a : _ ——- —_ Ai it, Ab i co - ——— ee a ae ee I sie wale om ei " \ y Wii hu ‘ We Naat i in 4 iA i i} Me j fh , P i a! e) ily Fy ae TT ikl Lh 4 e iy if ‘\ -, 3) All ire Had 5 nA iui fee) eee ivi we i j Va 7 Lean iA he i J We EAU, Yas | Hiei iba LY at fie A a ene AY ti nt ty Wit Rh) My he a i \ bien i ’ q i . i ‘ wr , May i Wwn) Ny me re ait L I Yay iy ) Ain hye | . WH) Hi Wt y ai q i) May 4 n 4) x i i iy 0 ANNUAL REPORT OF THE BOARD OF REGENTS OF THE SMITHSONIAN INSTITUTION SHOWING THE OPERATIONS, EXPENDITURES, AND CONDITION OF THE INSTITUTION FOR THE YEAR ENDING JUNE 30 L92/ ( Publication 2927) UNITED STATES GOVERNMENT PRINTING OFFICE WASHINGTON 1928 ADDITIONAL COPIES OF THIS PUBLICATION MAY BE PROCURED FROM THE SUPERINTENDENT OF DOCUMENTS U.8.GOVERNMENT PRINTING OFFICE WASHINGTON, D. C. AT $1.75 PER COPY (BOUND) LETTER ACTING SECRETARY OF THE SMITHSONIAN INSTITUTION SUBMITTING THE ANNUAL REPORT OF THE BOARD OF REGENTS OF THE INSTITUTION FOR THE YEAR ENDING JUNE 30, 1927 SMITHSONIAN INSTITUTION, Washington, November 26, 1927. To the Congress of the United States: In accordance with section 5593 of the Revised Statutes of the United States, I have the honor, in behalf of the Board of Regents, to submit to Congress the annual report of the operations, expendi- tures, and condition of the Smithsonian Institution for the year ending June 30, 1927. I have the honor to be, Very respectfully, your obedient servant, C. G. Axspor, Acting Secretary. IIt , at K ‘d the Ty , ; 1 Nea i Bi a Taba oe oe CONTENTS Page LEGS, -OEs TTS ET bie pe ees 2g reo le el a nN lat ate nail AO seas IL a nai See arsie i TStILMtOM st. ON ne il GEE DEY" ofS ER OU ISH DILUTE 0 ai na a A ST ONY TD Beh NS oa SE il J PVANEE SENG HEREC van ON co Rel e¥ E25 01] HS ne a ea aR oR DELO a AR Pe 1 enencimee ONS lentil Onsen ere sete nate ee aN ee een ee er 2 TNO EN AY G1EIS) em eps oe ras 2 ed Able Bl aah CEN 2 9 nlp apr Dab gas Od 4 VEb sey GARG HBS Ey BESS $2010 ba ES HG LN la er Soa ga am Ae Ae ne < Smithsonian-Chrysler HWxpedition to Africa___.____________-___ 7 CHUECENESMNCLOLOSSIS: Im MUnONe == 222 ee ee 9 Minerale Coneciing it Ii Oxd COs esters ee eee a reser ema 10 ED lOMNe Or Terns in sama Ca n= eee eee oe ee ea 10 FATEH OLOSLCA WOT lb 4 Mee ee tan re eee eee eno ee ATL AE a a lay ATI OP OLOSIGAl SULVC VOL; AlaASKoe cote Sree see ote ea 12 Conterenceron the tuture of the Institution. 2. ee 18 Award of Langley medal to Col. Charles A. Lindbergh______-_--._-_- __ 17 SHEA Cd DSN Deiat hs OD FS aaa Aho th 7 IDR TR 18 TEATU OVER ERT VG oS pees ae tn aa lps i lige ape ete aa ite et Nar al ela 20 TOM SPACE oc Se) i ots Se Sd tao ca rent ls bua Saal tite eR aN A. SEs MARIN ei ata ete ae a 2 we EPC SEMEIL SS ELTA Ba a pe tl el sabe RNs AC Ca Apa Ce Diet a 22, cue hehe Se ek Dy eave ilk eae Se etre Mealy la ee ae NGE AL i A 25 | ies Let CS MUST Tap Bs FN LS ele eh diel ls ds A SR ae eat SENG Ea Se 25 i Pred ieor -Americn MLInoOlogy 22 Memes Te 26 LITE WA Sy esa eT ROY ad Ml BC) ET fl ld ee AN ape J Eo we 28 JETER OREN By EPH LTE 2G at aT Se TR pc Re legge aed Ot gee a ea 29 PEeTMneRy MUR ORISCRY ALON y 222,55. Sb a 31 International Catalogue of Scientific Literature________________________ 32 Lee Re BYU NIDYE Ny ‘sige! 5 8 CR Rene eR eRe Le YL 0 aR wg eR Soe oe Appendix 1. Report on the United States National Museum_____________ 36 2 Lepore onwne, National Gallery? of Art: oes See ee ee) 54 oe Reporhon phe hreer > Gallery oreArt. Ses 63 4. Report on the Bureau of American Hthnology______________ 66 5. Report on the International Hxchanges____________________ 80 6. Report on the National Zoological Park -________________. 92 7. Report on the Astrophysical Observatory__________________ 109 8. Report on the International Catalogue of Scientific HAVE RACING Ss 225 So ae eee De a a ee ieee me a Soe 114 eigveports on: the: libra yee ee ee 116 OP rveport.-on~, publications sees oe a 126 VI CONTENTS GENERAL APPENDIX The accomplishments of modern astronomy, by C. G. Abbot------------ Recent developments of cosmical physics, by J. H. Jeans_------------ The evolution of twentieth-century physics, by Robert A. Millikan_--~~- Isaac Newton, by Prof. Albert Hinstein-___-__---------~---------------- The nucleus of the atom, by J. A. Crowther___------—------------_----- The centenary of Augustin Fresnel, by E.-M. Antoniadi_-_--_------------ Soaring flight, by Wolfgang Klemperer___-_- J jl = ee eee The coming of the new coal age, by Edwin KE. Slosson_---------------- Is the earth growing old? By Josef Felix Pompeckj_-_._----_--------- Geolovical’ climates; by Wi. B. SCOth=== sete es 2 ee ee Geologic romance of the Finger Lakes, by Prof. Herman F. Fairchild_--- Fossil marine faunas as indicators of climatic conditions, by Edwin Paleontology and human relations, by Stuart Weller At the’ North Poles by incon: ENsworth] <2. 22-2 eee Bird banding in America, by Frederick C. Lincoln_-_-_---_-_-__-_--_--_- The distribution of fresh-water fishes, by David Starr Jordan The. mind of ani insect, by Roh. Snodgrass-_-8 2 a eee The evidence bearing on man’s evolution, by AleS Hrdli¢ka_______________ The origins of the Chinese civilization, by Henri Maspero Archeology in China, by Iiang Chi-Chao__-___ 2-4 ee Indian villages of Southeast Alaska, by Herbert W. Krieger___________- The interpretation of aboriginal mounds by means of Creek Indian cus- COMS, DY) DON RS WaT COn 2s ee Friedrich Kurz, artist-explorer, by David I. Bushnell, jr_-______________ Note on the principles and process of X-ray examination of paintings, by: “Alan ‘Burroughs 2 ees oe ee ee Lengthening of human life in retrospect and prospect, by Irving Fisher__ Charles Doolittle Walcott, by George Otis Smith William Healey Dall, by C. Hart Merriam LIST OF PLATES Modern astronomy (Abbot) : Page TEMP SSI TU UP Eee NAS Le aD ea Pg Se LS ee ee 166 Augustin Fresnel (Antoniadi) : TEN bryce: Ta es we eS oe eerie NE) Ltt ann Aly’ Soaring flight (Klemperer) : PRN RES. Tg Dh Leal ee SR A a fe aS ee ee Cc eee a ee 242 New coal age (Slosson) : SES TSTE ean eee ge ee ese ek a rae Bs Eh I es Re hae 248 Finger Lakes (Fairchild) : ESL a espe =p ee er einer ae See Sneek eee 298 At the North Pole (Ellsworth) : TELS E RS sd I oes ES cae a eee. ie ee ee ee ee ee 330 Bird banding (Lincoln) : 1 PAS ICES STS ee aN a ae ree ee ee eee ee 354 Distribution of fishes (Jordan) : PEE 6 75 SE ss ek a ce SIRS Le ea Se eR ce ee a 3590 TELE PE SASS Ue ER ze et 6 a ie eee eee Ob eSB Soe CHR ee as hs See ni 366 Indians of Alaska (Krieger) : TG ISIS 2s) UES Dag a Yc a a NB RCN eNO SOUL NOE nt NE 494 Creek Indian customs (Swanton) : ECLIPSE) Soa Nein at a ee aS De a RPG ie Ir 506 Friedrich Kurz (Bushnell) : LES RES! AL BSR 6 SS a Pr) re PRS ES eee BR 512 TENGE ooh a SE RS Te SL Meee es oe Pe ee ee Se ae ae 520 X raying paintings (Burroughs) : RT Seep op ee a tae ets See ee Lo ee ee ae ce i Pe 584 Waleott (Smith) : TEA ED He 9a SSP eae a ae Sena ne en aN E Ree ES er ee 555 Sa Ae same ee me es es we Re SS 560 Dall (Merriam) : Eee ea Lit a Le eee ee ee ee ee SO A 5 ee 563 ANNUAL REPORT{OF THE BOARD OF REGENTS OF THE SMITHSONIAN INSTITUTION FOR THE YEAR ENDING JUNE 30, 1927 SUBJECTS 1. Annual report of the secretary, giving an account of the opera- tions and condition of the Institution for the year ending June 30 1927, with statistics of exchanges, etc. 2. Report of the executive committee of the Board of Regents, exhibiting the financial affairs of the Institution, including a state- :) ment of the Smithsonian fund, and receipts and expenditures for the year ending June 30, 1927. 3. Proceedings of the Board of Regents for the fiscal year ending June 30, 1927. 4. General appendix, comprising a selection of miscellaneous memoirs of interest to collaborators and correspondents of the Insti- tution, teachers, and others engaged in the promotion of knowledge. These memoirs relate chiefly to the calendar year 1927. Ix ae le Bi il ee” kt i , ea oo, | os en "pe ee ee THE SMITHSONIAN INSTITUTION June 30, 1927 Presiding officer ex officio—CatvIN CooLincE, President of the United States. Chancellor—WiLLiAM Howarp Tart, Chief Justice of the United States. Members of the Institution: CALVIN Coo.LipcGE, President of the United States. CHARLES G. Dawes, Vice President of the United States. WILLIAM Howarp Tart, Chief Justice of the United States. FRANK B. Kettoae, Secretary of State. ANDREW W. ME Lon, Secretary of the Treasury. DwicuHTt Fintey Davis, Secretary of War. JOHN G. SARGENT, Attorney General. Harry S. New, Postmaster General. Curtis D. Witpur, Secretary of the Navy. Hupert Work, Secretary of the Interior. WILLIAM M. JARDINE, Secretary of Agriculture. HERBERT CLARK Hoover, Secretary of Commerce. JAMES JOHN Davis, Secretary of Labor. Regents of the Institution: Witt1AM Howarp Tart, Chief Justice of the United States, Chancellor. CHARLES G. DAwEs, Vice President of the United States. REED Smoot, Member of the Senate. Woopsrincre N. Ferris, Member of the Senate. JosEPH T. Roprnson, Member of the Senate. ALBERT JOHNSON, Member of the House of Representatives. R. WALTON Moore, Member of the House of Representatives. WALTER H. Newton, Member of the House of Representatives. CHARLES F. CHOATE, Jr., citizen of Massachusetts. HENRY WHITE, citizen of Washington, D. C. Rosert 8. Brookines, citizen of Missouri. Irwin B. LAvGHIIN, citizen of Pennsylvania. FREDERIC A. DELANO, citizen of Washington, D. C. DwicHt W. Morrow, citizen of New Jersey. Executive committee —HENRY WHITE, FREDERIC A. DELANO, R. WALTON Moore. Acting Secretary.—C. G. ABBOT. Assistant Secretary.—ALEXANDER WETMORE. Chief Clerk —Harry W. Dorsey. Accounting and disbursing agent.—N. W. DorsEy. Editor—wW. P. Trung. Librarian.—Witi1amM L. Corsin. Appointment clerk.—JAMES G. TRAYLOR. Property clerk.—J. H. Hr. D.@ | XII ANNUAL REPORT SMITHSONIAN INSTITUTION, 1927 NATIONAL MUSEUM Assistant Secretary (in charge).—ALEXANDER WETMORE. Administrative assistant to the Secretary—W. DE C. RAVENEL. Head curators.—WatiErR HouecH, LEONHARD STEJNEGER, Grorce P. MERRILL. Curators —PAUL BartscH, R. 8S. Basster, T. T. Bertore, Austin H. CiLarK, KF. W. CiarkKe, F. V. Covitne, Coartes W. GILMorE, WALTER Hovuan, L. O. Howarp, ALES HrpoLtiéKa, New M. Jupp, H. W. Kriscer, FReperRicK L. LEw- “pron, Grorce P. Merrriti, Gerrit S. Minter, Jr., CARL W. MiTMAN, ROBERT Ripaway, WaALpo L. ScHMiTT, LEONHARD STEJNEGER. Associate curators.—J. M. ALpRIicH, W. R. Maxon, CHARLES EH. Ressrer, CHARLES W. Ricumonp, J. N. Rosz, PAun C. STANDLEY, DAvip WHITE. Chief of correspondence and documents.—H. S. BRYANT. Disbursing agent.—N. W. DoRsEY. Superintendent of buildings and labor.—J. S. GoLpSMITH. Hditor—Marcus BENJAMIN. Assistant Librarian.—IsaBeL L. TOWNER. Photographer.—ARrtTHUR J. OLMSTED. Property clerk.—W. A. KNOWLES. Eingineer.—C. R. DENMARK. Shipper.—L. E. PErRry. NATIONAL GALLERY OF ART Director.—WILLIAM H. HoLMEs. FREER GALLERY OF ART Curator.—JOHN FILLERTON LODGE. Associate curator.—CarL WHITING BISHOP. Assistant curator.—GRAcE DUNHAM GUEST. Associate.—KATHARINE NASH RHOADES. Superintendent. JOHN BUNDY. BUREAU OF AMERICAN ETHNOLOGY Chief.—J. WALTER FEWKES. Hthnologists—Joun P. Harrineron, J. N. B. Hewitt, Francis La IFLescue, TRUMAN MICHELSON, JOHN R. SWANTON. Archeologist. H. H. Rosrrts, Jr. Hditor.—STANLEY SEARLES. Librarian. ELLA LEARY. Tllustrator.—Dr LANCEY GILL. INTERNATIONAL EXCHANGES Acting secretary (in charge).—C. G. ABBOT. Chief clerk.—C. W. SHOEMAKER. NATIONAL ZOOLOGICAL PARK Director.—WILLIAM M. MANN. Assistant director.—A. B. BAKER. ASTROPHYSICAL OBSERVATORY Director.—C. G. ABBOT. Research assistant.—F. HE. Fow es, Jr. Research assistant.—L. B. ALDRICH. REGIONAL BUREAU FOR THE UNITED STATES, INTERNATIONAL CATALOGUE OF SCIENTIFIC LITERATURE Assistant in charge.—Lronarp C. GUNNELL. REPORT OF THE ACTING SECRETARY OF THE SMITHSONIAN INSTITUTION C. G. ABBoT FOR THE YEAR ENDING JUNE 30, 1927 To the Board of Regents of the Smithsonian Institution: GrntLEMEN: J have the honor to submit herewith my report show- ing the activities and condition of the Smithsonian Institution and the Government bureaus under its administrative charge during the fiscal year ended June 30, 1927. The first 34 pages contain a summary account of the affairs of the Institution. Appendixes 1 to 10 give more detailed reports of the operations of the United States National Museum, the National Gallery of Art, the Freer Gallery of Art, the Bureau of American Ethnology, the International Exchanges, the National Zoological Park, the Astrophysical Observatory, the United States Regional Bureau of the International Catalogue of Scientific Literature, the Smithsonian library, and of the publica- tions issued under the direction of the Institution. THE SMITHSONIAN INSTITUTION THE ESTABLISHMENT The Smithsonian Institution was created by act of Congress in 1846, according to the terms of the will of James Smithson, of England, who in 1826 bequeathed his property to the United States of America, “to found at Washington, under the name of the Smith- sonian Institution, an establishment for the increase and diffusion of knowledge among men.” In receiving the property and accepting the trust, Congress determined that the Federal Government was without authority to administer the trust directly, and therefore constituted an “establishment” whose statutory members are “the President, the Vice President, the Chief Justice, and the heads of the executive departments.” THE BOARD OF REGENTS The affairs of the Institution are administered by a Board of Regents whose membership consists of “the Vice President, the Chief Justice, three Members of the Senate, and three Members of 1 se ANNUAL REPORT SMITHSONIAN INSTITUTION, 1927 the House of Representatives, together with six other persons other than Members of Congress, two of whom shall be resident in the city of Washington, and the other four shall be inhabitants of some State, but no two of them of the same State.” One of the regents is elected chancellor by the board; in the past the selection has fallen upon the Vice President or the Chief Justice; and a suitable person is chosen by the regents as secretary of the Institution, who is also secretary of the Board of Regents and the executive officer directly in charge of the Institution’s activities. The following changes occurred in the personnel of the board during the year: The term as a regent of Senator George Wharton Pepper expired upon his retirement as a Member of the Senate on March 8, 1927, and Senator Joseph T. Robinson was appointed by the Vice President to succeed him on March 4, 1927. Senator Reed Smoot was reappointed a regent by the Vice President on March 4, 1927. | The roll of the regents at the close of the fiscal year was as follows: William H. Taft, Chief Justice of the United States, chancellor; Charles G. Dawes, Vice President of the United States; members from the Senate, Reed Smoot, Woodbridge N. Ferris, Joseph T. Robinson; members from the House of Representatives, Albert John- son, R. Walton Moore, Walter H. Newton; citizen members, Charles IF. Choate, jr., Massachusetts; Henry White, Washington, D. C.; Robert S. Brookings, Missouri; Irwin B. Laughlin, Pennsylvania; Frederic A. Delano, Washington, D. C.; and Dwight W. Morrow, New Jersey. GENERAL CONSIDERATIONS Death of Secretary Walcott—On February 9, 1927, the fourth secretary of the Smithsonian Institution, Charles Doolittle Walcott, passed from us. For 20 years Doctor Walcott had successfully guided the destiny of the Smithsonian, and his death is a severe blow to the Institution and a great bereavement to his friends and associates on the staff. This report is not the place to review in detail the life and work of Doctor Walcott—that will be done later in a biography to be published in the general appendix to the Annual Report of the Board of Regents. Jt has been my privilege to be closely associated with Doctor Wal- cott during the entire 20 years of his administration. He took a genuine kindly interest in his associates, rejoiced without any ges- ture of appropriation in their successes and the growth of their reputations, and sorrowed in their disappointments and troubles. From his long life of affairs he was always ready to quote wise or illustrative passages, so that his counsel was most helpful and saga- cious. He was highly approachable, even in temper, and exceed- REPORT OF THE SECRETARY 3 ingly simple in all his habits. For many years he occupied a leading place in the business of his church, and he had a strong un- troubled religious faith, crowned by full confidence in a future life. Of commanding height and noble features, he was physically every inch a worthy head of the Institution. A strong and experienced administrator, of indefatigable industry, he was able not only to shape its administration but to carry on at the same time his own world-renowned researches in geology and paleontology. It has been said that 70 per cent of existing knowledge of Cambrian and Pre- Cambrian paleontology is due to him, and of this one-half was ac- quired by him while secretary of the Smithsonian Institution. The late secretary was a man of the widest interests. He was prominently in public life in Washington for many years before coming to the Smithsonian, having served as director of the United States Geological Survey. At that time, also, he secured the passage of a law organizing the forest surveys of the country, and organized and directed for five years the United States Reclamation Service. He took a leading part in the affairs of the Carnegie Institution of Washington, which he had been largely instrumental in founding, and also a leading role in the promotion and encouragement of the new science of aeronautics, culminating during the World War in his appointment by President Wilson as a member of the National Advisory Committee for Aeronautics. During the war he served as chairman of its executive committee and later as chairman of the committee itself until his death. He was prominent in the National Research Council, for several years president of the National Academy of Sciences, and president of other scientific societies of national scope. One of the most important steps taken by Secretary Walcott in the last years of his administration was the approval of a definite campaign to increase the endowment funds of the Institution. This project is mentioned in his last two annual reports, that for 1926 outlining the preliminary steps taken. Although the matter has perhaps moved more slowly than anticipated, nevertheless very definite progress has been made, and there is real promise of a suc- cessful outcome of the project. Doctor Walcott, like Secretary Langley before him, regarded the totally inadequate income of the Institution for research and publication as presenting a crisis in its affairs, and it is earnestly hoped that plans for increasing that income, so vital to the future work and reputation of the Institu- tion, may be carried on successfully. Gifts—¥our especially noteworthy gifts and bequests came to the Institution during the past year—the Canfield mineralogical collec- tion, the Roebling mineralogical collection, the John Donnell] Smith 4 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1927 herbarium and botanical library, and the Canu collection of French Cenozoic and Mesozoic fossils, exceeding 100,000 specimens. ‘The Canfield collection of minerals came as a bequest from Dr. Frederick A. Canfield, of New Jersey. It contains some 9,000 minerals, many of them unique and all of exceptional quality, and to insure its con- tinued development Doctor Canfield also bequeathed to the Institu- tion the sum of $50,000, the income from which is to be used for that purpose. The Roebling mineralogical collection was presented to the Smithsonian by Mr. John A. Roebling, of Bernardsville, N. J., in memory of his father, Col. Washington A. Roebling, who died in July, 1926, willing the mineral collection to his son. The Roebling collection contains over 16,000 specimens, including practically every known mineral species. Mr. Roebling also accompanied his gift with an endowment fund of $150,000 for its development. ‘The John Don- nell Smith herbarium and botanical library form the most munifi- cent gift of botanical material ever received by the National Herba- rium. The Smith herbarium, containing well over 100,000 specimens, all well preserved and excellently mounted, is particularly rich in Cen- tral American material, with numerous type specimens of species de- scribed by Captain Smith in his own extensive botanical researches on the flora of that region. Under the terms of the will of the late Catherine Walden Myer, and by an agreement with the other legatees named in the will, the Institution has received in cash the sum of $3,649.91 and notes secured by certain property in Washington amounting to $14,618. The will stipulated that the income from this bequest should be used for the purchase of works of art for use and benefit of the National Gallery of Art. FINANCES The permanent investments of the Institution consist of the fol- lowing: Total endowment for general or specific purposes (exclusive of Freer: funds)! v2 ea snp hi ee eed 0 py ee eee ate yon 8 aig $1, 885, 279. 75 Of this total there is deposited in the Treasury of the United Statessas providedhpyetaw— 2-2-3265) 3 ee ee ee 1, 000, 000. 00 Deposited in the consolidated fund: Miscellaneous securities, ete., either purchased or acquired by gift; cost or value at date acquired~_—___4_ 2 3738, 759. 75 Charles D. and Mary Vaux Walcott research fund, stock Cait) i: wales reas tes Bees vtec: are oi a toe he 11, 520. 00 The sums invested for each specific fund or securities, etc., acquired by gift are described as follows: REPORT OF THE SECRETARY (oy | | SINT TR Cee 8 NG ee $14, 000. 00 $40 456.46 | foe es $54, 456. 46 Warm mrnebureay, Bacol find = 22+ £3: oe eee ie on |. Se 62):272 Ossi t= = ae aan 62, 272. 93 [DUTTA ECE Uh CTC (OE Man eS ee Ebel re te | el aie aN | T2688 009 ec eeme eee 1, 728. 09 LER a 8) 9 OSTA 6 ES Ea el |e a 35; 000::00>|2=== 5222222. 35, 0C0. 00 bapel tipidits seen fo 8 es ee lt eect 0 Ce ae Se es A oe ee 500. 00 PEMD IM IMGs oes oe aes cee 2, 500. 00 500: 00" (bse eo ae 3, 000. 00 eALOMUNe TICHEV TUNG sess toh 2 oe Ser ae ee Seco ase a RE is fh et ak ee 1, 223. 33 Hodgkins fund: COP TUHGE | Lag. Ove STs TS as a eee 116, 000. 00 375275500) hee ee eS aoe 153, 275. 60 SY aC ELIT Cie pet Ae 2S STD ek 100; 000: OD) hae ee Sea eo net ae a Be 100, 000. 06 Brice Hughes fund - 22-22. cee. < st eeze.3-|----5 eS eee 14,458: 90,)2£ =. sees ses oe 14, 158. 90 Lucy T. and George W. Poore fund__-_--_-_- 26, 670. 00 PANS A8 he: UN Ue aan eas 47, 966. 42 Adisom i ver fund = 22287 6 2 Fe eS See 11, 000. 00 Ls ae Kt pik Se es a 18, 299. 16 UN GGS thine be Se Scns ey hk ee oh 5S0. 00 Oofea4 |=ise2 See. 947. 34 TES) eVE CE OG BPRS SRS Rs OR er ene ae ee eee ees 7150000; 00; [P= so e2 eso 150, 000. 00 Crearre td pamiord 1UnGe- 22 2. 2. 4} are 1, 100. 00 B752 727 hee oe 1, 775. 72 Simippsen ind 2-242 teed st ee a Sk 727, 640. 00 1 SIG AO) esa on Ss 729, 156. 40 Charles D. and Mary Vaux Walcott research READ ES Se A I ee a i eg eee rd Pyne een a data i (et are $11, 520. 00 11, 520. 00 rites Lema irene. Sew anes es S 1,000, 000.00 | 373, 759. 75 11, 520.00 | 1,385, 279. 75 The Institution gratefully acknowledges gifts from the following donors: Dr. W. L. Abbott, for collecting expedition to Haiti and Santo Domingo. Mrs. Laura Welsh Casey, further funds for expenses in connection with Casey collection of Coleoptera. Mr. Walter Chrysler, further funds for expedition to Africa to collect animals for National Zoological Park. Mr. Childs Frick, for explorations in vertebrate paleontology: National Academy of Sciences, for paleontological researches. Mrs. Cornelia Livingston Pell, for care of Pell collection. Mr. John A. Roebling, for the establishment of the Roebling fund for care of Roebling collection of minerals, and for other purposes. Mr. Homer E. Sargent, for manuscript on Salish basketry. Dr. Frank Springer, further funds for publication of volume “American Silurian Crinoids,” and for other purposes. Mr. Chas. T. Simpson, for work on West Indian shells. Mr. H. B. Swales, for purchase of specimens, ete. ‘The Institution has also received contributions from the following friends for the funds as listed below Endowment campaign expense fund: Mr. Frederic A. Delano, Mr. Dwight W. Morrow, Mrs. Mary Vaux Walcott. Endowment fund: Mr. John Baker, Mr. W. C. Condon, the Gould Co., Mr. J. Wrank Haan, Mr. Paul Hartley, Mr. S. M. Henrie, Mr. George A. Knapp, Mr. W. C. Rogers, Mr. H. Seddon, and Mr. Hans Wilkens. The Institution also received from the estate of Catherine Walden Myer the sum of $3,649.91, a payment on account of a bequest for purchase of works of art for use and benefit of the National Gallery - of Art. 74906—28——2 6 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1927 Freer Gallery of Art.—The invested funds of the Freer beques: are classified as follows: * Courtand. rounds: tind eee ey ee ee $365, 441. 13 Court and grounds, maintenance fund________---_--_----------- 78, 953. 36 Curator find ==). eee fos Oe Berne ih fre ae ae ee 316, 830. 25 Residiary legacy a. sik eee ae eB ee ee 3, 410, 655. 87 TT Ob CU este sah DU OG 2s ea tn i em 4, 171, 880. 61 The practice of depositing on time in local trust companies and banks such revenues as may be spared temporarily has been con- tinued during the past year, and interest on these deposits has amounted to $3,813.38. The income during the year for current ex- penses, consisting of interest on permanent investments and other miscellaneous sources, amounted to $65,392.21. Revenues and princi- pal of funds for specific purposes, except the Freer bequest, amounted to $320,977.75. Revenues on account of Freer bequest amounted to $249,737.84; amount received from sale of stocks and bonds, $1,152,- 735.58 ; ee a total of $1,788,843.38. The disbursements, described more fully in the annual conan of the executive committee, were classed as follows: General objects of the Institution, $57,518.69; for specific purposes (except the Freer bequest), $305,220.90; and investments and expenditures pertaining to Charles L. Freer bequest, $1,358,165.70. The total of balances on hand June 30, 1927, from all funds and mainly bearing interest on deposit, was $202,827.49. The following appropriations were made by Congress for the Government bureaus under the administrative charge of the Smith- sonian Institution for the fiscal year 1927: International Hixchane gece 2 ek ed eae $46, 260 American) Hthn 010 Siy= rh eas 2 a 57, 160 International Catalogue of Scientific Literature__.___.______________ 7, 500 Astrophysical Observatory ..2.22 3-24-5225 ss ye oe 31, 180 Additional ‘assistant Secnetanyes 2) se Pks ae eee ae oe 6, 000 National Museum: I vbigen DD geMen ate RED. oN nie toal ikierc wk we Sn aeMe tar aie EY ace ooo 2 $23, 730 Heating and? 11s inten eee See see SS aes ee tenn eae 78, 140 Preservation of }collections22. 2.205 8) trot ait e ae 450, 000 ASA OU Tb ovear yy oY Uh sfc eens neg MaDe OB ame Marea WRLey Pe TEER 12, 000 BQOKS ee NN I ai Sean a aon oe ae eg 1, 500 Postage oa Seo ak ee ere 8 ea 450 565, 820 Nwtional (Galles yo ier n iste ae oe a ea ee 29, 381 National’ Zio} OT Gene aires oe ata TTI Oe a ep 178, 199 Printing ‘and! binding Bele eet hihi = ee pee ae ee Cad ee eee 90, 000 pb 1 Maes AM el nome Mate Eth RaW a rah 1, 006, 500 1The sinking fund has been discontinued and each fund credited with its portion of same. REPORT OF THE SECRETARY 7 EXPLORATIONS AND FIELD WORK More than 30 field expeditions, in which the Smithsonian Institu- tion took a leading part, went out during the past year. The record is doubly interesting, in view of the fact that almost no unrestricted funds for field work were available, each expedition being separately financed either by the generosity of some friend of the Institution or through a cooperative arrangement with some other organization whereby the costs and collections were shared. Such a program of field work is of necessity more or less haphazard, since each oppor- tunity presented must be grasped whether or not it fulfills the exact objects most valuable to the Institution. The more desirable method, obviously, and the one that would be followed if the Institution had complete financial independence, would be to map out in advance the essential expeditions in accordance with a definite plan. The year’s field work covered such widespread territory that an enumeration of the countries visited will be of interest. Abroad, Smithsonian expeditions worked in South West Afrita, East Africa, Sumatra, China, Alaska, Canada, Mexico, Guatemala, Costa Rica, Panama, Ecuador, Peru, Chile, Facdaien Haiti, England, France, and Germany. In the ee hots California, eee and Monts led with three expeditions each; Washington and Louisiana followed with two each; and Montana, Eee, New Mexico, Mississippi, New York, and New Jersey were visited by one expedition each. Brief extracts from accounts of only a few of the expeditions will be given here to indicate the nature of the work and its preliminary results. Accounts of other field work will be found in the reports on certain of the bureaus under administrative charge of the Insti- tution, appended hereto, namely, the National Museum, the Bureau of American Ethnology, and the Astrophysical Observatory. The Institution also publishes each year an exploration pamphlet, giving an illustrated summary of them. SMITHSONIAN-CHRYSLER EXPEDITION TO AFRICA The outstanding expedition of the year in point of popular in- terest was the Smithsonian-Chrysler Expedition to Africa to collect live wild animals for the National Zoological Park, under Smith- sonian direction. The expedition was financed by Mr. Walter P. Chrysler, automobile manufacturer, and headed by Dr. W. M. Mann, director of the National Zoological Park; the other members were Mr. Stephen Haweis, artist and naturalist; Mr. F. G. Carnochan, of New York; and Mr. Arthur Loveridge, of the Museum of Com- parative Zoology at Cambridge. Mr. Charles Charlton was sent by the Pathé Review to make a motion-picture record of the expedition. 8 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1927 Leaving New York March 20, 1926, the party arrived in Dar-es- Salaam, Tanganyika Territory, East Africa, on May 5. A license to collect was received from the governor of the Territory and headquarters were established at Dodoma, 250 miles inland. Collecting was successfully carried on for some months at various localities in the Territory, the animals being sent back to Dodoma to be held there until the close of the work. One of the cliief de- siderata was a young rhinoceros, and although adult specimens were numerous, no young were seen. In the Ja-aida swamp country, where Doctor Mann went on the search for these animals, the hunt proved rather exciting. Doctor Mann says: Altogether we saw 22 rhinos. Our safari was charged once while on the march, and four times at night rhinos charged through our camp. But in all of these we failed to locate a single young specimen. Five different times we crawled into the scrub 30 or 40 feet from a rhino to see if it had young and were disappointed each time. One locates these rhinos, by the way, through the tick birds, which make a loud twittering at the approach of any suspicious object “to the rhino on which they are clustered for the purpose of eating the ticks which are so abundant on its body. Theoretically they serve a useful purpose to the rhino by warning him of his enemies. Actually we found they were useful in leading us to where the rhino were lying, for we were attracted by the birds to each of the rhinos that we found. The night charges are simply the result of the stupidity of the rhino. We eamped usually in the vicinity of water holes, and when the nearsighted beast came to water late at night or early in the morning he would suddenly notice that there were fires and natives dbout. Whereupon he would put his head down and charge through in a Straight line. On these occasions the natives have a frantie desire to get into the tents to be near the white men and the guns; the white men, on the other hand, have a frantic desire to get out of their tents, and the result is a collision at the entrance. Two rhinos came into our camp the same night. At Tula, where the expedition next camped in the hope particu- larly of securing giraffes, animals were abundant. Two native sultans, Chanzi and Chaduma, joined forces with us for a week, bringing with them about 500 natives. With the help of these we had the most successful trip of the expedition. Some of the boys from a mountain near by had had some experience in netting game. They make a coarse seine of native rope in sections about 5 feet high and 15 feet long. These were placed in a row, until they made about 1,000 feet of native fence, one boy hiding behind each section. The two lots of natives would double over their ends and join in a circle about a mile in circumference, then closing in toward the net. The object was to drive animals into the net, but nine times out of ten they would break through the line. Occasionaily, however, they came straight on. One day a herd of over 50 impalla was surrounded. This is the most graceful antelope in Africa and a great leaper. Most of them sailed right over the net, but five fell short and we got them all. Fortune was with us as far as impalla were concerned, for it is one of the most delicate animals to handle, and yet all of ours reached Boston alive and in good condition. Wart hogs were captured in the same way, and a troop of four were added to the collection. REPORT OF THE SECRETARY 9 Giraffes, however, proved to be very difficult to capture. A young one was finally separated from the herd and caught, but unfortunately died from pneumonia soon after. A pair was later obtained, how- ever, from the Sudan Government. The expedition embarked from Dar-es-Salaam with about 1,700 live animals, nearly all of which were safely transported over the long journey to Washington. This is by far the largest single collection ever brought to the National Zoological Park, and greatly increases the value and popular interest of the park’s animal exhibits. COLLECTING MICROFOSSILS IN EUROPE Dr. R. 8. Bassler, curator of paleontology in the National Museum, spent August and September, 1926, in collecting microfossils in France and Germany and in studying the geology of various classic localities in those countries. Microfossils have proved to be of the greatest value in the determination of underground geological struc- ture, particularly in connection with the location of oil. The National Museum collections are rich in fossil micro-organisms from the Ameri- can Mesozoic and Cenozoic rocks, but descriptions of many of these have never been published because their relationship to European species was not clear. To obtain the needed European material for comparison was the primary purpose of Doctor Bassler’s expedition. The first two weeks were spent in company with Dr. Ferdinand Canu, of Versailles, the most eminent student of microfossils on the Continent, who has been the joint author with Doctor Bassler of several large publications on the American fossil bryozoa. At this time Doctor Canu presented to the Museum his entire collection of I’rench Cenozoic and Mesozoic fossils, containing at least a hundred thousand specimens fully labeled as to horizon and locality. Doctor Bassler proceeded to the Rhine Valley, where he studied in succession the broad plain around Strassburg, the valley to Mainz, and the valley of the Main River from Mainz to Frankfort. In the Rhine gorge a first-hand knowledge was obtained of the Devonian stratigraphy of this classic area and important collections of De- vonian fossils were secured. Various regions in Germany were studied with profit both in the amount of good study material secured and in the information re- garding stratigraphic relationships. The classic Mesozoic region north of the Hartz Mountains was visited in company with Mr. Ehrhard Voigt, an enthusiastic student of microfossils at Dessau, Germany. Mr. Voigt also accompanied Doctor Bassler to other regions celebrated in German stratigraphy, particularly the potash areas around Stassfurt, the drift region around Dessau, and other regions to the north, and finally to the island of Riigen on the Baltic. 10 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1927 At the town of Sassnitz on Riigen were located the “ Kreideschlem- merei” or chalk-washing establishments. An important industry has been developed around the use of chalk for various whitening pur- poses, but the chalk must be pure and free from fossils and flint fragments. ‘To accomplish this, the chalk is passed through the washers and all the fine and coarse débris is sieved out and thrown aside, leaving the water with its dissolved material to settle. In the pile of débris resulting from such washing many fossils have been discovered in this area. Not only were many excellent echinoids, brachiopods, and other large fossils picked up in the dump heap but literally billions of microfossils were obtained simply by shovel- ing up several boxes of the fine débris. MINERAL COLLECTING IN MEXICO In collaboration with the Mineralogical Museum of Harvard Uni- versity, Dr. . W. Foshag, of the National Museum, conducted field work in that part of the plateau of northern Mexico within the States of Chihuahua, Coahuila, and Durango, for the purpose of collecting representative minerals from that region. Mexico is very rich in minerals, producing, for instance, over 40 per cent of the world’s silver, yet but few mineralogical collections have been made there. Doctor Foshag was in the field nearly five months, and over two tons of material was collected and shipped back to Washington. Cordial cooperation was given by Mexican Government officials and by American mining engineers in charge of the mines visited. Some of the interesting features of the trip are described in the following extracts from Doctor Foshag’s preliminary account: Sierra Mojada, one of the districts visited, owes its discovery to a band of smugglers attempting to elude pursuit. The ore bodies extend for a distance of 6 kilometers along the foot of a limestone cliff 2,500 feet high. The district is unusual in that lead, zinc, silver, copper, and sulphur have all been mined here. The great length but shallow depth of these mines makes it more economical to work them by the old Spanish methods than by modern ones. Much of the ore is brought to the surface on the backs of peons, often up ladders made of notched logs, popularly called “ chicken ladders.” I1t is said that a strong peon will carry loads in excess of 100 kilos (220 pounds.) In the northeastern part of the State of Durango, near the village of Mapimi, is the Ojuela mine—one of the greatest lead mines of the world. Within this one mine are over 550 miles of tunnels driven to extract the ore. The camp itself is perched on a steep limestone mountain. Before the town, rises an almost vertical cliff of Cretaceous limestone 2,000 to 3,000 feet high. It is in the hills lying at the-base of this cliff that the ore bodies lie. EXPLORING FOR FERNS IN JAMAICA Dr. William R. Maxon, associate curator of plants, United States National Museum, spent June and July, 1926, in botanical collecting REPORT OF THE SECRETARY a in the Blue Mountain region of Jamaica. This expedition, made possible through the cooperation of the American Association for the Advancement of Science, the New York Botanical Garden, and the United Fruit Co., had for its specific object the collecting of material needed in the preparation of an account of the ferns of Jamaica. The importance of this study is thus explained by Doctor Maxon: The ferns of Jamaica were among the first to be described from the New World, but in many instances the names originally given them came later to be applied loosely to related but distinet kinds from other regions, with much resulting confusion. To afford a proper basis for studying the diverse fern floras of tropical America as a whole, it thus becomes of prime importance to know thoroughly that of Jamaica, an end that can be attained, naturally, only with the aid of adequate material. Of the 500 species of ferns and fern allies described or known from Jamaica, nearly all are found in recent large collections brought to American herbaria from that island; yet there are a few collected by Sir Hans Sloane in the latter part of the seventeenth century, and by Swartz about a hundred years later, that still are known only from the original specimens preserved in Huropean museums. Present field work is concerned therefore in the re- discovery of these “lost” species and of other very rare ones described more recently, but equally also in the discovery of new kinds, and in assembling data as to the distribution, characteristic habitats, habits of growth, and interrelationship of those other species that are comparatively well known. In all, some 15,000 specimens were collected, which will be of the greatest assistance in the preparation of the proposed monograph of the ferns of Jamaica. ARCHEOLOGICAL WORK IN CHINA An archeological survey of the Féng River Valley, southern Shansi, China, was carried out in the early part of 1926 by Dr. Chi Li, of the Freer Gallery of Art Expedition to China. Carrying letters of introduction to the governor of Shansi and other influ- ential officials, and accompanied by Mr. P. L. Yiian, of the Geological Survey of China, Dr. Chi Li began his trip at T’ai-yiian. Ancient temples, embellished with iron and stone images, tombs of emperors whose deeds are lost in the haze of tradition, and mounds of prehistoric potteries were found, all of which promise a rich field to the archeologist. An excerpt from Doctor Li’s report gives something of the fascinating interest of the exploration. On the 19th we set out to visit the supposed tomb of the Emperor Shun, and on the way stopped at certain temples in Yiin-ch’éng. In Shansi-t’ung-chih, it is recorded that the stone pillars of these temples were formerly the palace Pillars of Wei Hui-wang (3835-370 A. D.), recovered from the ruined city south of An-i Hsien. Some of them are now used as the entrance pillars in Ch’én-huang Miao and Hou-t’u Miao, and those of Ch’én-huang Miao certainly 12 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1927 show peculiar features which are worth recording. Two pillars, hexagonal in section and carved with dragons coiled around them, are found at the entrance. The left one is especially interesting, because in the claws of the dragon are grasped two human heads with perfect Grecian features—curly hair, aquiline and finely chiseled nose, small mouth, and receding cheeks. One head with the tongue sticking out is held at the mouth of the dragon, while the other is heid in the talons of one hind leg. It is an unusually fine piece of sculpture in lime- stone, wonderfully spaced and with the most graceful lines. The right one is inferior in its workmanship; evidently the two were not executed by the same hand. I saw 28 of this kind of pillar in the succeeding two days, but most of them were crude imitations. It is possible, however, that some are of the ancient type and were made earlier than others. The whole subject is well worth more detailed study. ANTHROPOLOGICAL SURVEY OF ALASKA A reconnaissance of anthropological and archeological matters in Alaska was undertaken during the spring and summer of 1926 by Dr. Ale’ Hrdlitka, curator of physical anthropology in the Nationa] Museum, under the auspices of the Bureau of American Ethnology. An archeological reconnaissance of Alaska presents many difficulties. Although Alaska is as large as one-third of the United States, it has less than 200 miles of good roads; the interior is practicaily impass- able except for short stretches during the brief summer; and trans- portation by boat is very hard to obtain and very expensive. ‘The people of Alaska, however, were found to be most helpful and gener- ous, and with their help Doctor Hrdlitka was able to overcome many of the difficulties encountered. When the Bering Sea was reached, he was fortunate enough to find the revenue cutter Bear willing to help, and on it he was enabled to inspect the sites of archeological interest along the Seward Peninsula, the Kotzebue Sound, and through the Arctic Sea up to Barrow. The journey led from Vancouver to Juneau, thence to Seward, Anchorage, Eklutney, Nenana, and Tanandé. From here the route ied inland from the junction of the Tanana to the mouth of the Yukon, concluding with the voyage in Bering Sea. _ - Doctor Hrdlicka collected many artifacts of metal, bone, and ivory, examined skeletal remains in many old burial places, examined the differentiation between Eskimo and Indian in physical and cultural characters, and observed the conditions governing the possibilities of the Mongoloid migrations through Bering Sea, which are sup- posed to have populated the Americas. He was convinced that such migrations were so easy as to have been indeed inevitable, and that the Eskimo and Indian races trace from a common Mongoloid stem, having its American dispersal from the Alaskan peninsula. The ancient Alaskan artifacts discovered point to a high grade of native art, almost on a par with the high cultures of Mexico, Yucatan, and Peru. REPORT OF THE SECRETARY 13 CONFERENCE ON THE FUTURE OF THE INSTITUTION An outstanding event in the history of the Institution was the conference held at the Smithsonian on February 11, 1927, to advise with reference to the future policy and field of service of the Insti- tution. The President, the Vice President, members of the Cabinet, and a group of the foremost American scientists and industrial lead- ers met under the chairmanship of Chief Justice Wiliam Howard Taft to hear addresses on the past record and present great possi- bilities of the Institution, to inspect a specially arranged exhibit in the main hall of the Smithsonian Building, showing the nature and scope of the researches and publications at present under way, and to discuss informally the most promising directions for the future work of the Smithsonian. The chancellor, Chief Justice Taft, in opening the conference, re- viewed briefiy the history of the Institution from 1826, the date of the making of Smithson’s will, emphasizing the basic soundness of the charter provided by Congress after eight years of deliberation. But this charter alone did not make the Smithsonian the leader of American science in its early years and a world-renowned agency for the increase and diffusion of knowledge to the present day. The plan of organization outlined and put into effect by the first secre- tary, Joseph Henry, did that. His plan has proved to be so wise and fruitful of great results that it has never been found necessary to alter it materially. Mr. Taft also emphasized the fact that the Smithsonian Institution is not and has never been properly con- sidered a Government Bureau, this popular misconception having arisen from the fact that the Institution still administers for the Government seven of the public bureaus, which arose from its early activities. Mr. Taft concluded his address thus: Joseph Henry had the vision to understand clearly what Smithson meant his foundation to be, and the energy and character to make it that. The Smith- sonian has now come to a time when, without the support of the Nation, it can no longer continue to be what Henry made it. And yet the need for just such an Institution as it has been is no less than the need was 80 years ago. In some respects the unique opportunities are even greater. This Institution is not the product of a moment; 80 years of the toil of great men have gone into its making. There is that about it which can not be replaced. The regents have felt it their duty to reveal to a leading group of representa- tive American citizens what it is and does, and to advise with them what its future shall be. For that reason they have invited you here. They wish you to see the broad and comprehensive scope of the Institution, competing or interfering with nobody, cooperating with all, reaching the basic problems of mankind and of the time, with a view to furnishing the information through which alone they can be solved. They wish you to see what the future possi- bilities of the Institution are, and if you think them worthy of realization, to advise us as to how we may go about achieving it. 14 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1927 Following the chancellor’s address, Doctor Abbot, as acting secre- tary, spoke on “The Smithsonian Institution—Its Activities and Capacities.” Reviewing the origin and growth of the Government bureaus which by direction of Congress remain under Smithsonian direction, he showed how they arose from private Smithsonian initia- tive, and continued at private Smithsonian cost until they became large public necessities. The activities of the Institution, past and present, were brought together under 13 heads, as follows: 1. It carries on original scientific investigations with its own staff. 2. The Institution subsidizes other researches by men not directly connected with the Institution. 3. It publishes new knowledge, gained by its own and outside workers, in the form of large memoirs and smaller original papers, which it distributes free to 1,500 libraries and learned bodies in every country of the world. : 4. The Smithsonian evolved the International Exchange Service and is now the official channel for the exchange of scientific intelli- gence between the United States and the world. 5. For over half a century the Institution has been building up in the Library of Congress the foremost scientific library in this coun- try, now totaling nearly 700,000 volumes. 6. It fosters the scientific development of schools, museums, and institutions through its free distribution of scientific literature, by the loan of research men, by the gift of over a million specimens, by the distribution of instruments, and by its advice. 7. The Institution cooperates with every department of our Government. 8. It answers by mail an average of 8,000 questions a year on scientific subjects. 9. It gives occasional lectures and courses of lectures and radio talks. 10. It fosters research by conferring medals of honor on eminent discoverers. 11. It procures foreign diplomatic and learned recognition and assistance to expeditions going abroad. 12. It fosters American scientific progress by providing headquar- ters for the American Association for the Advancement of Science and the American Association of Museums. 13. It administers seven governmental bureaus in addition to the Freer Gallery. The acting secretary next presented in some detail the wonderful opportunities ahead of the Institution in many lines of scientific research, using as a concrete example his own field of investiga- tion, namely, astrophysics. He stated that there was a vast deal REPORT OF THE SECRETARY 4 63) not yet known about the rays of the sun, which support all life, make all weather, and directly or indirectly supply all power. Knowledge of four things about the sun is particularly needed at the present time: 1. Which rays are best for human health and growth, and at what intensity? How do these intensities change by day, by year, by altitude, and by latitude? Physicians come to the Smithsonian now for information on the influence of sun rays on child health. We can not give them the answer, nor can anyone else, because the investigations have not been made. 2. What rays and in what intensity promote growth and reproduction in the great food and otherwise commercially valuable plants? Are useful modifications of these plants possible by the regulation of radiation? How do plants use solar energy to make chemical energy, and can we improve upon their processes and accomplish photosynthesis directly? 8. Can solar rays advantageously be used directly for power? 4, Can studies of solar variation foretell good and bad weather conditions? The Smithsonian is particularly fitted through its lohg experience and trained personnel to attack fundamental problems, and is only restrained from doing so by lack of funds. Examples might be cited for nearly every branch of science. The acting secretary concluded his address by calling attention to the fact that private endowment is essential for a continuous pro- gram of pure science research, and to the unique strategical position of the Institution for the most effective increase and diffusion of knowledge. After an address by Frederic A. Delano, Regent of the Institution, emphasizing the great opportunity before the Smithsonian of becom- ing the motivating head of all governmental, quasi governmental, and private research work in the field of pure science, and an introduction to the special exhibits by Assistant Secretary Alexander Wetmore, the conference viewed the exhibits grouped around the main hall. These dealt with the present work of the Institution in anthropology, geology and paleontology, biology, and astrophysics, and also illus- trated its activities in the diffusion of knowledge through its publica- tions, its scientific library, its International Exchange Service, and the International Catalogue of Scientific Literature. After a luncheon for the conferees, which was attended by the President of the United States, an informal discussion was held on the main purpose of the conference, “to advise with reference to the future policy and field of service of the Smithsonian Institution.” The chancellor, Mr. Chief Justice Taft, as chairman, turned the direc- tion of the discussion over to Mr. Dwight W. Morrow, regent of the Institution, who in turn called upon a few of the distinguished guests to comment upon the past or the present or the future of the Institu- tion. The speakers included Dr. John C. Merriam, president of the Carnegie Institution of Washington; Dr. William Henry Welch, 16 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1927 director emeritus of the School of Hygiene and Public Health of Johns Hopkins University; Dr. S. W. Stratton, president of the Massachusetts Institute of Technology; Dr. Simon Flexner, director of the Rockefeller Institute for Medical Research; Dr. W. W. Camp- bell, president of the University of California; Dr. Henry Fairfield Osborn, president of the American Museum of Natural History; Dr. George EK. Vincent, president of the Rockefeller Foundation; Mr. Chauncey J. Hamlin, president of the American Association of Mu- seums; Gen. H. M. Lord, Director of the Bureau of the Budget; and Senator Reed Smoot. The very definite concensus of opinion was apparent from the dis- cussion that the Smithsonian Institution has a most important place to fill in future as the inspirer and coordinator of research in pure science as it had been in the past, and that both governmental and private support should unite in making available more adequate means to enable it to carry on that worthy mission. Chairman Mor- row, in closing the discussion, said in part: I have been deeply impressed with this meeting. I, like Doctor Wexner, have learned much about the Smithsonian to-day. It is a great honor to be associated in any way with such an institution. It is a great honor to those of us on the Board of Regents to have so many distinguished men respond to Gur invitation to advise with us with reference to the future policy and field of service of an institution which has had so honorable a past. We are particularly grateful to those of you who have taken part in the discussion. In the course of the conference there has been some discussion of the funds available to the Smithsonian from the Government for those bureaus which are administered by the Smithsonian and those funds available from the original endowment of the Smithsonian. I am sure that General Lord is correct when he tells us that there has been a greater percentage of increase in the Government appropriations for the bureaus administered by the Smith- sonian than for the other Government bureaus. We must all remember, however, the point that Doctor Merriam brought out when he referred very beautifully to the work designed to be done by the original Smithsonian Foundation as the “holy of holies.” This “holy of holies” remains pretty much as it was when John Quincy Adams induced Congress to grant the charter which makes the work of James Smithson go on. * * * Now, when one thinks of the splendid history of the Smithsonian Institution, when we think of what devoted men have been doing and are doing upon inadequate salaries, it seems to me that the only way to resolve this dispute as to whether the Smithsonian Institution should be supported by the Gov- ernment or supported by private benefactions is to get the Government and the private benefactors into such a state of mind that they will vie with each other, the benefactors insisting that they should do it all and the Government insisting that they should do it all. And in saying good-bye to you, I should like to leave a text in your mind. * * * You will find the text in one of the earlier chapters of Deuteronomy. It reads like this: “Thou shalt not muzzle the ox when he treadeth out the corn.” That was a practical injunction to a practical people. The ox, who was doing a real work, should not be muzzled. I offer no apology to the devoted * REPORT OF THE SECRETARY | 17 men who have been rendering this Institution service in comparing them to the cx. The ox has a very ancient and a very honorable lineage. If the historians are correct, the ox, as a bearer of burdens, goes back much further than the horse. The ox is perhaps the most ancient burden bearer for mankind. And the devoted men that have been running this institution, what have they been doing? They, too, have been bearing the burdens of mankind, the burdens of the future generations of men. “Thou shalt not muzzle the ox when he treadeth out the corn.” AWARD OF LANGLEY MEDAL TO COL. CHARLES A. LINDBERGH The Langley medal of the Smithsonian Institution has been awarded only four times since its establishment. The first three awards were to Wilbur and Orville Wright, to Glenn H. Curtiss, and to Gustave Eiffel, and on June 11, 1927, the fourth award was made, this time to Col. Charles A. Lindbergh for his magnificent nonstop flight from New York to Paris. It thus continues to be characteristically a medal for pioneers in aeronautics. The award was voted to Colonel Lindbergh by the Board of Regents upon the recommendation of a committee of leading aeronautical authorities, and the official notifi- cation was made to him in person by the acting secretary at the National Press Club reception in the Washington Auditorium. He said: The Smithsonian Institution knows how to appreciate the pioneering work of brave men. You will recall, as a single example, our honored one-armed hero, Major Powell, who dared for science the first passage of the uncharted raging waters of the Grand Canyon of the Colorado, strapped in his boat. We are not less stirred to admiration by your own daring in the first nonstop flight from New York to Paris over the boisterous Atlantic through icy clouds that threatened death. Nor is the Institution failing to appreciate, sir, the precious results in the encouragement of aviation, in the strengthening of ties of international friend- ship, and in the progress of science, which have already begun to flow from your achievement. The Smithsonian has in its gift a medal which commemorates the name of Samuel Pierpont Langley, the third secretary of this Institution. He had the audacity to believe in the practicability of the art of flying when all men were ridiculing it; and he adventured his own high reputation as a man of science to laY the groundwork of exact experiments, and to make pioneering flights of large models, which demonstrated the soundness of his faith. The Langley medal has hitherto been presented to Wilbur and Orville Wright, to Glenn H. Curtiss, and to Gustave Hiffel. Thus it is from all points of view the medal of pioneers. It is highly fitting that it should now be awarded to you, sir, the pioneer of audacious, solitary flight to distant shores. Therefore, acting on the unanimous recommendation of an eminent com- mittee of award, the regents of the Smithsonian Institution have voted to you the Langley medal, and have recorded their action in this paper signed by the chancellor, Mr. Chief Justice Taft, which I now present to you. The actual medal, in gold, is being struck in Paris. I hope that when it is received you may do the Institution the honor to appear on some suitable occasion and receive it in person. 18 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1927 ANNOUNCEMENT OF AWARD BY THE BOARD OF REGENTS JUNE 4, 1927. The Langley medal of the Smithsonian Institution was established by the Board of Regents in 1908 as a tribute to the memory of the late Secretary Samuel Pierpont Langley and his contributions to the science of aerodromics. This medal has been awarded— To Wilbur and Orville Wright on February 10, 1909, “for advancing the science of aerodromics in its application to aviation by their successful inves- tigations and demonstrations of the practicability of mechanical flight by man”; To Glenn H. Curtiss on February 13, 1918, “for advancing the art of aero- dromics by his successful development of a hydroaerodrome whereby the safety of the aviator has been greatly enhanced”; To Gustave Hiffel, of Paris, on February 13, 1913, “for advancing the science of aerodromics by his researches relating to the resistance of the air in con- nection with aviation.” Believing that the achievements of Capt. Charles A. Lindbergh entitled him to consideration as a recipient of this medal, the acting secretary of the Insti- tution appointed a committee, which has made the following report: THE JOHNS HOPKINS UNIVERSITY, Baltimore, Md., June 3, 1927. The BoarD OF REGENTS, SMITHSONIAN INSTITUTION, Washington, D. C. GENTLEMEN: The committee designated by the Acting Secretary of the Smithsonian Institution, consisting of Dr. Joseph S. Ames, chairman; Admiral D. W. Taylor, Dr. S. W. Stratton, and Admiral H. I. Cone, to consider the award of the Langley medal at this time has unanimously voted that Capt. Charles A. Lindbergh, for his magnificent nonstop flight from New York to Paris, is justly entitled to receive this medal, and recommends that it be awarded to him by the Board of Regents of the Smithsonian Institution. Very truly yours, (Signed) JosePpH S. AmEs, Chairman. The Board of Regents has approved the above recommendation of the com- mittee, and I take pleasure in announcing that the Langley medal of the Smithsonian Institution is hereby awarded to Capt. Charles A. Lindbergh for his flight from New York to Paris, made on May 20 and 21, 1927. Wo. H. Tart, Chancellor, Smithsonian Institution. By the Chancellor: C. G. Assot, Acting Secretary. ° SMITHSONIAN RADIO TALKS The series of Smithsonian radio talks over station WRC of the Radio Corporation of America, begun in 1923, continued during the year with undiminished popularity. As in previous years, the program was under the direction of Mr. Austin H. Clark. This is obviously an effective method of diffusing knowledge of scientific matters, one of the primary functions of the Institution. An increas- ing number of the talks have been published as magazine or news- paper articles, thus insuring their permanent preservation. Because REPORT OF THE SECRETARY 19 of the increasing demands on the time of station WRC, it became necessary to include the talks on the National Zoological Park, given last year as a distinct series, in the regular series of Smithsonian talks. During the Smithsonian-Chrysler Expedition to Africa, under the direction of Dr. W. M. Mann, letters from Doctor Mann were read over WRC to keep the public informed of the progress of the expedition. Twenty-nine talks were presented between November 24, 1926, and June 29, 1927, as follows: November 24, 1926: Bringing Home Living Animals from Africa. Dr. William M. Mann, Director, National Zoological Park. December 1, 1926: Early American Animals—Hlephants and Others. Dr. James W. Gidley, National Museum. December 8, 1926: Shooting Stars. Dr. Willard J. Fisher, Harvard College Observatory (read by Mr. Austin H. Clark). December 15, 1926: An Observatory Among the Hottentots. Dr. Charles G. Abbot, assistant secretary, Smithsonian Institution. December 22, 1926: The Invasion of the Snowy Owl. Dr. Alexander Wetmore, assistant secretary, Smithsonian Institution. January 5, 1927: Natural History in Louisiana. Mr. Percy Vicscea, jr., State biologist of Louisiana. January 19, 1927: Dialogue between Miss Sarah W. Clark and Dr. William M. Mann on the subject of his experiences in Africa. January 26, 1927: The Antarctic Continent. Prof. Sir Douglas Mawson, the University, Adelaide, South Australia. February 2, 1927: Some African Reptiles. Miss Doris M. Cochran, Na- tional Museum. February 9, 1927: White Ants or Termites. Dr. Thomas E. Snyder, Bureau of Entomology. February 23, 1927: The Romance of the Lighthouse Service. Mr. John S. Conway, Deputy Commissioner of Lighthouses. Mareh 2, 1927: Oyster Farming. Mr. Herbert F. Prytherch, Bureau of Fisheries. March 7, 1927: American Wild Horses. Dr. James W. Gidley, National Museum. March 16, 1927: Fishery Products in the Arts and Industries. Mr. Lewis Radcliff, Deputy Commissioner of Fisheries. March 21, 1927: Beetles; what they are and what they do. Dr. Edward A. Chapin, Bureau of Entomology. March 28, 1927: Watchmakers as Inventors. Mr. Carl W. Mitman, National Museum. April 6, 1927: The Study of the Sun. Mr. F. E. Fowle, Astrophysical Observatory. April 18, 1927: The Sea. Mr. Austin H. Clark, Smithsonian Institution. April 20, 1927: Frogs and Toads. Miss Doris M. Cochran, National Museum. April 27, 1927: The Honey Bee. Mr. James I. Hambleton, Bureau of Entomology. May 4, 1927: Mice. Mr. Arthur J. Poole, National Museum. May 11, 1927: Fossil Footprints in the Grand Canyon. Mr. Charles W. Gilmore, National Museum. May 18, 1827: Who owns Potomac Park? Dr. George P. Merrill, National Museum. 20 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1927 May 25, 1927: Museums. Mr. Chauncey J. Hamlin, president, American Association of Museums. June 1, 1927: The Black Hills of South Dakota. Dr. James W. Gidley, National Museum. June 8, 1927: Goldfish and Other Aquarium Creatures. Mr. Glen C. Leach, Bureau of Fisheries. June 15, 1927: Snakes. Mr. Charles 8S. East, National Museum. June 22, 1927: The Gold Coast. Mr. Charles H. Knowles, director of agri- culture, Accra, Gold Coast. June 29, 1927: The coins of Asia. Mr. T. T. Belote, National Museum. PUBLICATIONS The 12 series of publications issued by the Institution and its branches constitute a chief means of diffusing knowledge, correspond- ence, exhibitions, and lectures supplementing. The first secretary of the Smithsonian, Joseph Henry, said: It is chiefly by the publications of the Institution that its fame is to be spread through the world, and the monument most befitting the name of Smithson erected to his memory. These publications cover nearly every branch of science, although anthropology, biology, geology, and astrophysics have predominated. As most of the publications present the results of research in pure science, the great majority are naturally technical in character. ‘Two annual publications, however, are intended for the general reader— the Smithsonian annual report and the Smithsonian exploration pamphlet. The Smithsonian annual report has from the first been enriched with a general appendix made up of a selection of some 30 articles reviewing in nontechnical language recent advances in all branches _of science and interesting phases of modern research work. Many of the articles are reprinted from journals which have little or no circulation in this country, and would therefore otherwise probably never be seen by American readers. The following eight titles se- lected at random from the 30 articles in the general appendix to the 1926 report, which will appear early in the coming autumn, will indicate the character of these papers: Influences of sun rays on plants and animals. Excursions on the planets. Cold light. The cause of earthquakes; especially those of the eastern United States. How beavers build their houses. Fragrant butterflies. Omaha bow and arrow makers. Preventive medicine. REPORT OF THE SECRETARY pa | Ten thousand copies are printed of the reports and they are dis- tributed free as long as the Institution’s quota lasts. The annual Smithsonian exploration pamphlet is a profusely illustrated account of the field expeditions in which the institution took part during the year. Many of the pictures are extremely interesting, forming a first-hand record of the natural conditions and human activities in far-off parts of the earth. The exploration pamphlet for 1926, is- sued in April, 1927, described 35 separate expeditions, many of them to remote regions such as South West Africa, East Africa, China, Sumatra, Siam, and the interior of Alaska. One hundred and eighteen volumes and pamphlets were published during the past year by the Institution and the Government bu- reaus under its direction. Of these there were distributed a total of 182,846 copies, which included 24,775 volumes and separates of the Smithsonian annual reports, 18,199 volumes and separates of the Smithsonian miscellaneous collections, 17,178 Smithsonian special publications, 110,580 publications of the National Museum, and 10,711 publications of the Bureau of American Ethnolegy. The titles of the individual papers are listed in the report of the editor of the Institution. Allotments for printing—The congressional allotments for the printing of the Smithsonian report to Congress and the various publications of the Government bureaus under the administration of the Institution were practically used up at the close of the year. The appropriation for the coming year ending June 30, 1928, tatals $90,000, allotted as follows: Annual report to the Congress of the Board of Regents of the Smith- DAME ad ESTES BK 4 ee eA De ah hc ht A ea aE aha Pa 2 pes eR $10, 5080 RHETT MV SOURI Hee eet bed eo bored Joe 4 be SL aE Lhd A ENS 2 44, 000 nrc pou pAmericanr Bithimolog yes ste lts vy tetvers eth fe errs ye de ates 26, 800 MIO M An Galerva Ol VAT = tae eet ae Fe aot oa 500 Mer naebioM a lbp Gham ees | IS ee eT ee ek ee Se Sy 300 International Catalogue of Scientific Literature______________________ 160 TES ERO VaESL MALAY OS Karen CE NE) Pe i {ee OS ee Sac AE ie, Op alien Si tenia Rte i 300 ENS ICH TONS (et a CO) SEIT Ved COI Vie kes a NA ae the ee ee 500 Annual report of the American Historical Association___.__________ 7, 000 Committee on printing and publication—aAll manuscripts sub- mitted to the Institution for publication either by members of the staff or by outside authors are referred for consideration and recom- mendation to the Smithsonian advisory committee on printing and publication. The committee also considers matters of publication policy. During the past year five meetings were held and 83 manu- scripts were considered and acted upon. The membership of the committee is as follows: Dr. Leonhard Stejneger, head curator of biology, National Museum, chairman; Dr. George P. Merrill, head 74906—28-—8 22 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1927 curator of geology, National Museum; Dr. J. Walter Fewkes, chief, Bureau of American Ethnology; Dr. William M. Mann, director, National Zoological Park; Mr. W. P. True, editor of the Institu- tion, secretary; Dr. Marcus Benjamin, editor of the National Mu- seum; and Mr. Stanley Searles, editor of the Bureau of American Ethnology. LIBRARY The accessions to the libraries of the Institution and its branches, exclusive of the Bureau of American Ethnology, totaled 9,060. ‘The outstanding gift of the year was the John Donnell Smith botanical collection of 1,600 volumes, which will be deposited in the section of botany of the United States National Museum. This library was really presented to the Institution in 1905, but until last year only a part of it had been transferred to Washington. . ‘t iy MARES RY” faa eeut TAL Th? h19 SIR Ban ff } wnt ht: Evi iihoaisieeke 2 Capea oda pare ih ab Be itt agate edd oriaee st th ‘SHtotshl hal ett eget an | wai eit pein is nae rhestt- es ao whee te jade SOG amalar ashe sonia ie: henites outs, a gtatiibh | A pa THE NUCLEUS OF THE ATOM? By J. A. CROWTHER The University, Reading, England Since Rutherford in 1911 first propounded his nuclear theory of the atom, the evidence which has been accumulated from many and varied phenomena has been so weighty, and so consistently in favor of his suggestions that there is now a very general agree- ment among physicists that the nuclear hypothesis embodies the es- sential truth about atomic structure. The atom of any substance is now regarded as being made up of a central core, or nucleus, of almost incredibly small dimensions (in which, nevertheless, prac- tically the whole of the mass of the atom resides), surrounded by a swarm of negative electrons. The nucleus, as a whole, is posi- tively charged and under its attractive force the negative electrons describe around it circular or elliptical orbits, in much the same way as the planets circulate around the sun. Since the normal atom is electrically neutral, the resultant positive charge on the nucleus is equal to the sum of the charges on the planetary electrons. If we take the charge on a negative electron as our unit of charge we may say that the positive charge on the nucleus of an atom is numerically equal to the number of planetary electrons it contains. The problem of atomic structure thus divides into two parts—the determination of the arrangement of the planetary electrons, and the structure of the central nucleus. The first of these problems has been attempted, with remarkable success by Niels Bohr, and the general outlines of his solution are well known to most readers. The second problem is now being attacked by Sir Ernest Rutherford and his pupils. In many ways it is the more difficult problem of the two. ‘The motions of the planetary electrons are responsible for the optical and X-ray spectra of the atom; while their arrangement determines its chemical and physical properties. There is thus a wealth of experimental data to guide the adventurer in this realm. The nucleus, on the other hand, is a world remote and inaccessible. It is true that its charge determines and controls the electronic orbits, but at the distances at which these electrons revolve the evidence shows that the nucleus acts merely as a point charge, and reveals nothing of its structure. The only properties definitely assignable to the nucleus are mass, and, where the element is radioactive, radioactivity. These 1 Reprinted by permission of the Editor, Prof. E. Rignano, from Scientia, International Review of Scientific Synthesis, vol, XXXIX, No. CLXVII-3, Mar. 1, 1926. Publishers, G. E. Stechert and Co., New York. 209 210 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1927 are our only guides to a study of atomic nuclei. These simple means in the hands of Sir Ernest Rutherford have already sufficed to give much information about these minute, but important structures. Most of us have, at some time or other, discovered the presence of a chair in a pitch dark room by the simple process of colliding with it. This is essentially the method developed by Sir Ernest Rutherford for his investigations of the nucleus. High-speed pro- jectiles of suitably small dimensions are fired through matter and from the number and magnitude of the deflections which they under- go, inferences are drawn as to the number and nature of the obstacles which they have met. Suitable projectiles for the purpose are found in the « particles from radioactive substances. The a particle is an atom of helium which has lost two electrons, and thus carries a double positive charge. But it is known from the work of Mosely cn X-ray spectra that the number of planetary electrons contained in the atom of a given element is equal to the atomic or ordinal number of the element. Since helium is No. 2 in the order of the elements it has, normally, two planetary electrons only. Hence the a particle is the nucleus of the helium atom, stripped of its plane- tary electrons. If a parallel beam of such particles is projected through a thin sheet of matter the majority of the particles emerge without ap- preciable deviation. A small fraction are, however, deflected through considerable angles, occasionally through more than a right angle. It was this observation which originated, and indeed necessitates, a nuclear theory of the atom. A particle of the mass and speed of an « particle can only be deviated through a sensible angle when it collides with an obstacle of mass comparable with or greater than its own. The experiments showed that this was a comparatively rare occurrence. But in passing through the thinnest sheet of gold leaf the « particle must pass through at least a hundred atoms of gold. The atom, as such, is, therefore, not a structure which can deflect an a particle. On the other hand, particles capable of producing large deflections do exist in the material. We are driven to the conclusion that the mass of the atom is not distributed uniformly through its bulk but is concentrated in a particle whose dimensions are much smaller than that of the atom, in other words in a nucleus. A more detailed study of the deflections undergone by the deflected a particles enables us to estimate with fair accuracy the dimensions of the nucleus. The majority of the collisions studied are not of the nature of the collisions between, say, two billiard balls, where one particle actually impinges on the other, though collisions of this type have been observed. The a particle and the atomic nucleus are each positively charged and thus repel each other with a force vary- ing as the inverse square of the distance. The deviation in most NUCLEUS OF THE ATOM—CROWTHER 211 cases is due to this electrostatic repulsion, and the “ collision ” between the particles thus resembles the sweep of a comet through the solar system; the only difference being that the « particle is repelled, while the comet is attracted, by the central sun. The solution of the problem is fully worked out in books on Dynamics, and its extension to the case of the scattering of a beam of a@ particles is quite simple. Tt can thus be shown that, assuming the deflections to be caused by an electrostatic force varying inversely as the square of the distance, the fraction of the whole number of particles scattered through an angle greater than ¢ by a sheet of matter of thickness ¢ is 7254 : wT nt cot? 5 where » is the number of atoms per ec. c. in the material, V the atomic number, and 7’ the kinetic energy of the « particle; e being, as usual, the unit electronic charge. All these quan- tities are well known. ‘The theory has been tested with great accu- racy by Chadwick, using sheets of copper, silver, and gold, and the measured deflections were found to agree with those calculated from the formula to an accuracy of at least one per cent. The « particle and the nuclei of copper, silver, and gold thus act like point charges repelling each other in accordance with the law of inverse squares at least up to the minimum distance of approach of the a particle to the nuclei in these experiments. This minimum distance was found, by calculation, to be of the order of 510-% cm. Since the inverse square law could certainly not apply if the particles came into actual contact, the radii of the nuclei must certainly be smaller than this distance, which gives us, therefore, an upper limit to the size of the nucleus. The radius of an atomic nucleus is, therefore, certainly less than one two thousandth of that of the atom. The matter can, however, be pushed a little further. The force between an « particle and a nucleus will be smaller as the charge on the nucleus becomes smaller, that is to say as the atomic number of the atom becomes less. Thus the smaller the atomic number of the scattering element, the nearer will the « particle be able to approach its nucleus. The minimum distance of approach also becomes smaller as the velocity of the « particle increases. Hence by using scattering substances of low atomic number and high speed « particles we can get closer and closer to the mysterious world we are investigating. Some experiments, made originally by Rutherford and extended by Chadwick and Bieler, on the scattering of « particles by hydrogen are of peculiar interest in this connection. The problem becomes a little more complex when the « particle is being scattered by a gas the particles of which are themselves free to remoye, but an exact solution can be obtained, on the same assumptions as to the nature of the collisions as were made in the previous case. The hydrogen nuclei should be scattered in all direc- tions, by the force of the impact, in numbers and with velocities 212 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1927 which can easily be calculated. Using a particles of comparatively small velocity these calculations were actually verified. When, how- ever, the experiments were repeated using the fastest a particles avail- able, those emitted by Radium C, the agreement between the experi- mental observations and the theory completely broke down. The hydrogen nuclei instead of being scattered in all directions as required by the simple theory were found to be projected mainly in the direction of the oncoming e« particles, and the number set in motion was also greater than was to be expected. At the very close distances of approach reached in these experiments (about 410% cm.) the inverse square law of force completely fails to describe the phenomena, and the particles no longer act like point charges; in other words they are revealed as structures with an extension in space which now has to be taken into account. The observed direction of projection of the hydrogen nuclei would be obtained if the projectiles, instead of being spherical, were flat- tened disks. A number of flat disks traveling face forward through a cloud of pellets would project all the pellets with which they came into contact in a direction identical with that in which they them- selves were traveling. The parallelism of the projected hydrogen nuclei is not quite so extreme as would be observed if the colliding particles were actually flat. Chadwick and Bieler were able to show that the actual distribution of directions among the hydrogen par- ticles was just what would be obtained if the a particles behaved like perfectly elastic spheroids having major and minor axes of 8X 10 cm. and 4X10-** cm., respectively. It is, of course, more than improbable that this rather crude picture represents the actual a particle, or helium nucleus. What we can assert, however, is that outside this spheroid the helium nucleus behaves approximately as a single point charge, while inside the spheroid the repulsive forces increase so rapidly that the hydrogen nuclei are driven from it, as if from a highly elastic and rigid surface. At such distances then we are approaching the actual structure of the helium nucleus itself. These calculations were made on the assumption that the dimen- sions of the hydrogen nucleus, the other partner to the collision, were negligibly small in comparison with those of the a particle. There is much fairly strong, though indirect evidence, for this assumption. Aston’s important measurements with the mass spectrograph have shown that every atom has a mass which is represented, almost exactly, by a whole number if the mass of the oxygen atom is taken as 16. The most reasonable explanation of this remarkable fact is that every nucleus is built up of a whole number of particles each of mass equal to unity on this scale, and presumably, therefore, hy- drogen nuclei. It is true that the mass of a hydrogen nucleus, on this scale, is somewhat greater than unity, 1.0077, but modern electrical NUCLEUS OF THE ATOM—CROWTHER 213 theory would lead us to expect that the mass of the hydrogen nucleus would be somewhat less when it was closely packed together with other similar particles than when in an isolated state. It is generally held at present that the hydrogen nucleus is the positive counterpart of the negative electron; the second of the two fundamental units from which all matter is built. For this reason Sir Ernest Ruther- ford proposes to call it a proton. The mass of any atom would thus be that of the protons contained in its nucleus. The uranium nucleus must therefore contain about 238 protons, inclosed in a volume whose radius is certainly not more than 6 10-" cm. The proton is clearly then a very minute particle. Assuming that Aston’s experiments indicate that every atomic nucleus is built up of an integral number of protons, we can easily determine the constituents of any given nucleus. The mass of the nucleus, that is to all intents and purposes the mass of the atom, tells us the number of protons contained in the nucleus; the atomic num- ber of the element gives us, as we have already seen, the resultant positive charge. Except in the case of hydrogen the atomic number is less than the atomic weight. Consequently part of the charge on the protons must be neutralized by a negative charge, presumably supplied by an appropriate number of negative electrons. The helium nucleus, for example has a mass of four, and must, therefore, contain four protons. Its nuclear charge is, however, two, and consequently, since the charge on the proton is numerically equal to that on an electron, the helium nucleus must also contain two negative electrons. It is interesting to notice that, since an electron has a diameter of about 410-18 em., and the volume of the proton is negligible, this structure would have dimensions agreeing quite closely with those suggested by Chadwick and Bieler. The presence of negative elec- trons in the nuclei of the radioactive elements is proved by their B ray activity. The majority of the high speed electrons making up the 8 radiation undoubtedly come from the disintegrating nucleus. The presence of negative electrons in the nuclei of the lighter ele- ments is, therefore, not surprising. It will be seen that on these suppositions a nucleus with a given nuclear charge can be built up in many different ways. Thus the lithium nucleus, with a resultant charge of three, might equally well consist of six protons and three electrons, or of seven protons and four electrons. Since the chemical and physical properties of an ele- ment depend only on the arrangement of the planetary electrons, which in turn depends only on the resultant nuclear charge, both the nuclei would give rise to atoms possessing the same properties. Both kinds of atoms, the first with an atomic mass six, the second with atomic mass seven, have been observed by Aston in lithium. The 74806—28 15 214 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1927 phenomena is known as isotopy, and is obviously explained on the theory of the nucleus propounded above. The difficulty is, in fact, to explain why the number of isotopes is so few. The explanation will no doubt be forthcoming when more is known of the laws governing the nuclear structure. It is clear from these facts that the nucleus of an element of high atomic weight is a complex structure containing many particles. Assuming the atomic weight of uranium to be 238 and its atomic number 92, its nucleus must contain 238 protons and 146 electrons condensed in a volume the radius of which is no more than 6X10-? cm. The question naturally arises what is the “ cement ” which holds together this swarm of highly electrified particles in so small a space and how are they arranged in it? To these questions we have at present only the beginning of an answer. Some quite recent experi- ments of Bieler have shown that in very close proximity to the nucleus new and unexpected forces are apparently brought into play. We have seen that the a particles are able to penetrate much nearer to the nuclei of elements of low than of high atomic number. Experi- ments on the scattering of a particles, similar to those by which Chad- wick was enabled to verify the inverse square law of force, were carried out with scattering materials of much lower atomic number. It was found that the deflections of the a particles in such substances were distinctly less than the theoretical values. With aluminum as the scattering substance, the difference amounted to nearly 7 per cent, even with the more slowly moving a particles, and increased to as much as 29 per cent with the fastest rays, which, of course, approach the nuclei more nearly. It seems clear that at the very small distances reached in these encounters the inverse square law is no longer sufficient to account for the observed phenomena. Hither the law of force between two electrical charges changes when their distance apart is very minute or some new force jis called into play which falls off with increasing distance so much more rapidly than the ordinary electrical force that it becomes inappreciably small at finite distances. Bieler found that his results could best be explained by assuming the existence of an attractive force between the nucleus and the a particle, varying inversely as the fourth power of the distance between them. This attractive force would exactly balance the electrostatic repulsion between the nuclear charges at a distance, which was calculated to be 3.4xX107* cm. from the center of the aluminum nucleus. Out- side this distance the force between the colliding particles was entirely repulsive; inside this distance it would be entirely attractive. A positive particle which succeeded in penetrating within this charmed circle would thus fall into the nucleus. That the law of force between two complex structures like atomic nuclei when brought very close together can be adequately repre- NUCLEUS OF THE ATOM—-CROWTHER 215 sented by so simple a law of force is somewhat improbable. That the force should change from one of repulsion to one of attraction seems to be necessitated by the very existence of a nucleus. It is, moreover, corroborated by some very recent experiments by Rutherford. An a particle approaching an aluminum nucleus will be repelled, and will, therefore, be spending its energy until the critical circle is reached. Once this point is passed it will fall spontaneously into the nucleus, gathering fresh energy as it goes. We can, indeed, regard this critical circle as a high mountain ridge surrounding a small, deep, circular valley in which the nucleus lies. In electrical language the circle is one of maximum potential. Now, suppose we fire an a particle up this rising slope. If its initial energy is insufficient to carry it to the top, it will come momentarily to rest and then roll back again down the slope. If, however, it has enough or more than enough energy to carry it over the ridge, it will fall into the valley beyond; that is, into the nucleus. What happens under these circumstances was already known from earlier experiments. The aluminum nucleus is disintegrated and one or more protons, or hydrogen nuclei, are ejected from it. A similar artificial disintegration can be produced by the same means in other elements of low atomic weight. The minimum energy which an a particle must have to produce this disintegration must obviously be sufficient to carry it over the crest of the potential slope. Direct measurements showed that the disintegration of alumi- num was not effected unless the a particles used had an initial energy corresponding to that which they would acquire in falling freely through a potential difference of 2,800,000 volts. Neglecting any trifling losses of energy which the a particle may undergo in its path due to other causes, the height of our mountain ridge must therefore be about 2,800,000 volts in electrical units. The matter can also be tested from the other side. The proton expelled must have come from the valley over the ridge, and, even if it topped the ridge with no remaining velocity, its final velocity on leaving the atom must be at least that which would be produced by a free fall down the outer electrical slope, since in this part of its journey it is being vigorously repelled by the nucleus it has left. The hydrogen particles will thus be expelled with a minimum energy corresponding to that gathered during a free fall through the full potential of the critical layer. By actual measurement Rutherford found that the minimum energy with which the particles were expelled corresponded to a fall through about 3,000,000 volts. The very close agreement of the two estimates affords the strongest evi- dence for the actual existence of a surface of maximum potential surrounding the nucleus, and for the change in direction of the force at this point from which it was deduced. 216 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1927 The problem of the arrangement of the protons and_ electrons within the atomic nuclei is still unsolved, but evidence is rapidly accumulating which should ultimately provide a solution when we have discovered how to deal with it. Some information is provided by experiments on the disintegration of the nucleus. It is interesting to notice, for example, that in radicactive disintegrations the parti- cles ejected are invariably either helium nuclei, forming the « rays, or electrons forming the B rays. On the other hand, the particles ejected during the artificial disintegrations studied by Rutherford seem to be invariably protons. ‘The most probable suggestion at the moment is that the protons and electrons in the nucleus tend to combine to form very stable helium nuclei. Some, however, either because they are present in insufficient number to build up the helium structure, or for other reasons at present unknown, are in a compara- tively free state, and are thus more readily dislodged by shocks from without. This view is supported by the fact that all efforts to dis- integrate the atoms of carbon and oxygen, whose atomic masses are exact integral multiples of that of helium, have so far failed, though other elements of neighboring atomic mass are disintegrated with ease. It is also possible to conceive of the nucleus of an element of high atomic number as possessing a solid core of protons and electrons, arranged in some kind of gpace lattice much as the atoms of sodium and chlorine are arranged in a crystal of rock salt, while other elec- trons and protons, not yet combinable into the structure of this central core, circulate around it in a series of nuclear orbits. Exact and delicate measurements recently made by Ellis, and by Meit- ner, on the y ray spectra of the radioactive elements have shown fairly conclusively that Bohr’s thecry of X-ray spectra which has been applied with so much success to elucidating the arrangement of the planetary electrons in the atom, can be extended to the char- acteristic y ray spectra of these radioactive elements. The emission of y radiation is, however, a function of the nucleus. Even within the nucleus, then, it appears that we have “quantum ” orbits, asso- ciated with definite energy levels, corresponding, though governed perhaps by other laws, to the electron orbits and levels in the outer — part of the atom. Experiments, to the degree of accuracy required, are difficult and the results are not always easy to interpret without ambiguity. We may reasonably hope, however, that before long the nucleus, inconceivably minute as is its size, will yield up its secrets under the mass attack which is now being launched against it, with results as fascinating and as important as those obtained in ihe investigation of the structure of the outer parts of the atom. a Smithsonian Report, 1927.—Antoniadi PLATE 1 Ht = HTH He iy HH Ht POPE eh CAO oR Sotte tte Sculp d’apres PORTRAIT OF AUGUSTIN FRESNEL (AFTER A PICTURE BY TARDIEU) THE CENTENARY OF AUGUSTIN FRESNEL! By H.-M. ANTONIADI [With 1 plate] This illustrious man is the dominant figure in optics. The success of his attacks upon the problems connected with light has been with- out equal. He succeeded where Newton failed and made clear the mysterious nature of light. Augustin-Jean Fresnel was born at Broglie, in the Province of Normandy (Eure), on May 10, 1788. As a child he gave signs of his predilection for the sciences, and at the age of 16 he entered the Keole Polytechnique, in Paris, later finishing his training as an engi- neer at the Ponts et Chaussées. In 1815, upon the return of the Emperor from the island of Elba, he declared his allegiance to the Bourbons, passing the “one hundred days” in a quiet retreat in scientific meditation. Before considering the scientific work of Fresnel we should exam- ine the optical theories prevalent when he entered the field. EZmpe- docles in ancient times was the first to conceive the idea that the propagation of light was not instantaneous, a fact which Roemer demonstrated in masterly fashion at the Observatory of Paris in 1675. ‘Twenty-four centuries ago Democritus, the founder of the atomic theory, considering the very essence of light, attributed it to very tenuous particles shot out from the luminous body. This was the origin of the emission theory adopted by Newton in the seven- teenth century, following his celebrated experiment upon the decom- position of light in passing through a prism. Already, however, Leonardo da Vinci, in the fifteenth century, and subsequently Male- branche and Hooke, of the time of Newton, had had a glimpse of the undulatory nature of light. Huyghens further developed this idea and studied the course of light rays through birefringent crys- tals. He developed his famous law, and as a medium in which the rays of light might be propagated brought out the idea of the ether, an ideal substance, so to speak, of extreme rarefaction and with which the ancients believed the whole universe to be filled.2 1 Translated by permission from L’Astronomie, Paris, June. 1927. ?That is the arepos aidjp, the infinite ether of Heraclides of Pontus and of the Pythago- reans, the real discoverers of the heliocentric system of the universe 2,000 years before Copernicus (Stobée, Physics I, 24). 217 218 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1927 Euler was following in the path of Huyghens when Newion, enter- ing the scene, objected that, if light were due to waves, the latter would invade the space behind a body, thus making shadows impos- sible. ‘This, however, proved to be a double-edged weapon, for, while reducing his opponents to silence, Newton himself could not escape from the consequences of his own arguments and he had to explain very artificially, by added suppositions, the rings shown by thin lamina just discovered by him. Newton was not in optics the transcendent man that he was in the universal attraction due to gravity. He had stated a definite dislike of hypotheses but no man was more prone to use them; starting from false premises, he piled error upon error. His emission theory has died, never to return. This state of affairs continued up to the beginning of the nine- teenth century, when Thomas Young, the most gifted of English scientists since Newton, in his turn took up the undulatory theory of light. After starting his career with the excellent discovery that the accommodation of the eye was produced by changes in the curva- ture of its crystalline lens, with rare sagacity he showed that the principle of interference already utilized with sound was applicable to light. He thus explained the rainbow tints of thin lamina and Newton’s rings and subsequently the colors of striated surfaces. He studied polarization, determined the lengths of light waves, and attributed to the ether the properties of a solid body, but he was somewhat frustrated by the phenomenon of diffraction of light, dis- covered like interference by the illustrious Itahan physicist, Grim- aldi of Bologna, who gave to the phenomenon the name by which it is still known. This period was notable for a succession of discoveries as curious as they were unexpected. In 1808 the French physicist, Malus, . professor at the Ecole Polytechnique, discovered polarization by reflection when from his house he was examining with a prism of Iceland spar the image of the sun reflected from the glass windows of the Luxembourg in Paris; in 1811 Arago noted the beautiful colors of lamina of mica traversed by polarized light, as well as the rotation of the plane of polarization by crystals of quartz; in 1812 Biot brought to light new relationships between the reflection and the polarization of light by crystallized bodies; in 1813 Seebeck called attention to the polarization of light rays in passing through tour- maline, and Brewster to the colored bands about the axes of a double- axis crystal; and finally, in 1814, Wollaston showed the rings of Iceland spar. Fresnel, in 1814, commenced the researches which led him from discovery to discovery with a speed unexampled in the history of science. His name is especially known to the public by his invention of the lighthouse lens, which bears his name and which replaced very advantageously the older reflectors. It not only augments the amount AUGUSTIN FRESNEL—ANTONIADI 219 of light but allows the economical construction of a lens of great size from glass segments of relatively small size in juxtaposition. The lamps constructed with Fresnel concentric wicks were twenty- five times more brilliant than those then in use. These inventions, however, were only incidents in his career. He independently rediscovered the phenomenon of interference and at once tried to apply it to the explanation of phenomena of refraction in the wave theory. His success was complete; but learn- ing that Young preceded him, Fresnel, a scientific hero, retracted any claim to the discovery.* Later he was to come in ahead of Young. Let us note here that there is no parallel to be drawn between the case of Young and Fresnel on the one hand, and that of Adams and Le Verrier on the other. For Young, self-taught, was a very great man, who had distinguished himself by the publication of original and splendid researches; whereas the remarkable mathe- matical discovery of Neptune was wholly due to the genius of Le Verrier, who shares the glory with no one. Differently from Young, who considered luminous waves to be longitudinal like those of sound, Fresnel introduced for the first time the fundamental conception of transverse vibrations of the ether, that corner stone of the undulatory theory of light. He proved that certain birefringent crystals did not follow the law of refraction of Snell and Descartes and formulated the true law. He showed the possibility of producing double refraction by pressure in glass prisms which ordinarily do not show it. The knowledge of that time was greatly extended and developed by his researches upon the phenomena of interference. With Arago, he brought to light the modification in interference in the case of two rays polarized in different azimuths. Then he found the law of the phenomenon shown by the colors of thin plates of doubly refracting crystals. The discovery of chromatic polarization by Arago was completed by Fresnel by that of circular polarization. Finally, his experiment with two mirrors giving interference fringes, alternately dark and bright, is classic. Young, like Huyghens and Euler, could not reply to the crucial criticism of Newton regarding shadows. It needed Fresnel’s genius. Through the latter’s superior mathematical insight, it was shown that the inflection which Newton supposed should exist did occur behind opaque bodies, but that the divergent waves effaced each other, giving rise to shadows. His great generalization embraced in its first onslaught all the phenomena then known; further, the facts discovered by Malus, Arago, Biot, and others were not only thor- oughly explained, but were shown to be a necessary consequence of ?In 1823 Young wrote that Fresnel had recognized ‘‘ with the most scrupulous justice and most generous candor” the priority of his colleague upon this particular point. 220 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1927 the undulatory hypothesis. This generalization was truly impres- sive. Hamilton, of Dublin, taking up the theory later where Fresnel had left it, found from his calculations that at four points on the surface of the wave in a doubly refracting crystal the ray is not just doubly separated but rather broken into an infinite number of components. This was confirmed experimentaily some time later by Lloyd. . As much an experimenter as a mathematician, Fresnel submitted the results of his calculations to the control of well-conceived and well-executed experiments. As he tried to visualize that which he suspected in the invisible theoretical domain, he often had recourse to imagination—that daring and wonderful faculty which, duly in- spired and bridled, becomes the most powerful instrument of discovery. The French Academy of Sciences opened its door to Fresnel in 1823. Filled with honors in France and elsewhere, he had the un- happiness of seeing his health, always delicate, weaken more and more. He died in his fortieth year at Ville d’Avray, July 14, 1827. I'resnel was well judged by Tyndall, among others: His brain was too vigorous for the body with which it was associated; that body prematurely became a ruin; and Fresnel left this world leaving behind him a name immortal in the annals of science. There are things which are better than science itself. Character outweighs the intellect. It is particularly pleasant to those who love to think well of human nature to see united a great mind and an upright character. This union was found in this young Frenchman. In his ardent discussions of the undulatory theory he bore himself with integrity, claiming only his rights, and ready to accede their rights to others. He early recognized and praised the merits of Thomas Young. It was indeed Fresnel and his compatriot Arago who revealed to Hngland the consciousness of the injustice done to Young by the Edinburgh Review. I wish to read to you a short extract froma letter written in 1824 by Fresnel to Young, for it throws a pleasant light upon the character of Fresnel, the French philosopher : “For a long time,’ writes Fresnel, “this sensitiveness, or this vanity, which we call the love of glory, has been much dulled in me; I work far less to gain public approbation than an approbation within myself which has always been the most pleasant recompense for my efforts. Without doubt I have often had need of the prick of vanity to arouse me to follow out my researches in moments of distaste or discouragement; but all the compliments which I have been enabled to receive from Messieurs Arago, de La Place, or Biot have never given me as much pleasure as the discovery of a theoretical truth and the confirmation of my calculations by experiment.” * Tyndall rightly saw in this letter an example to be followed. Science should be cultivated for itself, for the pure love of truth, and not for the applause or the material advantages which may accrue from it. ‘Six lectures on light, delivered in the United States of America in 1872 and 1873, fifth edition, p. 210, 211. This letter is dated Nov. 26, 1824. SOARING FLIGHT’ By WotreANa KLEMPERER [With 11 plates] I consider it a very great privilege to have been asked to speak to you within these venerable walis which have witnessed the infancy of many a discovery that later became a milestone of the progress of civilization. Flying is one of them. It was the dream of man for several thousand years. To this generation this dream came true by the most remarkable development of aviation, in which American genius played an important role. Man now can fly higher than the highest mountain, faster than the swiftest bird or cloud; the power of thousands of horses can be concentrated in an engine occupying but a few cubic feet capable of lifting many tons of freight into the air. On the other hand, we have also learned to soar in the air for hours without any motor at all. Many people wonder how this is done, whereas the motor-driven airplane is quite familiar to them. Strange that it is not the other way around. For the great soarers among the birds—the albatross and seagull, the eagle, buzzard, hawk, and vulture—are masters of the art of flying without any expenditure of motive power. They display it before our very eyes, sailing without flapping their wings for hours at a time. Had their secrets been understood earlier, they could have taught man to fly long before any motor was invented. In fact, the pioneers of aviation, such as Lilienthal and the Wright brothers, started on this track. It was by coasting down from hills in their early motorless gliders that they acquired the first real flying experience necessary to understand the basic mechanics of flight. Had not the automobile engine happened to be developed just at that time, the history of flymg might have assumed an entirely different aspect. But thus, the rapid suc- cess of the motor-driven airplane seemed to render further gliding experiments unnecessary and it was not earnestly resumed until 1Lecture presented at a meeting of the Franklin Institute held February 10, 1927. Reprinted by permission froin the Journal of the Franklin Institute, vol. 204, No. 8, September, 1927. 221 222 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1927 after the World War, which had brought a tremendous impulse to flying. This impulse had resulted in spectacular improvements of design and engineering, in a marvelous perfection of piloting and performance and, simultaneously, in giving scientists a chance and stimulation to advance theoretical and systematic empirical knowl- edge to a very satisfactory degree. When gliding was resumed in Germany in 1920, it was done with the intention of applying this accumulated technical knowledge to the original problem of duplicating the soaring flight of birds. A meet- ing reunited those interested in the idea and organized the first experimental gliding contest. A camp was pitched near the top of Mount Wasserkuppe in the Rhén Mountain district. This mountain rises about 2,000 feet above the plain to its north, surrounded by smaller hills. Its slopes offer all topographical varieties from gentle erassy grades bare of trees to rugged gorges and fir-covered hollows. Initial success was modest, but we soon learned to make prolonged glides and we saw we were on a promising track. In the following year gliding developed into soaring. A series of duration flights increasing from 5 up to 20 minutes, some of them covering distances of a few miles and the first so-called cross-country flights without a motor, aroused nation-wide interest. A society for the promotion of soaring flight was organized and now the Rhén Mountains have become a classic stadium of the air where annual meetings and contests are held. Glider schools and, recently, an elaborate permanent research institute were established there. Our primitive tents were gradually replaced by more per- manent buildings; auto roads were built. No more the flyers them- selves have to carry their own food and tools uphill in a two-hour hike from the nearest little town, sometimes getting lost in the heavy fogs ‘or clouds which only too often justified the wet name of that mountain. The year 1922 brought spectacular progress. It was due to favor- able weather conditions during the three weeks of the meeting and to the lessons learned by designers and pilots in the preceding con- tests. The slopes of the Wasserkuppe, which formerly had not even been known to many, were crowded with thousands of spectators, who were thrilled watching the human birds for hours soaring above their heads, three and four at a time. The absence of any motor and its noise, together with the slow speed of the glider flying against the wind, enables the pilot above and the crowd below to carry on oral conversation, and to furnish the flyer with meteorological information. Great emotion prevailed when the first one-hour mark was reached. The pilot, cruising at some distance from the peak, would every once in a while return to near the starting-point and the watching crowd and inquire about SOARING FLIGHT—-KLEMPERER 220 how long he had been up in the air. When he had climbed too high for the voice to be intelligible, then scores of spectators would be grouped to form huge live numerals on the ground indicating the number of minutes flown. Since then soaring has been taken up in various other countries as well, especially in England, in France (on the coast of the English Channel), in the Alps of Switzerland, Italy,and Austria, in the hills of northern Czechoslovakia, on the North African coast of the Medi- terranean and in the Crimea range of southern Russia. In Ger- many, Rossitten, on the East Prussian coast of the Baltic Sea, became another center of soaring flight sport and research. Not to mention all the scattered hills where local glider clubs have taken up training for the bigger national annual events. In spite of all this surprising development, soaring flight has not so far revolutionized the aspects of commercial or military aviation nor could anybody earnestly expect it to do that. The main reason is: Soaring depends primarily upon the wind exactly as a sailing vessel on the water does. Then many people will ask: What is it good for? This would be a question similar to: What is yachting good for in the age of ocean liners? There are three purposes for which soaring flight is pursued. First of all, it is an unrivaled sport. I am unable to describe by words the sublime pleasure one experiences in gliding over hills and valleys, silently, like the eagle, cruising or hovering, rising or de- scending at will. The ample controllability makes you feel like them, master of the air. The constant alertness watching for favorable air currents and studying their relations to the varied scenery below provides thrill and challenge. A few weeks in a glider camp is out- door life in the word’s fullest meaning. Soaring flight requires also a certain amount of scientific training, engineering sense, and physi- cal skill. Thus it most perfectly blends all the elements requisite for a recreational and educational sport such as the rising generation so appreciates. Aside from this pedagogical value, the scientific research labo- ratories, both those governmental and those connected with the aero- nautic industry, discovered a treasure in gliding. The most diffi- cult problem in aeronautical science is the proper correlation between theory and research experiments on one side and the complex phe- nomena of practical flight on the other. The application and veri- fication in practice of the results of theoretical investigations is often just as difficult as the laboratory investigation of some acute prac- tical problem. The aerodynamical conditions in the wind-tunnel laboratory where models are tested in an artificial air stream are in many respects far from identical with those prevailing in actual flight. Gliding and soaring flight now offer supplementary experi- 924 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1927 mental means, as a full-size flying laboratory, for investigating problems in which the elimination of interference of a propeller slip stream with the lift of wings, stahility, and control is essential. A third field wherein the glider is useful is in the abundance of opportunity it affords for acquiring aerial experience which is of unlimited value in the training of future commercial and private flyers. Glider champions, as a rule, afterwards became superior air- plane pilots, whereas the reverse did not hold so generally, although, of course, many of the new pioneers of soaring flight were much benefited by their previous extensive motor fiying experience. No doubt, gliding constitutes an excellent means of initial aviatic train- ing and has thereby already done much to make aviation popular and to promote air-mindedness. In fact, any motor flight is terminated by gliding down to land. Of course, the idea of soaring flight is to glide not down but level or even to gain altitude. Now let us see how this is done without a motor. Theoretically, we may distinguish between “ static ” soaring flight and “ dynamic” soaring flight, although in practice they may over- lap or blend. The principle of static soaring is trivially simple. It consists in gliding down in a rising current of air. Provided the vertical velocity component of the air current exceeds the minimum rate of descent of the machine, any airplane can climb without a motor at a rate of ascent equal to that excess. A wind blowing over a vast plain, suddenly confronted with a large mountain range extending across its path, would, of course, be deflected upward. A wind blowing at, say, 32 feet per second up a slope 1:4 would furnish 8 feet per second lifting component. An airplane flying at 60 feet per second and having a gliding angle of 1:8, thus a natural rate of descent of 714 feet per second, would still be carried up at 14 foot per second and yet proceed at 28 feet per second against the wind. However, this would soon carry it too far upwind, out of the zone of vertical deflection. This is why the soaring birds and experienced glider pilots cruise weaving to and fro along the mountain ridges, always trying to keep within the zone of strongest lift. Of course, the wind does not exactly follow the contour of the hillside in equidistant flew lines. As far as the windward side of the wind obstruction is concerned, model experiments in wind tunnels have given interesting results and perspicuous flow pictures can be derived by calculation, using the method of sources and sinks. A combination of sources and sinks is so chosen that the fictitious fluid produced by these sources and washed leewards by the flow represent- ing the wind is completely housed within a shape that coincides with SOARING FLIGHT—-KLEMPERER 225 the contour of the mountain. Then the direction and magnitude of the local velocity anywhere in the field can be calculated by simple geometrical addition of the horizontal wind to the resultant influence of all sources and sinks upon that point. Since the equations of the stream lines happen to be identical with the equations of the equipotential lines in an electric field, several investigators have made experimental use of this remarkable analogy and derived flow structures by electrically sounding in a tank filled with an electrolyte between electrodes shaped according to the bound- ary lines of the flow problem. Actual full-size measurements of the wind texture on the wind- ward side of the coast at the Rossitten soaring flight site were accomplished last summer by taking motion pictures of the clouds left by smoke rockets fired up to various heights. The results of these experiments and others made with ammonia clouds revealed that the acceleration of the wind right above the crest and the upward deflection at the bottom of the slope are somewhat smaller than would be expected from the analogous po- tential flow. Explanation is anticipated to be found in friction and the thermic gradient. The best locations for static soaring are usually to be found at some distance windward off the crest. The useful zone may extend to considerable altitude, at times twice as much as the height of the mountain above its base. Obviously, the vertical deflection com- ponent decreases with higher altitude. Thus a glider which has a well-defined minimum rate of descent will find a definite “ ceiling ” above the crest, beyond which it can not climb in static soaring. Very favorable conditions occur above horseshoe-like formations of gorges. The leeward side of the mountain is feared for its treacherous descending currents, weird whirls, and dead zones. It is easy to see that there is no fundamental difficulty in remain- ing aloft for an unlimited duration as soon as the pilot has found a sufficiently wide area of sufficiently strong rising wind currents, as long as he sticks to it and the wind endures. In fact, some of the duration record flights were made by patiently cruising in figure eights above the same place and extended far into night-time, when landings had to be made in the light of automobile headlights and flares. The longest duration ever flown by a glider was 12 hours and a few minutes, attained by Herr F. Schulz in 1924 on the Ros- sitten coast.2 The same pilot has later flown nine hours with a passenger. Jt is considerably more difficult to cover large distances, how- ever. The first distance flights were made by climbing to the 2On May 5, 1927, he beat his own record, staying aloft 14 hours 7 minutes. 226 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1927 “ ceiling ” and then taking a flat glide across or more or less with the wind. Later we learned to pick up altitude under way. At Rossit- ten, Herr A. Martens managed to sail all along the chain of coast dunes for some 15 miles and back to his base. The plucky Darmstadt college glider team finally perfected the art of sailing from mountain chain to mountain chain across valleys and plains. A wonderful feat was the winning of the Milseburg prize by Herr Nehring, their youngest member. The task was to start from Mount Wasserkuppe, to fly to the Milseburg, an ancient rock castle some 7 miles distant, to circle it and to return to the starting point, without a motor, of course. After climbing some 500 feet above the crest in a moderate wind blowing about across the direction of his goal, he crossed the valleys and intermediate hills and arrived near the castle in good fashion. Due to other hills surrounding the Milseburg and impairing aerial conditions there, he lost a good deal of height. Thus it looked as though he would never be able to complete the return trip. How- ever, by making clever detours to the windward slopes of various other hills, he managed to gather enough lift again to negotiate the worst gaps and valleys and finally alighted only 400 feet from his starting point. This flight strikingly demonstrated what tre- mendous possibilities long-distance soaring in hilly country presents. Vertical currents are not entirely confined to mountainous regions. Every cumulus cloud is the top of one. The variations of solar radiation and of the thermal capacity of different varieties of soil cause the atmosphere to heat very irregularly. Above some localities hot air rises, above others cold air descends. In tropical regions such thermical drafts attain formidable velocities. In Guinea, Central Africa, the French scientist P. Idrac has measured vertical velocities ranging from 2 to 5 feet per second. By means of kites, he lifted wind-speed meters up into the strata where vultures were soaring at the time. Airmen do not like to fly in clouds. However, they are vis- ible indicators of the rise of saturated air. To glide not only from mountain to mountain, but also from cloud to cloud, was the ambitious goal the soaring flight pioneers had set out to attain. During last year’s Rhén meeting, the German pilot Herr M. Kegel was caught by a thunderstorm. ‘Threatening clouds came rapidly rolling up toward the Wasserkuppe. ‘Two other pilots who also were in the air decided to land. Kegel, however, drove right up to the front of the monstrous roller and clung to it. Soon he was out of sight of the amazed spectators. He let him- self be carried by the clouds’ upwash as high as about 4,000 feet, and thus actually traveled a distance of 40 miles. Eventually, he headed leeward out of the region of the disturbance and beat SOARING FLIGHT——-KLEMPERER 220 the storm for a safe landing. The whole flight had lasted three- quarters of an hour. According to his own account, he must have had a thrilling time when he was bounced about by the violent cross currents in that aerial whirlpool, visibility at times completely extinguished in the dense mass of turbulent foam. ‘There is no doubt about Herr Kegel’s ability as a pilot, but it may be men- tioned that he had also built his machine himself in his spare time and it was one of outstanding efficiency and workmanship, too. There is some advantage in flying in adverse weather. Quite a number of spectacular soaring flight events were indeed distin- guished by rather unsettled weather conditions. The stormier, the greater the chances for reaching high altitudes. Gliders have often climbed 1,000 feet above the crest of the mountain. Since 1921 the gliders were out in any weather up to gales of 45 miles per hour. Only a dead calm would confine them to idle waiting. What a difference from the state of affairs during the early days of motor- driven aircraft. No airman will deny that learning how to buck gales immediately close to mountain ridges constitutes a very valuable training for meeting unexpected aerial situations. In a flat country, even in the absence of meteorological dis- turbances, vertical currents may be induced, for instance, at the border line of a smooth and a rough surface. Imagine the wind blowing over a great grassy plain or a great body of shallow water, then striking an adjacent forest, the trees of which obviously absorb more energy per unit of area. The friction layer in which braking impulse is transmitted will here extend higher than above the smocth plain. The retarded air has no other escape but upward deflection. Ravens and buzzards can sometimes be seen soaring a short distance leeward of such border lines of surface roughness. When one only temporarily happens to find profitable upward currents, it is obviously best to concentrate production of lift during these favorable periods, by rising or by storing kinetic energy in order to gain some reserve to draw upon while negotiating the lull. In fact, the wind is almost never like a viscous stream. It contains turbulence and there is something like one-third of the chances for the occurrence of vertical turbulence components. Fortunately, the mere inertia causes any airplane to gain from such vertical pulsa- tions a slight increase in lift or a slight reduction of drag. Katz- mayer, in Vienna, proved this by model experiments in the wind tunnel, introducing artificial cross-wind pulsations. The theoretical explanation of the phenomenon is this: Any upward fluctuation causes the relative air stream to strike the wings at some inclina- tion upward, thereby inclining the resultant air force forward. In the descending phase of the fluctuation the reverse holds, thus in- 228 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1927 clining it backward. The pull of the first case and the additional drag in the second would eventually cancel out, if they were of equal magnitude. However, in the rising phase the angle of attack and, consequently, the lift are increased, in the descending phase they are decreased. Therefore the forward component wins. Lift is auto- matically concentrated during the period when power is transmitted from the air to the machine. The airplane combs the fluctuation. We often call this phenomenon the “ Knoller-Betz ” effect, after the names of two scientists who independently published the first explan- ations in 1912 and 1913. It may be that this is the same phenom- enon which causes discrepancies between the results of wing-model tests conducted at various laboratories or under different conditions of turbulence. Flying through vertically pulsating air, the operation of the elevator in a certain rhythm, would yield an optimum power gain a little in excess of that natural gain which would be derived from inertia alone. However, there is no conspicuous periodicity in the vertical wind fluctuations and it would be extremely difficult for the ‘pilot to estimate their harmonic constituents ahd, above ali, to dis- criminate in time between vertical and frontal gusts. The utilization of the latter is a different proposition and leads us to dynamical soaring proper. It is obvious and well known that the horizontal mean velocity component of the wind can not be captured from any free-fiying vehicle. It can be by a kite which is connected to the solid ground by a cord. Soaring flight is in some languages calied “sailing flight.” The comparison with sailing does not lack some justification. The sailing vessel depends upon its simultaneous contact with two mediums, the sail with the air, and the keel with the water. Without the keel part it would be helpless. A round nutshell without a keel would drift uncontrollably with the wind. So would a sailed ice sled put on balls. Furthermore it is only the relative motion between these two mediums that can be utilized. When the wind blows with the same velocity and direction as the river flows, sails are dead and worthless to the river craft. Now, where is the other medium to lean against from an aircraft totally surrounded by nothing but the wind? It can only be portions of the wind which move at velocities different from the average. The wind is almost never uniform. In one place and at one instant it moves faster than at another. It is these irregularities from which, in dynamic soaring, energy is drawn. Conventional types of air- craft, contrary to naval craft, lacking the advantages of maneuvering at the contact surface of two media, can not get hold of them simul- taneously. Thus we have to merge into each of them alternately, relying on inertia as a substitute for the mast and rigging. SOARING FLIGHT—-KLEMPERER 229 On a sailing boat, the angle of attack of the sail by the wind and that of the keel by the water lie toward opposite sides. The equiva- lent condition has to be brought about in dynamic soaring by facing the two portions of the wind in opposite directions. This involves certain maneuvers which deserve some particular investigation. Let us consider an idealized form of gustiness. Imagine the wind to fluctuate between the extremes of 20 and 60 miles per hour. Let the acceleration during the freshening period be constant, say 4 feet per second”, or one-eighth of that of a dropped body. It would take 10 seconds between two extremes. Suppose we had been fiying facing the slow 20 miles per hour wind. Now the wind freshens up. If we should not react, we would gain excess speed against the air due to our own inertia. However, we do not want more speed, since our litt just balances our weight. Thus we decide to throtiie down our motor, and assuming the drag of our machine to be one-eighth of its weight, we could just shut off that engine completely. Our drag would just retard us so much that our speed against the swelling gust will be constant, and we continue our level flight, without any pro- puisive power other than the reaction of inertia. However, this con- dition will last only 10 seconds. Upon reaching the climax of the gust, the negative acceleration of the calming-down period would have a retarding effect on us and we would need twice our normal engine horsepower in order to catch up with it. After completing the cycle we would have gained nothing ai all. However, the idea of this sort oi dynamic soaring is not to wait until the lull spoils the temporary gain, but to turn away in the meantime. Then when the calming-down stroke arrives, one is headed already the other way and gets another free hit equal to the preceding one, since now we transport the impulse from the fast wind portion into the slow one. This manipulation is by no means a mysterious case of perpetual motion. In fact, the airplane or bird so circling picks energy from that stored in those meteorological irregularities. Its action some- what resembles that of a traflic cop on the road, slowing down fast elements of (wind) trafitec and speeding up slow ones, with the result of smoothing the entire motion. If he does a good jeb there is nothing left for his fellow farther downstream to do. it is interesting that not the actual accelerative structure of a gust is what counts, but the average acceleration only, between the times of change of course of the craft. If this is the same or more in pro- portion to gravity than the ratio of drag to lift of the airplane or bird, the soaring effect is 100 per cent. The conditions assumed in our numerical example happen frequently in the atmosphere, and, since we can refine glider design so as to reduce drag to one-twentieth of lift, chances of riding the gusts would not look sad at all. How- 74806—28——16 230 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1927 ever, it is very difficult for the pilot to foresee what is going to become the peak of a gust. Besides, it is impossible to make an infinitely sudden turn. Thus one has to turn away from the gust quite a little before he gets his full share of the beneficial acceleration nor will he have reached quite the opposite flight direction on time to get all of the reverse. In addition to this, even a quite moderately banked turn consumes an additional tribute of power in the form of the increased drag induced by the increased wing lift necessary to overcome the centrifugal force of the turn. Thus, after all bills are paid the profit is materially cut down. For instance, if one simply circled “synchronically” in a slow but powerful gust of harmonical rhythm, he may practically gain about one-third of the energy theoretically available. On the other hand, if satisfied with only a fair fraction of the entire possible gain, you may fly across the wind and merely sway from your course somewhat in serpent fashion, corresponding to the lateral accelerations, always with a trend of keeping weatherly. In fact, this is a very reasonable method to be resorted to when flying along ‘a mountain ridge, and in some instances I am quite sure I picked some valuable gain from such lateral gusts this way. A Frenchman, Mr. A. Sée, demonstrated how energy can be gained from lateral gusts by merely rolling the machine while yielding to the yaw, so as to present the raised wing always to the luff side. However, every pilot knows this to be a somewhat delicate maneuver and trying it I once almost heeled over in the face of a rugged peak, having underestimated the force of a blow which apparently shot from an adjacent gorge. The excessive banking and subsequent recovery by a dive spoiled more altitude than had been gained. If the gust is also accompanied by a variation in wind direction, this can be quite useful to a glider endeavoring to take those unavoid- able turns always in the sense of the turning of the acceleration vector. Indeed, an optimum condition would be what may be termed a circularly polarized gust. An airplane properly curving would be centrifuged like a heavier particle in a rotary separator. Trying to head toward the pole of the whirl, the ship would be dynamically impelled. Whether similar conditions actually occur in the atmos- phere outside of tornadoes, I do not know. We have seen the necessity of performing some sort of a change of flight direction during the climax of a gust. But there is no rea- son why it is confined to the horizontal plane. Someone may prefer to do it vertically. However, by mere analogy it can be seen that it would take continuous looping the loop, synchronous with the oscilla- tions of the gusts in order to get anything like a fair portion of the entire available energy. This is impossible. Again, a fraction of it is obtainable by performing certain vertical rocking movements. SOARING FLIGHT—KLEMPERER Zo They are characterized by alternating pulling up and diving down synchronously with the acceleration phases of the gusts. The im- portant thing about them is that they must consist of at least one primary oscillation and its first harmonic. Thus in a harmonic gust the two branches of the path will look unsymmetrical, the diving part being done somewhat steeper than the climbing. The mechanism of this performance has been compared to making a car travel uphill on a scenic railway structure by oscillating the whole structure hori- zontally, in the plane of travel. It is quite possible to derive some profit from occasional strong gusts by this rocking method, but it would be in vain to hope to rely on this alone for support. Horizontal and vertical gustiness of the wind may occur combined. When they happen to be synchronous, their relative phases are of importance. Professor v. Karman has shown that, in proximity to the ground, the surface friction causes the combination of freshening and descending or of fading and ascending to occur more frequently than the reverse. For any particle coming down from above, where velocity is greater, brings forward impulse with it; whereas any particle that happens to rise from the retarded layer below carries braking impulse with it. This reasoning would lead us to believe that an airplane flying low over the ground would gain less when headed against the wind, but more when fleeing before the wind, as com- pared with what it would gain from vertical oscillations without a horizontal component. The same principle can be applied to explain a long-known phenomenon which has puzzled early experimenters. A light wind vane balanced and mounted on a horizontal axis, intended to show the vertical inclination of the wind, seems to indicate an upward trend of the average of the irregular fluctuations amount- ing to some 2 to 4 degrees on a level plain. Of course, the wind can not spring from the ground. The explanation is that the rising elements are slower, the sinking elements are faster. Thus although no more air rises than falls, on the average, the apparent angle of the resultant motion is greater for the slower, and smaller for the faster particles. The mere time average of the direction of an irregularly fluctuating vector has no physical significance. Really measuring the vectorial fluctuations in the atmosphere is a very interesting but delicate technique. The introduction of the electrical hot-wire anemometer and directional anemometers into micro-meteorology promises many scientific possibilities. Electrical anemometry is based on the principle of exposing a fine platinum wire electrically heated to the air current to be explored. The temperature the wire assumes under the cooling influence of 232 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1927 the air flow is electrically measured or controlled and with refer- ence to the power input gives a clue to the local velocity. The regions of different wind-speed travel in the turbulent atmosphere and the great difficulty is to anticipate when they will strike you. However, there are also places where they can be found quite stationary. On the leeward side of a blunt wind obstruction there is a dead zone, a wake, so to speak, a short dis- tance adjacent to which the wind may blow at full force. Sea- gulls, swallows, and swifts are masters of the art of soaring back and forth between such layers. The mechanism of the capture of kinetic energy is very similar to that of circling in gusts. The bird glides in the dead zone toward the tower, wall, bosket, or whatever forms the obstruction to the wind. Suddenly the bird weaves across the contour line of the dead zone into the open wind where, due to its inertia, it receives a powerful lift. After having made enough headway against the wind, it circles and coming down-wind shoots back into the dead zone, where the tremendous velocity it has acquired is a big store of kinetic energy which is gradually used up in patrolling for food until it becomes necessary to resume the cycle again. Nobody would suggest trying to duplicate such stunts with gliders, because the combination of the human brain—hands—steering mech- anism—moment of inertia of the wide-spanning machine is very much slower than the corresponding chain of reaction within these birds, and chances would merely be of crashing into some rock. However, layers of different wind velocities may often be found one above the other. Asa rule the wind higher up is faster than down below. The energy stored therein can be caught by alternately gliding down- wind in the upper layer, descending into the lower one where the relative surplus velocity is kept in reserve, then turning around and pulling up into the upper layer again. Here a powerful inertial lift is the reward of the whole maneuver. Vultures have been seen circling this way in India, descending and ascending rhythmically in inclined orbits. In places where the discontinuity zone separating the two layers is sharp, this phenomenon is even noticeable on regular motor air- planes. In the Karst Mountain range behind the east coast of the Adriatic Sea sometimes a peculiar meteorological condition occurs. A strong uniform westerly warm wind, called sirocco, sweeps in from the sea at the higher altitude. Cold air, called bora, rushes down the slopes of the bare mountains, mainly from an easterly or north- easterly quadrant. Wuind-speed drops as sudden as 60 feet per second west against 15 feet per second northeast can be encountered in pass- ing down from the 2,800-foot level to about 2,000 feet. IF lying there, SOARING FLIGHT—-KLEMPERER 233 we experienced the sensation that in trying to spiral down one way we were unable to bring the machine down to land on the flying field in the hollow, the motor throttled way down, whereas circling the other way around between the mountains, we would be knocked down so vehemently one had to open full throttle again to prevent crashing into the rocks that lined the field. It may be superfluous to mention that the inversion zone was rather rough riding and bumpy, too. Sometimes the altitude of the zone of wind inversion was indi- cated by peculiar formations of many small clouds rapidly forming and disappearing. I should not wonder if similar conditions pee be encountered in parts of the Rocky Mountains, also. Even without a pronounced border surface between two dizbiniat wind layers, there can be energy stored in accessible form where the wind is gradually increasing with altitude. This sort of power gain is most suitable for a machine capable of a high rate of climb. The gain in terms of the original rate of climb is approxi- mately equal to the proportion of gravity to which the product of the vertical gradient of the wind velocity and the forward speed of the airplane amounts. This is the reason why, even above a level plain, airplanes generally climb better against the wind than before the wind, which, after the very take-off, would make no difference if the wind did not increase with height. A racer would experience a difference of about 20 per cent in the rate of climb between the two directions of flight in an atmosphere where the wind speed would increase by 10 feet per second per 1,000 feet altitude, which is not exceptional. An interesting suggestion has been made by a Bavarian inventor, Herr Wolfmiiller. His device is the true aerial counterpart to the sailing boat, and really deserves the name of sailing flight. His argument is this: The sailboat uses a high mast to make the sails reach way up into the strong wind. Why not build the air- plane so big that its upper and lower extremities extend into differ- ent layers of wind, the upper wings to act as sails, the lower ones as a keel? The idea sounds fantastic. But what he actually did is to fly two kites, one raised way up high, the other one kept low. The two strings were tied together and let go. On evenings when the wind was known to blow from the opposite direction at the higher level than down close to the ground, these kite teams would travel many miles, and he did not always recover them. Being of rather elaborate design, they even could be stabilized at certain relative angles and made to travel across the wind at considerable speed, just as a sailboat cruises. Interesting though the principle may be, it is not very likely to be put to practical use. The principles underlying the various methods of dynamic soaring flight may seem to many rather remote ideas. Yet dynamical prob- 234 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1927 lems are not at all strange to everyday life. There is a rather pecul- iar financial analogy to soaring flight, viz, making money from dynamical sources. Soaring in gusts is ruled by much the same con- ditions as buying and selling stock, always making a change of policy coinciding as best possible with every climax. Soaring between sta- tionary wind layers is equivalent to trading across international boundaries, buying merchandise where there is abundance of it and importing it to where it is lacking. The loss due to centrifugal force represents the freight and import duty. Dynamic climbing in a vertical wind gradient is very strikingly paralleled by the business condition in a country where currency is being inflated, the inertia of the money devaluating during circulation being essential for the profit of those who issue it and the loss of those who furnish the values. Even the deeper cause for the maintenance of such an unstable situation, being some greater disturbance of much bigger vol- ume than the individual’s concern, finds its perfect parallelism in soaring flight. Practical soaring flight depends not only on the wind structure and the pilot’s skill, but also to a large extent on the design of the glider. Theoretically, of course, any airplane can be flown as a glider provided plenty of power is presented in the aerological situation to meet the modest aerodynamic efficiency of the machine. Extended soaring flights have indeed been made with regular air- planes, the motor just shut off, for instance, by the French heuten- ant Thoret on a horseshoelike bay on the North African coast. The most interesting development, however, was that of the modern gliders, machines specially designed for use without a motor. In their design lightness in spite of strength and aerodynamic refine- ment were carried to unusual extremes, which later did not fail to have some marked influence upon modern design of motor-driven aircraft, too. The structures of most gliders are made of wood. Very thin ply- wood varying in gauge from three thirty-seconds down to one thirty- second of an inch for the total of the three plies, is the preferred material. Wooden beams and trusses joined by plywood gusset plates are assembled to the most intricate and elaborate internally trussed bridge works. Cantilever wings weighing less than 5 ounces per square foot are built with ample strength. Waterproof casein glue is used exclusively and nails are religiously avoided by many de- signers, since with a well-glued joint they contribute nothing to strength but considerably to weight and deterioration. The weight of successful gliders varies from about 250 pounds down to as little as 90 pounds. Two people can handle them on the ground. SOARING FLIGHT—-KLEMPERER 235 Much ingenuity has been displayed in facilitating disassembling and road transport. This feature was a great asset for the con- testants after long-distance glides in the hilly country. In the glider field the question of monoplane or biplanes has been rather decidedly settled in favor of the monoplane. Extremely large aspect ratio (=span: wing chord) became some sort of a dogma. The production of lift by wings is inseparable from evok- ing induced drag, proportional to the square of the load per wing span. In the glider, all protruding structures being carefully avoided to a much greater extent than is possible on a motor air- plane, the more the ideal of the nothing-but-wing machine is ap- proached, the more the induced drag becomes decisive for efficiency. Theoretically this was quite well understood. It was the merit of the gliders to have practically proved the correctness of the theory of aspect ratio and induced drag in full size. Wing spans con- sequently grew wider and wider and wings spanning twelve times their chord became quite common. A gliding angle of 1:20 was reached with them. Of course, in order to accomplish this it is essential also to avoid struts and external bracing, with their para- site resistance. Structurally, it is quite a task to build a light wing spanning 30 feet from root to tip on the cantilever principle, having only 5-foot base depth or less, at the root. Responsible designers of the old school were quite hesitating to risk something lke that, so it took the boldness of college students to demonstrate that it can be done. The idea of the large wing span was in the course of events perhaps exaggerated and overemphasized by amateurs. A few accidents due to wings failing by torsion or vibration happened, although none of serious consequences to the pilots. They had the welcome effect of stimulating research on wing flutter, which since then has greatly increased knowledge for its prediction and avoid- ance. The tapering of wings toward the tips has been demonstrated to contribute enough to structural and aerodynamic efficiency to justify the manufacturing complication. The gliders have done much to demonstrate the merits of the thick and semithick wing sections, and the advantages of well-rounded leading edges for a wide useful range of angles of attack, whereas the particular merits of one or another special wing section are often overemphasized. Nowhere can the suppression of parasite resistance be carried to such a perfection as in the modern glider. Some of them resemble a bird in a striking manner. There is nothing but a wing, a tail, and a stream-lined body, just large enough to tightly house the pilot. Every aviator will agree that the field of vision from a glider’s cock- pit is perfect, incomparably better than from that of any regular 936 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1927 tractor airplane. One can see to the last second the very spot where he is going to land. In fact, there was hardly anything as thrilling as the various spot-landing contests which have been a regular fea- ture in glider meetings since 1922. A plot is marked, a few square feet on a lawn on a plateau a couple of miles distant from the hill! where the gliders take off, and only about 100 feet lower in level; a place which could never be reached by mere gliding without soaring. At the 1923 Rhoén contest the prospective victor having alighted only 50 feet from the goal, was quite surprised to be beaten in the last hour by some one who made 35 feet. This was considered pretty good among aces. It was only the average in last year’s contests when the records followed in rapid succession: 210, 131, 105, 65, 62, 48, 32, 28, 20, 19, 18, 15, 11, 8, and 6 feet. There would be no sense in trying to beat such performances. But this reflects very strikingly the wonderful training the glider pilots acquire, too. Glider training is lots of fun. On account of the slow velocity against the wind, and of the absence of any combustible fuel, the danger and hazards are remote. A smart high-school boy of 16 once learned gliding in his own homemade machine by being towed like a kite and his instructor running alongside and shouting up to him what to do with the controls. A preferred method of training is now to first give the student some rides in a two-seater glider with dual control, before he is turned loose to solo on a very sturdy and foolproof training glider. Then he is put on a more sensitive type for advanced training until he may try to compete in the contests on the highly refined champion machines. A very striking development of glider design is the single-track landing gear. Wheels have been abandoned not only for their resistance in the air but also on account of difficulties in coming to a stop when landing on an incline. Most gliders are equipped with skis as originally used by the Wrights. Some sort of springs are preferably inserted between skis and body. It was found quite feasible to land on one single central ski, in spite of the targest wing span. The pilot can manage lateral stability with the flaps until the machine comes to a standstill. Then it may tilt over so one wing tip may rest on the ground. A glider can safely be landed in places that would scare any motor airplane pilot to death, in underbrushes, in hollows, on steep inclines, or jumping over boskets and fences. After having stalled in the air, flying speed may be recovered after a drop of something lke 25 feet. Quite a number of rather unorthodox designs have been built and flown as gliders with interesting success. Among them are tandem wings, tailless planes, with pronouncedly swept-back wings, slotted wings, machines having the control planes in front of the main wings, SOARING FLIGHT—-KLEMPERER 237 and others incorporating flapping wings. An interesting experience was gained with an extremely light tail-first machine. It became longitudinally unstable when starting, due to the vertical gradient of the wind close to the ground, it is believed. The normal gliders are equipped with elevator, rudder, and aile- rons, and are controlled very much like “real” airplanes. Control surfaces are often comparably large, but the length of the tail is short in comparison with the wing span. Many efforts have been made with a view to eliminating the vertical rudder. The birds have evidently quite good control without it. However, all attempts at copying the ideal warping and folding mechanism of the birds’ wings or at replacing it by some other device have not so far pro- duced anything decidedly superior to a rudder. Various kinds of wind brakes mounted on the wing tips, which on a glider have such a long leverage, have been tried with partial success. Flexible camber wings and tiltable wings have been flown quite successfully, although the advantages claimed do not seem to be exactly in pro- portion to the complication. Some device with which to control the gliding angle independently of the angle of attack and speed does have some definite usefulness, however. Some inventors believe certain special wing and steering mecha- nisms to be capable of performing dynamical soaring flight auto- matically. Such devices, it seems, are not very likely to meet with success. There is a fundamental difficulty involved, closely connected with the problem of distinction between vertical currents and hori- zontal gusts and with the correct utilizing maneuver depending on more than what can be mechanically and aerodynamically grasped from aboard. In practice, the interpretation of the sensation of equi- librium depends to a large extent on the visual observation of what happens. One can fly with his eyes closed for a while, but not a bit in dynamical soaring. Neither can a bird in pitch-dark night. Most of those inventions are the involuntary result of a confusion of the problems of dynamical soaring and that of stabilization in straight flight. The two problems are by no means identical. In fact, the stabilizer is intended to make the machine let the gust pass as unno- ticed as possible. In dynamical soaring, on the contrary, the gust must be responded to by a vigorous motion in order to wrest energy from it. However, there is a deeper meaning to this confusion: The knowledge of the direction of gravity is a fundamental condition for any creation of a lift with which to oppose that gravity. On the solid ground or even on a big and sluggish air liner in calm air there is no difficulty to that, and we are so familiar with it that we are thoroughly accustomed to consider the direction of gravity as an established reference basis. Yet, on a glider performing dynamical 238 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1927 soaring flight it becomes quite an indefinite fiction bare of sensible qualities. ‘The reason for it is that all dynamical maneuvers involve actions of inertia, and it is just the task of the dynamically soar- ing machine to steer in such a way that the inertia forces do not on an average cancel out, with respect to axes inherent to the craft. Thus, dynamical soaring is the true materialization of Einstein’s famous fictitious box within which all mechanical means completely fail to distinguish any essential difference between inertia and gravity. Once the two are entangled they can not be separated by instruments. In order to describe fully the status of motion of a body freely moving in space, we have to state six elements, the three components of velocity and the three components of rotation in space. All mechanical instruments based on the principles of masses, springs, liquids, pendula, and gyroscopes combined and carried on board the aircraft are subject to the combined influence of both gravity and inertia, too. So, in order to determine the vector of gravity we have to subtract from the resultant the vector of inertia. We can meas- ure by six aerodynamical instruments such as anemometers and wind vanes the six equivalent data about the relative motion of the ship in the surrounding air. This suffices, evidently, in calm air. However, as soon as I suspect, or know, that the atmosphere is involved in an irregularly accelerated motion with reference to the earth, I am at a complete loss to determine the amount of the influence of this fact by means of any instruments of mechani- cal or aerodynamical kind carried aboard. The unknown data must be supphed by having recourse to other physical fields. In practice, I mentioned, it is the field of vision. To do that auto- matically by means of instruments is at present pretty well beyond available instrumental facilities. Theoretically, instruments utiliz- ing such extraneous fields as the magnetic field, the dielectric field or the air-density gradient may be given consideration, but whether sufficient accuracy and quick response will ever be attained is hard to fancy. Besides, weight, bulk, and complication are big handicaps for the use of automatic apparatus and even instruments in general. Just the same it is of great scientific interest to investigate with whatever instruments are feasible, into the details and intricacies of soaring flight. Recording altimeters, air-speed meters, and so- called accelerometers, which, however, are really not indicating acceleration proper, but a component of the resultant air force, have been of great assistance to both pilots and students. You can, while flying, by watching these instruments simultaneously with the hori- zon and the other physical sensations, interpret much better whether you are gaining or losing energy, in every phase of the gust. Angle of attack and yaw meters, however primitive they may be, are also a valuable asset. A wealth of information has been accumulated SOARING FLIGHT—-KLEMPERER 239 lately since elaborate surveying stations were installed on the Wasserkuppe and Rossitten gliding centers. A number of con- tinuous surveys of outstanding flights were recorded stereographically and evaluated afterwards, reconstructing the complete path of the glider in space. This work was originally started by taking syn- chronous readings from a theodolite and a range finder, but later on these instruments were replaced by pairs of kinema-theodolites disposed at the ends of bases, about one-eighth of a mile long. Several pictures were thus ground per second, insuring a very dense record. Not only true soaring flights were thus surveyed, also special straight glides were taken occasionally on particularly calm morn- ings. They served to get the aerodynamic characteristics of the machines themselves, independent of any soaring action. The application of gliding to scientific research is at present somewhat limited by the method used to get the glider started. It requires the windward slope from a mountain crest, whence it is catapulted into the wind by means of a rubber cord pulled by a crew of from four to eight people. In hilly country this method works exceedingly well; but one had often wondered how much more gliding would be popularized if some method of take-off could be devised to depend less on topology. I once tried to attach the glider on a captive balloon of the Swiss air service, and to take off from there. The glider was suspended some 100 feet below the basket, slightly aft of its own center of gravity, to keep its nose down. Unfortunately, this entire system being a gigantic double pendulum, immediately started to perform lateral oscillations. The balloon would yaw and travel to one side, the plane would prefer the opposite side. The motion was not fast but amplitudes were increasing. I was unable to check the oscillations by use of my controls. Since the machine would also always bank toward the wrong side I was forced to cut loose only to be thrown into a spin to recover from which the altitude was insufficient. There remains * the possibility of fitting the glider with a small auxiliary engine, just as they do on sailing yachts. Thus the glider may take off in the plains and fly under its own power to any place, where, upon meeting soaring flight conditions, the engine is throttled down or shut off and the real sport begins. The auxiliary engine would also help out a glider that happens to drift away from lifting currents or runs into a dead calm. As a matter of fact, a modern 3 Quite recently Herren Espenlaub, Raab, and Katzenstein made successful experiments by having a glider attached to and towed by a motor-powered airplane. Having been so dragged to considerable altitude, they cut loose and glided back to their base. They also towed a glider from one town to another via air. 240 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1927 glider requires no more than about 114 horsepower net for sustenta- tion. All kinds cf motorcycle engines have already been tried, varying from the smallest 2-horsepower variety of light European bicycle motors up to the size of four-cylinder racing motorcycle engines. Remarkable flights were made with such machines, taking off on as little as 7 horsepower as well as soaring with the motors shut down. Clever devices were designed for starting the engines up again while in flight. However, it soon became evident that avail- able motorcycle engines were not thoroughly reliable and suitable under the conditions of flight. The British motor industry was the first to visualize the necessity of developing from the motorcycle engine a special light aircraft motor. Horizontal twins, two- cylinder V-types, four-cylinder block and three and five cylinder radial motors now cover the range of 25 to about 60 horsepower, which is usually referred to as the light airplane class. All of them are air-cooled. Startling flights were made with astonishingly low-powered ma- chines, which demonstrated that the real light airplane, as developed from the super-eflicient glider, is by no means a fine weather craft but can be put to very severe service and yet retain a great deal of the poetry and sport romance of the true glider. It was with a tiny 25-horsepower, two-cylinder motor in his neat little monoplane that Botsch two years ago flew more than 300 miles from the Rhine to Berlin in 314 hours. A Messerschmitt two-seater cantilever mono- plane of 40-foot span, powered by a similar engine, crossed the Alps at 13,000 feet from Bavaria into Italy under the most adverse weather conditions. Mileages as good as 60 miles per gallon are not uncommon with the light planes. ‘The most striking feat was Botsch’s victory in a competition two years ago, for a flight circling Mount Zugspitze of the Alps, 10,000 feet, starting from and return- ing to Munich. He won first prize with a small 14-horsepower light plane against competition of all classes, among which were motors as strong as 200 horsepower, since the prize was to be awarded for the least consumption of fuel. He used only something hie 2 gallons, doing everything else by deliberate soaring flight, skillfully utilizing the various currents in the mountainous country. Unfortunately, among the motors at present available, there seems to be none that meets all of the ideal requirements at once, such as a really low weight per horsepower, fair number of cylinders insur- ing perfect balance on a light mounting, irreproachable reliability under flight conditions, little wind resistance, and last but not least a popular selling price. As soon as this goal is reached there will be comparatively little difficulty in building a reliable and fairly fool- proot light airplane of high efficiency, and capable of soaring fight, SOARING FLIGHT—-KLEMPERER 241 accommodating two people, slow and safe to land, of amazing fuel economy and negligible maintenance cost, the wings to fold back for housing in any garage. There is little doubt that this generation will live to see and use it and flying will become as popular as motoring. Only then, the interesting possibilities of soaring fight will be realized and the results of past research apphed. Pure soaring will not fail to retain a favored rank among outdoor sports. In Europe, gliding has contributed very much to the popularization of flying by bringing the younger generation into active contact with it. It is organized and stimulated by various disinterested private societies for the promotion of aviation. It is not, in general, a quick return business proposition. But I hope to have shown that it com- bines sport with education, art, and scientific research, a combination rare in this materialistic age and not unworthy of encouragement from those who consider it a sacred privilege to contribute toward the development of new art and science. » */ (ea Loge Le ip fT ote, & Shy : i ‘ et beds < a dF ro : . \ OG : : 1s ‘ " Ltt + ¥ : 4 hat i Pihheast the} Dirge 6 le ath Oe gues Pete +% { { Seay 1 « r f tke:h,t? pad 288 i 4 yiithy Was AY he RE om O Py ASN ¥ ; - : 7. ) 7% vs > aah " { Aga hex. Se IhOE eh aj ee} Hen st s Tt ee ae pty ' KT, my. » Aa nae rt Uabenis tre ciee OT) Saat ied tak | * ta Smithsonian Report, 1927.—Klemperer PEATEs ‘< Fo eS OSS, ABOVE THE RHON COUNTRY Smithsonian Report, 1927.—Klemperer PLATE 2 1.—WAITING FOR WIND 2.—A TAKE-OFF. NOTICE THE ENORMOUS WING SPAN. (ESPENLAUB) Smithsonian Report, 1927.—Klemperer PLATE 3 aa | 1.—SPOT LANDING CONTEST. (E. MEYER) 2.—ELABORATE INTERNAL TRUSSWORK OF A GLIDER WING Smithsonian Report, 1927.—Klemperer PLATE 4 11 Fine. tie 1.—GLIDER UNDER CONSTRUCTION AT AACHEN COLLEGE en I Cok Ti Thawe un ME TaR Ue pee! Mm mam py my aavan 4 : m, www T se 2.—A GULL-LIKE DESIGN. (AACHEN) Smithsonian Report, 1927.—Klemperer PLATE 5 1.—A FLEET OF TRAINING GLIDERS 2.—A TRAINING BIPLANE GLIDER Smithsonian Report, 1927.—Klemperer PLATE 6 [ 1.—CENTRAL LANDING SKI 2.—SpPoT LANDING Smithsonian Report, 1927.—Klemperer PLATE 7 — 1.—A TYPICAL LIGHT PLANE OF GLIDER DESCENT 2.—A‘‘FLAPPER” EXPERIMENT. (ZEISE) Smithsonian Report, 1927.—Klemperer PLATE 8 1.—WARPING WINGS. (HARTH) 2.—TAILLESS GLIDER. (LEUSCH) Smithsonian Report, 1927.—Klemperer PLATE 9 1.—WING-TIP BRAKES. (KOLLER) 2.—STARTING THE GLIDER. (DARMSTADT) Smithsonian Report, 1927.—Klemperer PLATE 10 a 1.—ONE WAY OF HAULING THE GLIDER UP HILL 2.—ROTATABLE FOOTBALLS AS A LANDING GEAR. (HANOVER) Smithsonian Report, 1927.—Klemperer PLATE 11 [ eee eee ANOTHER WAY OF HAULING THE GLIDER UP HILL THE COMING OF THE NEW COAL AGE? By Epwin 3. Stosson Director, Science Service, Washington, D. C. [With 1 plate] We stand at the opening of a new era in the utilization of coal, for here and now are being discussed as actual operations processes and projects which a few years ago were purely theoretical and commonly considered chimerical. In talking of the “old coal age” and the “new coal age” I am not referring to the Carboniferous period and the later deposits, for I am here concerned not with the formation of coal but with its consumption. In the old coal age, which has lasted now some 600 years, we knew nothing better to do with coal than to burn it. But in the new coal age now opening we have found that coal can be put to better purposes than to be burnt in its crude state; that when we use it merely as a fuel we are losing compounds that may some time be worth more to the world than the heat obtained. We are beginning to realize the value of coal as a source of raw material for the synthetic chemist. In 1806 King Edward I issued a proclamation making the use of coal as fuel in London a capital offense and one man was executed for the crime. Five hundred years later Col. George Shoemaker was threatened with arrest for attempting to sell a few wagonloads of coal in Philadelphia. When it was first proposed to burn coal by piecemeal, using the gas. for lighting and then the coke for heat- ing, the idea met with furious opposition. Scott, Byron, and Napoleon were among those who made fun of the crazy notion. A German paper in 1816 (Koelnische Zeitung, March 28) condemned the project of street lighting on six points: (1) Theological, as blasphemous, since God had divided the light from the darkness; (2) juridical, people should not be compelled to pay for gas they do not want; (3) medical, the emanations were injurious to health and people would stay out late and catch cold; (4) moral, the fear of darkness would vanish and crime would increase; (5) police, 1 Reprinted by permission from Proceedings of the International Conference on Bitu- minous Coal, Noy. 15-18, 1926. 243 244 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1927 the street lights would frighten horses and embolden thieves; (6) economical, great sums would be sent to foreign countries. The use of coal in locomotives and steamships was likewise con- demned and ridiculed on the start. In 1804 the British Admiralty declared it their duty “to discourage the employment of steam vessels as * * * the introduction of steam vessels was calculated to strike a fatal blow to the naval supremacy of the Empire.” Yet in spite of this warning from the highest authority the British Empire has somehow managed to survive the introduction of steam navigation. We laugh at the people of 600 years ago because they thought that coal was not fit to burn. But will not the people of 600 years hence laugh at us because we thought that coal was fit for nothing but to burn? We look back with scorn to the time when efforts were made te prohibit or restrict the burning of coal as it is carried on to-day. But may we not look forward to the time when efforts will again be made to prohibit or restrict the burning of coal as it is carried on to-day? Im fact, capital punishment has already been advocated, though in jest, for such a crime of wastefulness. The secretary of the British Royal Commission on Oil Fuel, Admiral Dumas, said not long ago: I wouid like to see a government official hanged at every lamp-post where gas is burned, because benzol goes up with the flame. He had in mind the impending shortage of gasoline, for which benzol, otherwise known as benzene, is a suitable substitute as motor fuel. President Baker is more sanguine, although less sanguinary, in his predictions, when he said in his opening address of the Inter- national Conference on Bituminous Coal: In less than a generation the present methods of shipping coal to be burned in its raw state under boilers hundreds of miles from the mines will appear to have been primitive and rudely unscientific. The familiar phrase for anything particularly expensive or extray- agant, “It costs like smoke,” implies doubtless an unconscious reali- zation of the fact that oxidation is the reversal of the synthetic reaction, the undoing of the constructive activity of animate nature. The plant builds. Man utilizes. Fire destroys. Now, one of the most wasteful forms of smoke was that which poured uninterruptedly during the great part of the last century from the open tops of the beehive coke ovens. In fact, one can yet see these prodigal flares on the Pennsylvania mountains as he looks out of his Pullman window in the night. Novw, this is not merely a waste of fossil fuel, which we already begin to realize will not last forever, but there is also a loss of a variety of compounds that can be made very useful if THE NEW COAL AGE—SLOSSON 245 properly worked up. Ifa ton of bituminous coal is heated in a closed retort, instead of the open beehive, we may get besides the gas and the coke a dozen pounds of ammonium sulfate and a dozen gallons of tar. The ammonium sulfate is valuable for a fertilizer, since it will feed nitrogen to the crops, and the tar on redistillation will yield a dozen products out of which some 200,000 distinct organic com- pounds may be made, some of which are extremely useful to mankind. The war has taught the United States a lesson in economizing the by-products of the distillation of coal. In 1913 nearly three-fourths of our coke was made in beehive ovens, which wasted the tar, ammo- nia, and light oils. In 1925 the ratio was reversed and more than three-fourths of our coke was made in ovens that saved these by- products. Last year was the peak in American coal-tar production, over 528,000,000 gallons; but 60 per cent of the tar so recovered was afterwards consumed as fuel instead of being worked up into chemical compounds. Tars can be easily and cheaply stripped of their phenols and cresols to supply domestic needs without materially reducing the fuel value of the tar. Yet the burning of untreated tar is on the increase in our country. In the old days before the war when men wanted to get more gasoline than petroleum contained they knew no other way to get it than to smash up the big molecules into little ones, to break down the heavy oils to make light oils. This “cracking” process was regarded as a great achievement in its day, and quite rightly, since we could be running few automobiles without it. But the world is passing into another era now, the age of synthesis, when the chem- ist will build up instead of breaking down. Starting with the com- monest and cheapest materials, air, water, and coal, the chemist can construct at will all sorts of valuable compounds for which we for- merly had to rely upon nature, if indeed we could find them at all. The veteran French chemist, Prof. Paul Sabatier, of Toulouse, opened the door to the new era with the key called “ catalysis.” Before the end of the last century he found that hydrogen gas could be made to unite with carbon-monoxide gas in the presence of finely divided nickel and produce methane, well known in natural gas. Now, these two constituents, hydrogen and carbon monoxide, are easily made by passing steam over red-hot coal, the “ water-gas ” process. Many other metals and compounds have since been found to act like nickel as a catalyst; that is, they speed up a process by their presence without being used up or appearing among the products. The building blocks used by the synthetic chemist in this new game he is playing are mostly the four ordinary elements, carbon, hydrogen, oxygen, and nitrogen. We may combine their initials 74906—23—_17 246 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1927 and call these constituents CHON for short. Nitrogen and oxygen have been impartially apportioned by Providence to every country in exact proportion to its area. Hydrogen may be obtained from water which neaven showers upon most lands in sufficient abund- ance. Carbon also is distributed equally and freely in the carbon dioxide of the atmosphere, but in such minute amount that we must employ the plants to collect it for us, especially those which lived in the Carboniferous period, when vegetation was more abundant and worked cheaper than it does to-day. To effect the liquefaction of coal, all that is necessary is to add water to it. But this is not a problem in simple addition, like dissolving a lump of sugar in a cup of coffee. It involves linking up electrons, and usually heat, pressure, and a catalyst are needed to effect the union of the atoms. What kind of chemical compounds might be made from the coal, air, and water? Obviously all the multifarious substances composed of these elements that exist in the three kingdoms of nature, animal, mineral, and vegetable. We have the same raw materials to work with as the plants and animals and the same source of energy, and we ought to be able to make anything that is made by any living creature if we only knew enough. But we can go much further and make hundreds of thousands of carbon compounds that never existed until they were invented in the laboratory. It has recently been demonstrated to the surprise of the com- mercial world that methanol may be made from coal and water. Methanol is the same liquid as has hitherto been commonly known as “methyl alcohol” or “wood alcohol,” but this name has been the cause of frequent and sometimes fatal confusien by those who think the alcohols are fit to drink. Ethyl alcohol looks very much lke her smaller sister methyl, but the two can be distinguished by their physiological reaction on the human system. Ethyl may make u man blind drunk but methyl may make him drunk blind. Methanol in its proper place, which is outside the human stomach, is a use- ful article in many manufactures and some 8,000,000 gallons have been made in America annually by the distillation of wood. But this method of manufacture is now hard hit by a new and cheaper process developed in Germany, which uses water gas as the raw material. Various other alcohols, such as butyl alcohol, made in America by fermenting corn, are made in Germany from water gas. Such liquids are finding a new and extensive field as solvents for the cellulose lacquers which are being used on automobiles and furniture. They are likely to displace in large part the paint and varnish which have been employed from time immemorial, since they can be either THE NEW COAL AGE—SLOSSON 247 sprayed or laid upon a surface; that is, applied either with the air brush or the hair brush. The water gases that in some sections of the United States are still allowed to escape from coke ovens unused are at the mines of Bethune, France, cooled and condensed and utilized for making methane, benzene, ethyl alcohol, and ammonia. Owing to the catalytic process for synthetic ammonia invented by Fritz Haber, Germany is now exporting fertilizer instead of importing it, as before the war. About 425,000 tons of free nitrogen from the air is now fixed for fertilizers by catalysis every year, and this takes the place of 2,700,000 tons of Chilean nitrate. But Muscle Shoals still stands idle. Benzene, which can be be made from coal in various ways, is the mother substance of the aromatic family of chemical compounds, a family of over a hundred thousand and rapidly growing. Among these are the synthetic dyes and drugs that have made the world brighter and safer in our generation. One of these products, car- bolic acid, is familiarly used as an antiseptic and is nearly as useful, though much less familiar, as one of the two components of bakelite. The other component, formaldehyde, is also an antiseptic and also made artificially. If such synthetic resins could be cheapened as much as General Patart foresees, they would be used for the finish- ing and furnishing of houses and find innumerable and inconceivable other applications. The chief stimulus to such investigations in Europe is the search for homemade motor fuel. We Americans are not much interested in this question now, but some day we shall be, and meantime it is interesting to watch their chemists trying to see how many different things they can make out of common coal, like children playing with the Chinese tangram. When kerosene first came into use as a lamp illuminant, it was called “coal oil,” for it used to be supposed that petroleum had somehow been formed from coal. Later that theory was called in question, and geologists are still disputing the origin of oil. We seem likely to use it up before we find out where it came from. But even if coal oil turns out to have been an inappropriate name in the past, it may prove to be true in the future, for petroleum can be made from coal, and some day we may all have to make it that way. For the less oil we have the more we use. The lower the supply in the ground the higher the output of our refineries. This increase in consumption can not keep up forever, however liberally you may estimate our unseen supply underground. 248 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1927 The countries that are short on petroleum are already contriv- ing substitutes. The Germans, who were well supplied with coal but had little oil before the war, began experimenting on methods of making artificial petroleum. Since they have lost some of their best coal fields through the war and oil is harder to get than ever, they have been still more active in such research, and they have been amazingly successful of late. Theoretically it is simple enough. Petroleum is a mixture of compounds of hydrogen and carbon. Just hitch up these two elements, and there you are! But there are other hitches in the proceedings. Either carbon or hydrogen will unite readily with oxygen, but they have little liking for each other. Only when stirred up by high heat and forced into contact by high pressure will they combine. Under these conditions the carbon and the hydrogen gas unite in all sorts of ways and form gaseous, liquid, and solid products of various usefulness. The coal for this process does not have to be of a special quality, as is required in making gas or coke by our present methods. Any kind or form of coal can be used, and high yields of the hydrogen- ated products are said to be obtained from the brown coal and lignite of which the United States and many other countries have an abundance. Peat may thus be worked up to gasoline and other marketable compounds; also pitch, tar, sawdust, and any vegetable material. When the first trolley car ran down the street of a southern city, an old negro watching the mysterious vehicle from the sidewalk was heard to remark: Dese Yankees is quah people. Fust dey come down heah and free de slaves; den dey come down and free de mule. That is a good summary of the progress of civilization. The first animal that man enslaved was man. Next he shifted the burden in part to the back of the ox and the horse. Now human slavery is at an end and we are gradually getting to the point of releasing the lower animals from their enslavement. Eventually all the hard work of the world will be done by engines run by inorganic power. Modern civilization is based upon such utilization of inanimate energy. The number of people who can live on the earth and the comfort in which they live depend upon how much energy can be obtained and how economically it may be employed. Of all con- ceivable sources of energy only the sun’s rays are actually available and these not directly. Until some practicable solar engine is in- vented we must rely upon indirect means of making the sunshine work, Smithsonian Report, 1927.—Slosson PLATE 1 DR. FRIEDRICH BERGIUS, OF HEIDELBERG, INVENTOR OF A PROCESS FOR THE LIQUEFACTION OF COAL BY TREATMENT WITH HYDROGEN UNDER HIGH PRESSURE (Photograph by Science Service, Washington) THE NEW COAL AGE-—SLOSSON 249 The energy radiated by the sun reaches the earth through 92,- 000,000 miles of empty space as cold as can be. When the rays come into our atmosphere, they heat up the air and so set up currents in it. That gives us power for windmills. When the rays strike the sea, they heat up the water and evaporate some of it, which, carried away by the wind, falls on the mountains as rain. That gives us power for our water wheels. When the rays fall on a green leaf, they are set to making cellulose. That gives us fuel for our engines. There are then three ways in which to engage solar energy, two physical and the third chemical. I suppose the first employment of external energy in the history of the world was when some prehistoric savage discovered that he could save himself walking by floating downstream astride of a log. Doubtless the second was when some other genius discovered that he could make the wind propel his log canoe across still water by hoisting a skin as a sail. The third method, the chemical process of using solar energy, came with the invention of the steam engine 150 years ago. The chemical means of utilizing sun power, that is, combustion, is at present our chief dependence, but the little green leaves work too slowly for us. They can not keep up the pace that modern life demands. So we have drawn upon fossil fuel, upon the carbon- aceous accumulations of the Paleozoic period. The iron horse feeds on subterranean pastures. We stoke our engines with the giant ferns and mosses that grew in Wales or Pennsylvania long before human life began. In the green laboratories of the curious vegetation of that remote era, the light waves from the sun acted as they do to-day, dissolving in the plant the bonds that connected the carbon and restoring the oxygen to the air. We now reverse the process and reunite the carbon of the coal beds with the oxygen of the air and so revive the sunshine that fell upon the earth millions of years ago. But we have for a century been living upon our carbonaceous capital. We have skimmed the cream of our coal beds and wasted about 99 per cent of its power. The concentrated fluid extract of fossil fuel, petroleum, is even more limited and has been still more recklessly wasted. Coal is scarce in many parts of the world and oil will soon be scarce everywhere. The Southern Hemisphere is con- spicuously deficient in coal. Africa, South America, and Australia have not enough for their own needs and will have to. borrow from their northern neighbors. The most obvious distinction between plants and animals is that the former have roots and the latter have legs. Plants are mostly sessile; animals more or less mobile. Man, having only two legs and 250 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1927 being devoid of the wings of the birds and the caudal propeller of the fish, is at a natural disadvantage compared with the migratory members of the animal kingdom, but in the twentieth century he has surpassed them all and raised himself farthest above the vege- table stage. By the aid of his engines he can now outfly the eagle, outswim the fish, outpull the elephant, and outrun the deer. This new freedom he has employed unprecedently in tourist travel and mass migration. The mobility of modern man is due to his tapping of subterranean stores of fossil fuel, coal and oil. The expansion of Europe is based upon the expansion of gases. The power of the peoples which now dominate the world in war and peace is the pressure of mutinous molecules released from bondage. Modern civilization is based upon atomic anarchy. This is the force that in war propels the cannon ball and explodes the shell and in peace pushes the piston of the steam engine and the automobile. Steam reigned undisputed for about a century, say, from 1776 to 1876. After that date came the internal-combustion engines, which were more efficient and com- pact, since they produced pressure by the explosion of their own fuel and needed no fire box or boiler, the Otto engine using gas in 1877, the Daimler engine using gasoline in 1892, and the Diesel engine using crude oil in 1897. These made possible in the twen- tieth century the airplane and the automobile, the motor boat and the motor cycle, the tractor and the tank, and gave to shop and farm a convenient motive power requiring no engineer or fireman. The mobility of man is measured by the mobility of the power he employs. Consequently the efforts of technologists are now directed toward increasing the fluidity of fossil fuel; the finer the particles the more fluid the form. The cheapest and most abundant source of energy is coal, but this is solid and deeply embedded in the rocky matrix of the earth’s crust. Krom this matrix the coal has to be torn lose by explosives and then broken into lumps smail enough to be shipable and shovelable. By putting fuel into powdered form it can be blown into a furnace on a blast of air. But combining it with hydrogen we can reduce the carbon to a liquid form and by heat convert it into a gaseous state where all the molecules are free and independent. But the atom is not the limit of divisibility, although that is what its name implies. As we now know, it is possible to break up the atom, and its finer fragments, electrons and protons, afford us a still more fluid form of energy, the electrical current. ‘To transport solid coal from mine to the factory requires a large part of its power. To transport water from the mountain to sea requires no power. It will flow downhill of its own accord if you will only provide it with THE NEW COAL AGE—SLOSSON 251 a sloping channel or an empty pipe. To transport electricity from a point of high potential to a point of low potential requires no power. The current will flow downhill of its own accord if you will . only provide it with what is for it an empty pipe, that is, a copper wire. And the electric current will travel far faster than the coal train or the flowing stream. So the efforts of inventors are now con- centrated on methods of increasing the mobility of energy by such means as converting coal into a liquid form, or converting its energy into the electrical fluid. The greatest scientific achivement of the nineteenth century, in the opinion of those who lived in that century, was the formulation of two fundamental physical laws of the universe, the conservation of mass and the conservation of energy. According to these, matter and energy were immutable in amount and neither could ever be created or destroyed in the minutest measure. But the twentieth is an unsettling century. Such mental revolu- tionists as Einstein, Planck, and Bohr have opened our eyes and widened our outlook. We can not be so cocksure about many ideas as were the simple-minded scientists of the former century. Some of the generalizations which seemed to them absolute and universal principles of nature appear to the more critical eyesight of the pres- ent generation to be disguised definitions, similar, as Eddington puts it, to the Great Law to which there is no exception, that there are 3 feat’ in every yard. For instance, the law of the conservation of energy. We see a lump of Wee coal giving off energy at a great rate as radiant heat and light. Where did that energy come from? Where was it when the lump was cold, if no energy can be created in the course of com- bustion? The reply of the nineteenth-century chemist was clear and decided. The energy was there all the time in exactly the same amount, although its presence could not be demonstrated, because it was in the form of “potential energy.” Obviously this was un- answerable as an argument, although not very enlightening as an gongs We are nowadays disposed to suspect that this “ poten- tial energy ” was put into the coal by logic rather than by geology, and that if it exists in nature at all it is in the nature of the human mind. The twin laws of the conservation of matter and energy are as useful as ever, for they still serve to clarify our conceptions and to guide our experimentation. No experiment has ever been able to detect the slightest flaw in them, and it may never be possible to de- vise tests so delicate as to disclose any discrepancy. Yet neither law is now regarded as absolute in itself, and it seems that we shall have to substitute some general law which will include the two and allow for the transformation of matter into energy and vice versa. FEin- 252 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1927 stein has worked out the formula for the equivalence of matter and energy, so we can now calculate how much heat will be produced if _ acertain mass of matter is annihilated. This idea has been welcomed by the astronomers, who have been hard put to it to devise means of keeping up the furnace fires of the sun as long as mankind would like to live. They have now figured out by Einstein’s formula that the sun is losing weight, through the destruction of its material and the emission of immaterial energy, at the rate of 4,000,000 tons a second. But even though wasting away at this appalling rate the sun can hold out for 10,000,000 million years.? This gives a welcome exten- sion of time for the life of our world and permits us to hope that we may get our social system perfected before we all become Eskimos. This principle of the interchangeability of matter and energy must apply to all chemical reactions where heat is produced or absorbed. Wherever coal burns there matter is being converted into radiant en- ergy. Wherever a green leaf grows there matter is being manufac- tured out of solar energy. In such cases of course the quantity of matter or energy transmuted is too small to be demonstrated. In the burning of coal the heat evolved means a loss of about 1 part in 10,000,000,000 of the joint mass of the carbon and oxygen combined. But this loss of matter becomes appreciable when we consider the world-wide consumption of coal. If we assume that all coal is pure carbon and that the combustion is always complete, the carbon di- oxide produced by all the coal that burned in a year throughout the world would weigh about 5,000,000,000 tons. This would involve a disappearance of matter amounting to half a ton. The substance of the world is therefore being slowly consumed by the combustion of coal. But such loss is continually being replenished by the sun- shine that falls upon vegetation and is there fixed in the form of cellulose. The problems we are considering are world-wide questions in which the whole human race is concerned, for they deal with the subterranean stores of wealth-producing energy which are the com- mon inheritance of the population of the planet.. These treasures are limited and irreplaceable, and upon them our modern civiliza- tion is supported. The main question, and the only one with which science as such is concerned, is to see that this endowment of fossil fuel is not wasted but utilized to the greatest advantage of the present generation and posterity. Who owns it, and who makes the most money out of it, are minor matters that do not affect the main question. Germany lost a large part of her coal trade through the world war. England lost a large part of her coal trade through the labor war. But neither of these affects directly the coal that is 2 Heyl, Fundamental Concepts of Physics, p. 72. THE NEW COAL AGE—SLOSSON 253 still in the ground. Coal is coal Whether it is dug by Germans, British, or Frenchmen, or as in the case of American mines, by all the races of Europe working together. The nation that deserves the most credit is that which makes best use of its share of fossil fuel, and making the best use of it does not mean using it up fastest. We owe a duty to posterity, and we con- demn a spendthrift father who dissipates his fortune and leaves his son destitute. When we learn that 60 per cent of the coal tar pro- duced in the United States is burned for fuel, we feel that something is wrong, but we do not know how to remedy it. We can not compel a man to save by-products that he can not sell or to work land that does not pay. The frequent admonition of a mother to her child at table, “ Eat your crust; some day you may be starving and be glad to get it,” is not convincing. The normal child can not conceive of ever being hungry enough to eat that crust, and he can not see how eating the crust now would provide it for him on that hypothetical day of destitution. We can not store up unusable stuff for an in- definite future nor refuse to make use of our buried treasure for the present needs on the ground that our grandchildren may make more out of it. There is no world organization that can exercise the right of emi- nent domain over natural resources and compel a country to stop wasting its coal and oil or to employ its unused land and water power. But all the same, and all the more, we should all rejoice when anyone discovers how to make a profit out of a waste product or how to make a process more efficient. When a way is found to convert a low-grade lignite into a high-class motor fuel, or to make manufactured alcohols and acids of the gas that used to flare from the tops of blast furnaces, or to clear the air of our industrial towns, or to raise the efficiency of a fuel by low-temperature carbonization, he has thereby benefited the human race, living and to come, whether he makes money out of his patent or not. All knowledge goes ulti- mately into a common pool from which every man may draw what he can use. Pure science is essentially international, however it may be nationally applied. “at -~ ee IS THE EARTH GROWING OLD?! By Joser WELIx POoMPECKIS When geology treats of the age of the earth, it bears in mind only a portion, indeed only a very modest fraction of the period of the earth’s existence. This relates to the time taken for the formation of only the outer shell of the whole earth’s globe, where there lies the possibility of geological exploration. For the evaluation of that length of time which elapsed from the very beginning of this earth to its present state we have no certain basis, no sufficiently sure means for estimations. The con- fines of the universe provide no further help than such as can be gained relative to the hypothetical evolution of the stars based upon the phenomena of the meteors, the planets, the suns, and the varied forms of the nebule. Though such ideas rest upon physical laws, nevertheless they are purely hypothetical. The length of time for observation by mankind, so far elapsed, has not been sufficient for us to have convincing observations as to the development of a star. Even the “nove” give us no. clue; in their short life of brilliancy we gain knowledge only of an ali too short catastrophic episode in the life of a giant star, knowing nothing of the star’s life previous to the catastrophy. Whatever hypothesis as to the development of the earth we keep in the foreground for the following details, the history of the earth, in point of time, begins with the moment recorded for us by the oldest observed rocks. What we know of the rocks of this outer layer of the earth— with the exception of relatively few and quantitatively trivial samples from the bottom of the oceans—relates only to the continents and islands. In comparison with the earth’s whole bulk, these rocks are an extraordinarily small portion. We can penetrate into the earth’s crust only a little over 214 kilometers, about one two-thousand-and-eight-hundredths of the 1A discourse (introductory paragraphs omitted) delivered in the new hall of the Royal Frederick-William University, Berlin, by the rector on Aug. 3, 1926, at the celebration held in memory of its founder. Translated and published by permission. 255 256 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1927 earth’s radius. This is in the deepest boring, that of Czuchow,? in upper Silesia, driven by the Prussian Government, purely for the solution of important scientific questions. However, the crust fortu- nately does not cover the earth as a homogeneous layer. It is broken up endlessly into fragments. The separate pieces are multifariously and greatly piled upon and against one another. Great masses are often folded and thrust into the most complicated patterns. There- with is offered to us the possibility of gaining an insight into a con- siderably greater depth of the earth’s crust. Take, for example, northwest Germany. Despite the slight differences in the altitude of this region, because of the juxtaposition of portions of the earth’s crust belonging to very different geological formations and ages, we can here inspect an equivalent thickness of 12 kilometers of sedimen- tary rocks, dating from the Devonian to the end of the Cretaceous. American geologists estimate the possibility of thus gaining an insight down to a depth of 100 or more kilometers of the earth’s crust. This is surely too large an estimate. It results from a sum- mation of the greatest depths estimated from rocks occurring in separate regions. The addition of such maximum magnitudes gives us a false picture, since in the different regions of the earth, in the same geological epoch, under differing geological conditions, quite different thicknesses of rocks may have been formed. A depth of 30 kilometers is hardly too small an estimate for the depth of the rocks belonging to all the known strata of the earth. Here we consider primarily the layers of sedimentary rocks—sandstones, limestones, etc.—which occur in numerous modifications due to the action of the atmosphere, water, ice, wind, organic life, and which form the unique evidences of the earth’s history. But nowhere is this documentary rock book, making up our knowledge of the earth’s history, complete throughout the 380, or let us say 100 kilometers. Nowhere at the surface of the globe have there occurred continuously throughout time the formation and conservation of these stratified rocks. The first rock of sedimentary nature could be formed upon the earth only when there was already a solid substratum upon which and from which sedimentation was made possible. The examination of the oldest and deepest known rocks—those of the Archean age— shows the simultaneous occurrence of sedimentary as well as igneous rocks. ‘The latter exist in such relationship to the sedimentary ones that it is indeed impossible that out of these solidified masses the first 2 Czuchow, which was the deepest German and Old World boring, has been surpassed by the boring of Prickett’s Creek, W. Va., reaching a depth of some 40 meters more than Czuchow. °F. W. Clarke has computed that the mass of all the sedimentary deposits is sufficient, if spread in a layer over the whole earth’s surface, to cover the earth only to a depth of 800 meters, if we take in consideration a thickness of the earth’s crust of 16 kilometers. IS THE EARTH GROWING OLD?—POMPECKS 257 substratum could have been formed upon which was laid the first sedimentary stratum. By the manner and means of its occurrence, one type of rocks always requires the existence of the other. It is therefore impossible that the oldest known rocks were the first formed. Now let us postulate, instead of the more generally known Kant- Laplace hypothesis, the Chamberlin-Moulton planetesimal theory. The latter surely more readily explains many phenomena of the solar planetary system than does the older hypothesis. With Cham- berlin and Moulton we see the earth increasing in mass through the accretion of those small cosmic bodies, the planetessimals. The earth is thus increasing even at the present, although, indeed, in comparatively small amount, through its encounters with meteors and shooting stars.* According to Chamberlin the earth could support organic life by the time it had reached the diameter of Mars; that is, with a volume of only one-ninth of its present amount. Be that so, the earth, in order to sustain life, must then already have had a rocky crust and pressing upon this a hydrosphere and an atmos- phere. The formation of sediments would then have taken place, and since that time the earth’s crust, in round numbers, must have increased in thickness some 3,000 kilometers. How very decidedly thin is the earth’s shell, which we know, in comparison with this great thickness ! Compared with the great size of the earth itself, that part of its crust which is known to us is indeed very petty and the lapse of time necessary for its formation surely vanishingly small compared with the eons which have passed since the birth of the globe itself. Since the arbitrary appraising of the complete age of the earth by Buffon, now more than 150 years ago, as 74,600 years, repeated researches have been undertaken to evaluate the lapse of time re- quired not only for the formation of the earth’s crust but also for the formation of the various rock strata which make up that crust. The various estimates differ greatly. The various premises lead to divergent results. Figures for the length of time which must have elapsed to ac- count for the formation and accumulation of the sedimentary de- posits known within the earth’s crust have been obtained from the abrasive effects of the surface waters, from the amount of the newly accumulated sediments, and from the extent of the geo- logical changes at the earth’s surface. The resulting values for *An unpublished computation made by my esteemed friend, E. A. Wuelfing, indicates a total of some 38,650,000,000 shooting stars which the earth annually encounters. Their mass could easily amount to a respectable number of tons, 258 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1927 the absolute age of the sediments within the earth’s crust vary greatly among themselves, from 30 up to 400 million years.’ ‘This should not be surprising, for if to-day the rate of formation of sedi- mentary matter varies greatly in different localities so it must have been in the past. It is, moreover, difficult in the estimation of the lapse of time to make satisfactory premises. It is an undoubtable supposition that the salt content of the oceans originates from the rocks of the continents (the last end of volcanic activity) and that this salt was carried by the fresh water of the land into the oceans, increasing their salinity; from estimates of the rate of import and deposition we can determine the lapse of time for the existence of the oceans, at least since pre-Cambrian times, and there- with the ages of the sediments in the sea regions of past ages. Values of 100,000,000 to 340,000,000 years have thus been reached.® Apparently very trustworthy estimations of the lengths of smaller durations of time in geological history have been recently made. The water melting from the inland Scandinavian ice has resulted in the formation of the so-called Bindertone. De Geer recognizes in these, in their alternation of fine sand and clayey material, the influ- ence of yearly variations in the rate of melting of the ice, whence, for the Scandinavian peninsula, he has computed the time elapsing from the beginning of the retreat of the diluvial ice until the present as 12,000 years. Sdrgel saw in the rock sequences of the Thuringian diluvium the decisive influence of cosmic factors, the cyclical varia- tion in the obliquity of the ecliptic, the eccentricity of the earth’s orbit, as well as the variation of the perihelion distance of the earth and the variation in the intensity in the sun’s heat dependent upon these. From these he placed the beginning of the north German diluvium more than 580,000 years ago. The physical chemists consider that the surest method of estimating the ages of rocks depends upon the amount of the radioactive trans- formation products present, due to the passage from uranium and thorium to lead and helium, respectively, in the minerals of volcanic origin. The basis for this surety is the fact that radioactive proc- esses are wholly independent of surrounding chemical and physical conditions and pursue their transformations slowly indeed, but at the same speed for all time. Using the rate of transformation of uranium or thorium, the absolute age of a number of volcanic rocks, differing in geological periods, has been computed. Although the values obtained are not fully concordant, generally the results are 5 We quote only a few values: Sollas reckoned 34,000,000 to 80,000,000; Phillips, 38,000,000 to 96,000,000; Walcott, 55,000,000 to 70,000,000; de Lapparent, 67,000,000 to 90,000,000; Geike, 100,000,000 to 400,000,000 years. Ami Boué sometime since pub- lished a very complete summary of the older estimates. ° New estimates due to Sollas give 100,000,000 to 175,000,000; to Holmes, 210,000,000 to 340,000,000; and to Schmiedel of at least 300,000,000 years. IS THE EARTH GROWING OLD?—POMPECKJ 259 of the same order of magnitude, and large. For the duration of the diluvium about 1.5 million years was computed. Uranium minerals from the Carboniferous age indicate a lapse of 335 million years and rocks from the pre-Cambrian, the period wherein there is direct evidence of a rich and already much differentiated organic life, a lapse of 1,000 to 1,600 million years.’ § The values obtained in this manner exceed from fourfold to much more those obtained from other geological methods. They are, indeed, very much greater than most estimates based upon the Kant- Laplace hypothesis as connected with the cooling of the earth from a molten condition to its present temperature. Whether it is possible that a more thorough knowledge of the course and duration of the radioactive processes may reduce the age values deduced from such processes—and Joly has already raised objections against the very high values won through the uranium-lead reactions—or the values obtained from geological evidence come nearer the truth, one thing remains certain: The scanty section of the earth’s body, which we know geologically, is old. Gradually we have regained our lost respect for great values. Even the approximately 300,000,000 to 400,000,000 years, which is indicated by the salt method applied to the sedimentation within the earth’s surface layers, suffice for the indication of a very high figure for the age of these layers known. However, we must assert very strongly that we are far from able by geological means to set the time of the beginning of the formation of the crust of this earth. Evidently the complete time for the exist- ence of the earth must be very manyfold that of the geologically determined period of the earth’s history.° Is this earth, whose age is so many millions of years, as thus read from the rocks within its crust, really growing senile? And this riddle is well asked. We speak of the stars as growing old along the sequence from the white stars to the yellow, from the yellow to the red; the moon is believed to have rapidly aged and died; the cosmos presses on to a warm death; life on this globe presses on to a cold death. 7 How widely the estimates of ages from the uranium and thorium minerals may vary is indicated by the work of L. A. Collins (Amer. Jour. Sci. 5th series, vol. 12, July, 1926). The following ages for pre-Cambrian minerals of Australia were estimated: For a fergusonite, 620; a mackintoshite, 1,475; a pilbarite, about 3,840 million years. How- ever, the last-named mineral is annotated as “‘ altered,’ so that within it the lead-uranium relationship should not be normal but the range from 620 up to 1,475 million years does not seem very small. 8 The late Professor Barrell (Bull. Geol. Soc. of Amer., vol. 28, 1917) estimated the time since the beginning of the Cambrian period at 700,000,000 years, basing his con- clusions mainly on radioactive data. (Translator’s note.) 2 Nernst, arguing generally from the Kant-lLaplace theory, estimates the period of the earth’s existence as a hot liquid ball as equivalent to the length of time which has elapsed since the formation of the earth’s crust, as obtained from the earliest uranium minerals, i, e., about 1,500 million years. 260 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1927 Yet what shall we understand as the aging of this earth? Where and how will this aging be expressed ? Shall we carry over to the earth without further qualification the physiological ideas and processes of growing old, which in many instances are not exactly qualified or known? May we apply such ideas to an inorganic body like the earth? Evidently the earth, in its processes, presents no picture of de- velopments equal to organic developments. The biological changes in the life processes of an organism are bound with the wonderful protoplasm through the highly specialized phenomena of assimilation, dissimilation, organic growth, and reproduction. The petrologist in discussing the earth’s volcanic rocks may in- deed speak of magmatic “assimilation ”; but the inorganic “ assimila- tion ” in the earth’s crust, in the earth’s body, is nothing more than a “solution” within the molten mass through the addition of a foreign substance within an existing molten substance. Similarly magmatic “differentiation” is not to be compared with organic “ dissimilation.” It is nothing more than one of the various reac- tions between the components of the magma according to their relative quantities and relations to each other and the variations in the pressure and temperature of the surroundings. Though, following the planetesimal theory, we talk of the earth erowing to its present size, yet this growth is not taken in the sense of the growth of an organism through the actions and reactions of the latter’s protoplasm. The growth of the earth is to be taken merely as a simple increase in bulk through the accretion of cosmic bodies. There was, and is yet to-day, an assimilation of these bodies into the earth’s substance through weathering and various transforma- tions; but there is here only an addition to the earth of matter, similar to the substance of the earth, coming to it from outside space. If we might speak of the moon, as W. H. Pickering expresses it, as a late-born child of the earth, and if the depths of the Pacific Ocean indeed show the womb from which the moon was torn out of mother earth’s body, this process of the division of a heavenly body into two is least of all to be taken as an instance of organic reproduction. In general what then shall we take as an expression of the life of the earth that we may measure its growing old? The life of an organism is bound up with protoplasm and its motion. With what is the life of the earth bound? Neither its existence nor yet its length of existence is to be taken as the sense of its life. If we are to draw a parallel from the life of the organic world, then the life of a star IS THE EARTH GROWING OLD?—POMPECKJ 261 should be evidenced by the changes which occur within it through the motions of its component masses. For the earth this will mean to us alterations through movements of masses upon and within the earth’s crust, the evidence for which is documented in the manner and nature in which the rocks of the earth’s crust occur. The mass movements of the earth’s crust are manifold. There are the movements of the atmosphere and the hydrosphere and their effects upon the rocks of the earth’s surface through weathering, chemical transformations, mechanical transportation, the accumula- tion of material, the formation of new rocks, the movements of glaciers with their effects upon the earth’s surface, etc. The inter- mixing of the rocks of the lithosphere occurs in great variety— through faulting, the earth’s crust breaks into great blocks some of which rise, some sink; through folding, the massive mountains and mountain chains rise between immobile blocks; through warping, the earth’s crust is arched up in some places, in others it is depressed. The seas accompany such movements by invading the lands in places and in turn are forced to retreat. Paroxysms of trembling in the earth’s crust occurring as earthquakes, and the mad outbursts of vol- canoes are bound up with movements of the great blocks of this crust. Finally there are the slight tidal movements within the crust, the tides of the ocean and the slight, restless movement of the earth’s axis of rotation. All these movements may be taken as the expression of the life of the earth, that Berget has attractively sketched in his beautiful book, “ Life and death of this globe.” An organic body (organism), by virtue of its construction out of protoplasm, possesses the ability to pass through its life processes; but this ability is active only when its protoplasmic cell exists in the proper relations to ight and warmth, to water and air, and with the necessary food supply. Similarly at least a very great part of the expression of earth-life is possible only through the determin- ing interaction of its surroundings and the cooperation of cosmical influences. Over all stands the mastery of the eternal laws of cosmical physics. The motions of the atmcsphere and the hydrosphere are developed, widely influenced, and kept in their courses through the cosmical element of the radiation from the sun, the earth’s rotation, and the changing position of the earth in its orbit. In their motions, as well as their actions upon the rocks of the earth’s crust, the atmosphere and hydrosphere are greatly directed and influenced by the action of gravity. Therewith there is a striving, though often interrupted, within the earth’s crust, and indeed throughout the whole earth, toward a position of gravitative equilibrium. The rocks formed under the action of the hydrosphere and atmosphere through the 74906—28-——18 262 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1927 transformation of preexisting rocks of the earth’s crust, and the re- peated overlaying of these upon other regions, alter the local gravita- tional proportion. Therewith result gravitational readjustments of far-reaching effects. The increased local loading through the heaping up of newly formed rocks creates in that region a subsiding movement beneath which there ensues a compensating sideways thrust. The thrust results in an upward movement of the earth’s crust elsewhere. Movements of the earth’s crust in one place set in action other readjusting movements elsewhere. These readjustments of the earth’s outer shell are more or less bound up with the parox- ysms of earthquakes and of volcanic actions. And the volcanic reactions continually make rise new masses from the depths to the earth’s surface for the geological action of the atmosphere, water, ice, and organic life in a new cycle. The building of the long, lofty mountain chains stands in close relationship with the mass movements ensuing from the action of the hydrosphere and the atmosphere. In the uplifted mountain chains, their altitude when rightly oriented relative to prevailing winds richly loaded with moisture results in a great increase of rain. Fur- ther the surface offered to weathering is much greater than on a level plain. Because of the increased altitude and consequently increased fall for the water, the movement of waters in their channels is greatly increased, and the latter’s carrying power is much augmented. In the neighboring plains, where the movement and consequently trans- porting power of the water is much diminished, the decomposition products, due to weathering and abrasion, will be heaped up. In gathering places, in geosynclines, this mass of matter thus dragged down from the higher ranges upon sinking sedimentation plains, serves for the formation of thousands of meters of new rocks. Out of these areas, as earth history repeatedly shows, new mountains come into existence while the former highlands are worn in propor- tion to the abrasive action of the water. None of these mass movements of the earth’s crust occurs and works independently. Ali these life expressions interlock with each other. They show themselves in the most complicated interrelation- ships. In all these complicated occurrences, their continual, pulsat- ing work forms the manifested whole of this earth’s life, the chang- ing episodes of which the rock-made archives of the earth preserve. Though the unity and heterogeneity of this earth’s life stands clearly before us, the next consideration is veiled in uncertainty: What is the unique actuating impulse which leads to this whole inter- acting complex of the life-assertions of this earth? What originates the impulse which gives to the earth’s body the movements which constitute its life? . IS THE EARTH GROWING OLD?—POMPECKI 963 The answer seemed simple in the period of the unlimited sway of the laws of Kant and Laplace. The loss of heat by the earth entailed a shrinking of its body; this led through the crumpling movements in the relatively solid shell to a distinction between high and low, between mountains and lowlands. Herein lay the cause of all the complexity of the movements to which the earth’s crust bears wit- ness. An especially fortunate form of reply at one time seemed to have been given, an enlightening explanation of the origin of the high and low places on the earth from which would follow necessarily all those movements which we are considering as the life of the earth. This reply came from Lowthian Green in his happy thought of the tetrahedral remodeling of the spheroidal earth. The corners and the edges of this tetrahedral earth were, as this illuminating theory explained, the necessary high regions which caused, directed, and influenced the movements upon and within the earth’s crust. But unfortunately all too numerous and weighty objections can be brought against a theory based upon a loss of heat and the conse- quent contraction, as well as against one consequent to the laws of the nebular hypothesis relating to the contraction of the earth’s crust, especially as connected with the reactions of a hot interior upon the outer crust. Such theories can not be brought into general recognition. Just as there are great objections to the nebular hypothesis in elucidating the relations within the plane- tary system, so there are to it for the explanation of the movements which constitute the earth’s life history. In our need for an explanation of these events in the develop- ments observed in the earth’s crust we readily, perhaps too readily, resort to the phenomena of radioactivity. Out of the energy released from the radioactive processes we could conceive a simple explana- tion of the phenomena of the earth’s life. Are we right in this? However, it seems that at present we must rest content with our knowledge of these phenomena of the earth’s life, their interrela- tionships, alternations, and sequences. And now let us get back to to-day’s question: Is the earth growing old? Out of the 400 to 1,600 million years of the earth’s history of which we know something, can we detect such changes in the evidence of the earth’s life as would lead us to the conclusion that there is a crippling in these activities? Such a crippling would mean “ erow- ing old.” So far as the rock records of the earth are legible, the “actuality ” principle, enunciated by Hutton and more fundamentally stated by Hoff and Lyell, holds for the processes within the earth’s crust 264 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1927 throughout all the time of the history of the earth known to us. This principle, which has influenced the thoughts of geologists for nearly 100 years, is taken to hold now only in the sense that never upon the earth’s crust have forces been active other than those which are acting at present. Indeed even the oldest known series of rocks tell us, as do those of to-day, of the chemical and physical weathering of the previously existing rocks, of the transport of the weathering products by water and wind. They tell of the accumulation of these products in the lowlands which then existed in opposition to the highlands. They indicate an atmosphere and a hydrosphere with their movements and as to-day, also, the influence of the cosmical agency in the radia- tion from the sun. From the manner of juxtaposition of even the oldest known rocks there may be inferred the breaking of the earth’s crust into huge blocks and mountain building movements of the same nature as those of later periods, just as in the more recent periods, glowing liquid from the depths was pressed through and out of the earth’s crust. In one detail only does the evidence of the earth’s earlier life differ from that of the present: The evidence of organic life is not handed down to us in the same manner as it is from later periods. That organic life did exist in the Archeozoic era the presence of lime and carbonaceous deposits demonstrates. But the Archaic life was less developed than in subsequent times and conse- quently its influence in the building and transformation of rocks was of less importance than later. Always, throughout all time, the same forces, the same manifesta- tions of the life of our earth have been at work as to-day. But not always have they had the same relative importance. Even to-day they do not work the same in all places nor at the same time. Weathering and denudation are much greater in mountainous regions, in the Alps, for instance, than in the flat lowlands in the north of Germany or on the wide plains of central Russia. Weathering and denudation work quite differently under different climatic conditions, as, for instance, upon the east and west sides of the South American Andes. The accumulation and transport of weathered rock is greater in mountain valleys and on the declivities of high peaks than upon the same base in the plains. The action of glaciers is limited geo- graphically, topographically, and by climatic conditions to certain regions. ‘The motions of the earth’s crust through earthquakes and volcanic disturbances occur in some regions very much more than in others. In the same places the destructive and constructive forces change even now with the season and climatic changes. The same conditions held in the past. The nature and amounts of movements and the results varied at the same time in different re- IS THE EARTH GROWING OLD?—POMPECKJ 265 gions. The differing composition of rocks formed contempora- neously in different regions shows this as well as the varying amounts of the existing rocks formed in the same time at different places. In the same region the formation of rocks varies in time sequence; that is, the factors leading to the accumulation of rocks have varied in intensity and action in the course of time. In the sequence of the rocks of the earth’s crust we find almost endlessly occurring cyclic or rhythmic variations. Some of them are directly the consequences of movements in the scaffolding of the earth as shown in the rock series conditioned by the transgression and regression of the seas. Others document the influences of the rhythmical climatic variations which are in their turn bound up with the motions of the earth’s crust. W. Ramsay was able to show this convincingly in his fine study, “ Orogenesis and climate.” Rhythms are the most evident, the most striking features found in the developments of the earth’s history. The great massive upheavals of the earth’s crust like that of the Scandinavian Peninsula, the subsidings like that of the bottom of France, occur rhythmically. They allow the sea to flood the land and then to recede. The repeated alternations of sea and land are rhythmical. The formation of mountain chains by the foldings of the earth’s crust is rhythmical. Volcanic activity occurs rhythmi- cally. The great ice ages of the earth occurred rhythmically and were differentiated rhythmically among themselves. Rhythm dominates the onward flow of the earth’s history; never was there uniformity in its paces. Do these geological rhythms reoccur at equal*lapses of time, or are the intervals becoming longer between rhythms of the same class? Are the expressions of the separate acmes becoming weaker? Is there any increasing insensitiveness of the earth to the actuating forces offering an evidence of old age? Let us consider the formation of mountain chains through folding. In the oldest period of the earth’s history known to us there is such a widespread folding of the earth’s crust known that it is indeed ubiquitous. It amounts to a general wrinkling of the earth’s surface. Although it is impossible with any success to apply the methods of geology to determining the times of relative occurrence of the rocks of the Archaic times in regions separated from each other, we can at least conclude from the discordances between the Archaic rock series that the formation of the foldings of that era did not owe their existence either to a temporary process or one general throughout that period. For the subsequent foldings of the Algonkian era, although even here the comparisons are yet uncertain, we can say °266 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1927 that in both time and place the foldings are conformable. Then there come three great foldings, well recognized in time, place, and nature, the Caledonian, the Variscian, and the Alpidian. Each one of these three is not—as was assumed in the older interpreta- tions—geologically speaking, the work of one time; rather each one is the result of a great number of different folding phases, which among themselves and at. different places were of differing intensi- ties and were separated by periods of relative rest so far as faulting goes. We owe to Stille a striking comparison of the occurrence of separate rhythms, the localities of which are very restricted upon small mobile zones of the earth’s surface; in general these places are altered for each rhythm, showing the improbability of a really ubiquitous occurrence of the Archaic foldings. Expressing the times of the occurence of these mountain forma- tions in customary geological nomenclature, the youngest, the Alpid- ian, lasted with its 11 or 13 phases and their subphases, from the be- ginning of the Triassic to the end of the Tertiary, through no par- ticular length of geological time. There is a strengthening of its phases until the older Tertiary and subsequently a decline. In the principal phases the folding was extraordinarily strong. The quies- cent periods increased in length toward the Tertiary and then de- creased in the more recent Tertiary. From its predecessor, the Variscian folding, it was separated by the geologically short quiescent period of the Triassic and in some places by the upper Dyas and the Triassic. The Variscian folding period, with its four or five phases, occurred during the Carboniferous age and far into the Dyas, and in certain regions, to the end ‘of it. Its phases, varying greatly in intensity in different regions, are separated from each other, so far as the sedi- mentation indicates, by relatively long periods of rest from faulting. The Caledonian folding period was separated from the Variscian by the Devonian age, which saw no folding of notable intensity. In this period there are only two folding phases recognizable, separated by almost the whole Silurian. The later, the true Caledonian fold- ing, was the stronger and the wider spread. The long period of quiescence of the Cambrian and the lower Silurian separates the Caledonian folding from those of the pre-Cambrian, the Algonkian and the Archaic times, which are to be placed in no definite com- parable relation with the three later periods. No geological evidence known up to the present gives a basis for. the assumption that the time intervals between the three periods of folding should be increased. The number of folding phases in the three periods increases and the intervening intervals shorten rather than lengthen from period to period. IS THE EARTH GROWING OLD?—POMPECKJ 267 Thée intensity of the folding, neglecting the wholly undetermined relations of the Archaic-Algonkian times, has certainly not de- creased; it has rather increased. It is difficult to reconstruct the mountains of the remote past out of the worn-down remains and then to estimate the magnitudes of the corresponding foldings. We do indeed have many pictures of highly complicated foldings, in the broader significance of the term, in the Caledonian of Scotland and Scandinavia and in the Variscian Appalachians of North Amer- ica, but it seems to me idle to look in our Variscian Rhenish moun- tains for such foldings, for example, as the Simplon Tunnel has revealed in the structure of the Alps. The Variscian foldings in middle Europe were manifested upon a far broader basis than in our Alps. I gather from them the impression that on the whole they are less complicated than the more recent Alpidian. The Alpidian folding occurred over world-wide areas. Its extent was certainly not less than the Variscian; it is known to be greater than the Caledonian folding. All of this leads me to the conclusion that the possibility and the intensity of these movements of the earth’s crust in the mobile zone or in zones which may become mobile and whence mountains may be born, are certainly not decreasing. In the processes of folding there is nothing that indicates that the earth is becoming senile. During the geological present the earth is again in a relatively quiet period. The continental blocks stand under the influence of a geocratic period such as once followed the Variscian folding in Western Kurope during the upper Carboniferous, the Dyas, and the Triassic. Under the still effective influence of the Alpidian folding, the neigh- boring regions are subjected to such climatic factors that the move- ments and geological action of the hydrosphere are still very inten- sive. The amount of these actions will be quite different when these young mountains have been more and more worn down; for instance, the regional climatic differences will be equalized throughout middle Europe. There will then be a repetition of the picture which pre- vailed at first in the quiescent periods of the Triassic and the Jurassic. However, it will be only the expression of a temporary mode, not a senile weakening of the atmospheric powers. Since not confirmed by any geological evidence, the idea has been long given up of a steady decrease of the temperature of the earth from early times until the present, although it influenced geological thought for a long time. The demonstration of early ice ages in the Dyas, in the Devonian, in the pre-Cambrian, forces us to discard it because of the proof by Sartorious von Waltershausen, now three- quarters of a century old, that a rock crust at the earth’s surface of only 3 kilometers thickness practically makes the temperature of the 268 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1927 earth’s surface independent of that within. The temperature of the earth’s surface has in no way become permanently lower; instead it shows rythmical changes. The great ice ages of the earth’s history stand in close relationship with mountain ranges brought into exist- ence through foldings. For the Dyas and the Diluvian ice periods, at least, the dependence is clear. Apart from orographic and cos- mical causes the rhythms of the temperature depend upon the rhythmical feeding into the atmosphere of carbon dioxide of volcanic origin as well as upon the varying need of this gas in the formation of coal and the carbonate rocks. Arrhenius and Frech have noted the rhythm of these carbon-dioxide periods and shown their geo- logical importance. To-day, through the consumption of the coal beds by man in his industries, a new enrichment of the atmosphere with carbon-dioxide is taking place. He also thereby wards off the remote danger of the death of the earth through cold.*°. From the earth we read no sign of danger that the oceans and rivers may become solid ice nor that carbon-dioxide snow will fall, nor yet that the earth, at a temperature of absolute zero, will be covered by a new ocean of liquid oxygen and liquid nitrogen, while only hydrogen and helium will form the last tenuous atmosphere of the dead earth. The natural deliverer of this incomparably important breath of life constituted by the carbon dioxide of the atmosphere, together with the rich store of the gas dissolved in the waters of the oceans, is vulcanism. Besides the seismical tremblings of the earth’s crust vol- canic actions give us the most immediate evidence of the earth’s life. Their manifestations, the movements of the glowing liquid masses toward the earth’s surface, together with the accompanying and sub- sequent phenomena, are recorded throughout all geological time. They do not, however, occur with equal strength or at equal intervals. So far as the outcropping of the volcanic phenomena of the past is to be dated—and this not in every case with the desired accuracy—the uprising and the eruptions of volcanic masses cluster about the times of the great mountain-building foldings. They were generally closely connected, as is the case even to-day, with the mobile regions where this building of mountains was taking place through foldings, and occurred either near them or within them, or else in regions of active movements of the ground. As an expression of the life of the earth the rhythmical character of the phenomena of vulcanism is convinc- ing. How does the intensity of the volcanic activity of the present ” Doctor Abbot has shown that as long as there is anything like the present amount of water vapor in the earth’s atmosphere the effect of carbon dioxide just discussed will be nullified by the overwhelmingly greater similar effect of water vapor. (Note by translator.) IS THE EARTH GROWING OLD?—-POMPECKI 269 compare with that of by-gone times? The number of active vol- canoes since 1800 has been 231. The number of submarine outbreaks is unknown. The vulcanism of to-day was exceeded certainly by that of the past only for a few periods of equal shortness. The area of 900 square kilometers forming the surface covered with lava from the Skaptar eruption of 1783 on Iceland, the recent and near-recent lava flows building up the Hawaiian Islands or the Aetna, do not take second place when compared with the many eruptions of the distant past. That the vulcanism of the present period stands in close temporal connection with the Alpidian folding period should in no way be taken as prejudicing its dying out in our comparison of the activities of the geological past. Into whatever class of geological activity we probe, in no case are we led to the conclusion that evidence from the expressed move- ments indicates an on-coming senility of the earth. Everywhere rhythmical rising and falling, there is nowhere a continuous decrease of the curve of force. Although these rhythms in the life of the earth are so distinctly recognized, their cause is still to-day an unsolved riddle. Cosmical relations are recognized only in limited amounts and undetermined significance; or are the causes within the earth itself? Joly only recently estimated the relations between radioactive transformations and geological phenomena. He sketched in bold strokes a picture showing how this secret force of radioactivity could broadly account for these rhythms, the “revolutions” of the building of mountains through folding and the great movements of the masses of the earth’s crust. It does not lie within my task to-day to go into his arguments, the only purpose of which would be to emphasize the rhythmical nature of the geological events for the understanding of the geological “life” of the earth which we have been discussing. If really in the radioactive processes is to be found the “ magic ” which might be the unique causation factor for these manifestations of the life of our earth, then under the circumstances may we not wholly lay aside the idea of any aging of the earth as interpreted in these pulses of the earth’s crust? If the physical relations within the earth’s crust, which Joly assumed in the compensating processes rela- tive to the development of radioactive energy, do not occur with the complete balance that Joly assumes, if there would occur a storing up of energy beneath the earth’s crust and within the earth’s body, then a crippling of the earth’s pulses would be rendered impossible. In- stead, then, of becoming a crippled earth, of becoming stiff in its actions, may it not rather be going toward the catastrophe of a “Nova ”? 270 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1927 I must stop the further spinning of such yarns as to the future of this earth, mindful of what that fine satirist, Roderich, once wrote in the album of a geologist: Man sagt von deinem Wirken wohl am besten: Du prophezeist uns die Vergangenheit. (The best we can say of your work: You prophesy for us the past.) : The past of the earth, so far as geology unrolls it for us, and the present tell us nothing of an aging of the earth. Die Erde lebt; sie altert nicht. (The earth lives; it is not growing old.) a | ee —% : a GEOLOGICAL CLIMATES * By W. B. Scorr HISTORICAL STATEMENT Very early in the history of our science it became evident that the earth had passed through great climatic changes, and the effort to find an explanation of these changes which should be adequate and satisfactory has never ceased till this day. There has of late been a revival of interest in this problem, and many new works on the subject have appeared in this country, as well as in England and Germany. One great obstacle in the way of finding convincing explanations for past climatic changes was the fact that since weather records have been kept no definite changes of climate could be detected, though it was admitted that those records covered too short a period of observation to be at all decisive. Some historians, notably Gibbon, in his famous Decline and Fall of the Roman Empire, have attempted to prove the reality of climatic changes within the historic period, especially in central Europe, but the evidence is not satisfactory. The appeal to agencies still in operation, the study of which constitutes dynamical geology, would seem, therefore, to be impracticable. The uniform distribution of the vegetation of the “ Coal Measures” over immense areas, involving very great differences of latitude, is of itself a problem that has not been satisfactorily solved even yet. One of the most eloquent of Hugh Miller’s descriptive passages is his imaginative reconstruction of the climate and weather conditions which obtained in the great bogs and marshes of Carboniferous time. As coal is composed chiefly of carbon, which had been derived from the atmosphere through the agency of living plants, it was taken for granted at that time that all of it had existed in the atmosphere simul- taneously in the form of carbon dioxide; but this would have had very remarkable consequences, many of which were not known in Miller’s day. Miller does not seem to ascribe the climatic conditions to the atmospheric composition, since he gives no discussion of the causes of climatic change, but the juxtaposition of the supposed facts is suggestive. 1 Presidential address read before the Geological Society of Aimerica, Dee. 28, 1925. Reprinted by permission from the Bulletin of the Geological Society of America, vol. 37, Mar. 380, 1926. 271 272 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1927 Until Louis Agassiz propounded his glacial theory in 1840 it was assumed that the Recent epoch, or present time, was, climatically speaking, something altogether exceptional in the history of the earth, as before that, according to the universally accepted belief of the time, there had been throughout the ages an unbroken succession of mild and genial climates, without polar accumulations of ice and snow and with no well-marked distinctions of latitude. Agassiz’s conception introduced an entirely new factor into the problem, and was, indeed, so novel and revolutionary in character that it was long rejected by most geologists; and even so late as 1895 Sir Henry Howarth, a trustee of the British Museum, stigmatized it as “the glacial nightmare.” The theory made but slow progress toward general acceptance, until eventually the evidence became so cogent that nearly all geologists were converted to it. Nowadays it is taken us a matter of course and is taught in all the elementary textbooks. Thus it became necessary to account for a time of exceptional cold, though this was a matter of debate among those who accepted the glacial hypothesis. Some of the most eminent geographers maintained that the glacial epoch had been due to a greatly increased snowfall, bringing about accumulations in the winter which could not be melted in the summer, rather than to any great decrease of temperature. Thus it was uncer- tain just what the problem consisted of and just what it was that called for explanation. Gradually, however, the proofs of lowered temperature rather than of increased precipitation seemed irresistible, and now everyone accepts that view of the problem. It is not neces- sary to assume any increase of snowfall to account for glacial condi- tions; but, on the other hand, temperature changes would of them- selves necessarily have caused great alterations in the distribution of the rainfall. For example, the cold of Pleistocene times extended the rain belt so far southward as to make the now arid Great Basin a region of moist climate, supporting immense fresh-water lakes, while the rise in annual temperature which caused, or at least accompanied, the disappearance of the continental ice sheets restricted the rain belt to its present limits. After the general acceptance of Agassiz’s hypothesis, it was thus believed that, through much the greater part of its recorded history, the earth had had a mild, genial, and almost uniform climate, with- out definite climatic zones; that this condition had been broken by the cold of the Pleistocene, the partial recovery from which had led to the present order of things. CLIMATES OF THE EARTH'S PAST We now know, however, that the problem is much more com- plicated than would appear from this brief statement. In 1879 GEOLOGICAL CLIMATES—SCOTT 213 Blanford reported Permian glaciation from peninsular India—an announcement which was received with complete skepticism on the part of most European geologists, though followed by similar reports from South Africa, Australia, Brazil, and Germany. In 1905 I had the privilege of taking several geological excursions in South Africa, which had been arranged for the meeting of the British Association for the Advancement of Science, under the direction of Mr. A. W. Rogers, chief geologist of Cape Colony, and of Messrs. Hall and Kynaston in the Transvaal. One object which was of especial interest and importance to all of the visitors at that time was an examination of the evidence for the great Permian ice cap, and the geological party contained such eminent students of glaciers as Professors Penck of Berlin, Sollas of Oxford, Coleman of Toronto, and Davis of Harvard. The dis- tinguished Swedish geologist, Professor Sjogren, who was also of the party, told me that few continental geologists were prepared to accept the hypothesis of Permian glaciation. Yet the field demon- strations given us, especially at Riverton, on the Vaal River below Kimberley, were convincing to all of us, without exception. The bowlder clays and moraines and the ice pavements, with their characteristic polishing and striation, their hummocks arsl roches moutonnées, were every whit as complete evidence of glaciation as were the corresponding Pleistocene phenomena at home, and of precisely the same nature. But even the Permian (or “ Permo-Carboniferous,” as the English geologists prefer to call it) glaciation was not the only ice age of long past epochs. There is evidence, as yet incomplete, of glaciation in the Carboniferous of North America. The Bokkeveld of South Africa, a marine Devonian formation, contains large, faceted. polished, and striated pebbles and cobbles of unmistakable glacial origin, but ice pavements and bowlder clays of this period have not yet been found. The Silurian moraines of Norway were probably of local origin and do not indicate any widespread climatic changes. Very extensive bowlder beds, observed in China and Australia and originally referred to the Cambrian, are now placed in the later pre- Cambrian eras, while the tillites described by Professor Coleman in Ontario and those of British Bechuanaland in Africa are of a stil) more ancient date. Thus we have the remarkable fact that glacia- tion on a continental scale has repeatedly occurred, not less than fivs times and perhaps more, in the recorded history of the earth. These recurrent climatic phenomena can not be called rhythmical because. so far as we can judge, the intervals between them were not of similar length, features which render the problem of causation all the more complex and difficult. 274 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1927 So far as the ancient glaciations are concerned, the distribution of the ice is still a matter of uncertainty, because obviously only a relatively small part of the glacial deposits and ice pavements could have been preserved, in accessible positions, from such long- distant times. These ancient glaciations, too, add greatly to the complexity of the problem because of characteristics peculiar to themselves. For example, in South Africa, and perhaps also in Brazil, the movement of the Permian ice was from north to south, from the Equator poleward, the opposite of what we should have expected it to be. Furthermore, the enormous thickness of the bowlder beds, 1,000 feet or more, called the Dwyka conglomerate. fairly staggers the imagination when one compares it with Pleisto- cene moraines. The occurrence of great bowlder beds in penin- sular India, so near the Equator, is a very puzzling circumstance, which some climatologists believe can be explained only by a shifting of the earth’s poles. Because of those uncertainties, it will be advantageous to confine our attempts at explaining glacial climates to the Pleistocene, be- cause the evidence is still so very extensively and perfectly preserved, that the distribution of the Pleistocene ice sheets and mountain glaciers ean be determined with a certainty which can not be attained in the more ancient periods of ice action. If we can find a satis- factory explanation of the climatic phenomena of the Pleistocene, we shall not have far to seek for an explanation of the more ancient ice periods. There would seem to have been no glaciation on-a continental scale between the Permian and the Pleistocene. Throughout the Mesozoic and most of the Tertiary periods indications of climatic zones are obscure and doubtful, and there can have been no great accumulation of ice and snow at the poles. The Jurassic sand- stones of the now utterly desolate Antarctic Continent have yielded Cycad leaves much like those of contemporary Great Britain, and the Arctic fossil floras of Greenland and Alaska clearly demon- strate that, so late as the Eocene at least, these polar lands had luxuriant forests of large trees of the kinds familiar to us in tem- perate latitudes—a fact which indisputably proves the prevalence of much milder climates. That the Arctic regions were cooler than the area now covered by the United States is indicated by the absence of large reptiles, of palms and other subtropical forms from the far north, while they occur from Idaho and Montana southward; and the Eocene flora of the southeastern coastal plain, so beautifully reconstructed by Professor Berry, demonstrates a far warmer cli- mate than that of to-day, though not properly to be called tropical. GEOLOGICAL CLIMATES—-SCOTT Zhe In the interior of the continent, in the region of the northern Great Plains, there is a distinct climatic change between the Eocene and Oligocene, palms and large crocodiles disappearing from the area where they had been prevalent and abundant since the Middle Cretaceous. The change, though definite, was not extreme, and may well have been due rather to an increased altitude than to any gen- eral modification of climate. The Miocene flora of central Colorado was, except for the absence of palms, mueh like that of the northern Gulf region at present. The gradual refrigeration which marked the climatic transition from the warm Miocene to the cold Plocene is best registered in Europe. The German lignites, or brown coals, of Miocene date, have preserved a very full representation of the plants. In the older lignites the flora is that of the Mediterranean lands, with palms and other warm temperate trees, while the upper lignites of the same region indicate principally coniferous forests. The marine Pliocene beds in the east of England have beautifully recorded the oncoming cold. In the lower strata those beds contain 5 per cent of Arctic shells, a proportion which rises to 60 per cent in the upper strata. In the far north the Pliocene climate must have been severe, as is indicated not only by the Arctic species of shells just referred to, but also by the Pleistocene mammals, which descended to comparatively low latitudes before the advance of the ice. The familiar instances of musk oxen in Kentucky and Arkansas, caribou on Long Island Sound, seals and walruses on the coast of Georgia, mammoths and reindeer in the south of France, lemmings in Portugal, all show a complete Arctic assemblage of mammals, both terrestrial and marine. These could not have been developed overnight; they must have passed through a long period of adaptation to a climate which was steadily growing colder. The onset of glacial conditions found a fully adapted fauna of Arctic mammals, with nearly uniform cir- cumpolar distribution, though some forms, such as the woolly rhinoceros, were confined to one or the other continent, for reasons that we can not even conjecture. The interpretation of the Pleistocene deposits, even after their icemade character had been generally acknowledged, led to a long- drawn-out debate. Was the glacial epoch single or multiple? That the ice had been subject to many episodes of advance and retreat was admitted; the question was: Were these episodes mere fluctua- tions in the extent of the ice sheets, or were there actual interglacial times, when the ice altogether disappeared and the climate was greatly ameliorated? Time fails me to give any but the most super- ficial reference to this famous discussion. Suflicient to say that it is the all but unanimous opinion of students of this problem that there 276 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1927 were several truly glacial and interglacial stages when there were great climatic changes, and some, at least, of the interglacial times were actually warmer than the present. Very convincing evidence to this effect has been found on the north shore of Lake Ontario, _near Toronto. There a series of stratified, water-laid clays, contained between two bowlder beds, is divisible into an upper and a lower series. The lower and older series has many fossil plants which indicate a flora such as néw occurs several hundred miles to the south, in Kentucky and Tennessee. Of the upper series, the fossils resemble Labrador species and eloquently indicate the return of the cold, culminating in the ice sheet which deposited the upper bowlder beds. Professor Coleman has reported that on the shores of Hudson Bay large forest trees are found between two ground moraines, trees which are indicative of milder climatic conditions than those of Recent time in that latitude. Similarly, the interglacial mammalian fauna which occurs at Afton, Iowa, is decidedly suggestive of a warmer climate than the present for the region involved. In this case, however, the evidence is less convincing, for the habits of extinct species of mammals can only be conjectured, and as in the famous case of the Siberian mam- moth, some ludicrous mistakes have been due to inferences concern- ing the climatic adaptations of extinct species, reasoning from the distribution of their existing allies. Whether all the interglacial stages were characterized by a warmer climate than that of modern times, it is not yet possible to determine for lack of the necessary fossiliferous deposits. In any satisfactory theory of the Pleistocene climates we must account for world-wide climatic change, or series of changes, so that local causes are inadequate, for in all of the continents of both Northern and Southern Hemispheres there is proof of the great extension of glaciers in that period of time. Inasmuch, however, as the Southern Hemisphere is chiefly a region of sea, with but a rela- tively small amount of land, climatic fluctuations in that hemisphere have been and still are much less extreme than in the Northern, where there is so large a proportion of land. This is an explanation of the fact that in the South Temperate Zone Pleistocene glaciation was much less extreme than in the corresponding northern belt. This southern glaciation, as is so well exemplified in Patagonia, was chiefly confined to a great extension of the mountain glaciers rather than to the formation of continental ice caps, such as appeared in Kurope and on so vast a scale in North America. Penck has made it very probable that all over the world the snow line was lowered approximately 4,000 feet below its present altitude— an amount which he first deduced from his studies in the Alps and GEOLOGICAL CLIMATES—SCOTT QE subsequently confirmed by very widespread observations in other continents. Even in the Tropics the same rule would seem to apply. Mount Kilimanjaro, the highest mountain in Africa, which stands very near the Equator (3° south latitude), still has snow fields and glaciers near the summit, while the unmistakable ice marks of polish- ing and striation extend more than 5,000 feet below the present limit of the glaciers—a very different thing from the snow line. To pro- duce such climatic conditions, Penck has calculated that a lowering of the annual average temperature of about 9° F. below the existing standard would suffice. That amount, 9° F., is all that stands be- tween us and a recurrence of glacial conditions. — In brief, therefore, what we must account for is the long contin- uance, throughout the Mesozoic and earlier Tertiary times, of genial, nearly uniform conditions of climate, with zones only obscurely demarcated. ‘There was then, and probably always has been, a dif- ference of temperature between the Equator and the poles, as is indi- cated by the distribution of fossil floras, but a difference far less in amount than that which now obtains. In the latter half of the Tertiary period began a slow and gradual refrigeration, which had brought severe conditions in high latitudes in the early Pliocene— conditions in which the typically Arctic fauna of mammals had been differentiated. The increasing cold finally culminated in the wide- spread glaciation of the Pleistocene; but this was itself highly com- plex, from the climatic point of view. Within a short space of time, as geological time is measured, there were many extreme fluctuations of climate, four or more glacial, alternating with interglacial stages. It would be going beyond the evidence to say that in all the inter- glacial stages the climate was milder than at present, but it may have been so in all, and certainly was in some. Finally, the conditions were once more ameliorated, bringing about the present order of things. This is far from being a complete statement of the problem of geological climates, or even of the temperature factor in climates, but in this abbreviated and simplified form it will suffice for our present purposes. The solution of the problem in this form will offer quite sufficient difficulty for an evening’s consideration. Only a brief mention of the cognate climatic factors—moisture, precipita- tion, and prevailing winds—is permissible because of the limitations of our time. THEORIES TO EXPLAIN GLACIAL EPOCHS Wherever it is feasible, I have always thought that there is an especial charm in presenting scientific theories historically, as this method records the progress of discovery and interpretation, the 74906—28——_19 278 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1927 modifying of view necessitated by the discovery of new facts, and reveals the steps by which we have so gradually and laboriously advanced from the known into the unknown. In this manner we should learn that more than half a century ago hypothetical explanations of climatic change were put forward which, essentially and in principle, were almost exhaustive of the known possibilities. Sir Charles Lyell sought the explanation in wide- spread and radical changes in the distribution of land and sea. Taking the present continents, he showed that, without any alteration of size, shape, or altitude, great climatic differences could be brought about by grouping these land masses, first, as closely as possible around the Equator, and subsequently around the poles. The Vienna geologists, supported by the eminent astronomer, Father Secchi, maintained that the earth’s axis, and with it the poles, had been shifted, bringing certain regions which were formerly Arctic into the Temperate Zone, and thus changing their climate very completely. Dr. James Croll, of the Scottish Geological Survey, published his Climate and Time in 1875, a book which speedily became famous. Croll called attention to the fact that the size and shape of the earth’s orbit were not constant, but subject to change, which resulted in periods of maximum and minimum eccentricity. He contended that the hemisphere which had its winter in aphelion during a time of maximum eccentricity would pass through a period of glaciation. On this hypothesis glacial periods would recur alternatingly be- tween the Northern and Southern Hemispheres and rhythmically every 12,500 years. I have not been able to learn who it was that first suggested the internal heat of the earth as the cause of the former mild and uniform climates, and the gradual loss of the earth’s heat by radiation as having brought about the refrigeration of climate which has led to the present order of things. This conception is nearly as old as geology or the nebular hypothesis of Laplace. In modified form it has lately been revived by Doctor Knowlton. Finally, I may mention Lord Kelvin’s? suggestion that the cause of climatic changes on the earth should be sought in fluctuations of the sun’s activity, a suggestion which seemed to be made obvious by the connection between the weather and the maxima and minima of the sun-spot periods. Among geologists it is, perhaps, Professor Penck who has most strongly championed this view, for it is he who has most clearly brought out the universal nature of the climatic changes in the Pleistocene. 2The hypothesis of solar change as causing climatic changes on the earth was adopted by Penck, Prof. H. F. Reid kindly pointed out to me the fact that the suggestion was originally due to Lord Kelvin. GEOLOGICAL CLIMATES—SCOTT 279 Though the historical method of approach is the more interesting and, perhaps, the more instructive, it is in the interests of brevity and lucidity to deal with the various hypotheses which have been propounded to explain the climatic changes which have occurred in the recorded history of the earth in a more systematic manner. ‘The subjoined table presents a classified arrangement of the principal hypotheses which have been offered in explanation of the problem of climate. Obviously, it will not be practicable to devote more than a very brief time to the discussion of the various hypotheses. I. Terrestrial causes. A. The earth as a whole. (1) Changes in the eccentricity of the orbit. (2) Shifting of the earth’s axis. (3) Shifting of the earth’s exterior on the interior. (4) The internal heat of the earth. B. Atmospheric factors. (1) Variation in the proportion of carbon dioxide. (2) In the amount of suspended volcanic dust. C. Oceanic factors. Variations in salinity. D. Topographical factors. Changes in the area, altitude, and disposition of the land masses. II. Cosmical causes. A. Passage through cold regions in space. B. Variations of the sun’s activity. As the table indicates, the methods of explanation fall into two principal categories: (1) The terrestrial, in which the source of change arose on the earth itself; and (2) the cosmical, in which the cause lies outside of the earth or even outside of the solar system. Of the terrestrial agencies of change we may make two groups: (a) Those which affect the earth as a whole, and (0) those which are more or less local and partial in their operation. A. (1) Croll’s hypothesis was published when I was an under- graduate and just beginning the study of geology, and I can well remember the enthusiasm with which it was received in this country. “At last,” we said, “the climatic mystery, which has been troubling us for so long, has found a solution.” But the enthusiasm was short- lived, for its requirement of an ice age at intervals for each hemi- sphere of 25,000 years was found to be incompatible with the ascer- tained facts of geological history. Probably Doctor Croll himself would have been aghast at the number of glacial periods which the earth must have passed through, according to his supposition. The ten or at most twenty million years which in 1875 were allowed for the age of the sun have been almost indefinitely extended by the later physical discoveries. Had ice ages occurred with the rhythmical 280 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1927 regularity which Croll postulated, the Northern and Southern Hemi- spheres must each have had some 40,000 of them, which does not seem likely. A. (2) Shifting of the earth’s axis and the concomitant changes in the position of the poles are by most astronomers declared to be impossible. Into this astronomical problem we need not enter, for no position of the poles which has yet been suggested would get rid of the necessity of admitting climatic change. This hypothesis and the following one are not, strictly speaking, attempts to explain cli- matic changes, but to account for the distribution of fossil floras and faunas without assuming important changes in the earth’s atmospheric temperatures. A. (3) A shifting of the earth’s outer shell on the interior is a hypothesis much like the preceding, but differs in the suggested mechanism of change. Thus Wegener suggests that the vast Permian glaciation in the Southern Hemisphere was due to the junction of the southern continents around a pole in the Indian Ocean and that they have since drifted apart. But this suggestion, even if true, would not account for the facts; as Lake has pointed out, Permian ice sheets covered northern Baluchistan, which, according to the hypothesis, would then have been in the Tropics. Concerning the possibility of the shift itself Jeffreys remarks: A displacement of this type would produce important climatic changes, but so far no agency capable of producing it has been suggested. A. (4) It was long supposed that the ancient geniality and uni- formity which, for such vast stretches of time, characterized the earth’s climate were due to the internal heat of the globe, and the present severe climates of high latitudes have been brought about by the reduction of the internal heat by radiation. Aside from the question raised by the phenomena of radioactivity, whether the earth has actually lost heat (Joly even suggests that it may be gain- ing, rather than losing), this hypothesis postulates a continual change in one direction and fails to account for fluctuations of cli- matic conditions. Since the formation of a solid crust (assuming that the globe was once fluid) the very low conductivity of the rocks must have prevented the internal heat’s having much effect at the surface. The surface temperature of the earth must have been almost wholly main- tained by solar radiation practically ever since it became solid at the surface, and certainly throughout geological time. Conduction from the interior is in comparison quite unimportant. (Jeffreys.) B. (1) The foregoing hypotheses all deal with the solid earth as a planetary unit, using the term “solid” without prejudice to the conception of possible fluid portions of the interior. We may next consider the explanations which find the causes of climatic change in GEOLOGICAL CLIMATES—SCOTT 281 modifications of the atmosphere. It is universally understood that the atmosphere has a blanketing effect, permitting the direct rays of the sun to pass through it freely, but opaque to the dark heat reflected from the ground. In this way the air acts like the glass in a cold frame, which Tyndall poetically called “a trap to catch a sunbeam.” ‘This blanketing effect is least in thin, dry, and pure air and is greatly increased by the presence of vapor of water and carbon dioxide in the atmosphere. It has seemed a natural inference that a large augmentation of the amount of carbon dioxide present in the air would so raise the blanketing effect that genial climatic con- ditions would be produced, even in the polar regions. ‘There is, however, a fatal objection to this inference revealed by experiment, namely, that the amount of carbon dioxide already normally present in the atmosphere exerts nearly the maximum blanketing effect, and a large increase in the amount of gas would not produce a corre- sponding rise of temperature. B. (2) A screen of volcanic dust remaining long suspended in the upper atmosphere, as did the fine dust after the great eruption of Krakatoa in 1888, might so cut off the sun’s heat as to cause a refrigeration of the earth’s surface temperature, and such a screen has actually been appealed to as a cause of glacial climates; but the supposed cause seems neither actual nor adequate. There is nothing in known geological history which would justify us in supposing that such masses of volcanic material, diffused over the whole earth, were ever maintained for tens or hundreds of thousand years. 'The geological periods in which vulcanism was most active, such as the Ordovician and the Devonian, were not those of widespread glacia- tion. Indeed, the opposite conception is held by those who find the explanation of higher air temperatures in the greatly increased con- tent of carbon dioxide; they maintain that the most actively volcanic periods were the warmer ones, the carbon dioxide being supplied by the volcanoes. C. Ocean currents are familiar means of modifying climates, the warm and cold currents having a marked effect on the air with which they come into contact. It has been maintained that variations in the density of sea water, due to changes of salinity, would greatly modify the system of oceanic circulation. To this it may be objected that the great ocean currents are due to prevailing winds, and so long as the system of winds remained unchanged variations in the density of the water could have little effect on the currents. D. Changes in the size, distribution, and altitude of the land masses were, as we have already seen, first invoked by Lyell to explain the earth’s vicissitudes of climate, and of late there has been a strong revival of interest in causes of this nature, and three quite 282 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1927 recent books appeal to them as all sufficient for the purpose. Mr. C. E. P. Brooks has of late years (1922) published a very valuable and suggestive little book, The Evolution of Climate, which is devoted to this thesis. Professor Berry, from a study of the fossil floras of North America, reaches the same conclusion, as does sub- stantially Professor Ramsey, of Helsingfors, who published his observations and deductions in volume 64 of the Geological Maga- zine. To say the least, it is a remarkable coincidence that so many and so widely separated investigators should have reached the same conclusion from somewhat different kinds of evidence. In his lately published book, The Earth, its Origin, History, and Physical Consti- tution (1924), Dr. Harold Jeffreys, of Cambridge, devotes a con- siderable part of the appendix on “ Theories of climatic variation ” to an examination and criticism of the work of Brooks. It will serve our purpose excellently to quote a few extracts from Jeffreys’ review: In this way Brooks is able to show that more oceanic conditions, which actually existed, are quantitatively able to account for the mild climate of the Eocene period. A general elevation of the land proceeded throughout the Tertiary era, and when the Scandanavian highlands and the Rocky Mountains reached the snow line an ice sheet commenced to form. * * * The actual events during the glacial period and afterwards agree closely with Brooks's inferences. In particular, some sand dunes in north Germany, formed at this time, have their tips pointing to the west instead of the east, showing that the prevailing wind there at the time was from the east. This is exactly what would be expected from the presence of the Scandanavian ice sheet, which would produce * * * east winds over Germany. In many other parts of the world striking agreements are found. * * * Brooks’s theory is, there- fore, a very substantial contribution to our understanding of climatic change; but it does not furnish a complete explanation. * * * It appears as if the later stages, at least, of the elevation of the mountains took place under con- ditions when the snowfall was inappreciable, and that the ice sheet did not begin to form until some further change of climate, not attributable to the mountains, had supervened. The Cambrian, Ordovician, and Silurian folds, again, must have raised mountains quite comparable to those of the Tertiary, but do not appear to have been followed by glaciation on anything like the same seale, again suggesting that mountain formation, though it may be a necessary preliminary to glaciation, is not a sufficient condition for it. An elaboration of this same conception sees in the many climatic fluctuations of the Pleistocene an isostatic response of the earth’s crust to the load imposed on it by the immense accumulations of ice. The ice sheets were established, it is supposed, when the continents had risen to a high level, and under the enormous load of ice they again sank to an altitude at which the ice melted and snowfall was no longer sufficient to maintain the ice caps. Freed from its load, the land again rose td a height at which the ice was again formed, only to sink once more under the renewed load. 3 Jeffreys: Op. cit. p. 265, GEOLOGICAL CLIMATES—SCOTT 283 Many observations have been made which strongly suggest that the relation between loading of the land with ice and subsequent depression is more than coincidence. But if that were all, why did the process cease? Why was the last melting of the ice not fol- lowed by a renewed elevation of the land? It may be said that not time enough has elapsed since the last disappearance of the ice, end that we are slowly but surely advancing to a new glacial epoch. Perhaps so, but there is no sufficient evidence of a universal rise of the land in high latitudes, such as would be called for on this hypothesis. Furthermore, if diastrophic movements were the sole cause of the glacial and interglacial alternation, we should have no explanation of the fact that in some, at least, of the interglacial stages the climate was warmer than at the present time. Some ad- ditional factor is called for. I can not but agree with Jeffreys in his conclusion that, while dias- trophic movements of the earth’s crust are a very real cause of cli- matic change, they are insufficient to account for the accepted history of the vicissitudes of climate through which the earth has passed. The lowered temperature of the Pleistocene was a world-wide phe- nomenon and is registered in all the great land masses of both Northern and Southern Hemispheres. Even in the Tropics the ice limit was several thousand feet below that of thé present day. We have no satisfactory proof of a correspondingly universal upwarp- ing of the lands, and therefore the diastrophic hypothesis, as it may be called, is inadequate as the sole explanation of the facts. Tt should be added that a great deal remains to be learned con- cerning the Pleistocene glaciation of the Southern Hemisphere, for little intensive study has as yet been devoted to the problems in- volved. It is not definitely known, for example, whether glacial and interglacial alternations characterized the continents of the Southern as they did those of the Northern Hemisphere, nor how many glacial stages there were, or if, indeed, there was more than one. Obviously, a complete theory of the Pleistocene climates can not be formulated until much more has been learned regarding the southern continents in that epoch. II. So far we have dealt entirely with supposed agencies of cli- matic change which have affected the earth only, either as a whole or in part. In the second principal category of hypotheses the causes of climatic change are sought for in agencies entirely outside of the earth, and therefore cosmical rather than terrestrial. Croll’s famous theory might almost as well be put in the cosmical as in the terrestrial class, though it deals solely with the earth. A. It has been suggested that the solar system, in its known swift passage through space, traverses regions of different temperature, 284 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1927 which would produce a corresponding modification of the earth’s climates. This purely fanciful conception need not detain us, for space can have no temperature, which is a property of matter. That the earth could have received an appreciable amount of heat from some luminary other than the sun would involve so near an ap- proach to another star as to upset the equilibrium of the solar system. B. By a process of elimination we seem to be shut up to the con- clusion that we must look for the primary causes of changes in the earth’s climates in the sun itself, as originally suggested by Lord Kelvin. As we have just seen, the various terrestrial agencies which have been called on to explain these changes are inadequate of themselves, while changes in the sun would have universal effects. The connection between the sun-spot cycles and terrestrial weather has long been recognized, and the Smithsonian observatory, under the direction of Doctor Abbot, has shown that variations in solar radiation do actually occur, and to a surprising amount, from day to day, as well as through longer periods. The observing stations have been operated in regions of different climates and altitudes, so as to do away with the confusing effects of the earth’s atmosphere. The work is still in progress, and Doctor Abbot has lately been in Africa searching for a satisfactory site on which to place another control station, and we may hope soon to have a body of established facts concerning solar activity which will be most useful in the so- lution of our problem. The manner in which solar changes operate on the earth is a very complicated one, and if these changes are of no very great amount they would produce different effects in the various climatic zones. This has been well brought out by Mr. Clayton in a paper read last April before the National Academy of Sciences. As Jeffreys has pointed out, any hypothesis of this type is very difficult either to prove or to disprove; but we do know that the earth’s temperature depends on the sun, and that the sun’s activity is vari- able—not a long, slow decline. Hence arises the probability that solar changes are the principal cause of the earth’s variations of climate. This conclusion does not preclude the acceptance of the ter- restrial agencies as modifying the effects of solar change. Assum- ing the effectiveness of the latter, the Pleistocene history of the South- ern Hemisphere well illustrates such modifying effect. The vast area of the seas and the relatively small land surfaces produce an oceanic climate in which extremes of heat and cold are rare. All down the west coast of southern Chile and Tierra del Fuego, almost to Cape Horn, we find an evergreen rain forest of deciduous trees, most of which belong to a single species of the southern beech (Nothofagus). In this region there is little difference between winter and summer; os oe GEOLOGICAL CLIMATES—SCOTT 285 the weather is always cold, though never extremely so. In this in- stance the modifying effects of solar changes are produced by the distribution of the marine and continental areas. In the Northern Hemisphere, there is much reason to believe, diastrophic movements, both the orogenic folding and the epeirogenic warping of broad areas, have had an important bearing on the effects of solar changes, now opposing and reducing those effects, now assisting and increasing them. VARIATIONS IN RAINFALL AND THEIR CAUSES The second great factor in the determining of climates is moisture and its resulting precipitation in the form of rain or snow. Even more than temperature, precipitation is affected by topography and pre- vailing winds. High mountain ranges, which cut off moisture-laden winds, may throw a “rain shadow ” far across the continent, as do the ranges ot the Pacific coast region. ‘The remarkable monsoons of the Indian Ocean, a reversible system of winds, bring the rains to India when blowing from the southwest. Many similar instances of the effects of topography and prevalent winds might be mentioned, if it were worth while to do so; but these are well understood and it is not necessary to recapitulate them. Evidences of arid climates in ancient geological times where now are regions of pluvial conditions, are abundant, and such evidences are for the most part independent of fossils and are contained in the rocks themselves. Beds of gypsum and rock salt are indicative of aridity, for they are accumulated in salt lakes, which can not be maintained in regions of normal rainfall; and the distribution of such deposits in time and space, their geological and geographic arrangement, frequently enable us to demarcate the regions of special aridity. No doubt there were many others of which we do not know, the proofs of which have been swept away by denudation. The changes from pluvial to arid conditions, and vice versa, would seem to have been local in some instances, of immense geographical extent in others. The Ordovician of Siberia and the lower Carboniferous of eastern North America were, so far as we can judge, instances of locally re- stricted changes to more or less arid conditions, while nearly the whole of the Permian and Triassic periods show a belt all around the Northern Hemisphere of extreme aridity. Under the north German plain lies a vast body of rock salt of unknown thickness, for none of the very deep bore holes, which have been put down, reach the bottom of the salt. Making a reasonable allowance for the thickness of the salt body, it has been estimated that it represents the evapo- ration of a body of sea water three times as great in cubic content as 286 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1927 the Mediterranean Sea. The whole trans-Mississippian region of North America was a desert in Permian-Triassic times, though per- haps not so extremely arid as central Kurope; and even the eastern part of the continent, north of Virginia, was subarid; at least most students of the Newark formation are led to that opinion by the character of the sediments. If, now, we plot on a Mercator’s chart the known arid regions of the Permian and Triassic periods, we are immediately reminded of the desert zones which in both hemispheres encircle the earth at the pres- ent time. These zones of desert are the trade-wind belts, where the equatorial outflow of heated and expanded air descends once more to the earth’s surface. Such descending currents, being adiabatically warmed through condensation, are always dry, and hence the zone of desert where they impinge on the land. In both Northern and Southern hemispheres the Temperate Zones are areas in which the prevailing winds are westerlies, blowing some 80 per cent of the time from some westerly quarter. Equatorward from the westerlies in both hemispheres, lie the “ horse latitudes,” belts of light, variable winds, and beyond these again are the trade-wind belts. Between the northeast and the southeast trades is the equatorial belt of calms. The whole tropical wind system, with its five zones, swings north and south with the sun in its apparent path between the solstices, so that certain regions have the trade winds in summer but not in winter. Such areas are southern California and the southern parts of the great Mediterranean peninsulas of Kurope—the Iberian, the Italian, and the Balkan—and these all have nearly rainless summers, the precipitation of the year being concentrated in the winter. If we may assume that during most of the Permian and the whole of the Triassic periods there was such an increase of solar activity as to raise the surface atmospheric temperature some 8° or 10° F, above the present annual averages, this would have the effect of displacing or extending the trade-wind belt some hundreds of miles north of its present position (note well, confining our attention to the Northern Hemisphere), and with it the desert zone of the northern continents. That such would be the actual effect of a moderate rise of atmospheric temperature is made very probable by the converse effect of lowered temperature in the Pleistocene, to which reference has already been made. During the times of principal ice extension precipitation was so increased in what is now the arid and semiarid West that immense fresh-water lakes were established in the Great Basin, and almost. every valley in the Colorado Rockies and in the Sierra Nevada down to middle California was occupied by a great stream of ice. ee GEOLOGICAL CLIMATES—SCOTT 287 It may not seem legitimate to assume that the existing wind system extended so far back into the distant past; but as a matter of fact this system, aside from local currents, is in Davis’s phrase “ plane- tary,” and is determined by the earth’s relations as a planet. So long as the earth rotates on its axis and revolves about the sun; so long as its axis remains oblique to the plane of its orbit, producing differ- ences of temperature in different regions, so long must the general system of winds remain what it is now and what we have every reason to believe it has always been from the beginning of land and sea. Raising and lowering the atmospheric temperature will un- doubtedly shift the position of the wind belts, but will not affect them otherwise. . We have direct proof that in the Pleistocene, at least, the system of winds was substantially the same as now. Everyone is familiar with the fact that the western side of Europe has a much milder climate than the Atlantic coast of North America, with no such extremes of temperature. Great Britain and Labrador, Norway and Greenland, New York and Naples have much the same latitude. The difference in climate, which amounts to 10° of latitude, is due to the westerly winds, which reach Europe from the sea, eastern North America from the land. The same climatic difference, and for the same reason, obtains between the Atlantic and Pacific coasts of North America and between the American and Asiatic shores of the Pacific. During the maximum glaciation in the Pleistocene the extension of the northern ice caps was to latitude 50° in Europe and 40° in eastern North America, just such a difference as we find to-day. The studies of Professor Huntington have satisfied most geog- raphers of the reality of the desiccation, which has been in progress for the last 2,000 years, from central and western Asia to California. The desiccation has not been uniformly progressive, but subject to wide fluctuations, though the algebraic sum of the fluctuations is greatly increased dryness. Whether this increasing aridity can be correlated with rising temperature is not yet known, but it must be said that we know no cause of desiccation except greater heat. I should, perhaps, apologize to the members of the society for selecting as the topic of this address so hackneyed a problem as that of geological climates, in which it is hardly possible to suggest any- thing that has not been suggested many times before. It is, indeed, a threshing over of old straw. Yet there has been so emphatic a revival of interest in the problem of late years that I thought it might serve a useful purpose to offer a brief consideration, in classi- fied form, of the many factors of climatic change which have been brought forward in many lands and by many writers, GEOLOGIC ROMANCE OF THE FINGER LAKES * By Prof. Herman L. FAIRCHILD University of Rochester [With 6 plates] Superlatives have been exhausted in praising the parallel lakes of New York. They deserve the praise. But the beauty of the lakes and the charm of their setting are not more deserving than is the dramatic story of their making. In the lakes themselves there is no mystery. The water bodies merely fill the land depressions to overflowing. The romantic inter- est lies in the origin and history of the basins which hold the lakes. A misleading theory in former years, which yet appears in print, claimed that the basins were scooped out by a plowing action of the ice sheet of the glacial period. This explanation, which was even applied to the great Ontario Basin, was a popular and easy way of avoiding a complex problem in New York physiography. The fact that the bottom of Lake Cayuga is 54 feet below ocean level, that of Seneca 174 feet, and that of Ontario nearly 500 feet, was the singular and puzzling feature. But the Quebec Glacier, which overspread New York and New England and which admittedly had some abrad- ing effect, was not guilty of the valley deepening, although it had some part in producing the basins. The purpose of this writing is to describe the formation of the Finger Lakes basins, a romance in geology. The physical conditions and the length of time are so far beyond human experience that to appreciate the facts of the story requires of the reader some mental exercise, with constructive imagination. Many people do not like facts, if new, but prefer a world of unreality. If the reader happens to be of the latter class, he would better break away right here. Yet the story, like many truths of nature, surpasses any fiction of man’s invention. - We are so familiar with many lakes, large and small, that they seem to be normal and permanent features. On the contrary, they 1 Reprinted by permission from the Scientific Monthly, August, 1926, Vol. XXIII. 289 290 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1927 are unusual, exceptional, and transitory. Excepting the peculiar ones in Florida and on the Mississippi delta there are few lakes to-day in America, outside of glaciated territory. The oxbows in the flood plains of rivers are not counted. Most lakes may be defined as expansions of streams. But the basins or reservoirs are not made by the streams in normal flow. Some external interference or damming effect is necessary. Streams can not permanently dam themselves. Ice jams, log jams, and land- slides make temporary reservoirs. The singular and beautiful lake- lets near Syracuse, one in a State park, occupy cataract plunge- basins and are of very exceptional and interesting character. With their bounding cliffs they are fossil Niagaras. To-day Niagara Falls is drilling a similar bowl. The Syracuse Basins were carved by rivers which in function were true predecessors of Niagara. They were held up in forced flow by the front of the waning glacier. Perhaps they are the best example of streams making basins. But these lakelets did not exist while the rivers were flowing. In regions of land movement, as mountain districts, basins are sometimes produced by the bending and the breaking of the earth’s crust. The Jordan Valley and Dead Sea are examples of the latter. The basin of Lake Superior is thought to be due in part to crustal warping. But the basins of the Finger Lakes are in practically hori- zontal strata, lifted out of the sea and without serious deformation. As reckoned in geologic time, lakes are short-lived. They dis- appear either by the downcutting of their outlets or by the filling of their basins. Sand and silt are swept in by streams and by winds in arid regions, and vegetable growth assists the filling process. Shal- low lakes which recently existed in some of the New York valleys have already become plains or swamps. The extensive plains at the heads of the Finger Lakes, Seneca and Cayuga, for example, show the rapid filling by the detritus swept in by the inlet streams. The scores of thousands of lakes and lakelets in our Northern States and Canada came into very recent existence with the melting away of the Canadian ice sheets. Previous to the glacial invasions there were few, if any, lakes in eastern America. This implies that the Finger Lakes are not old. Indeed, they are very young, speaking in geologic lingo. Their life is reckoned only in tens, or at most, in scores of thousands of years. But the valleys in which they lie have been in the making for uncounted millions of years. The Finger Lakes are about the latest geologic features in the State. The cataracts and canyons are younger. Lake Ontario is the youngest great physio- graphic feature in America. The origin of the parallel valleys must first be learned, and then how they came to be dammed. This series of parallel valleys is FINGER LAKES—FAIRCHILD 291 probably the most notable in the world. That may sound like American bravado, but the challenge stands. Starting with the upper Tonawanda (Attica) Valley on the west, and passing eastward, the other pronounced valleys are: Oatka (Warsaw) ; Genesee; Cone- sus; Hemlock; Canadice; Honeoye; Mud Creek (Bristol); Canan- daigua; Flint Creek (Gorham-Orleans); Keuka; Seneca; Cayuga; Owasco; Skaneateles; Otisco; Onondaga; Butternut (Jamesville) ; Limestone (Fayetteville); Chittenango; Cowaselon; Oneida. The valleys which now hold lakes are marked by italics. (See fig. 1.) All these valleys drain northward into Lake Ontario. The series might fairly include a number west of the Tonawanda, that swing around into Lake Erie, and others on the east which lead into the Mohawk River. Some of the valleys, as the Oatka, Genesee, and Flint, once held lakes that are now represented by plains. The making of these north-leading valleys is a part of the story which makes demand on the scientific imagination. The history covers the many millions of years since central and western New York were permanently lifted out of the sea. The clear record of the long marine submergence is seen in the rock strata, several thou- sand feet in thickness, filled with remains of the varied life of the ancient seas. Remnants of the nearly horizontal strata constitute the broad, arching ridges between the valleys, with elevations up to over 2,000 feet above sea level. The valleys are the positive effect, having been carved by atmospheric and stream erosion out of the uplifted land. When the area of the western part of New York had been perma- nently raised out of the sea, it was a vast plain, declining southward. The Ontario and Mohawk Valleys did not exist. All the stream drainage of the area was southward, from Canada across New York into Pennsylvania. A wide belt of comparatively weak rocks lay east and west where the Ontario and Mohawk Valleys are now. In that belt the east and west tributaries of the primitive south-flowing rivers had an advantage, on account of the weaker resistance of the underlying rocks. They cut down faster and captured, or “ beheaded,” the rivers from Canada and developed the east-and-west depression that initiated the Ontario and Mohawk Valleys. Eventually a great trunk river, which we call Ontarian, occupied the depression that is now the Ontario Valley, probably flowing west- ward to the Mississippi. Of course, this great valley had two walls or drainage slopes. On the south wall, sloping northward, the streams flowed northward into the Ontarian River. During the long geologic time, probably part of the Mesozoic era, or age of reptiles, and certainly during the succeeding long Tertiary period, or age of mammals, the Ontario Valley was deepening and widening. 4 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1927 292 oHeqzodsyg Al[vpavd st Surddem oq} ey} ‘of1vjUO syv]T 1vau 3[eq OPI B JoAO AT[BOodSe ‘SaSin0d JOATI JUdTOUB 94} PeINosqo OS sBy Wp [vpRLD MUOA MUN NUALSHM GNV IVULINGO JO GADVNIVUC “IVIOVIDAUd YO ‘AUVILUAL ALVWI—'T ‘914 FINGER LAKES—FAIRCHILD 293 Its tributaries from the south were doing the same, and by head- ward erosion were eating back, southward, into the highland of the southern belt. Eventually these north-flowing rivers deeply in- trenched the highland, even into Pennsylvania. Thus all western New York and a belt of northern Pennsylvania was drained north into either the Ontarian or the Erian Rivers. (See the map, fig. 1.) It must be recognized that this northward New York drainage was the reverse in direction of the original, or primitive, flow on the old coastal plain. Of course the Canadian streams retained their southward flow, as seen to-day, until they reached the Ontarian River. The upper Susquehanna and its upper tributaries are prob- ably persistent examples of the primitive southward flow, but they have been beheaded by the Mohawk, flowing eastward. The parallel valleys of New York were carved in preglacial time by north-fiowing rivers; with the possible exception of Canandaigua and Keuka Valleys, which appear to have retained, through some distance, the primitive southward fiow. But even their streams be- came tributary to the northward flow. (Fig. 1.) If we ever have a geographic survey of the buried rock topography, it will doubtless show that the bottoms of the Irondequoit, Seneca, and Cayuga Val- leys are graded to the bottom of Lake Ontario. This will fully account for the depths of the unfilled portions of these valleys. One surprising element in the reversed drainage (shown in the map) was the capture of the old Susquehanna River. First it was diverted to westward flow, as retained to-day, through Binghamton, Owego, and Waverly. But it is believed that it was turned north- ward at Elmira and did the chief work of deepening the Seneca Valley. We might call this great river the Senecahanna, or the Susqueseneca. Most of the northward drainage in New York appears to have been concentrated in the Genesee and the Susqueseneca. We now have found the origin of the parallel valleys. Three questions now occur. Why the valleys are cut below sea level; how they were dammed, to hold lakes; and the cause of the digital ar- rangement, like fingers on the palm of the hand. It is difficult for people in quiet portions of the continent to realize that the land is not fixed and eternal. People in earthquake- ridden areas know better. Even continental areas move slowly up and down. During the long eons while the valleys were making, the land of eastern America was probably seesawing, up and down, as it had been doing in earlier time. Just previous to the glacial period it probably stood much higher than it is to-day, possibly two or three thousand feet. Certainly the bottom of the Ontario Valley was high enough to allow efficient flow to the sea of the Ontarian 74906—28——20 294 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1927 River. During the long earlier history of the north-flowing rivers, with lower and more steady position of the land, the valleys were greatly widened. Later, by the Tertiary uplift, the rivers were en- livened or rejuvenated, and they sawed down more rapidly, produc- ing the narrower, and steeper-walled, bottom sections of the valleys. Rivers are the valley makers. Mountain or Alpine glaciers modify the valleys which they occupy. ‘They are chiefly agents of trans- portation. Their minor work of erosion tends to widen rather than deepen their channels. They change stream, or V-shaped valleys, into U-shaped. But the ice work in New York was not that of stream glaciers but that of a widespread or continental ice sheet. It had little power of deepening valleys, but was effective rather in filling and damming the valleys. Lobations of the ice margin pushed into the old valleys, during both the oncoming and the recession of the glacier. But the lobes, pushing up the valleys, with imprisoned lakes facing them, were heavily loaded with rock-rubbish (glacial drift), and had little power of erosion. Moreover, the bottom ice in the deep valleys is believed to have been comparatively stagnant, serving as the bridge for the flow of the plastic upper ice. When the ice sheet was thick it moved southwestward, or diagonally across the central valleys. And, as noted above, the later lobations were too heavily loaded with bottom drift to do effective cutting. They piled their drift burden mostly in the hummocky deposits that now make the divides or water parting south of the lakes. (See fig. 2.) In general the ice sheet had only a smoothing or sandpapering effect on the land surfaces. It rubbed down the projections and filled the depressions, thus producing the remarkably uniform curving sur- faces which give the slopes of the Finger Lakes valleys their grace- ful outlines. During the later stand of the Quebec ice sheet it completely filled the northern ends of the valleys with its drift deposit, forming the wide plains north of the lakes. This drift filling makes the dams that hold the lakes. In addition to this northern blocking of the valleys another agency has helped to make the basins. This is the tilting uplift of the land. The weight of the Quebec ice cap, many thousand feet thick, depressed the land. When the ice was removed the land rose, slant- ingly in New York. The amount of slant, or uptilting, has raised the north ends of Cayuga and Seneca Lakes about 80 feet more than the south ends. As the outlets are at the north ends, it is evi- dent that the land movement is partly responsible for the lake basins. However, the “basin” character has been overemphasized. A true vertical profile of the basins shows that they are comparatively FINGER LAKES—FAIRCHILD 295 shallow. If the depth of Lake Seneca (618 feet) be represented on a diagram by 1 inch, then the length of the lake (36 miles) would be 26 feet. On the same scale the length of Cayuga would be 40 feet. And if the depth of Ontario be diagrammed as 1 foot, the a=} eS || SSS ONEIDA L i 370 * SOW ON DAGA & 364 RACUSE “PD le +h
  • CANNON 7 i a ‘* ee — ~oscee SK NS CORTLAND Be a Vhs to SS 8 oe aus, Oo ° cy ® o D *- 42 ue ‘eee ‘eeneam, % 2 RGR OES" 2 pis *, Le, BER my I Ro) “jee a C\y Bey vr 3 VU RY) WD ov' Fig, 2.—FWinger lakes and physiographic belts in central New York length of the lake would be nearly one-fourth of a mile. Evidently, no appeal is necessary to a fanciful deepening by “ glacial erosion.” The singular direction of the central valleys, converging north- ward, is an effect of the stream flow being directed by the general slope of the broader land surfaces, and the latter being determined by the character of the rocks in which the valleys were carved. 296 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1927 As stated above, the east and west Ontario-Mohawk depression was initiated on the outcropping belt of weak strata, and it became the master valley because of the great thickness of these nonresistant strata. In New York these weak strata are thickest on the meridian of Seneca and Cayuga Lakes, where in the vertical series of 5,150 feet of strata, between the Trenton limestone below and the Portage sandstone above, 4,500 feet are weak shales, 350 feet soluble lime- stone and only 250 feet sandstone. Consequently the south wall of the great Ontario Valley in the district of the Cayuga and Seneca tributaries receded rapidly producing the decided concavity as shown by the south shore of the present lake. Naturally the northward stream flow was directed by the prevailing land slopes and converged toward the district of more rapid erosion. The complex history of the Finger Lakes may be summarized as follows: (1) The original drainage on the uplifted sea bottom, or coastal plain, was southward across New York from Canada. Only a few cls 4 SENECA 1 Owasco SKANEATELES: 10 - | 1500 fr | 00 F 90 3008 Fic. 3.—Profile of lake region showing depth and greatest width of lakes. Base line is sea level remnants of that primitive flow now exist in western New York, with the upper Susquehanna and its tributaries in the eastern district. (2) Evolution of the great east-and-west Ontario Valley, in a wide belt of weak rocks, shales, and limestone, by the Ontarian River, beheaded the Canadian rivers. (3) Northward tributaries of the Ontarian River, on the south side of the expanding valley, ate back (southward), by headwaters erosion, into the Allegany Plateau, even to Pennsylvania. In this way was developed the remarkable series of parallel valleys; the reverse, in direction, of the original drainage. (Fig. 1.) (4) High elevation of eastern America, in later Tertiary time, enlivened the rivers by increasing their fall to the sea, and hence their velocity. This caused rapid down-cutting of the valleys (fig. 3), so producing the steeper lower walls of the central lakes, and the convexity of the slopes. (5) The high elevation of eastern America, possibly accompanied by a slight lowering of world climate, produced vast and deep ice sheets. The latest one, the Quebec Glacier, overspread New York, FINGER LAKES—FAIRCHILD 297 g > — 4 — psn ‘ a \( CI\\\ LS \ ae WW). tra ge! Pt.(eaprLey LBA ('F | Sw i a \ i “MN { Ne A \ = z <—Zs Ss —— yin ca ha: yt ok NA: x \ \ \\ SS h Tow YES WiZege WR he ——— SUA 2 FOr