is an assurance of reasonable careers in biology, suitable candidates will be 
forthcoming, and education at schools and in the universities will develop 
on sound lines. Lack of teaching of biology at schools has not led to a 
shortage of doctors. How, then, can it be mainly responsible for a shortage 
of other biologists ? It needs no inspired prophet to foresee a great 
development some day of the biological sciences : the work of pioneers 
to-day makes that sufficiently obvious. The next generation may live 
to see a development comparable with that of the physical sciences, and 
their applications, in the last thirty years ; but the time is not yet ripe. 
Until it is, our duty at universities is to keep our biological departments 
moderate in size, but high in quality. 

There is another consideration that one has to bear in mind in deciding 
how many students to encourage to specialise on any branch of science or 
technology. If the call for such specialists is small, it is clearly necessary 
to take into account what is being done at other universities. Universities 
are very human bodies ; if one institution makes a success of any particular 
new department, others will find a strong case to develop along similar 
lines. A little competition is healthy ; but the multiplication of specialised 
departments in different universities and colleges can easily be carried too 
far, resulting in an unnecessary waste of money. There are, for example, 
ten university schools of mining in Great Britain. This number can hardly 
be justified either by the demand for mining engineers at home, where 
there is little or no metalliferous mining, or by the demand overseas. In 
Germany, where there is a large metalliferous, as well as a large coal 
mining industry, there are only five schools of mining engineering of 
university rank. I feel that if the number of students were divided among 
fewer institutions the results would be better and the expenditure less. I 
do not suppose for a moment that anyone is likely to agree with me to the 
extent of abolishing any existing department, but I think we should learn 
a lesson from the past, and keep competition and local patriotism within 
reasonable bounds. 

I have thought it worth while to put these practical considerations 
before you, although they are not exhaustive and do not lead to any 
definite conclusion on the problem of the size of university departments of 
science and technology. In the end the optimum size is a matter of judg- 
ment ; my judgment, for what it is worth, is that on the whole there is 
no strong case for increasing the numbers of students of science and 


technology at universities. In thirty years' time this statement may look 
ridiculous, but one cannot foresee events so far ahead. Rather than any 
marked expansion in numbers should take place during the next five years, 
I should prefer to concentrate on giving the better man a better chance 
than he has now ; to improve the quality rather than to increase the 

It is commonly said of students of science that their general education 
is weak. The remarks of the committee on the education and supply of 
biologists may be taken as representative of a large body of critics, for 
they were based on the views of many witnesses. 

' Among boys taking science as their special line of study there is too 
great concentration on science to the neglect of other subjects. Our 
witnesses view with anxiety the prospect of a growing race of illiterate 
scientists unable to express themselves adequately or intelligently in their 
own language, and ignorant alike of history and of the forces other than 
the chemical and physical which make the world in which they live.' 

There is undoubtedly much force behind these criticisms ; and yet 
I think the poor student of science is apt to be maligned. The great 
growth of knowledge in nearly every department of learning inevitably 
means that we all become more and more ignorant of each other's special 
interests ; can it justly be argued that the young scientist who has little 
or no knowledge of history is more ignorant than the young historian who 
has no knowledge of science } Do we not, perhaps, tend to exaggerate 
the virtues of a general education, forgetting that many of the greatest 
men have had no education worth speaking of ? I remind myself fre- 
quently, and particularly on this occasion, of the fate of Mr. Joseph 
Finsbury, of whom it is written that ' a taste for general information, 
not promptly checked, had soon begun to sap his manhood. There is 
no passion more debilitating to the mind,' the author adds, ' unless, 
perhaps, it be that itch of public speaking which it not infrequently 
accompanies or begets.' And if you know the book you will remember 
that one of Mr. Joseph's lectures ' to the great heart of the people ' was 
entitled ' Education : its Aims, Objects, Purposes and Desirability.' I 
dare not continue the quotation. 

At the Imperial College I have colleagues who have had over twenty- 
five years of experience of successions of boys from secondary schools. 
They say, without hesitation, that the standard of general education has 
increased steadily throughout that period. I am newer to the work ; and 
when I reflect that so many of the present generation of secondary school- 
boys who find their way to universities come from the poorest homes, 
I think the standard of general education is to be praised rather than 
decried. I think also that the man who has ideas of his own, and a capacity 
for doing something really well, is more useful and more interesting, even 
though he may be unable to express himself adequately in his own language, 
than one who is merely capable of describing other people's work and ideas 
in elegant English. When all these allowances are made, however, there 
is undoubtedly room for improvement. There are many scientific men 


who write beautiful English ; and yet I suppose there is no gap in his 
equipment that the average scientific man deplores more in after-life than 
his difficulty in writing and speaking his own language well. I say this 
feelingly, as to me writing is a forced labour, and I am never satisfied with 
the result ; but with practice one can acquire a certain proficiency, and 
with the example of T. H. Huxley as an inspiration no one need altogether 
despair. My complaint of many young students of science to-day is not 
so much that they do not write clearly and concisely as that they do not 
seem to want to, which indicates insufficient practice and instruction at 
school to acquire a taste. Again, I should agree with the Committee that 
' a competent knowledge of one modern language (French or German, 
the latter in particular) is, quite apart from its cultural value, an essential 
element in the equipment of the adequately trained scientist.' Much 
of the best scientific literature is written in German, and if a scientist 
cannot read German scientific papers, he is severely handicapped. At the 
Imperial College we found it necessary many years ago to institute special 
classes in German. It should not be necessary. 

The schoolmaster is, however, in a quandary. There is a limited 
number of hours in the day, and if he taught all the subjects that he is 
advised to teach to all the boys — for everyone naturally thinks that his own 
special subject should form part of a liberal education — he would only 
succeed in producing a race of smatterers. He has to choose a happy mean 
between teaching more and more about less and less, or less and less 
about more and more ; and he not unjustly complains that during the 
last year of a clever boy's life at school he is hampered in his choice by 
the regulations and practice of universities. Schoolmasters at grant-aided 
secondary schools are in a special difficulty, for most of their pupils are 
not able to proceed to a university unless they win entrance scholarships. 
If university authorities complain that students are lacking in general 
education, it is for them to do their best, by altering the conditions of 
entry, or the standard of scholarships, to help schoolmasters to remedy the 
defects. I propose, therefore, to discuss briefly what changes are desirable. 
I shall base my remarks on the regulations of London University, and my 
own college in particular, but I think the regulations of other universities 
are sufficiently similar to make the discussion of general interest. 

The first university examination is the Matriculation examination. A 
matriculation examination, I take it, was originally intended to be an 
examination the successful passing of which entitled a candidate to be 
admitted to the privileges of a university. The London University 
Matriculation examination has long ceased to be anything of the sort — 
at any rate, so far as students of science are concerned. It would seem 
more appropriate to regard it as an examination which entitles successful 
candidates to be admitted to the privilege of becoming bank clerks. 
Certainly few university schools of science will admit a student at the 
normal age of eighteen on the strength of his having passed the Matricula- 
tion examination ; some further proof of his proficiency is required. At 
the Imperial College we have a special entrance examination which mainly 
consists of papers in mathematics and science, but includes papers 
in English and a choice of foreign languages ; but I cannot say that a 


candidate is refused admittance if he fails to do well in the English and 
Language papers, but does well in the other subjects. 

The next university examination is the Intermediate examination. 
The original object of such an examination was to test the progress of a 
student in his special subject of study at a university, after he had given 
evidence of a sufficient general education at the normal age of entry. In 
fact, if we agree that a university is a place where students learn to teach 
themselves, under the guidance of distinguished teachers, instead of 
learning under the strict discipline of school, the main object of an inter- 
mediate examination should be to test a student's capacity to teach him- 
self, and therefore to satisfy the authorities that he is fit to proceed with 
a course of study leading to a degree. Nowadays, as the Matriculation 
examination or its equivalent is passed by most intending students at the 
age of fifteen or sixteen, their remaining years at school are devoted to the 
special subjects of the Intermediate which many of them pass before they 
enter the university. They are encouraged to do so by university authori- 
ties. It saves us trouble, and gives the student time to acquire a larger 
stock of specialised knowledge in his undergraduate career. The next 
obvious step will be to take the degree examinations at schools, leaving 
the universities free to concentrate on postgraduate work ! 

While these changes have been taking place in school curricula, the 
standard of science entrance scholarships at universities has steadily 
risen ; and as most science scholarships go to boys who intend to study 
physics or chemistry at the university, the schools are encouraged — some 
would even say forced — ^against their will, to concentrate their advanced 
teaching on physics and chemistry. It is true that only a small proportion 
of the boys at any particular school intend to compete for scholarships, but it 
is impossible to segregate such boys altogether, and the standard of scholar- 
ship examinations, therefore, sets the pace for the higher school forms. 

The object of a scholarship examination is to discover the boys of 
greatest promise, not the boys who have been most successfully crammed. 
I think that schoolmasters are inclined to attach too much importance to 
the character of the papers set, and to give too little credit to the examiners 
for intelligence. It is not always the boys who get the highest marks who 
win the scholarships, and it is not so very difficult for an intelligent 
examiner to distinguish between an active and a congested brain. At 
the same time, I do agree with the criticism that the papers set are usually 
too difficult. There is too great an element of luck about a hard paper ; 
and first-rate ability in a candidate is shown more by the way he answers 
a question than by his knowledge of detail. I remember giving practical 
effect to these opinions when I examined in the Final Honour School of 
Chemistry at Oxford fourteen years ago. One of the two papers I set in 
physical chemistry was so apparently easy, that I feel sure that a more 
cheerful group of candidates never sat in the Examination Schools. I am 
confident, too, that there never was an occasion when an examiner found 
it easier to distinguish between the relative merits of different candidates. 
The first-class man answered the questions briefly, accurately, and to the 
point ; the second-class man wrote pages of irrelevant matter, to impress 
the examiner ; and the third-class man made elementary mistakes. 


It is not so easy as it may seem, however, to change the standard of 
scholarship examinations, and thereby to encourage a broader education. 
About a year ago we decided to review our policy at the Imperial College. 
Students come to the College with science scholarships from many 
sources ; but the chief sources are the Board of Education, who award 
Royal Scholarships tenable only at the College as well as State scholar- 
ships tenable at any university in England and Wales ; the London County 
Council ; and the College itself. For the past five years our scholarship 
examinations have been held in January at the suggestion of a group of 
headmasters of public schools, who advised that by doing so we should 
attract better candidates. We have not found this borne out by results ; 
we have not had enough good candidates in any year since the change to 
justify us in awarding the full number of scholarships ; and many of the 
better candidates have subsequently competed for and gained Royal 
Scholarships or State Scholarships which are higher in value. Our general 
experience leads us to believe that very few, if any, students of first-rate 
ability, who have specialised in science at school, are prevented from going 
to a university for lack of financial assistance. On the other hand, we 
believe that no scholarships are deliberately made available to assist able 
students who have not specialised in science at school to study science at a 
university. We have therefore decided to make the experiment of chang- 
ing the character of our January scholarship examination. We propose 
to set papers in General Science and Mathematics of quite a low standard, 
together with papers of a higher standard in History, Foreign Languages 
and English. The details are not yet settled,- but headmasters and head- 
mistresses were notified of the change this year, and their criticism and 
co-operation were invited. The scheme has had a mixed reception. 
We have received many encouraging, but many critical letters. Much 
of the criticism can be summed up by the phrase, actually used — ' It 
would not suit my Sixth, and I should not alter my Sixth to suit it.' Now 
schoolmasters cannot have it both ways ; they cannot say, on the one hand, 
that they are forced to specialise unduly at schools by the standard set by 
examiners for science scholarships, and, on the other hand, that they do not 
propose to make any change if university authorities listen to their 
criticisms. We intend to go on with the experiment, without any great 
hopes of the result ; someone must make a start, and the most unpromising 
experiments have often given surprisingly good results. At the same time, 
I fully realise that what one particular college does cannot solve the diffi- 
culties of the schools. If it is really the general view that the school 
education of a student of science is too narrow, then the best practical 
step is to reform the University Matriculation examination, and make 
it appropriate to the normal age of entry. If one of the larger universities 
did this, the eff'ect would be considerable. If it is not considered worth 
while, then criticism of the general education of the science student loses 
most of its point. 

I have put before you some problems of the present ; I want now, before 
I conclude, to touch briefly on a problem of the future. 


All university education in science and technology is designed primarily 
to produce teachers or professional scientists or technicians. Most 
engineering students intend to become practising engineers ; most 
chemists who do not enter the teaching profession become research 
chemists or chemical engineers ; most students of biology become doctors 
or professional biologists. A few graduates in science break adrift, and 
turn with success to other occupations : to the law, for example, to general 
administration, or even to literature ! Of His Majesty's present Ministers, 
one took a degree in biology at a Scottish university, and another a degree 
in chemistry at an English university. But these are rare exceptions ; 
most science graduates are specialists skilled in a particular branch of 
science, and ignorant of other branches. A hundred years ago it was not 
difficult for a scientific man to follow in detail the work of others ; now it is 
as much as a specialist can do to keep abreast of the progress of knowledge 
in the particular field in which he is interested. No one studies science 
at a university as a general education, as men study classics, philosophy, 
and history ; indeed no one can, for no university supplies the oppor- 
tunity. ' Modern Greats ' at Oxford includes the study of history, 
economics, philosophy and ' the structure of modern society,' but not of 
science ! 

During the present century there has been a struggle to secure a wider 
recognition of the value of scientific study and research, not only for the 
advancement of knowledge, but for the progress of civilisation. Now 
that this recognition is widespread ; now that we all see plainly the great 
influence of scientific discovery on social developments ; now that 
specialised departments of science are flourishing at universities ; surely 
an eff'ort should be made to provide for men who have no desire to become 
specialists, but who wish to study the broad principles and applications 
of science, for their own education, and as the best preparation for after- 
life in many spheres of human activity. The place of the specialist in 
industry and in the machinery of Government is assured. Large estab- 
lishments have grown up, mushroom-like, to meet the demand for industrial 
research. Biological research is also gaining recognition, but more 
slowly, for public opinion has not yet been educated to the point of realis- 
ing that, in the long run, it would be fatal to attach more value to industrial 
research than to applied biology. With all this increase of scientific 
activity, there has arisen an urgent need for skilled administrators and 
men in public life who have a real knowledge of the principles and methods 
of science ; not the kind of knowledge that is derived from conversation, 
listening to broadcast talks, and reading popular books, however good 
these may be, but that which is gained by serious study. We cannot 
complain that there are few such men among the present generation ; 
it is a great thing that there has been a change of attitude of mind. But 
unless something is done, there will be no greater number in the next 

Is the time ripe for action on the part of the universities ? I think it is. 
The great accession of knowledge in all branches of science may often 
seem bewildering ; but its effect has been to make the main principles 
clearer, and easier to teach, for a connecting thread runs through them. 


The foundations of science have been laid ; they will be strengthened in 
the future, but it is unlikely that they will be rebuilt. The structure that 
is built on them grows ever more coherent ; it can be studied as a whole, 
without examining in great detail any of its parts. The subjects of the 
university school I have in mind will include the study of the foundations 
and philosophical background of science ; of its history ; of the history 
of social development ; of the applications of science to industry, agricul- 
ture and medicine ; of problems of population and health — and the like. 
The student will learn that law and order in the universe is not a faith 
but a reality ; and that science is ' nothing but trained and organised 
common sense.' He will learn too, I hope, to acquire the spirit of that 
unprejudiced search for truth which is the basis of all fruitful scientific 

These are but vague suggestions ; the practical thing to do is to make 
a start ; and the best way to make a start is to select the right man to direct 
such a school — and there are men available — to put him in the right 
environment, and to give him the opportunity to work out his own ideas. 
That good would result I have not the slightest doubt. 






Ever since the beginnings of civilisation the rate of improvement in 
agricuhural technique has controlled and conditioned, to a considerable 
degree, the progress of the human race. This progress has been of two 
kinds — on the one hand an increase of numbers, and on the other a rise 
in the standard of life. 

At certain times and places better farming has meant no more than the 
possibility of a given level of subsistence for an increasing number of 
people. Indeed, where the available land has been limited, where condi- 
tions of climate and the like have favoured the increase of population 
and where the progress of agriculture has been relatively slow, we find all 
the essential features of that rather gloomy picture of man's economic 
destiny which Malthus conceived as normal. Broadly speaking, this has 
been the state of things, in China, during many centuries. Conditions 
among the Western nations have, however, become more and more unlike 
those that Malthus presupposed. He assumed that populations tend to 
increase in geometric progression, whereas in many countries population 
is already, or is rapidly tending to become, static. He assumed that the 
additional land, brought under cultivation in order to meet man's growing 
necessities, would be inferior in some respect to that already farmed ; 
but at present the tendency upon the whole is for farm land to go out of 
cultivation. Malthus could foresee no more than a slow and dwindling 
rate of increase in the productivity of the soil, each successive increment 
being obtained at the cost of a progressively greater amount of human 
toil; but recent additions to scientific knowledge have been enough to 
outweigh the effects of the economists' law of diminishing returns ; our 
increasing output of food is being secured with less and less toil, instead 
of more and more. The main result of the most recent agricultural pro- 
gress in the more advanced countries has been then to set free, for activities 
other than food production, an increasing proportion of the population, 
with, as a secondary consequence, the possibility of an unprecedented 
rise in standards of life. 

Before, however, we attempt to analyse the present situation of our 


industry, or try to predict its future, it may be well to cast our eyes back 
over some of the main stages in its evolution. This is the easier to do 
because on each of the main steps of the ladder some part of the human race 
has been left standing — providing a living relic of what was once perhaps 
the most advanced type of economic life. 

We have indeed — in Australia, in Ceylon, in Africa and elsewhere (and 
often under conditions quite favourable to agriculture) — remnants of 
those peoples who refused to become either tillers of the soil like Cain, 
or keepers of sheep like Abel. With them — women and children as well 
as men — life consists of an unremitting food-quest. Their dietary in- 
cludes articles like grass seeds, insect grubs, mice and snakes, yet they 
are often reduced to hunger and famine. They must wander over wide 
areas to secure their meagre fare and they have neither time nor energy 
to spare for the arts of civilisation. It is worth noting that their funda- 
mental disability is a lack neither of intelligence nor of manual dexterity, 
but of foresight. They cannot see beyond their immediate necessities. 
They will work for a daily wage but not for a yearly harvest. The Bush- 
ment of South- West Africa, for example, can be trained to become capable 
herdsmen, but they never become independent stock-farmers because 
they cannot resist the temptation to kill when they are hungry. 

When men first began clearly to anticipate their material needs, and to 
plan ahead in order that these might be supplied, they naturally strove to 
bring under control those species of plants or animals on which, in their 
earlier unplanned economy, they had been accustomed to rely. Thus 
the big-game hunters of the Asiatic plains became, in course of genera- 
tions, nomadic herdsmen. In the flood valleys of the Nile and Euphrates 
unaided nature solved what has elsewhere been the chief problem of the 
cultivator — the maintenance of the fertility of the soil — and there the 
greatest of our early civilisations were founded upon an assured supply of 
corn. But the herdsmen who have become nothing more have con- 
demned themselves to a very limited and an insecure existence. They 
may build up immense capital in the form of live stock, but they still 
live in tents and subsist entirely on meat and milk or, like the Massai, 
on blood and milk ; and a drought or an epidemic of stock disease may 
reduce them, in a few weeks, from a state of plenty to one of famine. 

Again the cultivators who have clung to plant life alone as a means of 
sustenance maintain, except in specially favourable localities, but an in- 
conclusive war with nature. On the one hand, the maintenance of soil 
fertility without animal manure has been usually, until the recent intro- 
duction of other fertilisers, a nearly insoluble problem ; hence land, 
becoming exhausted after a few years of tillage, has had to be again 
abandoned until such time as natural processes should restore its fertility. 
The periodic clearing of new areas, added to the routine operations of 
tillage and both carried out by means of primitive hand tools, give a very 
real meaning to the curse of Cain. Finally, a purely vegetable diet, 
often restricted to one or two specially productive plants, may be not 
only monotonous but seriously deficient in nutritive value. 

The contriving of a system of mixed farming, embracing both plants 
and animals, was a remarkable stage in the progress of civilisation. It 


has been surmised that it came about through the conquest of the cultivator 
peoples of Egypt and Mesopotamia by herdsmen peoples from the north- 
east. The combination did many things. It made possible the applica- 
tion of animal power to the soil. It enabled permanent agriculture to 
replace shifting cultivation. It provided at once greater abundance, more 
variety and greater security in the food supply. It enabled men to fix 
their abodes and thus made worth while the building of permanent 
dwellings and the accumulating of household goods. It set free human 
energy for the arts of civilisation. In short, it enabled the men who 
devised it to inherit the earth. 

But life for these innovators became not only fuller but also more 
complicated. Man had to organise the food supply not only of his family 
but also of his beasts, and to this end he had to bring under cultivation 
new species of plants and invent new methods of fodder conservation. 
As the mixed farmers spread over the world they had continually to 
exercise their ingenuity in adapting their system to the varying natural 
conditions of their new homes. 

This system was improved and modified during ancient and medieval 
times without undergoing any fundamental change. There was a minor 
hiving off of other industries from farming and a consequent growth of 
trade ; there were some temporary experiments in the mass production 
of food, especially by the Romans and by means of slave labour. But up 
till the time of the industrial revolution the typical citizen of the civilised 
world was the family farmer, looking to his own land to supply the bulk 
of his material needs and producing but little for sale. He remains to-day 
the typical citizen of many great and populous countries, and his class is 
easily the most numerous in the world. 

But the eighteenth century saw the beginnings of another great change. 
Primarily this had little to do with the business of growing food or other 
farm produce. It concerned what had hitherto been but minor industries, 
occupying the time of the farmer and his wife in winter evenings or 
employing a few village craftsmen — industries like the spinning of 
yarn and the weaving of cloth, the fashioning of ploughshares and of cart 
wheels. The successful application of mechanical power to these 
manufacturers meant their removal to convenient sources of power 
and, therefore, their removal from the farm. The separation of agriculture 
from other industries meant an increase in the exchange of goods, and 
this necessitated, in turn, the provision of improved means of transport 
and a great increase in the supply of money and credit. 

The agricultural changes which accompanied the industrial revolution 
were changes of organisation rather than of technique. There was 
(with the possible exception of Meikle's threshing machine) no new 
agricultural invention comparable to the spinning mule, the power loom, 
the new blast furnace or the steamship. The successful application of 
mechanical power to the soil was not to be achieved for another hundred 
years. But farmers had to replan their industry with their eyes upon a 
market rather than upon their own personal requirements. This favoured 
a degree of specialisation in production that had hitherto been impossible. 
It favoured a larger type of enterprise and led to the engrossing of farms. 


Because of the disappearance of the old fill-time home industries it 
necessitated a replanning of farm work. It required, of course, the 
investment of fresh capital, and thus gave the whip hand, within the 
industry, to those individuals with capital to command. 

The revolution was not carried through without a good deal of hardship 
to individuals — some of which, according to modern standards, amounted 
to grave social injustice. The enclosures of the old open-field villages 
of the English Midlands and the Highland clearances need only be 
mentioned in this connection. 

Indeed, there have been difficulties and hardships associated with all 
the major steps of progress that we have traced. Each departure from 
tradition required a fresh effort of will and made a new demand for 
courage and enterprise. At every stage there were people who thought 
that things were very well as they had been ; but these people have 
always been wrong. No reasonable interpretation of history can leave us in 
doubt that each great step in economic evolution has been amply justified. 
It is not only that a higher level of material prosperity has been attained, 
but that, upon the whole, this material prosperity has been turned by 
men to good account. No reasonable person would wish to return to 
the life of the Australian aborigine, the nomad or the African cultivator 
upon his patch of maize and yams. Many people feel, indeed, a strong 
if rather sentimental attraction towards the old peasant way of life. This 
is easy to understand, for most of us are removed but a generation or 
two from peasant homes. In truth, the modern business farm suffers, 
in some ways, by comparison with the peasant holding ; but only, as 
I believe, because we have not as yet fully succeeded in translating the 
economic advantages of the former into social good. The broad lesson 
of history, as I see it, is that we must take our courage in both hands 
and face the task that we now see before us. 

For some of the origins of our present agricultural problem we must 
go back to the seventies of last century, which marked the end of what 
has been called the golden age of British farming. At that time, in 
those countries where agriculture had been separated from the other 
industries, the division of national incomes between the two classes was 
favourable to the agriculturist — he got fair value, in terms of manu- 
factured goods and services, for his labour and enterprise. It is true, 
indeed, that where the agricultural class was divided into landlords, 
tenants and labourers there was, according to modern standards, a very 
inequitable division, as between rent, profit and wages, of the net gains 
from farming ; but this inequity was by no means peculiar to farming. 

Since the seventies the productive capacity of agriculture has constantly 
tended to increase more rapidly than the demand for agricultural produce. 
The one check in the process was caused by the Great War, but this has 
already been more than made good. The result has been that, except 
during the period from 1917 till 1921, when the boot was certainly on 
the other leg, agriculturists have failed to secure a due reward for their 
increasing efficiency. 

The rise in the output of world agriculture has been made possible, 
firstly, by a vast increase in the area of available land, and in supplies of 


the farmer's other primary raw materials. The process of expansion 
began with the opening up of the North American prairie for corn 
growing, following the building of railways and the invention of the 
binder. At first it was confidently predicted that the flood of corn 
would be only temporary, since a few years of ' prairie farming ' must 
exhaust the most fertile soil in the world. But the prairie soil was found 
to be different stuff from that of Western Europe, and its exhaustion 
proved to be a vain hope, or a groundless fear, according to the point 
of view. Moreover, one new country after another went through the 
process of agricultural development, and the problem of transport was 
solved not only for corn and wool, but also for meat, dairy produce, fruit 
and, indeed, for every commodity except the most bulky or the extremely 
perishable. But it is not only transport developments that have thrown 
open new fields to the farmer. Irrigation schemes and dry-farming 
technique have added great areas of what was formerly desert. Plant 
breeders, by producing quick-maturing strains of plants, have extended 
the northern limits of cultivation by a belt that embraces hundreds of 
millions of acres. The growing control of human and animal disease 
is creating the possibility of settlement and agricultural development 
over vast areas of the tropics which, as yet, have been hardly touched. 
Thus the old fear of overpopulation, which has coloured so much of 
past economic thought, has been removed to a distance that now seems 
incalculably far. 

Apart from land, the most important of the farmer's primary raw 
materials are fertilisers, and here it is enough to say there can be no 
anxiety about future supplies. The crisis in connection with the supply 
of nitrogen, which seemed thirty years ago to be approaching fast, has 
been completely averted. Nitrogen is now available to the farmer, in 
infinite quantity, at less than half its pre-war price. 

The other cause of the growing abundance of agricultural produce 
has been, of course, the application of the rapidly increasing body of 
scientific knowledge to the business of plant and animal production. 
I do not propose to weary you with a catalogue of recent advances in 
agricultural science, or to show how these have been translated by the 
farmer into improvements in practice. Two or three examples must 
suffice. The latest report on the Agricultural Output of England and 
Wales shows that (through the application of the sciences of genetics 
and nutrition) the average output of eggs, per bird, increased by 20 per 
cent, in six years. The use of the tractor and the combine harvester 
enables a reduction, in the labour cost of corn production, of more 
than 50 per cent. The output of meat, per acre of grassland, has been 
increased, at Cockle Park and on much similar land elsewhere, by more 
than 100 per cent., through the use of what was once a worthless by- 
product of our steel industry. A simple and cheap remedy has been 
found, almost the other day, for the ' rot ' in sheep which has often in 
the past killed a million sheep and more in a single year. And so on — 
more farm land and more fertilisers, more machines and more science, all 
leading to the same result of cheaper, easier and more abundant production. 

I am not suggesting that overproduction is the sole cause of the 


present crisis in world agriculture. Indeed, the immediate cause is the 
fall in the general price level following the contraction of currency. But 
a tremendous fall in prices, due to the same cause, occurred at the end 
of the Napoleonic wars without causing the general ruination of agri- 
culturists. The severity of the present crisis has been due, as I see 
the matter, to the preceding long period of inadequate returns in agri- 
culture, which left the industry with depleted capital and a burden of 
debt, and therefore unfit to withstand a period of general economic 
disorganisation. If the significance of rapid agricultural progress had 
been realised in time, and if nations had been prepared to accept its logical 
consequences, there might have been no necessity to-day to devise any 
revolutionary economic plan for the industry. For instance, it might 
have been foreseen that the cheap producer in the new countries must 
displace the dear producer in the old, and that as Canadian prairie was 
broken up. Midland clays must go down to grass. But no country was 
prepared to accept either a decline in the number of its agriculturists 
or a reduction of its home output of food. Rural depopulation was 
viewed with widespread alarm, and the extensification of farming was 
regarded as an evil implying almost moral turpitude on the part of the 
farmer. Again it might have been seen that, the world's requirements 
of bread being amply met, some of the surplus energies of farmers might 
have been diverted to the production of more interesting commodities 
like fruit or chickens or tobacco. But States, when they intervened at 
all, did so in the opposite sense — encouraging the production of the 
old necessaries and discouraging the expansion of consumption of 
luxuries. Such ideas die hard. It is still considered a meritorious thing 
to employ an agricultural labourer, but there is no particular feeling 
about the employment of barbers, haberdashers or electricians. It is 
somehow more honourable to plough a field than to let it lie in grass. 
It is a nobler thing to grow wheat (even if nobody wants to eat it) than 
peaches or strawberries. These notions are a legacy from the time 
when the world was hungry of necessity, and when people lived healthily 
in the country but died quickly in the towns. We must realise that 
these conditions have ceased to be. There is a superabundant organ- 
isation for food production, and there is no difficulty about breeding 
up a good and healthy human stock in the modern city. It seems to 
me that there is no argument for keeping unnecessary workers in agri- 
culture or for driving people back to the land. 

During the past few years there has been a rapidly growing realisation, 
in one country after another, that the farmer's economic lot was becoming 
unendurable, and a mass of different expedients have been devised, 
either by governments themselves or with their sanction and approval, 
to ensure something like a fair price for agricultural commodities. These 
measures are based on a wide variety of principles, and some are open to 
obvious criticism. For example, we have compulsory restriction of 
output ; monetary compensations by the State for restrictions voluntarily 
made ; even plans for the destruction of produce which is judged to 
be in excess of demand. We have direct State subsidies designed to 
make good the difference between cost of production and market price 


the fixing of internal prices by the State, combined with State control 
of imports and exports ; export subsidies ; tariffs designed to raise 
prices to a desired level ; restriction of imports, with or without tariffs, 
intended to adjust supply to demand. The list is by no means complete. 
Some of these measures, indeed, are not so much rational means to assist 
agriculture as the weapons of economic warfare, in which apparently one 
of the objects of strategy is to force upon the enemy more food than 
he can eat. 

It is perhaps necessary then to restate the fundamental (and essentially 
very simple) ideas upon which any real scheme of economic planning 
must be based. In the first place, successful planning necessitates the 
accurate prediction of demand and implies an undertaking, on the part 
of producers, to deliver the quantity of goods required. In the second 
place, it involves the fixing of a price for the commodity in question which 
will allow the producer a reasonable, and no more than a reasonable, 
reward, and only provided that (i) his technical methods and general 
management are reasonably efficient, and (2) the natural conditions and 
economic situation of his farm are reasonably favourable to the production 
of the said commodity. 

That the translation of these ideas into practice must be a hard task 
is obvious. Demand is not static, but is subject both to long-term changes 
and to temporary fluctuations, due in part to causes that are some of them 
accidental and some of them obscure. Planning must anticipate an 
increase of consumption demand, and indeed endeavour to stimulate it. 
Again, agricultural production is still subject to the accident of drought, 
epidemic disease and so forth. The determination of farming costs on 
which, under a planned economy, prices must be based is beset with 
rather special difficulties. Some people feel that these objections to 
planning are insuperable, and that the system presupposes a measure 
of understanding between one producer and another, between exporting 
and importing countries and between producer and consumer, that is 
quite beyond the bounds of reasonable expectation. Indeed, if the 
crisis had been less urgent, the institution of our marketing schemes 
should have been preceded by a period of research, experiment and 

One must protest most strongly against any notion that economic plan- 
ning is a panacea for all our ills or is any substitute for education and 
research. The main lesson of the Russian plan for agriculture is not, as I 
see it, that the basic ideas behind it were wrong — I believe they are essen- 
tially right — but that their translation into practice necessitated an increase 
of scientific knowledge and technical skill, and a change of economic 
and social outlook that could not be attained at the rate which the plan 
contemplated. There is a risk, I believe, that we shall fall into the 
same error and suffer some of the same consequences. Another danger 
inherent in planning is that it may be used primarily to further narrow 
national ends, thus becoming only another weapon in the armoury of 
economic war. It is easy to see how it might be used, in this country, 
with the chief objects of increasing our agricultural area merely at the 
expense of that of other countries ; of increasing our home production 


of food merely by causing a reduction elsewhere ; of finding jobs for our 
unemployed by throwing overseas producers out of work. It is, of course, 
true that scientific and industrial progress is making countries, in some 
respects, less dependent one upon another. Italy, by developing her 
water power, has reduced her need of our coal ; we, by building Billingham 
Works, have lessened our requirements for Chilean nitrate. Some 
increase of self-sufficiency is the inevitable consequence of progress. 
But it is still true that civilised countries depend largely — for the abundance, 
variety and security of their food supplies, as well as for many other 
material blessings — upon a free and large international exchange of 
goods. World trade has shrunk because our monetary system has been 
unequal to the task of maintaining its flow. People are idle because 
they cannot exchange, one with another, the things which they might 
produce. Mere one-sided restrictions on trade can form no part of 
any sane plan. International trade agreements, indeed, are an essential 
part of any scheme. 

Supposing that the marketing schemes succeed in restoring a level 
of moderate profitability to agriculture, there will still remain the con- 
siderable task of reconditioning our farms. Apart from the period of 
two or three years at the end of the war there has been no business 
inducement, for more than half a century, to put fresh capital into farming. 
Many of our existing buildings were planned at a time when wages 
were at less than a third of the present rates, and therefore with little 
regard to economy of labour. Some farms are of an uneconomic size 
in relation to modern kinds of equipment. . There are heavy arrears in 
the matter of plant and machinery renewals, of drainage and liming. 
There is also, in many cases, a heavy burden of debt. 

In some countries the problem of farmer indebtedness is so acute 
that it has been thought expedient for the State to intervene, e.g. by 
prohibiting mortgage foreclosures, by proclaiming moratoria on mortgage 
interest, or by making or guaranteeing loans at specially low rates of 
interest. These measures have become necessary because the long- 
continued underpayment of agriculturists has led to the severe depletion 
of agricultural capital, but in themselves they can provide no permanent 
solution of the farmer's economic problem, which is one of prices. It 
would seem that the recapitalisation of the industry could be most 
quickly brought about by the deliberate raising of prices, for a short 
period, somewhat above the ' fair ' level as previously defined. The 
profits inade would undoubtedly be largely reinvested in farming, and 
new capital would be attracted. Moreover, after a long period of under- 
payment, a short period of over-payment is no more than the farmer's due. 

Reorganisation presents the greatest difficulties in the case of those 
branches of the industry which, so far as can be foreseen, must suffer 
a permanent reduction of demand for their products. A case in point 
is the production of oats which has been from immemorial times one of 
the main departments of farming in this part of Britain. The general 
rise in the standard of living is causing a general decline in the use of 
oats for human food, and the substitution of mechanical for horse trans- 
port is gradually killing the alternative market. For other purposes, 


such as cattle feeding, or the manufacture of starch, etc., there are many 
competing commodities, such as maize, which are less costly to produce. 
The case of the northern farmer has a good deal in common with that 
of the Lancashire cotton spinner — both are suffering from the general 
depression, but also from a special decline in demand for their particular 
products. The permanent solution must be gradually to replace the 
oat crop by some other ; and State assistance to this end would be of 
greater ultimate benefit to the industry than a subsidy or other device to 
make oat growing again profitable. 

Let me conclude by trying to draw a picture of the changes in farming 
and in rural life that would be both desirable and possible in a world 
where the principle of a fair price was permanently established, and where 
agriculturists would fairly share the benefits from any future improvement 
in their efficiency as producers. I cannot, as I have already said, foresee 
any large increase in the numbers of people employed on British farms, 
or any large schemes of land reclamation which would add materially 
to our agricultural area. These things can be achieved only at a real 
and considerable cost to the consumer, for they would imply a displace- 
ment of cheap production overseas by relatively dear production at home. 

What one can foresee is the rapid spread of a variety of measures of 
reorganisation calculated to increase the output per unit of labour. 
Seventy years ago the rent of the land was usually, and by far, the largest 
single item of the farmer's expenditure ; ordinary farm land might pay 
a rent of three pounds an acre, while wages were ten shillings a week ; 
the landlord's share of the net output might easily be twice that of labour. 
Hence the chief objective in farming was economy of land — high output 
per acre. Now that land is abundant and rent a comparatively small 
fraction of expenditure, the chief object must be economy of labour. 

There is indeed already a growing tendency to fit the land and the 
capital to the man rather than the man and capital to the land. This is 
implied in the use of the word unit, which is becoming so common, for 
example, in relation to pig, dairy and poultry enterprises. The unit is 
a department designed with the primary end of providing the optimum 
amount of work for a whole-time skilled specialist, with or without a 
limited amount of less skilled or partially trained labour. The man 
is equipped with a labour-saving device whenever this will make possible 
an economic increase in his output, and his functions become, to an 
ever-increasing extent, mental in character. 

This kind of change must obviously tend towards an increase in the 
size of individual departments on the farm — one thinks, for example, of 
one-man units of 300 pigs or 2,000 head of poultry, or of two-men dairy 
units of sixty or seventy cows — and hence it must often imply either an 
increase in the size of the farm or, alternatively, some degree of simplifi- 
cation and specialisation of its organisation. This simplification, together 
with a growing tendency to delegate management to heads of departments, 
may be expected to reduce management as well as labour costs. Moreover 
a great part of the function of management in the past has been marketing, 
and the development of the marketing schemes may be expected greatly 
to reduce this side of the work. A ' clean-boot ' farmer on three or 


four hundred acres of ordinary land will no longer be able to justify 
his existence. 

The carrying out of this kind of reorganisation demands a new standard 
both of general and of technical education in the farm worker. Indeed, 
the provision of short courses of instruction for specialist workers — in 
pig-keeping, milk production, tractor work and the like — is an urgent 
need. The cash value of skill and knowledge must grow with the 
increasing responsibility of the worker. 

I well know that the whole idea of ' factory farming ' — the growth 
of machinery and the specialisation of labour — is repugnant to many 
people. The variety of occupations on the one-man mixed farm, the 
pride of individual ownership and so forth are held to compensate for 
unconscionable hours of labour and small returns. But I have never 
been able to see that inhuman personal relationships need necessarily 
go with specialised occupations, short hours and high wages. Indeed 
I believe that, on the factory farm, it is possible to cultivate a kind of 
team spirit which is essentially a finer thing than the rather narrow 
independence of the small-holder. In any case, the greatest obstacles to 
a richer and fuller country life have always been poverty and lack of 
leisure. If we can remove these obstacles we shall have done much. 




Thirty-ninth Report of Committee (Dr. F. J. W. Whipple, Chairman; 
Mr. J. J. Shaw, C.B.E., Secretary ; Prof. P. G. H. Boswell, O.B.E., 
F.R.S., Dr. C. Vernon Boys, F.R.S., Sir F. W. Dyson, K.B.E., 
F.R.S., Dr. Wilfred Hall, Dr. H. Jeffreys, F.R.S., Sir H. Lamb, 
F.R.S., Mr. A. W. Lee, Prof. H. M. Macdonald, F.R.S., Prof. E. 
A. Milne, M.B.E., F.R.S., Mr. R. D. Oldham, F.R.S., Prof. H. H. 
Plaskett, Prof. H. C. Plummer, F.R.S., Prof. A. O. Rankine, O.B.E., 
F.R.S., Rev. J. P. Rowland, S.J., Mr. D. H. Sadler, Prof. R. A. 
Sampson, F.R.S., Mr. F. J. Scrase, Dr. H. Shaw, Sir Frank E. 
Smith, K.C.B., C.B.E., Sec.R.S., Dr. R. Stoneley, Mr. E. Tillot- 
son, Sir G. T. Walker, C.S.I., F.R.S.). 

Organisation. — The first care of this Committee has for many years been 
the maintenance of the International Seismological Summary, and it was 
with great satisfaction that the Committee learned in the autumn of 1933 
that the University of Oxford had agreed to house .and pay part of the 
operating expenses of the I.S.S. for such time as the remaining costs of 
the Summary were met from sources outside the University. The Com- 
mittee decided that the balance in the general account on June 30, 1933, 
should be transferred to the Observatory. A sum of £75 recei\'ed under 
the terms of the will of the late Dr. J. Crombie was transferred at the same 
time. Further, the grant of £100 from the Caird Fund of the British 
Association was allotted to the Observatory. 

The financial arrangements for the International Seismological Summary 
were the subject of much discussion at the Lisbon meeting of the Seisnio- 
logical Association of the International Union for Geodesy and Geophysics. 
A special grant equivalent to £150 was made by the Association and the 
need for additional assistance was brought to the notice of the Union. 
The Bureau of the Union is now fully aware of the situation and it is hoped 
will be able to give liberal assistance. To provide, however, for the work 
of the next two years up to the next meeting of the Union the help of the 
British Association is required. The Committee is allotting £100 from the 
Gray-Milne Fund and submits an application for a like sum from the 
Association, i.e., for grants of £50 for two years. 

In 1933 the honorary degree of M.A. was conferred by the University 
of Oxford on Miss E. F. Bellamy in recognition of her valuable services to 
Astronomy and Seismology. Congratulations will be offered by seismo- 
logists in all parts of the world, who have good reason to appreciate the 
efficiency of the staff of the University Observatory. 

Travel times of earthquake waves. — The work summarised by Messrs. 
Jeffreys and Bullen in the last Report on the travel times of earthquake 
waves was communicated by Dr. Jeffreys to the International Seismological 
Association and will be published shortly by the Association, part of the 



cost being borne by this Committee. At the request of Prof. Plaskett the 
Committee considered the question what tables should be used in the 
International Summary for 1930 and subsequent years and recommended 
the adoption of the new Jeffreys-Bullen Tables. It is anticipated- that the 
utility of the Summary will be greatly increased, not only by higher accuracy 
in the determination of epicentres but also by the facilities for comparing 
the times of passage of waves from an individual earthquake with the 
standard times. 

It may be recalled that Prof. Turner regarded the accumulation of material 
for providing standard tables as one of the objects of the Summary and that 
in his last Presidential Address to the International Seismological Associa- 
tion he expressed the hope that new tables would be available for use in 
the 1930 Summary. 

Mr. J. S. Hughes has kindly prepared the following statement as to the 
present state of work on the Summary. 

International Seismological Summary. — The preparation of the third 
quarter of 1930 is well in hand. Delay has been inevitable owing to the 
necessity of awaiting the decision of the Seismology section of the Inter- 
national Geophysical and Geodetic Union at Lisbon, and from other 
causes, but at present the work is going forward at a satisfactory rate, in 
spite of the increasing number of observing stations now sending to Oxford. 

Beginning v/ith 1930, certain modifications have been introduced. The 
arrangement of the printing has been slightly altered in the interest of 
clarity and the method of making determinations has been revised so as to 
depend almost entirely on the P phases when these are available. Through- 
out the work the new tables by Dr. Jeffreys and Mr. Bullen have been used. 
These are a revised form of Dr. Jeffreys's earlier work, ' Tables of the 
Times of Transmission of the P and S waves of Earthquakes,' 1932. 

The Introduction to the Summary for the year 1930 contains an account 
of the alterations made and also the Bullen-Jeffreys travel-times for all 
the phases tabulated. These are P, S, PP, SS, PcP, ScS, PS, PKP, PKS, 
SKS, PKP2, SKKS, SKSP. Residuals for the phases P, PcP, PKP, 
PKP2 and S, ScS, SKS, SKKS may now appear in the columns headed 
' O — C ' (observed minus calculated) instead of just P, PKP and S, SKS. 

The Constants of Seismological Observatories. As a preliminary to the 
work on the travel times of seismic waves Mr. K. E. Bullen calculated the 
constants of about 350 seismological observatories. These constants are 
used as Cartesian co-ordinates but are actually the direction cosines of the 
vertical at each point. The table of constants has been published by the 
British Association during the year. 

The importance of the distinction between Cartesian Co-ordinates and 
direction cosines has recently been emphasised by the discussion in a 
paper by B. Gutenburg and C. F. Richter of the ' Advantages of using 
geocentric latitude in calculating distances.' It may be that the time is 
approaching when the spheroidal form of the earth will have to be taken 
into account in estimating all the distances used in detailed seismological 

Seismographs. — The Milne-Shaw seismographs belonging to the British 
Association have remained in operation at Oxford, Edinburgh, Perth (West 
Australia) and Cape Town. 

The seismograph which had been in operation at the Royal Observatory, 
Cape Town, was transferred in 1931 to the University a few miles away, 
the new site being much less subject to change of level and to disturbance 
by wind. Prof. Alexander Brown, who had accepted the custody of this 
instrument was impressed by the need for records of both horizontal com- 


ponents of the earth's motion, and during his visit to England in the autumn 
of 1933 it was arranged that, in view of the importance of the station, a 
second seismograph should be provided by the Committee. This instru- 
ment was supplied in May of this year. 

The attention of the Committee has been called to the desirability of a 
seismograph record in the island of Jersey, which is situated in a region 
where small earthquakes have been comparatively frequent in recent years. 
It was hoped that arrangements could be made for the installation at St. 
Louis Observatory, Jersey, of a Mainka Seismograph placed at the disposal 
of the Committee by Dr. Crombie's executors, but this has not proved 
practicable. The Committee is indebted, however, to the governing body 
of St. Louis Observatory, Jersey, for the consideration given to this matter. 

The Science Museum at South Kensington possesses an excellent collection 
of seismographs. A valuable addition to the collection is to be made shortly, 
a seismograph which will be kept in operation in view of the public. The 
records of this instrument will be on smoked paper, and there will be an 
alarm bell to give audible warning when an earthquake is being recorded. 
Mr. J. J. Shaw is providing this installation and expects to have it in 
operation during the autumn. 

At Kew Observatory, where three Galitzin seismographs are in operation, 
an additional instrument has been taken into use. This is a reproduction of 
the Wood-Anderson torsion seismograph which has proved of great value 
in America for the study of near earthquakes. The special feature of this 
seismograph is the minute moving system. It was suggested in 1913 by 
G. W. Walker that a seismograph might be made to go in a tumbler. This 
ideal has almost been reached in the Wood-Anderson seismograph ; the 
base of the case containing the moving system is only 5 ins. square and the 
height 12 J ins. The efficiency of the instrument may be judged by the 
fact that it recorded, on January i, 1934, an earthquake near Biarritz which 
was not shown on the Galitzin records. 

The Great Earthquake in India. — Amongst the earthquakes of the year, 
by far the most important is the one which occurred on January 15, 1934, 
in the north of India near the frontier between the Province of Bihar and 
the Native State of Nepal. To judge by the distance at which this earth- 
quake was felt, about 1,000 miles, it was one of the greatest on record. In 
the central area about 140 miles long and 90 miles wide, twelve towns with 
populations from 10,000 to 60,000 were completely wrecked, and there 
was great destruction of property over an area as large as Great Britain. 
In the circumstances it is remarkable that the estimated death roll in 
Bihar did not much exceed 7,000. This is attributed to the majority of 
the population living in low-roofed mud huts which, even when they collapsed, 
caused little injury. Large tracts of agricultural land were ruined by the 
coarse sand ejected from fissures and blowholes in the surface. 

The following graphic account of his experiences during the earthquake 
was written by Dr. V. D. Wyborn at Ord, 25 miles south of Darjeeling : 

' About 2.30 P.M. a sudden trembling of the ground started, accompanied 
by a rumble as of distant thunder. Trembling was steady for about 3 
minutes. Character of a rhythmic vibration about 2 beats per second (very 
much resembling that felt in a motor launch having a very vibratory or 
loose bearing petrol engine). The brick and steel reinforced house shook 
and rocked visibly and appeared as if it would collapse. Bottles shook and 
fell. Walls cracked and plaster fell. Walls collapsed in other places. 
Children were thrown off their feet. My sensation in the open garden was 
that of giddiness, sickness and insecure foothold as on board ship, with a 
vibratory motion from the ground as well as a heaving or wave up and 


down feeling. After 3 minutes of this, gradual subsidence occurred for 
I to I minute, and then calm. (A very slight tremor occurred again at 
about 3.3s P.M., duration about ic sees, or less.) One expected the earth 
to give way, but no cracks are visible. The lines of the building resembled 
a jerky shaking outline. The house appeared to sway and rattle itself to 
pieces the whole time. (I liken it to a rough-haired dog shaking itself.) 
People say they remember nothing like it. Several brick buildings a mile 
and more away are damaged also. 

' The rumbling appeared to come from south-west but may have been 
house noises or the galvanised iron roof and only apparent the first half 
minute I was in the house. I watched proceedings a safe distance out of 
doors. One felt giddy 15 minutes afterwards and there may have been a 
gentle wave motion of the earth after the 3 minute tremor.' 

British Earthquakes. — There was no considerable earthquake in the 
British Isles during the year, but small disturbances, some of which may 
have been due to the collapse of old workings in mines, were reported by 
the newspapers as occurring on the following dates : 

1933, October 28. Nottingham. 

1934, February 10. Roslin, near Edinburgh. 
1934, March 17. Coasts of the Bristol Channel. 
1934, April 23. Elvington, near Dover. 

1934, June 8. Dufftown, Banffshire. 

1934, August 16. Dingwall and Cromarty. 

Earthquake Prediction. 

It has always been the desire of seismologists to be able to give warning 
of earthquakes. A letter from the Director of the Observatory at Manila, 
communicated by Mr. F. Hope-Jones, suggests a new line of research. 
The Observatory has been equipped with a synchronome ' Shortt ' Free 
Pendulum, of the same construction as the Standard Siderial Pendulum at 
Greenwich. This type of pendulum has a variation of not more than 
about three seconds per annum. The Director's letter contains the 
following passage : 

' Another interesting feature which I have noticed in your Synchronome 
(and also to a slight extent in the two Rieflers which I have) is the sensi- 
bility to a tilt in the land. On more than ten occasions some three or four 
days before a local earthquake the rate of the clock has changed very abruptly, 
varying as much as a tenth of a second within twenty-four hours, and then 
suddenly assuming a very slight rate which it keeps until the 'quake comes. 
After the 'quake the clock generally resumes its old rate, or one very near 
to it. There may be other explanations for this strange performance, but 
it may also prove to be a helpful hint in the apparently impossible solution 
of a method of predicting earthquakes of tectonic origin.' 

Periodicity of Earthquakes. — The question whether earthquakes are more 
likely when the moon is in one position or another is frequently asked. 
An answer is to be found in a paper by Dr. C. Davison in the Philosophical 
Magazine for April 1934, ' The Lunar Periodicity of Earthquakes.' The 
earthquakes included in a number of catalogues have been investigated. 
The frequency 9f earthquakes tends in some cases to a maximum at the 
times of new and full moon but in other cases to a minimum. In the 
former category are such earthquakes in Japan as have their foci under the 
land, but Japanese earthquakes with foci under the sea are least frequent at 
new and full moon, as are the volcanic earthquakes of Honolulu. In the 
catalogues including earthquakes in all localities the minimum frequency is 


at new and full moon. This may be because the majority of world-shaking 
earthquakes have epicentres under the oceans. The figures involved in 
these comparisons are such as to imply that the chance of an earthquake in 
a favourable part of the month is of the order 25 per cent, greater than the 
chance in an unfavourable part. Since the publication of his paper Dr. 
Davison has made the remarkable discovery that the focal depth of earth- 
quakes in Japan is subject to a fortnightly period, the maximum depth 
occurring at the times of new and full moon. 

Accounts. — The General Account of the Committee has been closed, the 
balance having been transferred to the University Observatory, Oxford. 
The grant of £100 from the Caird Fund was allotted to the Observatory. 

The income of the Gray-Milne Fund has not recovered, the dividends 
due from the Canadian Pacific Railway having failed again. The principal 
call on the fund was on account of the new seismograph for Cape Town. 

Gray-Milne Trust Account. 







Brought forward . 

• 374 



Miss Bellamy (Honora- 

Trust Income 

. 46 



rium) . 


Bank Interest 



Milne Library . 




Fire Insurance 


Printing ' Constants ' 




Legal Expenses 


Secretarial Expenses . 


Carried forward 










Reappointment. — The Committee asks for reappointment, for the con- 
firmation of the grant of £100 from the Caird Fund, and for a special grant of 
£50 for the maintenance of the International Seismological Summary. 


Report of Committee 07t Calculation of Mathematical Tables (Prof. E. H. 
Neville, Chairman ; Prof. A. Lodge, Vice-Chairman ; Dr. L. J. 
CoMRiE, Secretary ; Dr. J. R. Airey, Prof. R. A. Fisher, Dr. J. 
Henderson, Dr. E. L. Ince, Dr. J. O. Irwin, Dr. J. C. P. Miller, 
Mr. F. RoBBiNS, Mr. D. H. Sadler, Dr. A. J. Thompson, Dr. J. F. 
Tocher and Dr. J. Wishart). 

General activity. — Seven meetings of the Committee have been held in 

Dr. E. S. Pearson, who found that he was unable, owing to pressure 
of other duties, to participate in the Committee's activities, resigned in 

The grant of £100 has been expended as follows : — 

£ s. d. 
Calculations connected with the Bessel functions 

5^0, Y}, h, h, -f and K^ 95 o o 

Secretarial and miscellaneous expenses . . . .500 


Cunningham Bequest. — (a) The first volume printed under this Bequest, 
namely the Committee's Volume III, containing Prof. L. E. Dickson's 
Minimum Decompositions into Fifth Powers, was published in September 1933. 

{b) Volume IV, prepared by Dr. E. L. Ince and entitled Cycles of Reduced 
Ideals in Quadratic Fields, was published in August. 

(c) Volume V, containing the prime factors of all numbers from i to 
100,000, is now in the press, and should be available before the end of 1934. 

Since the publication of the last Report, it was learned that Prof. J. 
Peters, of Berlin, had completed in 1930 the manuscript of a table similar 
in all respects to the table that the Committee had undertaken. Prof. 
Peters kindly offered to place his manuscript at the disposal of the 
Committee ; this offer was gratefully accepted. The table has thus been 
computed in triplicate. 

(d) The 6-register National machine was delivered in August 1933, and 
has proved to be the most powerful aid to table-making yet known. 

(e) The Brunsviga-Dupla, purchased in 1930, has been exchanged for a 
Brunsviga 20, of capacity 12x11 x 20. 

Bessel functions . — The publication of these tables, in two volumes, is now 
assured. A grant of £50 was made by the Royal Society, and a sum of £100 
was voted by the Council. Arrangements have been made with the 
Cambridge University Press for the subsidised publication of Volume VI, 
containing the four principal functions of order o and i , namely 

(i) Joi^) and Jiix) to 10 decimals for 

X = o-ooo(o-ooi)i6-ooo(ooi)25-oo. 

(2) YqW and Yi{x) to 8 decimals for x =o.oo(o-oi)2S-oo. 

(3) Mo, iVo, My and A^^ to 8 decimals for 

X = 25-oo(o-i)so-o(i)ioo(io)iooo 

for use with the equations 

.5'o(^) = -^0 sin X + Nq cos x 
Jiix) = Ni sin X - Ml cos x 
Yo(x) = Nq sin X - Mq cos x 
Yi{x) = —Ml sin X - A'j cos x 

(4) Io{x) and Ii{x) to 8 decimals for x = o-ooo(o-ooi)5-ooo. 
(s) Kq{x) and Ki{x) to 8 decimals for x = o-oo(o-oi)5-oo. 

(6) e-^/o(x), e-^/i(x), e^i^oW and e''Ki{x) to 8 decimals for 

X = 5.oo(o-oi)io-oo(o-i)20-o. 

(7) Auxiliary functions for the interpolation of Yq{x), Yi{x), Kq{x) and 

Ki{x) when x is small, i.e. less than 0-50. 

The copy for this volume, which will contain about 300 pages, is practi- 
cally complete, and composition will be put in hand shortly. 

The second volume, for which much calculation remains to be done, will 
contain functions of fractional order and of order higher than i, zeros of 
various functions, the Airy integral, the Kelvin functions ber, bei, ker, kei, 
and other allied functions. 

The issue of Nature for 1934 March 17 contained a historical account of 
the Committee's activity since 1888 in the calculation of Bessel functions, 
and of the financial difficulties that have impeded publication. The 
article, after referring to the possibility of the Committee's work merely 
resting in manuscript in a fire-proof safe, concludes 'It ought to be sufficient, 
by directing attention to this possibility, to ensure that funds will be pro- 
vided to . . . make available the result of so many years of voluntary work 
on behalf of mathematical students and others.' 


Airy integral. — The calculation of this integral has been begun. The 
tabular values will be included in the second volume of Bessel functions. 

Confluent hypergeometric functions. — 11 -decimal values of the functions 
M(a, 2, 10) and A7^(a, 2, 10) for a=oo(— 0-2) — ii-o have been computed by 
Dr. A. J. Thompson, and communicated to Dr. R. Stoneley. These 
functions are defined by 

,,, . a a(a + i)x* 0.(0. + iMa. + 2) x^ 

^ Y y(y + i)2! y(Y+i)(y + 2)3! 

Ar(a, y x)= x\ I ) + —, k -, I - + I - i ) + • • • 

^ ' " -^ Y Va Y / y(Y + i)2!voc a + i y Y + i ^ 

Sale of Volumes I-V. — Arrangements have been made w^ith the Cambridge 
University Press to sell, on commission, the Committee's Volumes I-V. 

Reappointment. — The Committee desires reappointment, with a grant 
for general purposes of £100. 


Second Report of Committee appointed to inquire into the position of Inland 
Water Survey in the British Isles and the possible organisation and con- 
trol of such a survey by central authority (Vice-Adml. Sir H. P. 
Douglas, K.C.B., C.M.G., Chairman ; Lt.-Col. E. Gold, D.S.O., 
F.R.S., Vice-Chairman ; Capt. W. N. McClean, Secretary ; Mr. 
E. G. BiLHAM, Dr. Brysson Cunningham, Prof. C. B. Fawcett, 
Dr. A. Ferguson, Dr. Ezer Griffiths, F.R.S., Mr. W. T. Halcrow, 
Mr. T. Shirley Hawkins, O.B.E., Mr. W. J. M. Menzies, Dr. A. 
Parker, Mr. D. Ronald, Capt. J. C. A. Roseveare, Dr. Bernard 
Smith, F.R.S., Mr. C. Clemesha Smith, Mr. F. O. Stanford, 
O.B.E., Brig. H. St. J. L. Winterbotham, C.M.G., D.S.O., Capt. 
J. G. Withycombe, Dr. S. W. Wooldridge). 

The Committee records with deep regret the death of Capt. J. G. Withy- 
combe, whose services on the Committee were of great value. 

I. This Committee was appointed after the meeting of the British Associa- 
tion held at York in September 1932, on the recommendations of Section A 
(Mathematical and Physical Sciences), Section E (Geography), and 
Section G (Engineering), and was re-appointed in October 1933, with the 
same terms of reference. 

On page 9 of the Committee's first report, presented in September 1933, 
its conclusions and recommendations are set out as follows : 

' (i) That, with regard to the first part of the Committee's reference, the 
position of Inland Water Survey in the British Isles is far from satisfactory, 
and that a systematic survey of the water resources of Great Britain is 
urgently required ; and, 

' (ii) That, with regard to the second part of the Committee's reference, 
the survey, to be of maximum utility, should be conducted by a central 
organisation, preferably under a Government department, independent 
of any interest in the administration, control or use of water. 

' The Committee have given further consideration to steps by which the 
work of the survey could be most expeditiously begun. They have formed 


the opinion that it would not be feasible, in the first instance, under present 
conditions, to move for the immediate establishment of an organisation to 
be financed by public funds, but rather that a beginning should be made in 
a comparatively small way, financed by subscriptions from individuals and 
bodies interested, with the prospect of being ultimately incorporated in a 
Government department. 

' With this in view the Committee have approached the Council of the 
Institution of Civil Engineers and have been gratified to learn that the 
Council were prepared, if they are so requested by the British Association, 
to appoint a committee to investigate the feasibility of carrying out the 
objects outlined in this Report on a self-supporting basis.' 

II. In pursuance of these recommendations the British Association com- 
municated with the Institution of Civil Engineers, inviting them to carry 
the inquiry further. In response to this invitation the Institution appointed 
a committee ' to investigate the feasibility of carrying out on a self-supporting 
basis the objects outlined in the Report on Inland Water Survey.' 

III. On June 8, 1934, this Committee was invited by the Committee of 
the Institution to co-operate in the formation of a small joint sub-Com- 
mittee, consisting of three members from this Committee and three members 
from the Institution of Civil Engineers Committee, with a view to advancing 
the inquiry. It was considered that this action would be of advantage and 
the invitation was accordingly accepted. 

IV. During the past year the Committee has reviewed the conclusions 
and recommendations contained in its first Report in the light of the improved 
financial position of the country and of the greater general interest in the 
subject as the result of the difficulties experienced during the exceptionally 
dry weather conditions. It was felt that the time was now opportune for 
the collection and correlation of data on inland water resources to be under- 
taken by some appropriate Government department, preferably one inde- 
pendent of any interest in the administrative control or use of water. The 
Committee therefore took steps to bring the matter to the notice of the 
Government through the agency of the joint sub-Committee mentioned in 
para. III. above. 

V. In June 1934 a letter and memorandum, signed by the Presidents of 
the British Association and Institution of Civil Engineers, were submitted 
to the Prime Minister, and on July 17 a deputation was received by the 
Minister of Health. A statement on the result of the deputation to the 
Government (together with a copy of the letter and memorandum) is included 
in the appended report of the joint sub-Committee to the two main Com- 
mittees. It will be noted that the Minister of Health stated that the sugges- 
tions put forward by the deputation would receive the most careful con- 
sideration of the Government. 

VI. The Committee has noted with satisfaction that the Committee of 
Scottish Health Services has, in its Interim Report, 1934,^ on Water Supplies, 
recommended that : 

' (i) A technical survey of the water resources and supplies of Scotland 
should be undertaken at once. 

' (2) A comprehensive inquiry should be held into the whole question of 
water supplies with the object of securing a more economical and more 
effective use of resources.' 

It is also satisfactory to note that during the past year progress has been 
made by a number of undertakings in the establishment of further and 
improved gauging stations. 

^ Ji.M. Stationery Office. 49/9999- i934- Price id. 


VII. The Committee recommends that, in order to continue its work 
with a view to achieving the objects outlined in the report of 1933, it be 
re-appointed for another year with a grant of £100. 

The Report of the joint sub-Committee is appended (A). 

Inland Water Survey. 

Joint Sub-Committee of British Association and Institution 
OF Civil Engineers Committees. 

July 25, 1934. 

Joint Committee's Report to Main Committees. 

Resulting from the meetings of the Institution of Civil Engineers Com- 
mittee on June 8 and of the Research Committee of the British Association 
on June 11, a joint sub-Committee was formed to discuss ' which Govern- 
ment department or departments should be approached in the matter, and 
the best method of approach.' 

Mr. W. J. E. Binnie, Mr. T. E. Hawksley and Capt. W. N. McClean 
were appointed by the former Committee and Vice-Adml. Sir Percy Douglas, 
Dr. Brysson Cunningham and Mr. W. T. Halcrow by the latter Committee. 

The Joint Committee held its first meeting on June 13 ; all members 
were present and Vice-Adml. Sir Percy Douglas was unanimously elected 

Itwas agreed that the Department of Scientific and Industrial Research was 
the right department to approach, and the Committee recommended that a 
deputation wait on the Prime Minister with a Memorandum presenting the 
case for the organisation of Inland Water Survey under the auspices of the 
above-named department. 

The second meeting of the Joint Committee was held on Monday, June 18, 
and all members were present. 

The draft Memorandum prepared by Dr. Brysson Cunningham, at the 
request of the Committee, was considered, amended, and approved. 

The Memorandum was then submitted to Sir James Jeans, President of 
the British Association, and to Sir Henry Maybury, President of the Institu- 
tion of Civil Engineers ; the Committee requesting their consideration as 
to whether the Prime Minister should be invited to receive a deputation 

The two Presidents agreed to present the Memorandum, a copy of which 
is attached together with the letter accompanying it. (See B, below.) 

The Deputation met Sir Hilton Young, Minister of Health, on July 17, 
and the official report which was given in The Times of July 18 reads as 
follows : 

' Water Resources 
' Suggested National Survey. 

' Sir Hilton Young, the Minister of Health, who was accompanied by 
representatives of the various Departments concerned, received a deputa- 
tion yesterday from the British Association and the Institution of Civil 

' The deputation was introduced, in the unavoidable absence of Sir 
James Jeans, by Sir Henry Maybury, and there were present Sir Percy 
Douglas, Sir Richard Redmayne, Prof. P. G. H. Boswell, Capt. W. N. 
McClean, Dr. Jefftott, and Dr. O. J. R. Howarth. 

K 2 


' The purpose of the deputation was to invite the Government to give 
favourable consideration to the institution of a complete and systematic 
survey of the water resources of the country, a subject on which a Committee 
of the British Association has recently published a report. 

' The deputation suggested that the existing records both of surface water, 
including river run-off, and of underground supplies were very incomplete. 
They urged that systematic records comparable with those of rainfall were 
much to be desired, and that a national survey was necessary in order to 
obtain statistics of this nature. 

' Sir Hilton Young, in reply, thanked the British Association and the 
Institution of Civil Engineers for the consideration which had been given 
to the matter and for the suggestions which had been made, and said that 
these suggestions would receive the most careful consideration of the Govern- 
ment. Sources of information were available through the Ministry of 
Health, the Geological Survey, and the Catchment Boards. It was for 
consideration whether the progress which was to be desired in the collection 
of statistics could not best be achieved by improving the existing means of 
gauging the flow of rivers and by improvements in the method of collecting 
and presenting returns.' 

The joint sub-Committee await with interest the result of the Govern- 
ment's careful consideration of the matter. 


The Rt. Hon. J. Ramsay Macdonald, P.C, M.P., F.R.S. 
Prime Minister, 

lo Downing Street, S.W. i. June 23, 1934. 

Sir, — We beg leave to submit herewith a memorandum on the subject 
of an Inland Water Survey, which is the outcome of the work of Committees 
of the British Association and the Institution of Civil Engineers during the 
past two years. In the belief that this is a matter of national urgency, we 
venture to ask whether you would be so good as to receive us and some of 
our colleagues as a deputation to discuss the matter further. 

We are, Sir, 
Your Obedient Servants, 
J. H. Jeans, 
President of the British Association for the Advancement of Science. 

Henry Maybury, 
President of the Institution of Civil Engineers. 

To THE Right Hon. J. Ramsay Macdonald, P.C, M.P., F.R.S., 
Prime Minister. 

Memorandum on Inland Water Survey. 

Sir, — The situation created by the present unprecedented shortage of 
water in the country and the emergency measures which have had to be 
taken in consequence impels us to lay before you a cognate matter of no less 
vital importance which has been a source of concern for many years past to 
responsible officials and those engaged in connection with water undertak- 


ings and all others interested in the flow of rivers and streams. This is the 
pressing need for a complete and systematic investigation of the water 
resources of the country carried out under auspices of an unquestionably 
impartial and disinterested character. 

The call for a national Inland Water Survey dates back for many years. 
It can be traced as far as the time of the eminent engineer Telford, who, in 
1834, prepared a report on the Means of Supplying the Metropolis with 
Pure Water. During the century which has elapsed since then, it has been 
repeated on numerous occasions in the proceedings of scientific and technical 
societies and in reports presented to the Government by various commis- 
sions of inquiry. Of late, it has become so widespread and insistent that 
in September 1932, at the instance of a number of engineers and scientists, 
the British Association appointed a representative committee of professional 
men and departmental officials to inquire into the whole matter and to 
consider the possible organisation and control of such a survey by central 

This committee made a careful investigation extending over many months 
into all the available sources of information, and in the end drew up a Report 
which was presented to the British Association in September last. The 
Report, a copy of which is appended, sets out the urgent representations 
which have been made from time to time during the past fifty years for a 
thorough examination and an efficient control of the national water resources, 
in accordance with the practice of other leading countries, which it is shown 
have instituted and maintain organisations for investigating, conserving and 
allocating their own supplies. By way of exemplification, it is only necessary 
to quote the following brief but emphatic statement from the Final Report 
(1921), of the Water Power Resources Committee of the Board of Trade : 

' We find that the difficulty in fairly allocating the natural sources of 
water is becoming greater year by year in England and Wales, and the evidence 
we have heard proves beyond doubt the urgent necessity in the national 
interests of some measure of control of all water, both underground and 
surface, in order that the available supplies may be impartially reviewed and 
allocated, and may be made to suffice for all purposes in the future. In 
consequence of the increase of population, the improvement in conditions 
of life and the growing requirements of industry, the demand for water is 
steadily increasing, and the problem of meeting future needs is giving rise 
to anxiety in many parts of England and Wales.' 

To this it may be added that the recently issued (1934) Report of the 
Committee on Scottish Health Services appointed by the Secretary of State 
for Scotland affirms, with equal conviction, cause for similar anxiety in 
Scotland, and urges that ' a technical survey of the water resources and 
supplies of Scotland should be undertaken at once.' 

Justifiably impressed by the overwhelming weight of evidence, the British 
Association Committee came unanimously to the following conclusions : 

(i) That a systematic survey of the water resources of Great Britain is 
urgently required, and 

(2) That the Survey, in order to be of maximum utility, should be con- 
ducted by a central organisation, preferably under a Government 
department, independent of any interest in the administration, 
control or use of water. 

After consideration of various alternatives, it was decided to recommend 
that a beginning be made in a comparatively small way financed by sub- 
scriptions from individuals and bodies interested, with the prospect of being 
ultimately incorporated in a Government department. 


Accordingly the British Association, having adopted the Committee's 
Report, invited the Council of the Institution of Civil Engineers to take the 
matter up, and they, in turn, appointed a Committee for the purpose of 
ascertaining whether it was feasible to carry out a scheme on a self-supporting 
basis. In view of the adverse replies received with regard to finance as a 
result of an appeal to the Catchment Boards and other authorities for technical 
and financial support, this has been found to be impracticable. 

The experience of the present drought has brought home to the public 
mind the vital importance of conserving the national water resources. 
Both the British Association Committee and the Committee of the Institu- 
tion of Civil Engineers now feel not only that they have every justification 
for so doing, but that the time is eminently opportune and propitious for 
an appeal to the Government to take action and to set up an organisation 
to undertake a comprehensive inland water survey. 

We suggest that effect might be given to this recommendation through 
the agency of the Department of Scientific and Industrial Research by the 
appointment of a special board, with a headquarters staff, to deal with the 
collection, collation and technical direction of water measurements and 
gaugings throughout the country. The records of water undertakings, 
river conservancies and catchment boards, as well as readings due to private 
enterprise, could be drawn upon for the supply of data, and further observa- 
tions and measurements made as may be found necessary. 

The Department of Scientific and Industrial Research, comprising as it 
does such related branches of work as the Geological Survey and Water 
Pollution Research, seems to us particularly adapted for scientific investiga- 
tion of this kind, and we are greatly influenced by the consideration that it is 
entirely independent of interest in the use and control of water, a qualifica- 
tion which we hold to be of the highest importance. 

It is not necessary at this stage to discuss in detail the system of organisa- 
tion for the proposed department, but in outline it might consist of an 
unpaid board with a salaried staff. Voluntary assistance by competent 
persons might be available in various parts of the country, as in the case of 
the British Rainfall Organisation. The department would undertake the 
publication of records at a suitable charge which should materially assist 
towards the cost of the survey. 

Before the most effective use can be made of the country's water resources 
it is imperative that the fullest information be available respecting the 
quantity and locality of supplies, and for this purpose a thorough and 
impartial survey is essential. 

We respectfully urge, therefore, that His Majesty's Government will give 
our recommendation their immediate and favourable consideration, in view 
of the important national interests which are involved. 

We are. Sir, 
Your Obedient Servants, 
J. H. Jeans, 
President of the British Association for the Advancement of Science. 

Henry Maybury, 
President of the Institution of Civil Engineers. 

At the Aberdeen Meeting, on the recommendation of Sections A 
(Mathematical and Physical Sciences), C (Geology), E (Geography), and 


G (Engineering), the following resolution was forwarded by the General 
Committee to the Council for consideration and, if desirable, for action : 

That the British Association awaits with great interest the result of the 
careful consideration which His Majesty's Government has promised to 
give to the question of an Inland Water Survey, and trusts that the 
Government will be favourable to the establishment of an organised 
survey of the water resources of the country on a scientific basis. 


Report of Committee appointed to co-operate with other Sections interested, 
and with the Zoological Society, for the purpose of obtaining support 
for the 'Zoological Record' (Sir Sidney Harmer, K.B.E., F.R.S., 
Chairman ; Dr. W. T. Calman, F.R.S., Secretary ; Prof. E. S. 
Goodrich, F.R.S., Prof. D. M. S. Watson, F.R.S.). 

The grant of £50 was paid over to the Zoological Society on June 2, 1934, 
as a contribution towards the cost of preparing and publishing Volume 
LXIX of the Zoological Record for 1932. The statement of the ' Record 
Fund ' given in the report of the Council of the Zoological Society for 1933 
shows that the balance in hand had again increased slightly, from 
£2,286 15X. ^d. to £2,317 i8j. zd. The loss on Volume LXIX is given as 
£1,055 i6i. dd., against which has to be set £246 7^. iid. received from 
sales of back volumes, leaving a net deficit of £809 85. 7J. This is met by 
contributions of £500 from the Zoological Society, £200 from the Trustees 
of the British Museum, and smaller sums from other contributing societies. 
It is clear that the Zoological Record could not be carried on without such 
help, and it is, therefore, most important that the support of the British 
Association should be continued. The Committee accordingly asks for 
reappointment, with the renewal of the grant of £50. 



Report of Committee appointed to inquire into the present state of knowledge 
of the Human Geography of Tropical Africa and to make recommenda- 
tions for furtherance and development (Prof. P. M. Roxby, Chairman ; 
Prof. A. G. Ogilvie, O.B.E., Secretary ; Mr. S. J. K. Baker, 
Prof. C. B. Fawcett, Prof. H. J. Fleure, Dr. A. Geddes, Mr. E. B. 
Haddon, Mr. R. H. Kinvig, Mr. J. McFarlane, Col. M. N. 
MacLeod, D.S.O.. M.C., Prof. J. L. Myres, F.B.A., Dr. R. A. 
Pelham, Mr. R. U. Sayce, Rev. E. W. Smith). 

In the Report for 1932-33, which summarised the past activities of the 
Committee, it was pointed out that the Government of Northern Rhodesia 
had responded to the request for answers to the questionnaire in respect of 
most of the Districts of the Protectorate. Two further reports have been 
received, making a total of thirty, while only two are now outstanding. 

During the past year it has been decided that the Committee should 
undertake the compilation of a small volume based upon these reports and 
comprising an account of the Social Geography of Northern Rhodesia. 
Considerable progress has been made towards this end by the Secretary, 
and a forecast of part of the content of the work is indicated in the Presidential 
Address to Section E (Geography) for the present year. At the same time 
the Committee felt that the original reports themselves constitute valuable 
documents which should be preserved and be made available to facilitate 
other research work in the fields of geography and anthropology. At its 
request, a special grant of £5 was made by the Council to enable the 
Committee to copy the originals by the photostat process on a reduced 
scale. But unfortunately this grant has been found to cover only half of 
the cost of copying. The Committee is therefore including a like sum in 
its present application, to complete the work. 

Contact has now been established with other bodies interested in its 
work and mentioned in its previous Report, and there is every prospect of 
close co-operation. 

The visit of Mr. S. J. K. Baker to East Africa has already borne some 
fruit by his publication of a paper interpreting the population map of 
Uganda (in the Uganda Journal, 1934) ; while Mr. Baker has also prepared 
a general population map of East Africa based upon all available material. 
The Committee has decided to approach the various Governments with a 
view to obtaining more detailed material for the compilation of population 
density maps of all the British territories. 

In the past year the paper by Messrs. E. A. Leakey and N. V. Rounce 
on the Kasulu District of Tanganyika has been published in Geography 


The Committee has spent £3 6s. zd. of its grant of £5, while a profit 
from sales of the pamphlet amounting to £1 55. 3^. has been handed to the 
General Treasurer. 

The Committee asks for reappointment with the addition of Mr. W. 
Fitzgerald, and applies for a grant of £25 for the following purposes : (a) to 
complete the photostat copying of the Northern Rhodesia reports ; {b) to 
cover expenses to be incurred in preparation of the work on the Social 
Geography of Northern Rhodesia with a view to publication ; (c) for the 
purchase and distribution of separate copies of articles communicated to 
societies for publication ; and {d) for secretarial expenses during 1934-35. 



Ninth Interim Report of Committee on Earth Pressures (Mr. F. E. 
Wentworth-Shields, O.B.E., Chairman ; Dr. J. S. Owens, Secre- 
tary ; Prof. G. Cook, Mr. T. E. N. Fargher, Prof. A. R. Fulton, 
Prof. F. C. Lea, Prof. R. V. Southwell, F.R.S., Dr. R. E. Stradling, 
Dr. W. N. Thomas, Mr. E. G. Walker, Mr. J. S. Wilson). 

Since their last report, the Committee have learnt with deep regret that, 
owing to serious illness. Prof. Jenkin has been obliged to abandon the work 
in which he and they have been so keenly interested. 

The Committee would like to place on record their very high apprecia- 
tion of the great value and importance of Prof. Jenkin's contribution to 
the solution of earth pressure problems. 

The Committee have received a report from Prof. Jenkin, in which he 
summarises his general conclusions at the stage when he was obliged to 
discontinue his researches. He also emphasises the practical importance 
of the subject, and the desirability of completing the investigation. The 
report is attached. 

The Committee have also before them a report from the Research 
Station, written by Mr. D. B. Smith, B.A., which is an account of his 
collaboration with Prof. Jenkin on the experimental work on Kaolin, which 
has been carried out at the Research Station since 1932. 

This work is not complete, but the Committee hope it will be published, 
either by the Association or elsewhere, because it contains very valuable 
information and also because it will give most useful guidance to future 

Although, if Prof. Jenkin had been able to continue his work, he would 
doubtless have made some further experiments on these lines, he has 
expressed the view that this particular field of investigation will not yield 
much further result. 

Nevertheless, Dr. Stradling is anxious that the Committee should continue 
to keep in touch with the work connected with earth pressures which is 
being carried out at Garston. 

The Committee too are anxious to do so, because they realise that this 
work will assist the solution of those earth pressure problems which are its 
chief interest. 

They therefore ask to be reappointed. 

The Mechanics of Granular Material 


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


The writer has been working at the theory of the mechanics of granular 
material for many years ; his researches have now been brought to an end 
by failing health. This paper summarises the general conclusions at which 
he has arrived, and may be of some use to those who follow ; it does not 
pretend to be a scientific paper, for no proofs of the statements it contains 
are given. 



So far as the writer is aware there has never been any thorough investiga- 
tion into the mechanics of granular material. The importance of the 
subject may be indicated by giving a list of some of the subjects for which 
a theory of the mechanics of granular material is wanted. 

1. Foundations (bearing pressures of soil). 

2. Retaining walls, dock walls, etc. (horizontal earth pressures). 

3. Earthworks (railway cuttings and embankments). 

4. Landslides and their prevention. 

(Items 1-4 have been entered without qualification, since clay 
and other cohesive soils have now been shown to be granular 
materials (see p. 249).) 

5. Cement, mortar and concrete (grading, ramming and measuring 

6. Roads (foundations, ballast, ramming and rolling both foundations and 
concrete and surface material). 

7. Silos, bins and hoppers for storing grain, coal, road-metal, etc. Design 
of the buildings and design of the valves and chutes for controlling 
the outflow. 

Dry Granular Material. 

The two physical properties of granular material on which their remark- 
able mechanical properties mainly depend are their compactability and 

Compactability denotes the most widely known property of granular 
material, namely, that its specific volume depends on the closeness of the 
packing of the grains. How to produce closest packing is unknown, and 
the primitive methods of ramming and shaking ^ are still used, though 
anyone who has experimented with them knows how uncertain their results 
are. Specific volume and closeness of packing are often measured by the 
' percentage of voids,' the term ' void ' being used to denote the spaces not 
occupied by the solid grains ; the spaces are still called ' voids ' when 
partly or completely filled with water. 

Dilatancy denotes the converse property of all granular material (except 
when very loosely packed) of expanding in volume when its shape is changed, 
i.e. when it undergoes shear strain. 

Dilatancy has been discussed by the writer in his paper on ' The Pressure 
Exerted by Granular Material,' Proceedings Royal Society, vol. 131, 1931, 
p. 53. Dilatancy causes granular materials to move in jerks instead of 
uniformly ; a familiar example is the alternate building up and collapse 
of the cone of sand in the bottom of an hour-glass. The cyclic movement 
of sand slipping down against a retaining wall is described in the writer's 
paper on ' The Pressure on Retaining Walls,' Proceedings Institution of Civil 
Engineers, vol. 234, 1931-32, Part 2, p. 103. This cyclic motion provided 
the clue to the theory of pressures on retaining walls given in that paper, 
which the writer believes to be the first paper to take account of the actual 
behaviour of granular material. 

The importance of dilatancy has been further emphasised by the writer's 
recent discovery that clay exhibits this phenomenon. He has been working 
for the past eighteen months exclusively on the mechanics of plastic China 
clay and has tested it in compression, tension, simple shear, shear plus 
end compression, and in compression plus hydraulic pressure, besides 

^ Cf. ' Good measure, pressed down, and shaken together ' (St. Luke vi. 38). 


making many special tests. All these tests indicate that China clay behaves 
as a very fine wet granular material (for definition, see p. 250) ; that is to say, 
exhibits compactability and dilatancy and cohesion due to the water content. 
As dry, wet and moist sand (as defined later) all exhibit the same phenomena, 
it is probable that all soils exhibit the fundamental properties of granular 

Cohesive Granular Material. 

The cohesive materials here discussed are only the granular materials 
rendered cohesive by the presence of water or other liquid ; all soils, 
including clay, except when baked dry, come under this definition, also 
freshly mixed cement, mortar, and probably concrete and plaster, before 
they set. Tar-macadam and such road materials are included. 

Just as the old theories of the mechanics of dry granular material, such 
as Rankine's, are necessarily imperfect because they neglect the effects of 
compactability and dilatation, so the old theories of cohesive granular material, 
arrived at by endowing such dry granular material with a shear strength, 
are also imperfect and may lead to very erroneous results. The writer 
has come to the conclusion that there are certainly two (possibly more) 
different types of cohesive granular material of common occurrence which 
possess quite different properties ; they may be called : 

1 . Moist granular material, and 

2. Wet granular material. 

I. Moist Granular Materials. — The common example of this type is damp 
(not saturated) sand. It has been much studied in agricultural research. 
Each grain is wet and where they touch a little disc of water forms, bounded 
by an annular meniscus. The surface tension on this meniscus exerts 
a small force, drawing the grains together. The magnitude of the forces 
and their dependence on the size of the grain and the amount of water is 
discussed in Fisher's papers, ' On the Capillary Forces in an Ideal Soil ' 
{Journal Agricultural Science, 1926, pp. 492-503 ; 1928, pp. 406-410). The 
' voids ' — i.e. spaces between the grains — are filled partly by air and partly 
by water. If the quantity of water is suflRcient to fill the voids, thus excluding 
air, the meniscuses disappear and the conditions entirely change. If the 
water dries up the meniscuses disappear and the conditions change to those 
of ordinary dry granular material, except when the material sets solid, which 
is notably the case when there is very fine granular material present — i.e. 
colloidal material — which ' glues ' the grains together. 

Compactability . — Moist granular material is compactable, like dry granular 
material. During compaction the percentage of voids decreases and more 
points of contact arise, so that the cohesive forces change. As the packing 
gets still closer a state may be reached when the voids are entirely filled 
with water, and cohesion will disappear. The material then ceases to be 
moist granular material. 

Dilatancy. — Moist granular material exhibits dilatancy just as dry granular 
material does. During dilatation the number of meniscuses is reduced and 
the cohesive forces change. Saturated granular material may be converted 
into moist material by dilatation, the free water being sucked into the voids, 
followed by air. This phenomenon was described by Osborne Reynolds 
in his original paper." 

An admirable material for experiments on this type of granular material 
may be made by stirring a few drops of olive oil into a beaker-full of the 
minute spherical beads known as ' glistening dew ' (vide Proceedings Royal 

* Videwol. 2 of OsborneReynolds' Scientific Papers, Cambridge University Press. 


Society, loc. cit.). The oil quickly coats every bead and provides the 
minute discs and meniscuses at every point of contact. Oil is preferable 
to water, which dries up too quickly. By varying the size of the beads 
and the nature of the liquid the properties can be varied. The writer has 
experimented with this material, but has made very few mechanical tests 
on it. The mechanical properties of moist granular material await 

2. Wet Granular Material. — Only extremely fine granular materials form 
stable masses when saturated with water, and it is only with these that we 
are here concerned. Saturated gravel or sand (except the finest) slumps 
down and the water drains off ; we are not concerned with such substances. 
Coarse granular material under water behaves like dry material (see the 
writer's Institution of Civil Engineers paper, loc. cit.). 

Very fine granular material, such as China clay powder, when stirred up 
with water only settles very slowly. If the sediment is removed from the 
water, more water drains off, but the mass remains saturated throughout. 
If the sediment is put into a filter press more water may be extruded, and 
the material remaining is a more or less plastic mass held together by the 
negative water pressure or ' suction ' of the water in the ' voids. It 
possesses resistance to deformation (shear strength), which is due to the 
friction between the grains held together by the suction.^ The suction or 
negative water pressure would draw in air but for the layer of water on the 
surface of the mass ; the suction draws this surface layer of water into each 
space between the surface grains, forming innumerable minute meniscuses 
which support the suction. 

Compactability. — Wet granular material, as defined above, is almost 
incompressible, since it is made up of solids and water ; but if the water is 
allowed to escape (as, for instance, in a filter press), it is just as compactable 
as dry granular material, and any type of ' working,' as before, facilitates 
the packing of the grains. A slight alternating torsion produced by rotating 
the piston of the press backwards and forwards through a small angle is 
effective, but how to produce the closest packing is not known. The 
unwanted extrusion of water from clay due to unexpected compaction is 
liable to interfere with all tests or methods of preparing test-pieces which 
are carried out in closed vessels. The sudden appearance of drops of water 
oozing out through the joints of the apparatus is a most familiar sight, and 
sets a limit to the range of many tests. Extrusion of water from a free 
surface never takes place. 

The permeability of ultra fine-grained material is very small, so that the 
water can only escape slowly, and time is required for compaction. 

Dilatancy occurs in wet granular material, as defined above, just as in dry 
granular material, but its results are different because the volume of wet 
material cannot expand (the minute elastic expansion and the minute 
expansion permitted by the increased depth of the surface meniscuses may 
be neglected at present). 

When wet granular material is sheared the incipient dilatation causes a 
rapid rise in the suction. The rise in the suction involves an increasing 
compressive stress which has two effects : firstly, it increases the friction 
between the grains and consequently the resistance to shear ; secondly, it 
begins to compact the mass. The combined result of the dilatation and 
this compaction is that the volume remains almost constant while the suction 
and shear strength rise. This action continues till one or other of two * 

* Molecular forces probably also have an appreciable efifect. 
^ A third condition appears to limit the strain in tensile tests on clay, but 
too few tests have been made to determine what happens with certainty. 


conditions supervenes : (i) either the suction reaches the maximum value 
which the surface meniscuses can bear, in which case they break and air 
enters the mass ; as the shear strength can get no greater the mass fractures, 
the air enters the plane of fracture and the break looks like a break in stone ; 
or (ii) the dilatation reaches its full value, the suction ceases to rise and the 
strength also ceases to increase ; the mass then yields freely in shear ; it is 
not broken in two. Both types of failure have been produced experirnentally 
in compression test-pieces ; the first is typical of non-plastic materials and 
the second of plastic materials, such as clay. 

At first sight the conception of simultaneous dilatation and compaction 
may appear paradoxical and unnecessary, but further consideration leads to 
the conclusion that it is the obvious way of accounting for the observed 
facts that the suction rises and the strength increases while the volumes 
cannot change. An interesting comparison may be made with the experi- 
ment quoted on p. 54 of the author's Royal Society paper (loc. cit.), in which 
an attempt was made to shear dry sand in a closed vessel ; dilatation 
prevented any motion till the sand crushed under a very large stress (the 
sand in that experiment had been closely packed so that further compaction — 
except by crushing — was impossible). 

This brief outline of what happens when wet granular material is sheared 
leaves out of account many factors which probably play important parts. 
The shape of the grains, and possibly their mechanical deformation, is 
believed to be important in determining the plasticity of clay. Again, the 
grains in clay are so small that forces which may be called molecular or 
electric must play an important part. What the relative importance of the 
diflferent factors may be has not yet been determined ; all that the writer 
claims is that China clay has been proved to exhibit compactability and 
dilatancy and must be classed as a wet granular material, whatever other 
properties it may have. The fact that China clay turned out to exhibit 
dilatancy, contrary to expectation, was the reason that the whole series of 
researches just completed at the Building Research Station turned out to 
be inconclusive. 


Now that the finest ground sand and the much finer China clay have 
been proved to exhibit compactability and dilatancy the writer has no 
longer any doubt that cements, plasters, mortars and concretes will all be 
found to exhibit the characteristic properties of granular materials, and 
that when mixed with water they will be found to belong to the classes of 
moist or wet granular materials as defined above. 

It would be diflScult to name any fundamental research that has such a 
close connection with buildings and roads as the investigation of the 
mechanics of granular material. The writer hopes that the work may be 
successfully completed at the Building Research Station. 



Interim Report of Committee on Stresses in Overstrained Materials (Sir 
Henry Fowler, K.B.E., Chairman ; Dr. J. G. Docherty, Secretary ; 
Prof. G. Cook, Prof. B. P. Haigh, Mr. J. S. Wilson). 

The Committee finds that the programme of investigation outlined in 
previous reports has proceeded more slowly than was anticipated, and no 
extended report is possible this year. Prof. Cook has published a paper 
on ' The Stresses in Thick-walled Cylinders of Mild Steel overstrained 
by Internal Pressure ' in the Proceedings of the Institution of Mechanical 
Engineers, and Prof. Haigh is presenting to Section G a paper recom- 
mending the more general specification and use in design of the Lower 
Yield Point of mild steel, which bears directly on the work of the Com- 
mittee. This is not put forward as a report, but will be referred to when, 
as is hoped, the Committee presents a full report next year. 
The Committee asks to be reappointed for another year. 


Report of Committee, with terms of reference stated below (Sir Henry 
Fowler, K.B.E., Chairman ; Wing-Commander T. R. Cave- 
Browne-Cave, C.B.E., Secretary ; Mr. R. S. Capon, Dr. A. H. 
Davis, Prof. G. W. O. Howe, Mr. E. S. Shrapnell-Smith, C.B.E.). 

The Committee was set up to review the knowledge at present available for 
the reduction of noise and the nuisances to the abatement of which this 
knowledge could best be applied. 

Sir Henry Fowler, K.B.E., was appointed Chairman, Wing-Commander 
Cave-Browne-Cave, C.B.E., Hon. Secretary, Mr. Capon and Prof. Howe 
were appointed members, and to these Dr. Davis and Mr. Shrapnell-Smith 
were added later. 

A grant of £io was made to cover correspondence, and at the beginning 
of May 1934, the Association, finding that there was a balance of £24 out- 
standing in one of their other accounts, allotted it to the work which was 
being done for the Committee on the reduction of exhaust noise. 

The Chairman wrote to The Times on September 30, 1933, inviting 
reasoned opinions from members of the public as to the noises which caused 
them most discomfort and inconvenience. 

A very large number of replies to that letter were received and analysed. 
They led definitely to the conclusion that the sources which caused most 
annoyance and inconvenience were inadequately silenced motor bicycles 
and cars, then motor horns, other road transport noises, and finally aircraft. 

No other noise caused half the complaint levelled against the last of this 
first group (aircraft). 

The Committee realised that the Air Ministry was doing everything 
possible to reduce the noise of aircraft as heard by passengers and also by 
persons on the ground. 

The Committee, therefore, decided first to devote their attention to the 
general problem of exhaust noise of motor bicycles and sports cars. They 
also decided to invite Messrs. Lucas, a firm who make a great variety of 


electric motor horns and other devices for giving the audible warning of 
approach specified in the Act, to prepare a paper examining the character- 
istics which render such a signal effective as well as those which cause it 
to be offensive. 

This paper will be read by Mr. E. O. Turner, and a demonstration of 
various sound signals will be given. 

Wing-Commander Cave suggested that in order to produce a general 
decrease in exhaust noise it was necessary not only to determine the principles 
on which better silencers should be based, but to outline an organisation 
whereby these principles could be given general practical effect. He pro- 
posed that the Committee should work towards the objective of enabling 
an authority to be set up to which manufacturers could submit new types of 
motor vehicle to be tested for a certificate of approved silence. 

For this purpose it would be necessary to determine a satisfactory instru- 
ment for measuring the noise produced by the vehicle and to specify the 
conditions under which tests should be made. 

It would also be necessary to indicate to this authority what should be 
accepted as a reasonable standard to which vehicles must conform. For 
this latter purpose he proposed to undertake some preliminary tests upon 
the silencers of motor bicycle engines. 

He was able to obtain the advice of the Motor Cycle Manufacturers and 
Traders Union as to the requirements which a silencer must meet. He 
then made some preliminary experiments ' to determine which general 
principles of noise reduction were the most effective. The results of these 
preliminary tests were encouraging, but the subsequent experimental work, 
carried out at the University College, Southampton, was only rendered 
possible by a donation of £50 made by Lord Wakefield to him for that 

A number of designers visited Southampton, and considered the pre- 
liminary results so far satisfactory that they selected and sent to Southampton 
a 2-stroke and 4-stroke bicycle, each of normal type, as sold to the public. 

Wing-Commander Cave's work and the conclusions which he has reached 
will be described in his own paper and demonstrated in trials on the road. 
They indicate that it is now quite possible to effect a great reduction of 
exhaust noise by the use of a silencer which results in a small increase of 
horse-power rather than a decrease when compared with that attained with 
the silencers as now commercially sold. 

The Committee wishes to express its great appreciation of the assistance 
rendered by the Motor Cycle Manufacturers and Traders Union in discussing 
the problem and then supplying Wing-Commander Cave-Browne-Cave 
with the two bicycles and every incidental detail he required. 

Dr. Davis, of the National Physical Laboratory, agreed to undertake a 
critical review of various instruments and methods available for measuring 
noise, with particular reference to the question of testing noises of a given 
type, e.g. exhaust noises. His conclusions will be given in his paper and 
suggest that, if agreement can be reached as to the conditions under which 
a test could be made, it is within the scope of suitable noise meters, which 
do not depend upon personal judgment, to determine satisfactorily whether 
the noise of a unit submitted for test does or does not exceed that of a 
standard noise of the same kind agreed to be the maximum acceptable 
under a regulation. 

The whole of the money allotted to the Committee has been spent, and 
if the full cost taken by University College, Southampton, were included, 
there would be considerable over-expenditure, even with Lord Wakefield's 
generous donation. 


The Committee prefers to wait until it has heard the discussion on these 
three papers before it makes any definite recommendation as to further 
work which should be undertaken. 


Twelfth Interim Report of Committee appointed to co-operate with a 
Committee of the Royal Anthropological Institute in the exploration of 
caves in the Derbyshire district (Mr. M. C. Burkitt, Chairman ; 
Dr. R. V. Favell, Secretary ; Mr. A. Leslie Armstrong, Prof. H. J. 
Fleure, Miss D. A. E. Garrod, Dr. J. Wilfrid Jackson, Prof. L. S. 
Palmer, Mr. H. J. E. Peake). 

No new excavation work has been undertaken by the Committee during 
the current year, but the excavation of the Pin Hole Cave, Creswell Crags, 
has been steadily advanced by Mr. Leslie Armstrong, F.S.A., and it is 
anticipated that this work will be completed during the coming autumn. 
The following reports have been submitted. 

Report on Excavations in the Pin Hole Cave, Creswell Crags. 

By A. Leslie Armstrong, F.S.A. 

Subsequently to the presentation of my last report, the section in the rear 
of the main chamber, then under examination, was completely excavated 
to the base level just prior to the Leicester Meeting of the Association, 
thereby enabling the complete stratification of the cave deposits, 17 ft. 
in thickness, to be exposed for examination by Section H during the visit 
to the cave on September 9, 1933. After inspecting the section the Chair- 
man and members of the Committee present agreed that the excavation 
of a further portion of the rear passage was desirable before closing down 
the work, and that ultimately a typical section of the deposits, similar to 
that exposed on this occasion, should be permanently preserved. The 
examination of an additional 15 ft. was therefore commenced during 
October 1933, and, at the time of writing, one-third of this length has 
been excavated to the base level, a total depth of 18 ft. ; a further one-third 
down to the 12-ft. level ; and the remainder to the depth of 6 ft. Though 
the width of this portion of the cave nowhere exceeds 5 ft., and in places is 
only 2 ft., progress has been slow and the work somewhat laborious on 
account of the layer of hard crystalline stalagmite, 9 in. to 12 in. in thickness, 
which crowned the deposit, and the numerous slabs and masses of fallen 
limestone which were cemented into it. Jumbled rocks, of large size, 
have also been unusually numerous within the cave earth and, in places, 
completely blocked the passage. The stratification, however, has been 
well defined throughout, and the two layers of fallen slabs which through- 
out the cave have so consistently separated the Mousterian (i) and (2) and 
Mousterian (2) and (3) levels have been equally well marked in this portion 
also. Having regard to the fact that the presence of so many fallen blocks 
must have always rendered this part of the cave unsuitable for occupation, 
it was anticipated that artifacts would be few, but that the chance of dis- 
covering human remains was promising. Unfortunately, the latter has not 
been realised, but artifacts, in all levels, have been more numerous than 
was expected. A cavity in the upper surface of the stalagmite, filled with 
slightly brecciated black earth, yielded pins of mediaeval type and a small 
Saxon brooch, in bronze, of cruciform pattern. A sherd of Iron Age 


pottery occurred in a similar cavity. The upper cave-earth yielded several 
artifacts of flint, including a fine battered-back knife from the Font Robert 
level, tools of limestone, and pieces of worked bone and reindeer antler. 

Fish scales and portions of a large egg, probably duck, occurred in the 
same level, also pot boilers of stone and fragments of charcoal around 
a possible, but not vi'ell-defined, hearth. 

Tools of quartzite, crystalline stalagmite and limestone, similar to 
specimens previously found, have occurred in each of the three Mousterian 
levels. Two finds of special interest have been made in the 12-ft. layer, 
Mousterian (2) in age. The first of these is a bone tool 2 in. long, roughly 
triangular in form, with a base i in. wide, cut into the form of two prongs, 
each I in. long. The second appears to be a bone " bull roarer." It is 
3J in. long, I in. wide, and of pointed oval form, perforated near one end 
and having an extreme thickness of about | in. 

In comparison with other portions of the cave, animal remains have 
been less numerous, and no additions have been made to the fauna already 
recorded. During the spring a number of flies were collected, infested 
with fungi. These I submitted to Mr. T. Fetch, F.R.M.S., who has 
kindly supplied the accompanying report, from which it will be observed 
that the specimens include new species of fungi and others of special interest. 
A report by Dr. J. W. Jackson, on the remains of small mammals, etc., 
collected, is also attached. 

I anticipate that the excavation will be completed early in the coming 
autumn, and I propose to leave an entire cross-section of the deposit exposed 
to view. This will form the most complete and representative stratified 
section of the Upper and Lower Palaeolithic cave deposits of Britain, and 
it is earnestly hoped the Committee will take the necessary steps to preserve 
it intact as a British type section, adequately protected against unauthorised 

Future Work. — An unexpected opportunity has presented itself for the 
immediate excavation of the Boat House Cave, on the southern side of the 
gorge and at its eastern extremity, through the draining of the lake which 
has hitherto occupied the bed of the gorge and prevented any examination 
of this cave. 

It will be necessary to undertake the work without undue delay. A trial 
section has yielded promising indications and proved that the deposits are 
entirely undisturbed. 

I propose, subject to the sanction of the Duke of Portland, to commence 
this work immediately upon the completion of the Pin Hole excavations. 

Report on Fungi occurring on Flies collected in the Pin Hole Cave. 

By T. Fetch, B.A., B.Sc. 

Five species of fungi have been identified on the flies collected by 
Mr. Leslie Armstrong in Pin Hole Cave. These are : 
(i) Hirsutella, new species, parasitic on Blepharoptera. 

(2) Stilbella Kervillei (Quel.) Lingelsh., parasitic on the Hirsutella. 

(3) Spicaria {Isaria) farinosa (Holms) Fr., parasitic on gnats. 

(4) Sporotrichum Isarice Fetch, parasitic on Spicaria (Isaria) farinosa. 

(5) Beauveria Bassiana (Bals.) Vuill., parasitic on a fly. 

Hirsutella sp. nov. — This fungus first forms discontinuous brown patches 
of mycelium on the body of the insect, and subsequently, erect fuscous 
clavae, up to 8 mm. long and 02 mm. diameter. In this condition the 
fungus is fertile and identifiable. 

Very frequently, however, the Hirsutella develops into long hair-like 


strands, 8 cm. or more long, frequently branched. In that state the strands 
are usually sterile. A similar phenomenon occurs in the case of the common 
tropical HirsuteUa on Hymenoptera, Hirsutella Saussurei, in which small 
clavae, a few millimetres long, are fertile, but the conspicuous long black 
clavae, 5 cm. or more long, are sterile. Several of these abnormal sterile 
forms of the new British species have been collected by Mr. Armstrong, 
but they could not be identified until the smaller fertile form was found. 
There is also a specimen in the Herbarium of the British Museum (Natural 
History), a fly {Blepharoptera serrata Fabr.) bearing long sterile hair-like 
clavae, collected ' in a stalactite cave,' Yealhampton, Devon, June 1906, 
which can now be assigned to the new British species of Hirsutella. 

Only one normal unparasitised specimen of this Hirsutella occurs in 
Mr. Armstrong's collections. 

Stilbella Kervillei (Quel.) Lingelsh. — This species was described by 
Quelet from specimens, apparently parasitic on flies {Blepharoptera), found 
in caves in France. It has since been found in caves elsewhere on the 
Continent. Mr. Armstrong's specimens, first found in the Creswell Caves 
in 1923 and recorded by Mr. F. A. Mason in Journal of Botany, August 
1931, pp. 205-207, were the first to be found in Britain. More recently 
several examples have been collected by Mr. Armstrong in Pin Hole Cave. 

Quelet described his species as having a simple white stalk and a yellow 
globose head, but with brown mycelium on the body of the insect, an un- 
usual difference in colour. Mr. Armstrong's first specimens agreed with 
Quelet's description, but in the examples from Pin Hole Cave many were 
apparently branched, up to twenty Stilbella fructifications occurring as 
short lateral branches of a long central stalk. On examination it was found 
that the central stem was really a Hirsutella clavae, and that the brown 
mycelium on the insect was Hirsutella mycelium, bearing typical Hirsutella 
conidiophores and conidial clusters. 

Thus Mr. Armstrong's specimens demonstrate that Stilbella Kervillei 
is not parasitic on insects, as was supposed, but is parasitic on another 
fungus, a Hirsutella, the latter being entomogenous. 

As far as is known, neither Stilbella Kervillei nor the Hirsutella have been 
found except in caves. 

Spicaria (Isaria) farinosa (Holms) Fr. — The large majority of the speci- 
mens from Pin Hole Cave consists of gnats, each enveloped in a greyish 
loose ball of mycelium. This mycelium bears a scanty grow^th of Spicaria 
conidiophores. On taking this into culture, the fungus proved to be 
Spicaria (Isaria) farinosa, the common Isaria oi Lepidoptera in this country. 

Sporotrichum Isariee Petch. — Some of the balls of mycelium on the gnats 
are pale brown. This colour is due to the growth on them of another fungus, 
Sporotrichum Isariee, which is parasitic on Spicaria (Isaria) farinosa. This 
fungus has been found previously in Yorkshire, Norfolk and Sussex. 

Beauveria Bassiana (Bals.) Vuill. — This common entomogenous fungus 
was found on one fly from Pin Hole Cave. It is generally distributed 
throughout the world, and is the cause of the disease of silkworms known as 

The Rodent Remains from the Pin Hole Cave. 

By J. Wilfrid Jackson, D.Sc, F.G.S. 

The rodent remains obtained by Mr. A. Leslie Armstrong, F.S.A., 
from the section excavated during 1933-34 readily fall into two main 
groups, a lower and an upper, according to the levels from which they 
come. Those submitted from the Lower Rodent-level, viz. 10 ft. to 


13 ft., comprise the following species : Lemmus lemmtts (L.) (very 
abundant), Dicrostonyx henseli Hinton (common), Microtiis ratticeps (K. & 
Bl.) (one jaw at 11-12 ft.), M. anglicus Hinton (a few jaws), M. arvalis 
(Pall.) group (a few jaws), Arvicola abbotti Hinton (three jaws), and Apodemus 
flavicoUis (Melch.) (= lewisi Newt.) (few jaws and skulls). The remains of 
Red Grouse {Lagopus scoticus Lath.) occurred at 10 ft., and those of 
Ptarmigan {Lagopus mutus Mont.) at 9 ft. 6 in. Rodent remains from the 
Upper Rodent-level, viz. 2 ft. to 5 ft., are as follows : Lemmus lemmus (L.) 
(few), Dicrostonyx henseli Hinton (common), Microtus anglicus Hinton 
(common), M. arvalis (Pall.) group (common), Arvicola abbotti Hinton (one 
jaw), Apodemus sylvaticus (L.) and A. flavicoUis (Melch.) (common), 
Evotomys glareolus (Schr.) (five jaws), and Muscardinus avellanarius (L.) 
(two jaws). The remains of Red Grouse and Ptarmigan also occurred at 
these levels. 

In addition to the two main levels, I have identified some rodent remains 
from 8 ft., as follows : Lemmus lemmus (L.) (two jaws), Dicrostonyx henseli 
Hinton (one skull), D. gulielmi (Sanford) (one skull), and Arvicola abbotti 
Hinton (one skull) ; also Red Grouse and Ptarmigan at 7 ft. 

Among the remains of larger animals are those of Woolly Rhinoceros 
(2-11 ft.). Reindeer (6 in.-i6 ft.). Horse (1-14 ft.). Bison (1-12 ft.). Giant 
Deer (9-12 ft.). Mammoth (6 in.-i4 ft.). Hyaena (1-17 ft-), Lion (8-13 ft.). 
Bear (2 forms) (1 ft. 6 in.-i5 ft.), and Alpine Hare (2-7 ft.). 

The Dormouse {Muscardinus avellanarius) does not appear to have been 
previously recorded from British caves, though I possess unrecorded jaws 
from the Late Pleistocene cave-earth at Dog Holes Cave, North Lancashire. 
On the Continent several forms of Dormice have been recorded from the 
' Upper Rodent ' layer (Magdalenian) of the Schweizersbild Cave. 

According to Mr. Armstrong, who has based his conclusions on the 
physical evidence and on the human artifacts, the levels 10 to 13 ft. 
(Lower Rodent-layers) antedate the first phase of the Maximum Glaciation 
of Britain (Mousterian). The level 8 ft. is placed immediately before the 
second phase of this glaciation, and the levels 2 ft. to 5 ft. (Upper Rodent- 
layers) are later than the second phase and earlier than the Magdalenian 
cold phase. Judging from the material submitted, the Arctic rodents 
were more numerous when the Lower Rodent-layers were being deposited 
and became scarcer at later stages. 


Report of Committee appointed to report on the Distribution of Bronze Age 
Implements (Prof. J. L. Myres, O.B.E., F.B.A., Chairman ; Mr. 
H. J. E. Peake, Secretary ; Mr. A. Leslie Armstrong, Mr. H. 
Balfour, F.R.S., Mr. L. H. Dudley Buxton, Prof. V. Gordon 
Childe, Mr. O. G. S.Crawford, Prof. H. J. Fleure, Dr. Cyril Fox). 

In accordance with the Committee's recommendation in its report last year 
{Report Brit. Assn., 1933 (Leicester), pp. 300-1), the Council has authorised 
the deposit of the completed catalogue (which has hitherto been entrusted 
to the Society of Antiquaries) in the British Museum ; the trustees have 
undertaken the custody and maintenance of the catalogue by the staff of 
the Department of British and Mediasval Antiquities ; and the whole 
catalogue and other records of the Committee have accordingly been trans- 
ferred to the British Museum. 


The Committee has therefore now only to report the completion of a few 
remaining record cards by Miss M. Anderson, and the record of a few 
recent accessions to certain museums, and finds in private hands. 

On the conclusion of its task the Committee desires to express its apprecia- 
tion of the long and devoted labours of its secretary, Mr. H. J. E. Peake, 
to whose foresight and persistence the initiation and achievement of this 
permanent addition to archaeological equipment were due. The close 
attention, the wide knowledge, and the tact, which such an enterprise 
entails can best be appreciated by those who have had some part in it, and 
will be long and widely recognised. 


Report of Committee appointed to co-operate with the Torquay Natural 
History Society in investigating Kent' s Cavern (Sir A. Keith, F.R.S., 
Chairman ; Prof. J. L. Myres, O.B.E., F.B.A., Secretary ; Mr. M. C. 
BuRKiTT, Dr. R. V. Favell, Miss D. A. E. Garrod, Mr. A. D. 

The following report has been received from the excavators, for the season 
1933-34 : 

' The excavation of Kent's Cavern was resumed on October 30, 1933, 
and continued weekly, in the " vestibule," up to May 28, 1934. 

' This work has opened up an area of about 160 sq. ft. of floor space, 
nearly one-half of which is directly under the British Association's site of 
the " Black Band," a hearth of Magdalenian times, worked by William 
Pengelly betw^een 1865 and 1880. The greatest depth to which excavation 
has been carried this season is 10 ft. 6 in. below the general floor surface — 
i.e. about 16 ft. below the old stalagmitic floor. 

' Large fallen blocks of limestone have prevented rapid exploration, as 
blasting by explosives in the Cavern is objected to by the proprietors as 
causing annoyance and inconvenience to visitors, and the rocks have to be 
exposed and broken up by hand labour. Under and between these blocks 
of stone were found remains of large animals, many of them coated with a 
deposit of stalagmite and sometimes embedded in a very hard mixture of 
stalagmite and cave earth. 

' The remains of animals usually found in the Cavern were present in 
good number, including those of horse, rhinoceros, deer, Irish deer, bear, 
fox, ox, badger, pine marten, and mammoth. 

' Some of the most interesting finds this season were : three foot bones of 
deer, all articulating ; three vertebrae of a large animal (? rhinoceros) in 
their proper anatomical relations, found embedded in stalagmitic material ; 
a first phalanx of a human finger, found 2 ft. below the floor level ; eight 
flint implements ; a flint core, 3 in. by 2 in. by 2J in., found at a depth of 
13 ft. 6 in. below the original floor level ; small tines of deer, probably used 
as borers, and a quartzite pounder. 

' Our thanks are again due to the proprietors of the Cavern, Messrs. 
Powe and Son, for their continued assistance.' 

(Signed) Frederick Beynon, Arthur H. Ogilvie. 
The Committee asks to be reappointed, with a further grant to meet the 
expense of unskilled labour to remove sifted earth from the excavation. 



Report of Committee, appointed to carry out research among the Ainu of 
Japan, on work done by Dr. N. Gordon Miinro in Yezo between Novem- 
ber 1933 a7id May 1934 (Prof. C. G. Seligman, F.R.S., Chairman ; 
Mrs. C. G. Seligman, Secretary ; Dr. H. S. Harrison, Capt. T. A. 
Joyce, O.B.E., Rt. Hon. Lord Raglan). 

Having travelled over a considerable part of Yezo, Dr. Munro finds that 
among the Ainu at the present day there are differences in belief and ritual 
in different parts of the island. Two factors are probably concerned in 
these differences, one ancient, the other modern, (i) In the old days 
tribal conflicts were common ; the Ainu do not seem to have been united 
under any central authority, and there was no general priesthood to establish 
a canon of belief or ritual. (2) The modern factor is brought about by 
the clash of culture between Ainu and Japanese, with the consequent 
change in the old mode of life of the majority of Ainu communities. 
Hunting on land being practically a thing of the past, the Ainu depend 
more than ever upon the river and sea for sustenance. No longer can they 
barter skins for necessities or luxuries, but are compelled to eke out a living 
by attending to horses, doing odd jobs and a little field cultivation, in which 
the women play a prominent part. Ainu shopkeepers are extremely rare, 
and carpenters, blacksmiths and suchlike are almost unknown. They 
have no opportunity to learn, and if they did the Ainu communities are 
mostly too poor to support them. Ainu psychology, too, is characteristic of 
a primitive folk in transition from unsettled occupations to those that de- 
mand patient application. A Japanese servant will usually stick to his or 
her work until finished, but ' my experience with several Ainu servants is 
that they are not interested in domestic work.' 

Considering these two factors together, it is perhaps remarkable that there 
should be as much resemblance as there is between the Ainu of one region 
and another. Possibly the strict exogamy developed in ancient times 
favoured the general levelling of ideas and customs throughout the Ainu 

In spite of the decay of the old mode of life among the Ainu, there are 
still a fair number of pure-blooded elders (ekashi) among the Ainu of the 
Saru district, much of the following information being due to an old ekashi 
of 80 years, and an accomplished ritual dancer, who does not drink, is as 
bright as a man of 40. 

Social Organisation. 
Inheritance and authority are patrilineal and marriage patrilocal, at least 
many inquiries north and south yielded only this answer. Descent, how- 
ever, is strictly matrilineal, and exogamy is or was rigidly enforced. The 
Rev. Dr. Batchelor has stated (Ainu Life and Lore, p. 15) that the family 
tie was stronger on the mother's side and that the brother of the mother was 
looked upon as the real head of the family. Dr. Munro's inquiries of at 
least a dozen ekashi in the Hokkaido, in various places, failed to obtain 
more confirmation than that the mother's brother had a voice, though not 
a decisive choice, in the selection of a husband for the daughter. In 
Saghalin, he was informed by two ekashi who had lived there, the mother's 
brother has still some authority over her children, and it is hoped to learn 
more about this by local investigation. Dr. Batchelor has also stated that 


totemism existed, but the instances given scarcely seem supported by 
sufficient evidence, though there seems reason to believe that the Ainu are 
totemic. The fortunate discovery by Dr. Munro of a secret girdle worn 
by all Ainu women which no man is allowed to see, has provided a clue to 
positive knowledge of clan organisation and perhaps acceptable evidence 
for totemism. 

While discussing magical measures against epidemic invasion, an ekashi, 
Rennuikesh, said that women, by waving their girdles, could restrain /)a^^oro 
katnui (demons of pestilence), conflagrations, and even tidal waves. He 
called these girdles upsoro tush, bosom or secret cord, and further inquiry 
revealed the fact that although he had never seen one it was stated in upash- 
koma (sacred traditions) that each kind of girdle was the gift of a special 
kamiii (god, spirit), whence its magic potency. ' I then recalled that when 
my house was burnt out last year a distant group of women, dimly lighted by 
the blazing house, were waving their arms to chase the zuen kamui from the 
village. Suspecting that they were then waving their girdles, I found that 
every Ainu woman here wears one. Cordial relations established through 
medical treatment of children and urgent cases, combined with gentle 
persuasion, gradually elicited frank information. I even obtained two speci- 
mens and had copies made in my house singly by women, and these were 
compared with a sufficient number of originals to make sure that they were 
faithful copies. To make a long story short, my investigation in this 
direction has been verified by genealogical records containing over 250 
names. These genealogies, selected from a total of over 400 names because 
they contain some infringements of the still operative prohibitions against 
incestuous marriage, have been sent to Prof. Seligman, who taught me the 
application of the genealogical method in elucidating social relations.' 

Before stating the main conclusions derived from these genealogies, some 
further information concerning the girdle must be given. The usual and 
more polite term for this is upsoro kut, ' secret belt or girdle.' In ancient 
traditions it is called a-eshimukep, or honourable (esteemed, revered) hidden 
thing. Each Ainu woman cherishes the belief that the length of cord is an 
invariable measure of identity given by a particular deity to a remote 
ancestress. Comparative measurements, however, show some difference 
between the lengths of cord attributed to one kamui. This is only what 
one would expect, seeing that an arm's length is the standard. Ainu 
women, too, do not discuss their kut between each other, and rarely see 
another kut outside of the family. Their confidence, therefore, is unabated, 
all emphatically declaring that the length and pattern are completely identical. 
The varieties examined up to date are attributed to : (i) Kamui Fuchi, who 
is generally recognised as authorising other kamui to bestow it ; (2) Kim- 
un kamui, a female bear, who, taking human form, married an Ainu ; 
(3) Horokei kamui, wolf — female, of course, like the others ; (4) Rep-un kamui, 
in all probability a grampus, chief sea deity, whose sister married an Ainu ; 
(5) Isepo-kamui, the hare, given tentatively as insufficiently investigated. 
Others heard of, but not seen, are the fox and deer. 

Dr. Munro arrives at the following conclusions, combining the criterion 
of the upsoro kut with results obtained by the genealogical method. He 
considers these two lines of evidence so mutually confirmatory as to render 
his conclusions quite definite. 

(i) It was forbidden to marry anyone of the same upsoro kut, the objective 
criterion of the clan. For those daring to infringe this prohibition the 
penalty was formerly death. Later it was mitigated to a fine, with com- 
pulsory alteration in the kut, apparently by reducing the number of folds 
in the cord, i.e., shortening the length of the distinctive line. Now, under 


Japanese law, marriages occasionally occur, but are disapproved by relatives 
and members of the village and regarded as bringing ill-luck not only to 
the parties concerned but perhaps to the community. 

(2) Formerly the levirate was a general custom, signified by a special 
name, matraie or matraire, ' wife-uplifting,' confined to this custom. Owing 
to poverty, more independence of women in tilling fields, and perhaps 
prevalent alcoholism of men, the levirate is no longer in vogue. 

(3) Two brothers might not marry two sisters — they were one flesh in 
the bond of the kut. Strict injunction against it is pronounced in the 
sacred traditions. In a genealogical list of upwards of 250 names there 
were five cases of such union. Though permissible in Japanese law, 
these cases of double marriage of brothers and sisters were a scandal in 
their villages. 

(4) The sororate was forbidden. 

(5) Marriage with a deceased wife's sister is said to have been forbidden 
formerly ; it is now unpopular. 

(6) Parallel cousins when children of two brothers could marry, bvit not 
the children of two sisters. 

(7) Cross-cousins could marry, unless, as might possibly happen, their 
mothers had the same upsoro kut, say of the wolf clan. In this district, 
however, cousin marriage is not conspicuous. In 98 marriages of the 
total genealogical list prepared, only two cases of such marriage occurred, 
both cross-cousins. 

(8) Uncles could not marry their nieces, nor aunts their nephews. 

The upsoro kut has been prominently treated here because it is the one 
criterion whereby the Ainu decide all questions of marriage. Clan kinship 
does not in fact imply unadulterated lineage. During the last fifty years or 
more, the Ainu have adopted poor Japanese children, girls taking the kut of 
their new mothers. This is not because the Ainu are infertile. Rather, 
it appears, it is because they have been impressed with the idea that the 
Japanese are so much superior. Orphan Ainu girls, too, when adopted into 
another family take the kut of their new mother, after due solicitation and 
offering to Kamui Fuchi, to whom pertains authority in such matters. 


On first acquaintance there seemed to be considerable difference between 
the religious beliefs and rites of north and south. There is the same 
fundamental generalisation of ramat, conceived either as spirit personality 
or (less definitely) as purposive potency. Everything is inter-penetrated 
by ramat in some degree : whether quiescent or quick, whether acting from 
spontaneous impulse or subservient to more personal ramat known as kamui 
can usually be decided by what it does. The word kamui, however (ka, 
above, over), is applied not only to the supernatural but to anything extra- 
ordinary or superb, Ramat and kamui express the quintessence of Ainu 
religion, while the ekashi, or elder, is at once priest and shaman. 

All Hokkaido Ainu employ the same means in soliciting and gaining the 
goodwill of the kamui, viz., innono-itak, or sacred talk, mainly invocation, 
achikka, libations, shinurappa, when offering to the dead, and — most 
important — inau. In the southern districts about twenty varieties of inau 
(sacred wands), the description of which would occupy much space, were 
examined and photographed. One noteworthy point is that for each kind 
of kamui a definite number of one or more kinds of inau are prescribed. 
In this respect there is little diflFerence in any of the southern kotan (villages) 
visited. Though the northern kotan are less familiar, there seems to be a 
little more difference in the numbers allotted, while the inau themselves are 


notably different. At Nibutani, Piratori, Mukwa, and Shiraoi, it is possible 
to tell at a glance what /eawm' are betokened by the number, kind, and position 
of inau at the inau-san shrine. 

The inau, which may perhaps on occasion take the place of living 
sacrifice, appear to be especially associated with the ramat of Ainu ancestors. 
For defence against certain kinds of wen kamui (evil spirits), they are mobilised 
in companies of six, each with its chief, sapane guru, armed with a sword, 
represented by a slip of wood. Among many kinds of trees selected for 
inau, the willow, as a tree of life, is prominent. Shutu inau are made of 
willow when stuck in the comers of the hearth, sacred to Kamui Fuchi, 
divine ancestress and deity of the home fire, through whom all communica- 
tions with the dead are made. 

Besides the domestic kamui are ' those without,' the good — i.e. useful — 
deities of the inau-san or outer shrine, or altar. Here we encounter much 
difference between those of north and south, and some difference between 
those of different villages. 

In some of the northern villages it was rather surprising to find that the 
sacred (ceremonial) window, rorun puyara, at the head of the hearth is not 
oriented invariably towards the east, as in southern districts, but faces the 
direction of current in a river, the assumed source of a food supply. As 
if to compensate for inattention to the rising sun, there is more regular 
worship of the sun at the inau-san, inau-sheM or fence, the family altar 
everywhere situated outside the sacred window, whence the ramat of bene- 
ficent kamui communicates with Kamui Fuchi at the hearth and gives help 
and comfort to the inmates. 

Amongst various interesting magico-religious expedients already fading 
away, mention should be made of the bull-roarer, recorded by Dr. Munro 
at Shiraoi fifteen years ago. 

Finally — lest this report grow over-long — it should be mentioned that 
Dr. Munro took from dictation about 70 or 80 innono-itak, for which the 
word ' prayer ' seems not inappropriate. Most of the innono-itak are as 
logical, on the given premises, as the prayers of higher religions, and as apt 
to vary as the latter do outside of a prayer-book. 


Report of Committee appointed to investigate blood groups among the Tibetans 
(Prof. H. J. Fleure, Chairman ; Prof. R. Ruggles Gates, F.R.S., 
Secretary ; Dr. J. H. HuTTON, C.I.E., Mr. R. U. Sayce). 

During the past year arrangements were made for obtaining blood groups 
of Tibetans. A small quantity of serum was sent from England for testing 
the serum produced by the Haffkine Institute in Bombay, India. A 
quantity of tested serum was then sent from India to the Medical Officer 
at a hospital in Gyantse, Tibet, but the results have not yet been received. 
A few results have been received, together with photographs, of tests 
made on Eskimos by a Canadian expedition to Pond's Inlet, Baffin Land, 
in 1 93 1. These are of greatest interest in showing that the blood groups 
confirm the evidence of crossing with Europeans obtained from the photo- 
graphs. Serum sufficient for testing 200 has been sent to the Canadian 
Government Expedition which recently sailed from Montreal for Hudson 
Bay to study the inland Eskimos in the tundra region west of Hudson Bay. 


These people were considered by Rasmusson to represent the most primitive 
Eskimos, and unlike many of the coastal Eskimos they have had very little 
contact with civilised peoples. When opportunity arises through some 
expedition it is hoped to be able to obtain the blood groups of the Congo 
Pigmies, because their blood grouping should throw definite light on the 
relationship of the pigmies to the negroes. 


Report of Committee appointed to co-operate with the Pen Dinas Excavation 
Committee in the excavation of Pen Dinas Hill Fort, Cardiganshire 
(Dr. Cyril Fox, Chairman ; Mr. V. E. Nash-Williams, Secretary ; 
Prof. V. Gordon Childe, Prof. C. Daryll Forde, Rt. Hon. Lord 
Raglan, Dr. R. E. M. Wheeler). 

The second season of archaeological work on Pen Dinas, an Iron Age Hill 
Fort half a mile south of Aberystwyth, Cardiganshire, began on August 6 
last, and will be concluded on or about September 1 5 . The funds available, 
including the British Association's grant of £25, are being expended almost 
entirely on labour, since the equipment has been obtained by loan from 
various bodies and individuals . Eight workmen are being regularly employed 
at a wage of 3SX. per week, so that the British Association grant has covered the 
cost of nearly two of the four working weeks that are almost completed. 

The southern area of the main fortress is being investigated this year. 
It has been found that the eastern ramparts formerly curved round to en- 
close the main (or southern) fortified area on the north, and a strong walled 
bank, originally some 12 ft. high, was fronted by a 7-ft. ditch and counter- 
scarp bank. 

At a later date the greater part of a lower lying plateau to the north was 
fortified by bank and ditch on a rather smaller scale and linked to the main 
fortress. At about this time a gap was driven through the main defences 
to give access to this area. On the lower rubble of the breached walls and 
over the filled ditch an incurved entrance, with a triple series of gate-posts, 
was constructed. This formed an inner gate to the fortress, which had to 
be reached by an outer entrance through the lower fortification of the 
northern extension. This outer entrance was as first constructed a wide 
(40-ft.) gap, with semicircular walling, possibly an open driveway for 
livestock. At a later period, however, this gap was narrowed to 14 ft. by 
extending the bank and walling from either side, and post holes suitable for 
heavy swing gates and a bridge were set up at the corners. 

A rectangular guard-house or dwelling-house, delimited by post holes, a 
packed earth floor, and slab hearth, has been found immediately within and 
to the south of this later outer gate. Finally, a third period of construction 
has been found at this gate in which the bank was heightened and extended 
on the outer side to the south. This extension covered the old ditch, and a 
second rock-cut ditch was in consequence constructed further east. 

Numerous flint flakes as well as iron and bronze fragments have been 
found, but no pottery has so far been discovered. 



Report of Committee appointed to develop tests of the routine manual factor 
in mechanical ability (Dr. C. S. Myers, C.B.E., F.R.S., Chairman ; 
Dr. G. H. Miles, Secretary ; Prof. C. Burt, Dr. F. M. Earle, 
Dr. Ll. Wynn Jones, Prof. T. H. Pear). 

Work has progressed along the following lines as laid down in last year's 
(final) report of the Committee appointed to inquire into the factors involved 
in mechanical ability : 

(i) The development of new manual tests with a view to simplifying and 
improving the measurement of the manual factor in assembly work. 

(2) The devising of new methods of administering the tests of mechanical 
aptitude, with a similar aim in view. 

(3) The development of easier tests of mechanical aptitude with a view 
to its measurement in elementary school children. 

(4) The devising of new tests of mechanical aptitude with a view to the 
further analysis of the mechanical factor. 

Data have been collected from the top two classes of an elementary school 
and from six forms of a junior technical school. Its statistical analysis is 
in progress. 

It is hoped that the Association will continue to support the work along 
the lines suggested in Part III of this report, by renewing, and if possible 
increasing, its financial grant. 

I. The Position at the Beginning of the Year. 

The results reported to the Association up to the beginning of the year 
may be briefly stated as follows : 

(a) The factors involved in assembling work. — Ability at the assetnbling 
operations investigated depends on two or more of the following factors, 
according to the particular operation : 

(i) A small general factor (' intelligence '), which is more evident in the 
mechanical assembling tests, and in the more complex of the routine assem- 
bling operations, and which tends to disappear from the less complex routine 
assembling operations and from simple tests of manual dexterity. 

(2) A ' mechanical ' factor, identified with the ' m ' factor in non-manual 
tests of mechanical aptitude, which is most conspicuous in the mechanical 
assembling tests, which tends to enter to a small extent into the more com- 
plex of the routine assembling operations, and which tends to disappear 
from the simpler of these operations. 

(3) A ' manual ' factor, which enters most conspicuously into the more 
complex of the routine assembling operations, to an obvious, though less, 
extent into the less complex of these operations and into the simple manual 
tests, and which tends to disappear, as a group factor, from the mechanical 
assembling tests. 

(4) A factor specific to each operation, which plays a larger part in the 
simpler operations, and diminishes in importance as the operation becomes 
more complex. 

{b) The measurement of the factors. — (i) The mechanical factor is best 
measured by the non-manual tests of mechanical aptitude. Of the mechani- 
cal assembling tests, the more difficult ones provide the better measure. 


(2) The manual factor is best measured by the more complex of the 
routine assembling tests. The measures afforded by the simpler manual 
tests are largely specific in character. 

(c) The reliability of the tests. — The reliability of the various measures 
employed in the research was investigated in detail. The coefficients were 
found to be generally high. Where the manual tests were concerned, 
reliability was found to depend upon the number of repetitions of the 
operation constituting the measure of ability rather than on the length and 
complexity of the operation ; and was found to be independent of the stage 
of practice attained by the group measured. The routine assembling tests 
were found to predict the ability to which a subject would attam, after 
practice, to about the same degree of accuracy as they measured his present 
ability (0-7-0 -9). 

(d) The transfer effects of practice atid of training. — An extensive myestiga- 
tion into the effects of (i) practice, and (ii) training, was also carried out. 
It showed that the effects of uninstructed practice at any one of the routine 
assembling operations failed to transfer to any of the other operations, 
whereas a course of training, involving exercises based on one of the routine 
operations produced effects which transferred to each of the other operations. 

II. The Past Year. 
Work during the past year has progressed along the following lines : 

(a) Further statistical analysis of the data.— The saturation of the various 
groups of tests with their respective factors has now been determined as 
follows, from data obtained from sixty elementary schoolboys : 

Twb non-manual mechanical aptitude tests v. the mechanical factor (m), 
o-8o, 0-71; together, 0-83. 
Ditto V. the general factor, 0-39, 0-36 ; together, 0-40. 
Three mechanical assembling tests v. mechanical factor, o • 39, o • 63 , o • 5 1 ; 
together, 0-73. 
Ditto u. general factor, 0-13, 0-42, 0-23 ; together, 0-31. 
Five more complex routine assembling tests v. manual factor, 0-56, 0-65, 
0-48, 0-37, o-6i ; together, o- 80. 
Ditto V. general factor, 0-35, 0-14, 0-27, 0-25, o-i6 ; together, 0-34. 
Four less complex stripping tests v. manual factor, 0-26, o-6i, 0-32, 
0-33; together, o- 60. 
Ditto V. general factor, 0-23, 0-09, 0-30, 0-20 ; together, 0-32. 
Similar determinations, with very similar results, have been made from 
data obtained from thirty-six elementary school-girls. 

(b) Development of new tests. — It was decided last year to concentrate on 
methods of measuring the group factors which the data had disclosed. To 
this end, the following new tests have been devised : 

(i) Non-manual tests of mechanical aptitude. — Diagram booklets have 
been prepared for use in conjunction with the ' models ' type of mechanical 
test, so that the subject's response may now be obtained in the ' selective ' 

Two new sets of easier models have been devised and constructed for use 
in the upper classes of elementary schools. These also involve the use of 
a specially prepared booklet. 

(2) Tests of the manual factor. — Six new manual tests, of the routine type, 
involving assembling and stripping, have been constructed. These involve 
various methods of winding and unwinding string from nails and of thread- 
ing string through beads and through eyes screwed into a board. They 


aim at increasing the saturation of the test with the manual factor by in- 
creasing the number of repetitions of the operation possible within a given 
time, and at simpHfying the administration of the test and reducing random 

(3) Paper-folding tests. — Two new tests of the paper-folding and cutting 
type have been devised with a view to the further analysis of the mechanical 
factor, and the possible provision of a more direct method of measuring it. 

(c) Collection of further data. — The new tests have been given to the top 
two classes of a boys' elementary school, and six forms of a junior technical 
school. These subjects have taken, in addition, the ' inventive ' forms of 
the mechanical aptitude tests, and four of the routine manual assembling 
tests which were employed in the work reported last year ; also tests of 
general intelligence. 

The statistical analysis of these very extensive data is still in progress. 
Reliability coefficients have now been calculated for most of the tests, and 
indicate high reliability. This, and the keenness shown by the boys in 
doing the tests, suggests their suitability as tests of specific ability. The 
necessary inter-correlational studies for determining how far the factors 
in these new tests are the same as those found in the data formerly collected, 
and how far they may be ' saturated ' with such factors, are still in progress. 
From the point of view of scoring, and ease of administering, the new tests 
are a very great improvement over the older ones. 

III. Future Work. 

It will be evident from Part II of this report that the most pressing thing 
now is to complete the analysis of the data that have been collected during 
the past year. The results thereby obtained may be expected tcf shed 
important light on the practical measurement of the ' mechanical ' and the 
' manual ' factors. It may also extend our knowledge of these factors, 
and possibly disclose other important vocational ' abilities ' associated with 
the new ' mechanical ' and ' manual ' tests, as well as throw light on the 
general principles of test construction. 

When this aspect of the work is completed, there are many other fruitful 
lines of research opened up by the results reported by this Committee last 
year. In particular, the extension of the methods of training employed in 
the ' training ' experiment would appear to lend themselves to valuable 
extension to many other forms of manual skill. 

It is hoped that the Association will render the continuance of this work 
possible by renewing, and if possible increasing, its financial grant. 


Report of Committee on the Anatomy of Timber-producing Trees (Prof. H. S. 
HoLDEN, Chairman ; Dr. Helen Bancroft, Secretary ; Prof. J. H. 
Priestley, D.S.O.). 

Two papers on the structure of the monotoid timbers — ' The wood anatomy 
of representative members of the Monotoides ' and ' New material of 
Monotes Kerstingii Gilg from the Gold Coast ' — have been completed and 
accepted for publication in the American Journal of Botany and the Kew 
Bulletin, respectively. 


The investigations show that 

(i) So far as wood anatomy is concerned, the Monotoideae are a very 
coherent and somewhat circumscribed group. 

(2) The wood anatomy of the group indicates a much closer affinity to the 
Dipterocarpaceae than to the TiHaceae or any other group. 

(3) The structure and properties of monotoid timbers are such that their 
cultivation for economic purposes cannot be advocated, although 
the timbers may be useful on a small scale locally. 

Detailed investigations of new monotoid material are in progress ; and 
work has been commenced on the systematic anatomy of the genus Ulmus, 
in order to throw some light on the problem of the identity and relation- 
ships of the British Elms. 

The Committee asks for reappointment, with a further grant of £10. 


Final Report of Committee on Fossil Plants at Fort Grey, near East London 
(Dr. A. W. Rogers, F.R.S., Chairman ; Prof. R. S. Adamson, 
Secretary ; Prof. A. C. Seward, F.R.S.). 

The investigations undertaken by the Committee have now been completed. 
The results have been published in a paper in the Annals of the South 
African Museum (vol. xxxi, pt. i, p. 67, 1933). A set of the specimens 
collected has been deposited in the South African Museum at Cape Town. 
The Committee desire to express their appreciation of the assistance 
granted towards the work. They do not ask to be reappointed. 


Report of Committee appointed to consider and report on the possibility of 
the Section undertaking more definite work in promoting educational 
research (Dr. W. W. Vaughan, Chairman ; Miss Helen Masters, 
Secretary ; Mr. E. B. R, Reynolds, Mr. N. F. Sheppard). 

The Committee met in January. Dr. W. W. Vaughan, Miss H. Masters, 
and Mr. N. F. Sheppard were present. 

The meeting decided that individual members should get in touch with 
other bodies interested in educational research. This has in many cases 
been done. 

The general nature of the problem was discussed, and notes made thereon. 

Prof. Hamley was proposed for co-option : he has been approached and 
has accepted. 

The Committee considers that its activities are reflected in the programme 
of the 1934 meeting. 



Second Interim Report of Committee appointed to consider and report upon 
the possibility of Quantitative Estimates of Sensory Events (Prof. A. 
Ferguson, Chairman ; Dr. C. S. Myers, C.B.E., F.R.S., Vice- 
Chairman ; Mr. R. J. Bartlett, Secretary ; Dr. H. Banister, Prof. 
F. C. Bartlett, F.R.S., Dr. Wm. Brown, Dr. N. R. Campbell, 
Dr. S. Dawson, Prof. J. Drever, Mr. J. Guild, Dr. R. A. Houston, 
Dr. J. C. Irwin, Dr. G. W. C. Kaye, Dr. S. J. F. Philpott, Dr. L. F. 
Richardson, F.R.S., Dr. J. H. Shaxby, Mr. T. Smith, Dr. R. H. 
Thouless, Dr. W. S. Tucker). 

(i) Experimental investigation of matters at issue and research into the 
records of previous work have been continued by or under the supervision 
of members of the Committee. 

(2) Theoretical discussion of the problem has been continued by means of 
reports from members of the Committee. These reports have been multi- 
plied by the kind assistance of the British Psychological Society and have 
been circulated to all members of the Committee. 

(3) Critical comments on certain of these reports have still to come in. 
It is hoped that they will be received by the autumn of this year, when the 
Committee will meet to discuss various aspects of the problem disclosed 
in the documents received, with a view to drawing up a final report. 

(4) The Committee asks to be reappointed without grant. 


(For reference to the publication elsewhere of communications entered in the 
following lists of transactions, see end of volume, preceding appendix.) 


Thursday, September 6. 

Discussion on The ionosphere (lo.o) : — 

Prof. E. V. Appleton, F.R.S. — Introduction. 

In the absence of data derived from measurements in situ, such as are 
possible for the lower strata of the atmosphere, information concerning the 
nature of the ionosphere (80 km. and above) is derived from ground observa- 
tions on (i) terrestrial magnetism, (2) luminous manifestations such as the 
aurorae, meteorites, etc., and (3) wireless wave exploration. Although the 
first indications of pronounced upper-atmospheric ionisation came from (i), 
the prosecution of (3) has proved, on the whole, the most fruitful. Wireless 
methods possess the marked advantage in that an exploration can be made at 
any time and it is not necessary to wait for natural sequences or irregularities. 

Wireless exploration consists in projecting waves (usually) vertically 
upwards and noting the characteristics of the returned energy. The 
quantities measurable are {a) the time of flight on the up and down journey, 
(b) the polarisation and phase changes, and (c) the intensity of the returned 
waves. Each type of measurement has been made to yield information. 
From measurements of {a) at different wave-lengths the somewhat compli- 
cated structure of the ionosphere has been broadly worked out and its tem- 
poral variations studied. From {b) conclusive evidence has been derived 
that free electrons exist throughout the whole of the ionosphere and are 
active electrical agents in causing the deviation of the waves ; while from (c) 
the frictional effect of air pressure on the free electrons may be estimated. 

Regular features. — The ionosphere is divided into two main divisions, 
Region E at an equivalent height of 100 km. and Region F at an equivalent 
height of 230 km. and above. In both regions the ionisation is replenished 
daily at a rate dependent on solar altitude, and during the night steadily 
decreases. (During the day a lower ' shelf ' is also formed on the main 
Region F.) The diurnal and seasonal variations are such as can be explained 
by assuming solar ultra-violet light as the ionising agency and recombination 
of electrons and ions as the dissipative influence. 

Irregular features. — {a) There is often formed a thin reflecting sheet of 
ionisation about the height of Region E. This may occur by day or night. 
Possible influences to be discussed in connection with the origin of this 
' Abnormal Region E ' are : 


(i) Extraneous ionising agencies (e.g. solar corpuscles and terrestrial 
thunderstorms) . 

(2) Horizontal motion of ionisation from more densely ionised regions by 
winds or diffusion. (The coefficient of lateral diffusion may be shown 
to be a maximum at about 100 km.) 

(3) Readjustment of ionisation already present due to tidal or thermal 
influence, bringing about a sharper gradient of refractive index at a 
particular level and thus giving rise to quasi-reflection as distinct from 
the normal deviating process. 

(b) The maximum ionisation content in Region F is often found to 
increase during the night. Possible influences to be considered are : 

(i) A nocturnal ionising agency. 

(2) Readjustment of ionisation distribution due to cooling and shrinkage 
of the atmosphere causing an increased electron concentration. 

(c) Very occasionally there are found subsidiary regions of ionisation 
(i) between Regions E and F, and (2) above the main Region F. These 
have been noted at both the Slough Radio Research Station and attheHalley- 
Stewart Laboratory, Hampstead. 

Freak wireless transmissions. — A careful watch was now being kept each 
day on what might be called the weather conditions in the ionosphere. 
Such work was being carried out at the Slough Radio Research Station and 
at the Halley-Stewart Laboratory at Hampstead. As often happened in 
the study of geophysical phenomena, abnormal events proved of special 
interest and importance. Both of the ionised regions were found to exhibit, 
occasionally, increases of ionisation even at night, when ultra-violet light 
from the sun could not possibly be reaching the upper atmosphere. 

In 1930, during some experiments carried out at King's College, London, 
curious increases of ionisation were noted in the lower of the two regions 
(the so-called Kennelly-Heaviside Layer). There appeared to be some 
influence maintaining and even increasing the ionisation which normally 
decreased during the night. The same effect had since been noticed in 
different parts of the world. He wished to put forward the theory that this 
abnormal ionisation, which he had found gave almost mirror-like reflection 
of the waves, might be responsible for the freak transmissions which had 
been noted from time to time in long-distance transmission. 

It had also been found that there was a fairly definite limit in the short 
wave-length range below which one could get only a quasi-optical range. 
Waves shorter than the limiting value (8 to 10 m.) usually pierce the 
ionosphere and leave the earth altogether. But calculation showed that 
under the abnormal conditions mentioned, which appeared to be connected 
in some way with both thunderstorms and magnetic storms, the limiting 
wave-length should be less than its usual value. 

Mr. J. A. Ratcliffe. 

Collisions between electrons and neutral molecules cause absorption of 
a wave travelling through the ionosphere. From observation of the 
resultant absorption deductions may be made about the frequency of 
collision of the electrons. 

Calculation shows that a region of absorption may be situated below the 
region of deviation of the wave, the extent of the absorbing region being 
determined by the height distribution of the electron collisional frequency. 
There is no need to postulate a lower ' layer ' of ionisation to explain this 


region of absorption. The existence of such an absorbing region is required 
to explain the absorption observed at different distances from a transmitter.^ 

Absorption of a wave near the top of its trajectory is related to the group 
retardation there, and from a comparison of the observed magnitudes of 
these quantities we deduce that the collisional frequency in the F region is 
about 5 X 10* per second, and in the E region is about 2 X 10^ per second. 
The extra group retardation of the ordinary wave on a wave-length of 
60 m. in the day-time perhaps explains why Eckersley ^ found it to be 
weaker than the extraordinary wave. 

To explain some unexpected results it has been suggested ^ that absorption 
determines the greatest frequency which may be reflected from the F region 
at midday in summer, whereas in winter the maximum electron density 
determines this critical frequency. If this is the case, then the temperature 
of the F region at a summer midday must be considerably greater than that 
at a winter midday. 

Automatic records have been taken showing how the height of reflection 
of wireless waves of a fixed frequency varies with the time of day. These 
records show the occurrence of intermittent reflections from a height of 
about 105 km. — that is, below the ordinary E region. Such reflections 
may occur by night or by day. They are presumably due to some ' abnormal ' 
source of ionisation. A statistical analysis indicates that they are probably 
related to the occurrence of (a) magnetic storms, and (b) thunderstorms. 
The opportunity of observing on a series of different frequencies in rapid 
succession occurred recently, during a thunder shower. During the 
shower wave-lengths down to 45 m. were reflected (partially) from a 
height of 105 km., whereas half an hour before and a quarter of an hour 
afterwards there were no reflections from regions below 250 km. (F region) 
on any wave-length shorter than 75 m. It appears as though the thunder 
shower had produced ionisation at a height of about 105 km. 

Mr. R. Naismith. — The polar ionosphere. 

It has been shown by Appleton that the main ionising agency for the 
E and F regions of the ionosphere in temperate latitudes is the ultra-violet 
light from the sun. 

It has also been suggested by Chapman that charged particles emitted 
from the sun may produce ionisation in the upper atmosphere, and the 
phenomenon of the aurora appears to confirm this theory. 

Observations made by the British Wireless Expedition during the second 
International Polar Year are exaiTiined with regard to these two theories. 
The first of these theories is examined with reference to the whole year's 
observations, but more particularly under the special condition existing in 
the Polar regions in the winter when no ultra-violet light from the sun is 
reaching the earth, and in the summer during the period of the midnight 

The maximum ionisation effects of charged particles are to be expected 
in northern latitudes. This theory is also examined with reference to the 
year's observations, but more particularly during periods of magnetic 

There is at present no unanimity of opinion on the relative importance of 
these two influences, but the present series of observations appear to indicate 
that both are necessary. 

> Proc. Rov. Soc, A, 115, 291 (ig^?)- ' Ibid., A, 141, 710 (1933)- 

» Proc. I.R.E., 22, 499 (i934)- 


Prof. R. H. Fowler, O.B.E., F.R.S., and Mr. G. B. B. M. Sutherland.— 
The specific heats of simple gases at high temperatures (11.30). 

When, some seven or eight years ago, analysis of the quantum states of 
simple molecules had advanced sufficiently far to be applied with confidence 
to the calculation of the specific heats of the simple gases, it was found, to 
the surprise of almost everyone concerned, that the accepted values at high 
temperatures were in striking disagreement with the theory. The disagree- 
ment begins to make itself felt, for example, for oxygen and nitrogen just 
above roon:i temperatures. This discrepancy has since then been much 
studied from two points of view- — first, to re-examine the specific heats 
by new methods and to see if they could be brought into agreement with 
theory ; and, secondly, to understand the meaning of the older measure- 
ments, which cannot be dismissed as being merely in error. Both these 
studies have now been successful. The discrepancy between theory and 
the older observations has been shown to be due to the very slow inter- 
change of vibrational energy in rather rigid molecules such as oxygen and 
nitrogen with the translational and rotational energy. 

Mr. J. M. Stagg. — The British Polar Year Expedition to Fort Rae, 
N.W. Canada, 1932-33 (11.55). 

Throughout the thirteen months ending August 31, 1933, upwards of 
forty countries co-operated in a world-wide organisation for intensive 
observations in meteorology and such allied fields of investigation as terres- 
trial magnetism, aurora and atmospheric electricity. During this period 
probably over sixty special stations and expeditions, many of them in high 
northei-n latitudes, participated in the general programme. As part of 
Britain's share in this International Polar Year an expedition of six men 
was sent to reoccupy the station at Fort Rae on the Great Slave Lake, 
N.W. Canada, held half a century ago by the First Polar Year Party. 

The objects of the expedition included the collection of complete and 
continuous observations of the main meteorological elements both on the 
surface and into the stratosphere, procuring continuous records of the varia- 
tions in the earth's magnetic field, and gathering as much information as 
possible about auroral phenomena in that part of Canada. Photographs of 
aurora from two base stations, so that its position in space could be deter- 
mined, were specially wanted. Measurements were also to be made of the 
various elements of the atmospheric electrical field near the surface at 
Fort Rae. 

To attain these objects in the somewhat extreme conditions of N.W. 
Canada special methods and safeguards had to be employed. 

The photography of aurora called for a means of continuous communica- 
tion over the 25 km. separating the main base and substation ; 4,700 simul- 
taneous pairs of photographs were taken, of which 75 per cent, are probably 
suitable for measurement. 

The reduction of the data brought hoine by the expedition is now in 
an advanced stage of preparation. But the work of adequate discussion 
and co-ordination with the data for all the other Polar Year stations will be 
a matter of several years. 

Prof. G. W. O. Howe. — The rotating field of a cylindrical bar magnet — a 
perennial chimcera (12.25). 

From time to time the question is raised : Does the magnetic field of a 
cylindrical bar magnet rotate with the magnet ? This question is ineaning- 


less ; the misconception which gives rise to it is due to the lines of force 
being endowed with a physical reality for which there is no justification. 
When the bar magnet rotates the electrons within it move relatively to one 
another through magnetised space and thus experience forces, but no 
meaning can be attached to the movement or non-movement of the magnetic 
condition of space which undergoes no change in magnitude or direction. 
The statement recently made by Prof. Cramp, that Faraday's description of 
an experiment was lacking in detail because ' he omitted the possibility of 
the e.m.f. being produced by a rotating magnetic flux cutting the stationary 
parts of the circuit,' is unfair to Faraday, who could hardly be expected to 
foresee that such a queer misconception would subsequently arise. Prof. 
Cramp admits after making about fifty (!) experiments that they are incon- 
clusive, as indeed they must be since they were designed to answer a 
meaningless question. Lines of force and tubes of magnetic induction are 
mathematical fictions : there is nothing material about them, nor do they 
represent discontinuities in space, which could be earmarked in order to 
detect their movement. Their number is a mere convention. 

Friday, September 7. 

Presidential Address by Prof. H. M. Macdonald, O.B.E., F.R.S., on 
Theories of Light (lo.o). (See p. 19.) 

Dr. F. W. Aston, F.R.S.— T^e roll-call of the isotopes (ii.o). 

The word ' isotopes ' was first used by Soddy to indicate atoms having 
identical chemical properties but different mass which he discovered among 
the products of radioactivity. Their presence in ordinary stable elements 
was definitely proved later by the mass-spectrograph. Of recent years the 
word has altered its meaning and is now used to designate any atomic 
species. By the study of mass-spectra, supplemented in a few cases by that 
of optical spectra, the analysis of the comnion elements may now be regarded 
as fairly complete. The main isotopic constituents are known for all but 
four — palladium, iridium, platinum and gold. The accuracy of the data 
varies in a wide degree from element to element, the analysis being easiest 
technically for the inert gases, and niost difficult for the rare earths and noble 
elements. Disregarding those of radioactive period less than one million 
years, the total number of isotopes now known is well over 240, about three 
per element. The isotopic complexity of elements of odd atomic number 
shows a remarkable regularity. Excepting hydrogen, none of these has 
miore than two isotopes. On the other hand, elements of even atomic 
number may be much more complex, tin having as many as eleven isotopes, 
and it is an interesting speculation whether or not the number may be 
extended indefinitely by increasing the delicacy of the methods of detection. 

Discussion on The structure of alloys (11.30) : — 

Prof. W. L. Br.\gg, O.B.E., F.R.S.— Introduction. 

We may conveniently define an alloy by two characteristics The first 
is the arrangement of the positions occupied by its metal atoms. A different 
geometrical pattern of the atomic sites characterises each phase of the alloy 
system, and is the essential feature which remains constant in a single-phase 
region although the composition of the phase may vary over a wide range. 
The second is the distribution of the atoms of each kind in a binary or 

L 2 


more complex alloy amongst the phase sites. This distribution varies of 
necessity as the composition varies, and may often be altered by thermal 
treatment although the phase remains the same. 

Recent developments have indicated the possibility of discovering an 
adequate theoretical basis for the explanation of both characteristics. 
Broadly speaking, the first depends upon the interaction between metal 
atoms and free electrons, the second upon the relative potential energies of 
the ordered and disordered distribution of atoms amongst the sites. 

Prof. G. I. Taylor, F.R.S.— ^ theory of plasticity in crystals. 

In many metallic crystals the most remarkable features of plastic dis- 
tortion are : 

(i) its geometrical nature, the strain consisting of a shear parallel to 
a crystal plane ; 

(2) the rapid increase with increasing plastic strain in the stress necessary 
for plastic flow. 

A theory is developed which accounts for both these phenomena as 
consequences of the production and subsequent migration, under the 
influence of molecular agitation, of a special type of singularity in the 
structure to which the name ' dislocation ' is given. 

Reasons are given for believing that dislocations can migrate through the 
crystal at a temperature far lower than that necessary for the interchanges 
which occur when a metal is annealed or when an alloy changes from one 
phase to another. 

In a perfect crystal structure a single dislocation might migrate freely, 
but the presence of other dislocations, each of which is surrounded by 
a field of elastic stress, will prevent the free migration of dislocations unless 
the shear stress externally applied is greater than that due to the integrated 
effect of all neighbouring dislocations. The stress necessary for plastic 
strain, now considered as due to migrating dislocations, therefore depends 
on the number of dislocations. A relationship is also found between 
plastic strain and the number of dislocations, so that the plastic stress- 
strain relationship is deduced theoretically. 

Dr. H. Jones. — Applications of the modern electron theory of metals. 

The electrical resistance of pure metals with reference to their place in 
the periodic table was discussed, and it was shown how the observed 
resistance of alloys leads to a better understanding of the resistance of pure 

The form of the Brillouin zones for a number of crystal structures 
associated with well-known metals and alloys was described and illustrated. 
The significance of the form of these zones in relation to the structure was 
considered with particular reference to the case of bismuth, and alloys 
possessing the characteristic y and s structures. From these considerations 
it was shown to be possible to find a theoretical basis for the well-known 
Hume-Rothery electronic rules. 

Mr. A. J. Bradley. — Atomic arrangement in alloys. 

The application of X-ray analysis to the study of alloys has yielded a 
great amount of fresh information impossible to be obtained by the older 
methods of metallography. The problem of differentiating between alloy 
phases and of determining phase boundaries has become much simpler, 


while in many instances X-ray work has shown the presence of phases 
difficult to identify by other methods. 

Each phase has a characteristic structure which in its salient features 
is the same for all alloys belonging to the phase, but a more detailed study 
shows that there are continuous structural changes on varying either com- 
position or temperature. Recent improvements in technique have made 
it possible to follow the changes in lattice dimensions to an accuracy of 
I part in 50,000. Detailed changes in atomic arrangement, e.g. the 
formation of superlattices, may be followed quantitatively by means of 
X-ray intensity measurements. The results of all such investigations are 
found to fit in with the data obtained from measurements of magnetism, 
electrical conductivity and other physical properties. 

Prof. G. P. Thomson, F.R.S. 

Visit to Natural Philosophy Department, Marischal College. 

Monday, September 10. 

Joint Discussion with Section B (Chemistry, q.v.) on The preparation 
and properties of heavy hydrogen (lo.o). 

Visit to Braemar for unveiling of memorial to Johann von Lamont. 

Tuesday, September 11. 

Symposium on Telescopes (lo.o) : — 

Mr. C. Young. — The y^-inch reflecting telescope of the David Diinlop 
Observatory, Toronto University, Canada. 

The equatorial mounting of the telescope is of the modified English 
or composite type, in which the tube is carried to one side of the polar axis. 
This axis is built up of steel castings with forged steel pivots mounted in 
self-aligning ball bearings. 

The driving circle is a steel casting with bronze rim, 8 ft. diameter, cut 
with 960 teeth. 

The forged steel declination axis weighs over 3 tons and is mounted in 
ball bearings. 

The tube comprises three parts : 

(a) The centre portion, a steel casting about 7 ft. diameter. 

(6) The upper, or lattice, portion constructed of duralumin ' I ' beams, 

with diagonal tension rods of duralumin, 
(c) The mirror cell. 

In the lower part of {a) an iris diaphragm is fitted allowing for a range of 
aperture from 12 to 74 in. 

The driving clock comprises a crossed arm friction governor driven by 
a weight which is automatically kept wound up by an electric motor. The 
clock drives on to a gear plate incorporating a ' Grubb ' type seconds 


All the motions of the telescope, viz. quick setting, guiding and clamping 
in both R.A. and declination, also focusing of the Cassegrain mirror, are 
electrically operated. 

The main mirror, now being worked at Newcastle-on-Tyne, is of a 
special Pyrex glass, 76 in. diameter by 12 in. thick and focal length of 
30 ft. 

The Cassegrain mirror gives an equivalent focus of 108 ft. 

The dome, which has a diameter, of 61 ft. with an opening 15 ft. wide, 
is fitted with motor-driven shutters and wind screens, and carries an elec- 
trically operated observing carriage for use at the Newtonian focus. 

The dome is mounted on a circular steel building 24 ft. high. 

Mr. W. M. H. Greaves. — The new 36-inch reflector at the Royal 
Observatory, Greenwich. 

Mr. C. R. BuRCH. — On null systems for testing concave telescope 

Zonal tests on concave specula have neither the accuracy nor the speed 
of null tests. The most delicate test — Prof. Zernike's phase-contrast 
test — is essentially a null test. We need a method of null testing paraboloids 
without using a full-size flat, and methods of null testing mirror curves 
other than conic sections — e.g. the Ritchey-Chretien curve. The asphericity 
of a 36-in. paraboloid of F/4 can be compensated with one 9-in. concave 
spherical mirror, one li-in. convex mirror aspherical by only | wave-length, 
and one \-m. flat. For an F/6 paraboloid, both compensating mirrors may 
be spherical. Asphericities up to a few wave-lengths may be compensated 
by a figured transmission plate, checked with an optical flat — in this check 
the transmission errors are seen multiplied by 4. The figured plate may 
conveniently be i in. diameter : the star is decentred so that the light 
passes through it once only, and the consequent astigmatism is annulled 
by two plane-parallel plates placed with equal and opposite obliquities to 
the central ray. By placing the figured plate at difterent distances from the 
star, a range of paraboloids can be tested. 

Mr. N. R. Campbell and Mr. C. C. Paterson, O.B.E. — Photoelectricity, 
art and politics : an historical study (11.30). 

(Ordered by the General Committee to be printed in extenso. See p. 445.) 

Wednesday, September 12. 

Dr. W. H. McCrea. — Observable relations in relativity (lo.o). 

The formulation of an invariant which represents ' spatial distance,' as 
measured by some prescribed experiment, in the space-time of general 
relativity has been studied by E. T. Whittaker and others. Also E. A. 
Milne has emphasised the importance of interpreting any given space-time 
in terms of the ' world-pictures ' of an observer belonging to it. In this 
paper it is shown how the apparent size, brightness, etc., of nebulae in certain 
models of the ' expanding universe ' can be calculated by fairly elementary 
methods. Thence one obtains, for example, the number of nebulae in a 
given range of apparent magnitude, and the relation between apparent 


magnitude and red-shift, which represent the type of relation which can be 
tested by observation. 

Mr. H. G. Howell. — Recent applications of spectroscopy (10.30). 

Now that the importance of the presence of small amounts of metallic 
impurities in alloys has been recognised, the practice of quantitative 
spectrum analysis is receiving much attention. The internal standard 
method involving a determination of intensity ratios is considered to be the 
most accurate, although for higher percentages of impurity the Barrett twin- 
spark method is preferable. 

The intensity ratio can be measured conveniently by using a rotating 
logarithmic disc. 

The biologist and medical research worker are using the spectrograph to 
determine the influence of minute traces of metals in the blood and spinal 
fluid, in plants and living organisms. 

Absorption spectrophotometry is providing much useful data about the 
equilibrium of certain chemical reactions which cannot be obtained by 
chemical methods. 

Absorption measurements have been of great importance in work on 
such obscure organic compounds as the vitamins. The spectra of haemo- 
globin and its related compounds are being extensively studied with a view 
to correlate changes in spectra with changes in chemical constitution. 

It has been reported that the absorption spectrum of the plasma of the 
blood of normal rats is different from that of those suffering from cancer, 
and that marked changes take place in the absorption curves at the approach 
of death. 

Demonstrations (continuously for the period of the meeting) : — 
Mr. C. R. BuRCH.— Pro/. Zernike's phase contrast test. 

An F/6 paraboloid is shown, the test being made null with the aid of a 
figured compensator. The errors of spherical aberration, coma, and 
astigmatism can be shown by changing the adjustments : zonal error can 
be shown by inserting a figured ' error-plate.' 

Mr. L. H. J. Phillips.— Pro/. Zernike's phase contrast method of 
microscopic illumination. 

The apparatus for this demonstration was kindly lent by Prof. Zernike. 

(Prof. E. T. Whittaker, F.R.S., in the chair.) 

Thursday, September 6. 

Discussion on The electronic theory of metals (lo.o) : — 

Prof. R. H. Fowler, F.R.S. — The quantum theory of metals. 

General introduction. Electron distribution laws ; the Fermi function. 
Thermionic work function and photoelectric threshold of an ideal metal. 
The free path phenomena ; Sommerfeld's elementary discussion for an 


ideal metal ; conductivity ; thermoelectric phenomena ; the transverse 
effects in a magnetic field. Meaning of the sign of the Hall coefficient. 

Next stages in the elaboration of the theory. Electron states in a periodic 
field of force. Brillouin's zones. Metals as insulators and semiconductors. 

Prof. C. G. Darwin, F.R.S. — The quantum theory of the free path 

The formal free path of Sommerfeld's theory is replaced by a properly 
calculated free path by studying the interaction between the electron waves 
of an ideal metal and the elastic waves (thermal agitation) of the ionic lattice. 
Bloch's integral equation for the distribution function. 

Dr. H. Jones and Prof. N. F. Mott. — Further developments of the 
theory (11.20). 

The form of the Brillouin zones for a number of crystal structures asso- 
ciated with well-known metals and alloys is discussed and illustrated. The 
significance of the form of these zones in relation to the structure is described 
with particular reference to the case of bismuth, and alloys possessing the 
characteristic y and e structures. From these considerations a theoretical 
basis is found for the well-known Hume-Rothery electronic rules. The 
nature of the X-ray emission bands of metals discovered by O 'Bryan and 
Skinner is discussed in the light of the Bloch theory. This leads to an 
examination of the optical transition probabilities from the conduction levels 
of the metal to the deep-lying K or L levels. A brief account of the optical 
properties of the alkali metals, including Zener's explanation of Wood's 
recent experiments, is given. 

Finally, the electrical resistance of pure metals with reference to their 
place in the periodic table is discussed, and it is shown how the observed 
resistance of alloys leads to a better understanding of the resistance of pure 

Prof. G. P. Thomson, F.R.S. 

Friday, September 7. 

Discussion on Utiified field-theories in physics (ii.o) : 

Prof. E. T. Whittaker, F.R.S. — The problem and some recent pro- 
posals for its solution. 

The problem to be solved. The earlier theories of Weyl, Eddington, 
Einstein, and Kaluza-Klein, compared with the more recent developments 
by Einstein-Mayer, Veblen, and Schouten-van Dantzig. Introduction of 
the fifth coordinate. Interpretation of the coordinates (i) in five- 
dimensional space, (ii) in four-dimensional space-time. Geodesies as 
world-lines of charged and uncharged particles. Interpretation of curva- 
ture. Deduction of the field-equations of gravitation and electricity. 

Dr. W. H. McCrea. — Unified field-theories and the quantum theory 

The formulation of Dirac's wave equation in projective relativity ; the 
physical significance of the result. Discussion of the general a priori 
possibility of including quantum theory in existing unified field -theories. 


Alternative possibility of obtaining unified theory of gravitation and 
electromagnetism by treating them as statistical properties of systems 
obeying a quantum theory. 

Dr. J. H. C. Whitehead. — Projective relativity (12.10). 

Generalised projective geometry, according to this presentation, depends 
upon the idea of a geometric object determined by sets of components and 
a transformation law. Whereas in affine geometry a geometric object 
(e.g. a scalar function or a contravariant vector) has one set of components 
in each coordinate system, a projective invariant has an infinity of sets of 
components. The transformation from one set of components to another 
in the same coordinate system can be explained in terms of a geometrical 
process analogous to projection in classical projective geometry. This 
explanation involves the use of an additional variable and, as when using 
homogeneous coordinates in the classical projective geometry of w dimen- 
sions, the formalism is that of {n + i)-dimensional affine geometry. 

The power of this treatment is largely due to the closeness with which the 
formalism copies the {n + i)-dimensional affine and Riemannian theories. 
In particular this applies to projective relativity, and if the ideas referred to 
above can be elucidated it should not be necessary to introduce a great deal 
of formal detail in the discussion of relativity. It will probably seem best 
to concentrate the formal work into a derivation of the equations of motion 
of a charged particle. Taking for granted the formulae which are obtained 
by the standard methods of Riemannian geometry, this should involve only 
a short calculation in the course of which many of the special features of the 
theory will be underlined. 

Monday, September 10. 

Prof. J. A. Carroll. — Some applications of Fourier transforms (lo.o). 
(i) The equation 

0{z)'= a[ I{z + <^t)g{t)dt . . . (i) 

— 1 

regarded as an integral equation for I(z), can be solved ' operationally ' by 
regarding z as an operator, and on writing down the equation of which (i) is 
the operational equivalent (image equation) and rearranging the terms, 
the operational form of the rearranged equation is the solution of (i), 
namely — 

I(u) ' 


where c is a suitably chosen path, and 

o ^ c 

+ 1 

g{t)dt,Gi3x)=a\ e-^"'g{t)dt 

This enables the validity of solution of (i) by the elementary method of 
Taylor expansion of I{z + ^t) and reversion of the series obtained to be 

Solution of the form (2) is troublesome to use when 0{z) is known 
numerically for real values of the argument only. lig{t) is assumed known, 


it is possible to regard ( i ) as an equation for p , inasmuch as ( i ) is only possible 
(if, e.g., I{x) is everywhere > o) for a unique value of p, given 0(2:). 

By forming the Fourier transforms of both sides of (i) it is possible froiri 
examination of the zeros of the periodogram to find p, and by a second 
Fourier transformation to compute liz). For example, if g(t) is -\/(i —t^), 


the transform 0{t) cos ut dt must vanish whenever u^j is one of the zeros 


oi Jiix) ; hence, since u is known at these zeros, P is determined. 

(2) If the probability of a quantity having a magnitude between x and 
X + dx is f{x)dx in one ' measurement,' the probability of a sum s to s -\- ds 
from n measurements is f,Xs)ds, where 

Ms) = J /.-I {s + t)f{t)dt. 

The computation oi fn{s), in successive steps, is very laborious, but if the 
transform g{u) oif(x) be constructed, 


giu) = y(^ fit) COS ut dt, 
taking /( — f) = f{t), then fi,{s) is obtained rapidly and simply as 


I V(2tt:) j- "^^ I g"{u) cos lit du. 

In illustration the method is applied to the probability of a given score 
after a given number of rubbers at contract bridge. 

Incidentally the method offers a convenient proof of the theorem that the 
distribution function for errors the result of a large number of small errors 
tends to the Gaussian law as the number of independent sources of error 
tends to infinity. 

Dr. W. L. Marr. — Desargues configurations from a quintic curve (10.50). 

If P is a point such that the lines joining P to five fixed points are tangents 
to a cubic curve at these five points, the locus of P is a quintic touching the 
conic of the five points at these points and passing through the other fifteen 
points of intersection of the lines joining them. The quintic can, however, 
be defined uniquely, and more simply, by these contacts and incidences, 
instead of as a locus. 

If six points are given on a conic, there are ten points P such that the 
lines joining P to the six points touch a cubic at these points. The ten 
points can be found as the relevant intersections of two quintics, but they 
can be shown independently to form the 1O3IO3 configuration arising in 
Desargues' theorem on perspective triangles, whence it follows that six 
quintics associated with six points on a conic have ten common points form- 
ing a Desargues configuration. If P is one of these ten points, three other 
of the points are on the polar of P for the conic. This result enables us to 
construct the configuration from one of the quintics and one of the ten 
points, and we find that the point can be chosen arbitrarily on the quintic — 
that is, that one quintic is the source of a single infinity of the 1O3IO3 


Mr. E. A. Maxwell. — Some examples in the theory of surf aces (11.10). 

The paper gives an illustration by example of certain general properties 
of surfaces. 

Denote by F^''{''C*)'' a surface of order 30, having as a-fold curve the 
rational quartic "C* (of order four and genus zero). The canonical surfaces, 
defined in similar notation by F^'^''*{"C*)'^'''-, are invariant for birational 
transformation. Now the curve "C'* lies on a unique quadric cp, meeting 
the two systems of generators in three points and one point respectively ; 
each ' three '-generator necessarily lies on a canonical surface, which there- 
fore degenerates into 9, together with a variable part. The curve of inter- 
section of 9 with F''"' is Noethcr-exceptional(i.e. a fixed part of every canonical 
surface), and, in fact, consists of 2C7 straight lines, generators of cp. In 
accordance with general theory, these may each be transformed to a simple 
point of a birationally equivalent surface : 

The cubic surfaces through the curve "C* may be represented by the 
prim.e sections of a thi'eefold locus F3^[6] of order five in six dimensions. 
The points of °C* correspond to the generators of a rational ruled surface 
i?'" of order ten on V ; the ' three '-generators of cp correspond to the points 
of a conic c. The given surface corresponds to the surface of intersection 
of F by a primal of order a ; this latter meets c in 20 points, each of which 
corresponds to a Noether-exceptional curve. 

Similar results are given for the surface F^'^(~C^y, the only other surface 
of this type. 

Sir A. S. Eddington, F.R.S. — Theory of electric charge and mass (11.45). 

The following principles (amongst others) are employed in the theory : 
(i) Indistinguishability . — ^A system of two particles No. i and No. 2 is 
described dynamically by giving as a function of the time the probability 
distribution of two sets of coordinates, q, q , together with an interchange 
variable 6 such that cos- is the probability that the particle at q is No. i 
When the particles are regarded as distinguishable (and always distin- 
guished without uncertainty) 6 is constrained to be zero. The Coulomb 
energy of electrons and protons is the momentum conjugate to 0. 

(2) Metrical Tensor. — The tensor g/ji,. giving the metric of macroscopic 
space must arise out of the fundamental conceptions of wave mechanics, 
and not as an extraneous datum. It is the energy tensor of the a priori or 
standard probability distribution of the particles. Since this distribution 
itself provides the metric of the space in which it is represented, the space 
automatically appears as uniform and isotropic. 

(3) Idealisation. — The most elementary equations of quantum theory 
which contain the definitions of charge and mass refer to highly idealised 
conditions. Formally the ideal uniform conditions prevail throughout the 
universe, since if the momentum of a particle is prescribed, its position 
in the universe is entirely unknown. The equations therefore apply strictly 
to spherical space and to hyperspherical phase-space. 

(4) Curvature. — Mass must arise out of curvature of space-time in 
quantum theory as it does in relativity theory. Curvature (by rendering 
space finite) limits the possible uncertainty of position, and therefore gives 
a minimum uncertainty and corresponding minimum expectation value of 

(s) Comparison Distribution. — Observationally the effect of mass is mani- 
fested in the study of the combined probability distribution of a particle 
and a physical reference body, but mathematically mass is defined as a 


coefficient in the simple probability distribution of the particle. The values 
of the masses of the proton and electron are determined by this substitution 
of a simple probability distribution for a double probability distribution. 

(Sir Frank Dyson, F.R.S., in the chair.) 

Friday, September 7. 

Prof. E. A. Milne, M.B.E., F.R.S. — A popular account of the significance 
of absorption lines in stellar spectra (i i .o). 

Dr. T. Dunham. — The new Conde spectrograph of the Mount Wilson 
Observatory (11.25). 

Prof. O . Struve. — Spectrophotometric investigations at the Yerkes 
Observatory (11.50). 

Prof. J. A. Carroll. — Accuracy of measurement in spectrophotometry 

(i) histrumental. — The effect of finite resolving power, etc., due to all 
causes may be represented as spreading a monochromatic source into 
a spectrum of intensity distribution K{T), T being the ' reduced ' wave- 
length. Thus a true distribution I{T) is observed as 0{T) where 

+ 00 
0{T)= I(T+ t)K(t)dt. 
■' -c» 

The practical solution and use of this equation is discussed, by the aid of 
Fourier transformation theory. 

(2) Photographic. — (a) The ability of a photographic plate to detect 
small changes in intensity distribution over a given region on the plate is 
discussed, and a quantity termed the ' Discriminating Power ' of the plate 
is defined and shown to be a useful criterion, analogous to Resolving Power 
in optical theory, whereby the performance of the plate used under specified 
conditions may be calculated. 

(b) Certain irregularities on a scale large compared to plate grain size 
are noticed and discussed in connection with variation of film thickness, 
measured optically by interference methods. 

(c) An estimate of limiting accuracy under optimum conditions. 

Mr. E. G. Williams. — Spectroscopic differences between giant and dwarf 
early type stars (12.40). 

The present procedure for determining absolute magnitudes by the 
spectroscopic method is unsatisfactory for the B and O type stars. It 
requires considerable modification and, until this has been effected, the 
intensity of the interstellar line of calcium is as good a criterion of distance 
as any, provided this intensity is measured spectrophotometrically. 

A number of typical early type stars has been selected for study. Their 
spectra show sharp lines and are free from such disturbing influences as 
axial rotation and the presence of emission lines. The stars have been 


divided into high and low luminosity groups (giants and dwarfs) by the 
interstellar line criterion. 

It is found that the intensity of both the hydrogen and helium lines is, in 
each subtype, greater for the dwarfs than for the giants, whereas the ionised 
lines of carbon, nitrogen, oxygen, magnesium, and silicon are relatively 
stronger in the giants. The effect for hydrogen is so marked, frona type 
BO to A, that it could be used for absolute magnitude determination provided 
the exact subtype of the star was measurable. This problem of exact 
classification is complicated by the fact that no line studied is free from 
luminosity effect. Ratios of line intensity for atoms of widely different 
excitation potential present the most hopeful solution of the problem, but 
any adopted method, though based on photometric measures, should be 
capable of adaptation for estimates of type and luminosity by the usual 
visual inspection. 

Report of Committee on Seismological Investigations. . 
Miss E. F. Bellamy. 


Thursday, September 6. 

(Dr. EzER Griffiths, F.R.S., in the chair.) 

Mr. R. S. Whipple. — A note on some of the difficulties of measuring the 
temperature of molten steel (lo.o). 

The problem of measuring the temperature of molten steel either in the 
furnace or in the ladle is one of great importance to the steel manufacturer. 
It is, however, one of great difficulty.' 

The committee appointed by the Iron and Steel Institute to study the 
heterogeneity of steel ingots formed a sub-committee to study the tempera- 
ture measurement side of the problem of ingot casting. This committee 
has devoted a great deal of time to the study of the problem. 

The temperature of the steel in a Siemens furnace is approximately 
1630° C, and the difficulty of inserting a pyrometer into the molten metal 
through the open door is almost insuperable. The tube protecting the 
thermo-elements must also be robust and non-porous, as the only elements 
that may be safely used at the present time for temperatures as high as 
1600° C. belong to the platinum group. The committee decided that at the 
present time the problem could only be solved by the use of optical pyro- 
meters, and that those of the disappearing filament type gave the most 
consistent results. Discrepancies in the results obtained showed that a 
careful study of the details of the pyrometers was necessary, and as a result 
exhaustive tests were made on the coloured and neutral glasses of the 
instruinents. With the introduction of new glasses and other modifications 
a considerable improvement has been made in the performance of these 
pyrometers. The readings obtained give the apparent temperature of the 
steel ; a correction must be applied to convert the readings to true 

The position cannot be regarded as satisfactory because there are so 
many factors involved in the determination of the temperature of molten 
steel by means of optical pyrometers, and this necessitates a considerable 
amount of skill when making the observations. 


Mr. R. Griffiths. — Some problems in the measurement of temperature in 

With the increasing need for closer control over the temperature in the 
manufacture of steel and its products the development of special forms of 
pyrometers has become necessary. For example, in rolling-mill practice 
the time required for taking an observation is a determining factor. Experi- 
ments are described w^hich have been carried out with the object of pro- 
ducing a pyrometer to satisfy the requirements. 

Mr. B. Lloyd-Evans and Mr. S. S. Watts. — A contribution to the study 
of flame temperatures in a petrol engine. 

It has been recognised for many years that the calculated maximum 
explosion pressure in an internal combustion engine is far greater than the 
measured pressure. The basis of this calculation is, that both pressure and 
temperature rise instantaneously when the piston is in its uppermost position, 
termed the T.D.C. (top dead centre). 

The authors have attacked the problem from the point of view of the 
temperatures produced, using the spectral line reversal system, developed 
recently by Dr. Ezer Griffiths and J. H. Awbery. 

In general, the tests showed that at the particular point considered in 
the engine, the temperature bore little relation to the pressure, this result 
being almost independent of the brand of petrol used. The maximum 
temperature on any given temperature/crank angle curve was of the order 
of 2100° C. and lasted over a much longer period of time than did the 
maximum pressure. It was also seen that combustion as denoted by 
tongues of flame lasted down to at least crank angle positions of 70° to 90° 
after T.D.C. 

As, however, the extinction of visible flame is not necessarily a criterion 

of the end of combustion, curves of ^t^t were plotted against crank angle. 

Had T been the average temperature in the cylinder at the moment con- 
sidered, then ^r should have been constant. This was far from the case, 

and, in view of the turbulence in the cylinder, it can only be concluded that 
combustion was still proceeding. 

Dr. Margaret Fishenden. — Radiation from non-luminous gases. 

As their temperature increases, radiation plays a more and more important 
part in the heat transfer from non-luminous gases containing water vapour 
or carbon dioxide. Methods of determining the radiation and convection 
from hot flue gases passing through a tube of internal diameter 10 in. are 

Mr. E. G. Herbert. — Periodic hardness fluctuations induced in metals by 
mechanical, thermal and magnetic disturbance. 

A brief account is given of the experimental stages which led to the dis- 
covery of periodic fluctuations. 

Typical results are given, in which periodic hardness changes were set 
up in pure metals, nickel, iron and gold, by mechanical, thermal and magnetic 
disturbances, and the fluctuations were stabilised by application of a magnetic 


The fluctuations appear to be electromagnetic, and may be allied to other 
known forms of electromagnetic oscillation. 

Description of a new method by which the fluctuations are autographically 
recorded, and correlated with changes in the elastic properties of metals. 

These records indicate that the modulus of elasticity of metals is not a 
stable but a fluctuating property, the fluctuations being periodic in character, 
and capable of being induced by magnetic disturbances, including the action 
of stray fields. 

Mr. O. A. Saunders. — Convection in gases at high pressures. 

Theoretical considerations show how the effect of pressure on natural 
convection in gases may be related to that of linear size. The heat losses 
from large surfaces in gases at atmospheric pressure can therefore be deduced 
from small scale experiments at high pressures. Some experimental results 
are discussed. 

Mr. H. DE B. Knight. — Industrial application of Thyratrons, with special 
reference to the control of resistance welding. 

The Thyratron is a gaseous discharge device through which current 
flows in the form of an arc and in which the current flow can be controlled 
by means of a control electrode or grid. A large range of such devices is 
available, with ratings varying from a fraction of an ampere to 100 amperes 
or more. These currents can be controlled with a negligible amount of 
controlling energy ; and, especially in high voltage circuits, the Thyratron 
provides an easy means of controlling considerable power. 

Particular reference is made to the application of the Thyratron in con- 
nection with resistance welding. In modern resistance welding applica- 
tions some metals can only be welded satisfactorily if the welding current 
is of very short duration. In addition, modern production methods require 
very high-speed operation with precision and reproducibility. These 
features are practically impossible to obtain when electromagnetic relays 
and contactors are employed to control the welding current ; but they are 
easily obtainable by the use of the Thyratron. 

A single impulse Thyratron-controlled spot-welder for pedal operation 
will be described and demonstrated. 

Mr. L. J. Davies and Mr. J. H. Mitchell. — Resonance radiations in 
electric discharge lamps. 

This paper aims at showing the importance of the phenomena of resonance 
radiations in connection with the nature of the light output from various 
types of electric discharge lamps. 

The resonance and general emission spectra, together with other physical 
properties on various elements, are discussed with a view to their possible 
utilisation in discharge lamps ; in particular resonance phenomena for the 
cases of mercury and sodium are dealt with in detail. 

Mr. H. R. Ruff. — The commercial production and utilisation of ultra-violet 

The large scale utilisation of ultra-violet radiation for such purposes as 
artificial lighting, manufacture of special chemicals and sterilisation of 
food-stuffs, utensils, and the water of swimming baths is assuming a rapidly 
increasing importance. 


This paper describes methods for the industrial production of ultra- 
violet radiation and some typical applications, and discusses also methods 
of rating such sources to enable the user to evaluate their worth for any 
particular purpose. 

Mr. L. J. Davies and Mr. R. Maxted. — Some aspects of modern road 

This paper deals with the application of light for the provision, on high- 
ways at night time, of a visibility sufficient for the requirements of modern 
traffic conditions. 

The optics connected with the process of seeing and distinguishing 
objects on artificially illuminated roadways are discussed. Light can be 
applied from moving vehicles or from stationary lighting points, and, for 
economical and other reasons, a mixture of the two methods, adjusted 
according to the traffic burden of the road, is a reasonable solution. 

Some possible lines of development are suggested. 

Monday, September 10. 

(Sir James Henderson in the chair.) 

Dr. EzER Griffiths, F.R.S. — Research on heat transmission and its relation 
to industry. 

In the design of structures involving the conservation of heat or cold, 
data as to thermal conductivity play an important part, and this is illustrated 
by consideration of typical cases which include buildings, furnaces and 

Measurements have been made on a variety of heat-insulating materials, 
and data are given for pumice concrete, aerated concrete, aluminium-faced 
asbestos paper, compressed fibre boards, etc. 

In the second part of the paper consideration is given to the question of 
the basic laws of the transfer of heat between gases and solids, and to the 
application of the data obtained to the design of batteries for the heating 
or cooling of air. 

When heated pipes are arranged in bank formation the second layer 
loses in an air stream more heat than the first, whether in square or 
in diagonal formation. In square formation the third layer loses the same 
as the second, whilst in diagonal formation there is an increased loss in 
the third layer over the second. After the third the coefficient is constant. 

The effect of fins fitted to the pipe in increasing the heat transfer is 
considered and data given. 

Dr. J. Small. — Thermal conditions round a hot circular cylinder in a stream 
of fluid. 

An experimental study of the variation in the rate of heat transmission 
from point to point round the surface of a heated cylinder in an air stream 
is made by means of an indicator built into the surface. When the cylinder 
is heated only in the region of the indicator a minimum value is recorded 
at the upstream generator as well as at generators which are about 90° of 
angle from the front. This minimum at the front is not obtained in ex- 
periments on a uniformly heated cylinder. The results are analysed and 
compared with those of other experimenters. 


The equation for the temperature distribution in a perfect fluid flowing 

c V d% (PQ 

past a heated body is Va/3^6 = f^ " tq* The usual assumption that -5^2 

is negligible as compared with t^ implies an indefinite rate of heat flow at 

the upstream generator of the cylinder. A solution which does not involve 
this assumption is obtained by a method of successive approximations based 
on an application of Taylor's Theorem. Constant temperature lines are 
drawn in the a, p field. 

Measurements of temperature of the air by means of a platinum resistance 
wire stretched parallel to a generator of a metal cylinder (heated internally 
by steam) and placed at different distances from its surface, show the 
characteristic spreading of the isotherms towards the sides of the stream 
beyond an angle of 90° from the upstream generator. 

Careful experiments in which the average rate of heat transmission from 
the surface is measured yield values higher than those obtained by most 
other observers, but closely agree with the recent results of Griffiths and 

Mr. A. H. T)o\5GhKS.— Modern building materials with a view to thermal 
insulation of buildings. 

During the last quarter-century, economic pressure, coupled with the 
increasing use of steel and reinforced concrete frameworks, has led to the 
cutting down of thicknesses of traditional building materials, such as brick, 
stone, slate and timber, in the building of walls, floors and roofs, resulting 
in an undesirable lowering of their overall heat and sound insulating qualities. 

Considerations of cost preclude any return to traditional methods, so 
that a solution must be found, (a) by new methods of design, such as 
various forms of cavity wall, based on more accurate knowledge of thermal 
phenomena ; (Z>) by the introduction of highly insulating non-structural 
materials for use in conjunction with the traditional structural elements ; 
(c) by the development of new forms of structural unit of substantially 
greater insulation value than the existing range, for use either alone or in 
conjunction with the latter. The above methods may of course be used 
either alone or in suitable combination. 

Much valuable work has been done during the past decade in regard to 
(6), for special uses such as refrigeration chambers, but cost has hitherto 
prevented its application to the wider field of general building practice. 

Increasing attention has been paid lately to (c) in an effort to avoid extra 
cost by a wider combination of functions in the material used. Such 
materials, in association with suitable kinds of tensile reinforcement, are 
found to approximate in many ways to the traditional timber element, 
without sharing its disadvantages in regard to fire, movement and rot. In 
fact they might aptly be described as forms of ' mineral timber,' and inter- 
esting results have already been secured by following out this line of thought. 

Mr. A. Lindsay Forster. — Glass silk as an insulator for heat and sound. 

Mr. F. C. JOHANSEN. — Problems of refrigerated railway transport. 

The relatively short duration of the journeys affects in several ways the 
economics of refrigerated railway transport in Great Britain. For example, 
the cold absorbed by the vehicle on loading and lost on discharging are 
an important proportion of the total refrigeration, and hence low thermal 


capacity, as well as low conductivity, is a desirable quality of insulated 
vehicles. The low density of appropriate insulators is also advantageous 
from the standpoint of haulage costs, but adequate endurance and retention 
of thermal properties affects the choice of material. Other good features 
aimed at in the vehicles are air-tightness, size and dimensions to accommo- 
date full loads, and ease of cleansing. With mechanically refrigerated vans, 
thermal capacity is less important since pre-cooling is easy. But mechanical 
refrigeration involves a large unit, and is economical only for long-distance 
regular traffic. For small vehicles, in random service, refrigeration by 
solid CO2 is generally very convenient, but immersion in the sublimed gas 
affects certain food products detrimentally. If, on this account, the gas is 
led into the insulation space, the choice of a suitable insulating material is 

Mr. A. F. DuFTON. — The equivalent temperature of a room and its 

The traditional method of determining the temperature of a roonn is by 
means of a thermometer, and until recently neither the cooling effect of 
draughts nor the influence of the teniperature of the walls has been fully 
appreciated. Although in terms of our sensations we say, ' It is colder now 
that the sun has gone in,' or ' Come round the corner ; it will be warmer 
out of the wind,' there has been' no scale of temperature to enable us to 
express how much colder or how much warmer. 

The temperature of an environment with a