...:.·

NATIONAL CARBON COMPANY, INC.

ELECT R ODE DIV I S ION

CARBI DE AND CARBON BUILDI :NG

:30 EAST 42~ STREET

Dr. Leo Szilard Pupin Laboratories Columbia University

NEw YoRJ{

ll6th Street and Broadway New York, New York

Dear Sir:

July 6, 1939

In accordance with your visit to this office yester­day, we are securing information from our Niagara Falls works as to our ability to supply you with one block of graphite, 16 11 square by 1611 long. We hope to have this information the early part of next week, and will vrrite you further when this is available.

In our conversation, the question was raised if the porous section of our standard graphite electrode contained hydrogen gas. We are securing this information from our manu­facturing dBpartment, as well as the bulk density of our Grade 2301 graphite powder. As stated, this graphite powder has an

-~~sh content of .2 per cent, and a mesh specification of 99.5 per cent through 200 mesh screen •

As you requested, we are listing below the analysis of our standard graphite electrodes:

Purity

Composition of Ash (approx.) SiC SiO Fe263 Al203

99% or over 0.02 to 1.0% ash

Trace 15.6% 27.1%

3.5%

7

Dr. Leo Szilard - 2 - July 6, 19.39

Ti02 4.6% V205 21.9% Cr2o3 None NiO 1..3% CuO None P205 None CaO 2.3.5% MgO None so.3 2.1% BaO 0.4%

Very truly yours,

CPBrower:AEG ELECTRODE DIVISION

c 0

p y

Dr. Leo Szilard

NATIONAL CARBON COMPANY, Inc.

Electrode Division Carbide and Carbon Building

30 East 42nd Street New York

Pupin Laboratories Columbia University 116th Street and Broadway New York, New York

Dear Sir:

July 6, 1939

In accordance with your visit to this office yesterday, we are securing information from our Niagara Falls works as to our ability to supply you with one block of graphi t e, 16!! square by 16" long. We hope to have this information the early part of next week, and will write you fur t her when t his is available.

· In our conversation, the quest ion was raised if the porous section of our standard graphite electrode contained hydrogen gas. We are securing this information from our manufacturing department, as well as the bulk density of our Grade 2301 graphite powder. As stated, this graphite powder has an ash content of .2 per cent, and a mesh specification of 99.5 per cent through 200 mesh screen.

As you requested, we are listing below the analysis of our standard graphite electrodes:

Purity

Composition of Ash (approx.) SiC Si0 2 Fe2o3 Al203

99% or over 0.02 to 1.0% ash

trace 15.6% 27.1%

3.5%

Dr. Leo Szilard

Ti02 V205 Cr2o3 NiO CuO P205 CaO MgO so3 BaO

Signed:

- 2 - July 6, 1939

4.6% 21.9% none

1.3% none none 23.5% none

2.1% 0.4%

Very truly yours,

C. P. Brower Electrode Division

UNIT OF U::"iTION OARDIDE ~ A~D GAR.BON GORPORATLON

C AHHOX SALES DIVISION MA I N OF'F' ICE A"' O F'AC T ORV

CLEVELAND

BRANCHES TELEPHONE

VANDERBILT 8700 NEW YORK

12 • 7 C ARB IDE & CARBO N BLDG

PITTSBURGH 1810 CLARK BLDG

CHICAGO 1318 CAR B IDE 6. C ARBON BLDG

SAN FRANCISCO Sz.q ADAM GRANT B L D G

PROFESSOR LEO SZILARD Columbia University Physics Dept. - Pupin Labor<".tories l20th Street & Broadway :lew York, Jew York

Attention: Llr. Semyon .E.. Krewer

Gentlemen:

NEW YORK

Julj" 21, 1939

Referring to your visit of July loth at our office and ~ronr int r est'rtobtaining very pure graphite m2terir>.l to be used in furthering your wor:{ in the destruction of atoms.

He have just been informed by our factory that they can furnish our gre.de /.GS gra) hite plat es ; the ash content of these plates will not be over .1% and will consist of spectro­scoDic traces of the followin.oz elements: chromilun, titanium, cal­cium, silicon, iron, vanadium, copper, nickel and nl8BUesium. We are unable to give any indication as to the percentage of the various constituents, as they \:ould vary from lot to lot and no :.tttempt is made to anazyze the &sh. The chief concern is to make sure that the a sh does not run over .l~s , but that is as fc·.r ~ s ··;e go.

Relative to whether there r-ould be any hydorgen or nitrogen present in this material E.nd hovr much, we can only say that there might be traces of lydrogon and possibly some of nitrogen present. Just hov.r much we o.re not in position to definitely state.

Vie can furnish this I GS materiel in the follor:ing si~e and 1)rice:

12 x 12 x 1 Plain leGS Plates In lots of 100 -------·-­In lots of 250 or over -

~-iJ. 90 each net 3.50 l1 II

F.O.B. our f actory. ~rerms -no Ctc.Sh discount, 30 days net. Prices subject to acceptance within 15 days from date. Approximate r;eieht per plate 9 .6 lbs. each .

Shipment can be made at the rate of 100 or 250 pieces within six weeks after receipt of order, 1000 pieces fourteen

-continued on sh~ et C2-

---

COLill.ffiiA UNIVEHSITY (2)

to sixteen weeks, 10,000 pieces a.t the rate of 2,000 pieces per week beginning fourteen to sixteen weeks after receipt of order.

To the above prices v.rill be added the amount of E:JlY taxes nm~' or hereafter imposed upon vendor resulting from sale or deli very under this agreement .

Trusting this information vrill be of some assistance, we are

Very truly yours

CArcBON S/~ES DIVISION

Office Supervisor

G. J. Gardner/fgw FH ••••

J

/ NATIONAL CARBON COMPANY, INC.

UNIT OF UNION CARBIDE 1!133 AND CARBON CORPORATION

CARBIDE AND CARBON BUILDING CAHI.B ADilRJ<;SS

"CAH:DON" NE\Y YORK 30 EAST FORTY-SECOND STREET

Dr. Leo Szilard, Physics Department, Columbie UniverSity, New York, N. Y.

Dear Sir:

NEw YoRK

July 13, 1939.

I am enclosing a bulletin describing our new material known as''Karbate" and a sample of 11Karbete 11 No. 2 which is impervious graphite. 11Karbate11 is either standard carbon or graphite material impregnated with Furfural and a catalyzer polymerized in situ. The ash in graphite usually runs less than 1% and it is doubtful if the impregnant adds to the ash of the 11Karbate 11 material to any appreciable extent. The writer is not in position to advise whether the hydrogen and nitrogen content of 11Karbate 11

is higher than normally found in regular graphite.

"Karbate" can be produced by the impregnation of any standard carbon or graphite materials and we believe you have a National-Acheson booklet which lists the sizes which are normally carried in stock.

If after you have examined the sample you can advise the sizes in which you are interested, we shall be very glad to quote you on them.

F.J.Vosburgh w.

Encl.

Very truly yours,

i?v--<r~~ ( '

Manager, New Products Division.

c 0 p y

NATIONAL CARBON COlWANY, INC.

CARBON SALES DIVISION

New York July 21, 1939

Professor Leo Szilard Columbia University Physics Dept.- Pupin Laboratories 120th Street & B~oadway New York, New York

Attention: Mr. Semyon E. Krewer

Gentlemen :

Referring to you visit of Zuly lOth at our office and your interest in obtaining very pure graphite material to be used in further­ing your work in the destruction of atoms. ·

VIe have just been inaormed by our factory that they can furnish our grade AGS graphite plates; the ash contents of these plates will not be over .1% and will consist of spectroscopic traces of the following elements: chromium, titanium, calcium, silicon, iron, vanadium, copper, nickel, and magnesium. We are unable to give any indication as to the percentage of the various constituents, as they would vary from lot to lot and no attempt is made to analyze the ash. The chief concern is to make sure that the ash does not run over .1% , but that is as far as we go.

Relative sa to vhether there would be any hydrogen or nitrogen present in this material and how mum , we can only say that there might be . traces of hydrogen and possibly some of nitrogen present. Just how much we are not in position to definite!t state.

We can furni~ this AGS material in the follo~ ng size and price:

12 X 12 X 1 Plain AGS Plates in lots of 100 ---------- % 3.90 each net in lots of 250 or over -- $ 3.50 each net

F .o .B. our factory. Terms - ·mo cash discount, 30 days net. Prices subject to acceptance within 15 days from date. Approximate weight per plate 9.6. lbs. each •

. Sh,i,~~\ can be made at the rate of 100 or 250 pieces within

-~

six weeks after receipt of oader, 1000 pieces fourteen to sixteen weeks, 10,000 pieces at the rate of 2000 pieces per week beginning fourteen to sixteen weeks after receipt of onder.

To the above price will be addxed amount of any taxes now or hereafter imposed upon vendor resulting from sale or delivery under this agreement.

Trusting this information will be of some assistance, we are

G.J.Gardner /fgw FH ••••

Very truly yoursm

Carbon Sales Division

G.J. Gardner (sign.) F.H.

Office Supervisor

B <4139

NATIO AL CARBON COMPANY, INC.

F ACTORIE S EDG E WATER 'WORKS --·-

CL EVE LAND. 0 .

FACTORIES

FOSTO R IA . O . PHI L ADE LPH IA . PA.

FR E MONT. 0 .

SAN F RAN C IS C O . C AL .

Prof . L. z Hard, uepartment of ~hysics, Columbia University, New York , N. Y.

Dear Prof . Sziliard:

CLEVELAND, G.

December 12, 1940 .

NIAGARA FALLS . N.Y. CLARKSBURG ,W. VA. COLUMBIA , TENN .

A qualitative spectroscopic test on a small sample of the graphite obtained from you yesterday shows boron in spectro ­scopically measurable quantities . As we explained yesterday , we do not yet know how much boron this represents . ,,e plan to try to obtain a semi- quantitative es timate in the near r'uture and will let you kno .~ the results. Also shown in the spect r o­gr ams were considerable amounts of vanadium and titanium , as well as silicon , iron , calcium , and magnessium . The vanaaium content seemed rather high for this type of stock .

The raference on the purification o1' graphite ·.vhich I promised you is given below . Other references on this subject will be found in the 11 Index t o the Literature on Spectrochemical Analysis 11 by v1 • .t< . ~lleggers anu. B. F . Scribner of the Bureau of Standards , published by the American Society for Tes~ing Materials .

11 Purification of Graphite ~lectroaes for Spectrochemical Analysis ' , by T. 1.1. Standen and L. Kovach, Proc . Am . Soc . resting 'lats . , ~ Pt . II , 79 - 86 (1935) .

Very s incerely yours ,

;JI~m/k~ RES~ARCH LABORATORIES .

H. G. ~.acPhe r son : kB

{ '

Mr . v. c. Uamister Research Laboratories National Carbon Company EdgeVI•ater Works Cleveland, Ohio

Dear Mr . Hamister :

c/o Department of Physics Columbia University New York City

December 16, 1940

I am writing to you to tell you how nmch Prof"essor Fermi and I enjoyed your visit. ~e feel that these conversations might prove very fruitful, and hope that there wj.ll be soon an opportunity to continue them.

I have asked Mr. 'acPherson whether he could possibly send us the ash of h~lf of a graph! te brick . 'e feel that if we test the ash and in addition have a soectrosconic analysis, we can be fairly sure of not missing those impurities which interest us.

ith best Wishes,

Yours very sincerely

L. Szilard

LS/eh

I '

Mr. H, G, MacPherson Research Laboratories National Carbon Company }~dge ·ater Worlts Cleveland, Ohio

Dear 1~r . acPherson:

c/o Department of Physics Columbia University New Yor'\t City

December 16 1 1940

Both Professor Fermi and I were very much interested in your letter of December lP. Naturally, we are anxious to hear from you the result of your semi-quantitative estimate of boron, when available.

We wondered if it ere possible for you to have ash froru ab ut half of one of our graphite bri~ks, about five pounds of gra bite, nrepared for us, so that we may test the ash ~th neutrons, If this were ossible, we would much ap~reciate your sending us the ash of about two and one-half pounds as soon as it is available, and the rest later, By testing the ash we micht be able to cor1·oborate your spectrosconic tests for boron,

I hope that there will soon be some other opportunity to continue the conversations which we have be un.

Very sincerely yours

L. Szilard

LS/eh

B ~139

NATIONAL c,ARnoN CoMPA.l"VY; INc .

FACTO~lES EDGEV\"ATER WORKS CLEVE.LAN D . 0 .

FACTORIES FOSTO R IA . O .

PHILADELPHIA . PA. FREMONT. 0.

SAN FRANClSCO.CAL .

Prof. L. Szilard, Department of Physics, Columbia University, New York, N.Y.

Dear Prof. Szilardz

CLEVELAND, 0. NIAGARA FALLS , N .Y. CLARKSBURG,W. VA. COLUMB IA , TENN .

December 18, 1940.

We are ashing at present over eight pounds (most of one brick) of your graphite. This has been in a furnace at 750°C. for five days now, and should be completely ashed within a few days more. The whole sample is within one furnace, and will be available all at the same time.

We will send you all but a small amount of the ash as soon as the ashing is complete. A small amount will be kept for spectroscopic tests.

Very truly yours,

:¥.-dm~~ RESEARCH LABORATORIES.

H.G.MacPharson:MB

B ~139

NATIONAL CARBON COMPANY, INC.

FACTO~IES EDGl:!:WATER W"ORKS CLEVELAND. C .

FACTORIES FOSTORIA. C .

PHILADELPHIA, PA . FREMONT. 0 .

SAN FRANCISCO.CAL. CLEVELAND, o. NIAGARA FALLS, N . Y . CLARKSBU RG,W. VA . COLUMBIA , TENN.

Professor L. Szilaru , Deuart1:1ent of Physics , Columbia University , New York, 1\j , Y.

Dear Professor Szilard :

December 23 , 1940 .

After ten clays in the furnace, four of six sections of your graphite block were completely ashed . The re'lains of the other two were transferred to platinum d.i::.lles and the ashing of them will be completed shortly . ''Ye are senaing und.er separate cover 1:.he ash we have , about l.b erams . The percent ash varied fror:1 !:lbout 0 . 045% to 0 . 06% in the four sections .

A small sampl.e of 20 grams of your graphite was ashed separately for spectroscopic examination ana founu to contain about 0 . 000078% boron by weight , or O. OOG086f. on a nQaber of atom basis . I believe that the probable error i n this test was about ~01. . According t.o 1:.he fie;ures given me by Professor Fermi , this is five times too much boron . ile will make a further spectro­s copic test of a sample of the ash of the large block , anu let you know the result .

Yours very truly ,

RESEARCh LABllHATuRIEb .

H. G. MacPherson :DD

I

cPh rson arbon Co np ny

Dear r . acPher·on:

D c oer lB, L~1D

V -ry any t n s for your · lett 1 o r: eo b r r:· • rh asn hich you .,)ent u i. being stu~-1 by rofos.or •ermi and we should ltno by Tu sd~ t t 1e latest .lether its absorption oorros on .s to the a.nount of boron hie 1 you found .

If I un erst·1 your lett r correctly, the mount of boron in our c rbon 1~ sli~ tly 1; s than one ~art in a million by v.--e1ght. Thi is cert:=dnly ·nore t r.n e should like to have, but in cert tin cirou ::.tancf~ ·, e might:. be r;bl to tolerate about this a ()Unt..

I sboul· likG to r 1se the au st1on heth 3 r you are able to tell from y ur ..:?0ctroscopic r.nnlysis 1nything about t .~e g· dolium, dy s ro siuxn, sa arium, an< .. perhz.Jp13 : l.,o europeum content o! our carbon. One part in three million by weight of go olium .. 'Oul ·• o- a:3 bu as on,, . art th illion of ron, wnerea.., u .. ' . rosiu. , samarium z d uropeu:n

may ba about . s bad e. boron at a~ue:l wotgl ts . If the te.<g;tr whicn. you vc !"1• de :JO far ave no clue £.s t the rare earths, .oull it t~• r be ;JOS;..ible: to · ~ _e a qu ntita .. tive soectrosconic test for the a.bo'le mentioned l" re earths in orde1• to see· iVhet'ler we h· v to .orry c.bout t '1e ?

A:'!J. I right in . sn1:1i c that in your vi · th( J~o is no en nee of an c~ d. ium conta., in·.,tion'? ~··S ··ou :uto :, cac rnium is about · ;J ba ~ as boron for equ 1 1ght"'• but I ;ur po. e tla cadmium oxid iti too volatile 'J re':l~in in t1 carbon

hen it L; g:r•phitized. I; t.li;:> correct?

ith m(;n th::nh.s and best ·1 J .s,

Yours vcr s1ncerel .. ,

LS:rl ( • ')O zilard)

~.H. G. tacPherson National Carbon Co;a any .ese· ch L~boratories

Edge ate!' 11 or~~s Clev land, Ohio

De r r. . cPherson:

420 ~ t 116 Stre t N York, New York

Decemb r ~o, 1940

~e r ceived a s co d sn1 ole f ash fro you · 1ch as I iled on ])ecet:J.ber t:"7 , hut s n t acco <tnied by 1y 1 tter. ~.I correct in SvU ing th~t thie is the ash of t.e re~aining one-third of or gr Plite brick, two-th rds of -11ch have been ashed previously, 1 ading to th first

nle of h of 1.5 granl whic1 you s nt us e"rlier?

The 1.!') gm. of sb has no'> been te"'ted by nrofessor Fe.r i.1 an • npears to sho"· an a.Lsor'llti.:m ich ·: ould corresuond to t ice as ;uch of Lor~n a 1nd1c t d by your · ectrosco ic analysis . I do not think that e c n con­clude 'i th b olute certainty fro, tl·~ s that th ash con­t in sot'ie otl er strong ab orbing ·" t1 rial , since Loth your sner-tr'JSr'onic ana ysi nd the absorntion , ea.sure­ments ~hich ere carri d out on the ash are correct on y ~thin fairly ide lDlits of ex rj ent l error. Never­

th le-s, it a -ears no necessary to c r y out a s~ ctro• scopic test for those rar . e rtt r} i ch ··ere na .. ed 1 n UJY lett r of Deoe11 bE"r ... 8, and I ~ r.ould very .ueh a:r,..,r ci e t to have your cofuwent on this oint .

lease note tnnt isl 1 ~ ing tyno...,r· n

as "' .. ether you could sco 1e test for thes

LZ/eh

r·y letter of .cal err r.

c rry ut rr.tre e. rtl ...

:Cecen.ber r..a cont lins <>hat I v: nted to as u litative spectra-

Your v y sir.cerely

(L o fztlard)

you

NA:l""IONAL C .I\...RBON COMPANY, IN C .

FACTORIES CLEVELANO.O.

PHILADELPHIA. PA .

EDGE"W"A"I'ER \.V"ORKS FACTORIES FOSTORIA,O.

FREMONT. 0 . SAN FRANCISCO,CAL. CLEVELAND, 0.

NIAGARA FALLS, N .Y. CLARKSBURG,W . VA. COLUMBIA, TENN .

Prof. Leo Szilard, 420 West ll6th Street, New York, N.Y.

Dear Prof. Szilard:

December 31, 1940.

In reply to your letters of December 28 and 30, the second sample of ash was, as you assumed, from the remaining one-third of your graphite brick. Small samples of the large batch of ash were given spectroscopic exposures. The final results on the amount of boron in these samples are awaiting a slightly better calibration with known amounts of boron. However, the results will probably not be far different from those already reported.

I doubt whether the graphite ash contains any of the rare earths which you mention. However, a suitable spectrogram has been taken to check some of the ash on this point and we will see if we find any of the lines of these elements. We will also check for cadmium, although I do not believe that cadmium is present for the reasons that you mention. I have made no actual measurements of the amount of titanium contained in the sample, but it should be mentioned that the titanium content seems to be very high from the spectrogram. I imagine that, based on the original carbon, there is over 0.01 percent titanium. The vanadium content is probably at least half this much. I believe it possible, therefore, that the neutron absorption measured by Prof. Fermi could be accounted for on the basis of the boron, titanium, and vanadium present.

RESEARCH LABORATORIES.

H.G.MacPherson:VE

\ I

NATIONAI_... CARBON COMPANY; INC .

F ACTO~IES

CLEVELAN D . Q . PHILADELPHI A . PA .

FREMONT. 0 .

SAN FRANCISCO,CAL.

Prof. Leo Szilard, 420 W. ll6th St., New York, N. Y.

EnG I !:W A'I'E H WonK s

C LEVELAND, 0.

FA~~RIES

FO ST O R IA . O ­NIAG ARA FALLS , N .Y. C LA R KS BURG ,W . VA.

CO LUM B lA , TENN .

January a, 1941.

Dear Prof. Szilard:

We have completed quantitative spectroscopic tests on two 10 mg. samples of the large batch of ash which we sent you from one of your graphite bricks. These showed a concen­tration of boron in the original graphite of 0.00008% and 0.00006%, in agreement with the percentage previously reported to you from an examination of a small amoun~ of ash.

In accordance with your letters of December 28 and 30, we obtained a spectroscopic exposure from your graphite ash suitable for examination for the presence of dysprosium, gadolinum, samariam, and europium. Since we have no standard samples of these elements in a pure form, the examination of the plates proved rather tedious involving the accurate measurement of the plates in the regions of several lines of each of the elements, taking care to avoid regions of coincidence with lines of other elements present . As a result of this work, however, we can state for certain that none of the above elements were present in the ash in a sufficient quantity to give lines on the plate. This probably means that their influence on neutron absorption is negligible. We also made an examination for cadmium but found none. In the course of our search for the rare earths, a trace of yttrium was found. However, I do not suppose that yttrium is an important contaminant since you did not mention it.

As a result of these tests I think it must be concluded that the high neutron absorption for the ash measured by Prof . Fermi must be made up of absorption by boron, vanadium, and titanium.

Very truly yours ,

~~~~~ RESEARCH LABORATORIES .

H. G. MacPherson:DD

Inc.

D ar ~r • oPh r on:

thank for your letter of ece.ber vl.

y u beet ol to di cove . e boron get :1e ra lute th u !1 the coke hich you u - e or rro ~ one f the furn ces into hich thi!! co e 1 t d'? It ~ uld be u.. ful to kno thi r. a soon o 1 ble o tnt: t. houl. be a.bl& to r ,ct'l deci ion concernin the ac ent of an order or f ur to of gra h1 te . Ir

r. ~ • o. ~ c. h r n, > g

L~;

cc: 1 - Pegram 1 - Fermi 1 - Szilard j::; - !i tchell

You s inc e y,

,(. h ~ ( o t.~silar )

ight

D ~· r r.

CC: 1 - Pegram 1 - Szi l ard 1 - Fermi 2 - :d.i tchell

rs nt

J nu·

Inc.

Ul" Vt!l") ... ruly 1

; '. ;;_ . (L, [.til r )

10,

• n

41

or

J:nu ry 17 , 1941

~r , IT. O. M cP ter .. on N tion 1 ~arbon Com,~ny, Inc .,

ron Laborator!P. Edge tor .1ork Cl veland.1 Ohio

In y 1 t. l~tt I t e hould sto., 1,rorr in:: :H>r t. a ore en bo t tLe di sci•apr ... ncy between til~ neutron a.b or~>tion of tn r.· sh tm · 1 ts s ect:ro ooplctilly ·· etomin(1 · boron content, flll r t ~er concentrate on the cuer.t1on of' h" ri in of the boron ~o ~s to enable the ~ tional c .rbon .omn n to rut in a b1c. 1 rJr .tour tonfl of ~t·e hi.te, con , :lnin .... t the mo t s.s muoh ·<O.ron 1\ s our yresent gr& hl te. Th:l f: • till . ·e to be t! e most. ur·gent to sk !..;incc , dha.ll n ... d :l n ::~ny cas another four t ns of ,:r· :>bite ve· t!\oon, end it would be deslr 1ble t ~t Jf\':>U1' com . .sn· should b -ble to SUi,)?ly 1 t.

t.nothar oint htt. co·ie u in ~h- .il nt1 . h1ch reQuires so~e ~or labor;.tory test~. e fin~ tt t f r om t~Hi ~rn<> n l1te::. of t.iw boilin ) li , of I3t,0;3 , rJ.ch i s 11 te \ly c s flgr ater than l50QOC t1, one c nnot at all

xclu"" 11· Jo·· ibility tr·t w!m1 tl·l gr hite 1~ ~urncd irJ oxyg n , t 7500C con. i er ble fraction of the B•,03 i s ea.rri .<. • 1w 'it tis n :,or by the cr rl' on die xi c.: ~ nio i 1roduc . '!his oulu c :rt nly ba :1 if ..,, e Tn c re clo ·e to 15QOOc li"id t e e>V";.t;:>orati.on h. " ntll h~ile th· re ·.~on bl ,.lua of lO hZn• In tne c1rcu t. nco · e !"ea r th:•t rha only

one- third o! t~Ht boron oont nt . the gre bi re ent i n the h . T ~e u .stiou tl' efor-# rt se. --,h t! .:r one eould u termin . t.l total '~O on content in the grrc te by u~ ting u .. t.w liec:. of gr~ ; hi te in n .... mo" · hu of chlorln en oll .. cttng the bOl'On cl".J.ori<.: e, tc ethar :1 tn t 1. other

chlorides '! ic ar, driven out . h £·moun· r boron could then b .. det r. in s. eetrosco•)iC 11¥ in t he conden d c:uor1d s .

it t 1\.

te y u en.

• c er n,

11 0 10! s1bl.

a-re look1n ::r f he rin. · &t you 10 ~. H

cc: 1 - Pegram 1 - Szilard. 2 - Mitchell

J nu ry 171 1941

h t . n~lin

uld be u rt

ul

i t r "'t t t i . )01 t.

00

I• l

I

NKCIO..r AL CARBON COMP.ANl.r, IN c . \

F ACTO ~ IES

CL EV EL A ND. C .

EDGEWA'TEU WOl.'l.KS FAC T O R I E S FOSTO R IA , Q.

PHILAD E LPHIA , PA. F REMONT. 0 - CLl~VELAND, o.

NIAGARA FALLS, N . Y . CLARKSBURG ,W . VA .

SAN FRANCI SC O ,C AL .

Professor Leo Szilard, Columbia University, Department of Physics, New York, N. Y.

Dear Prof. Szilard:

January 22, 1941.

In regard to the possibility of loss of boron by evaporation in the ashing process, it is my opinion , for theoretical reasons , that such a loss would be small . Graphite ash is generally alkaline in character because of its calcium content, and under alkaline conditions boron is not easily lost by evaporation , possibly due to the formation of berates. Furthermore, approximately the

COLUM BIA , TENN .

same amount of boron was found in two lots of your graphite , one a sample of 20 grams ashed for 36 hours , and one a large brick ashed for ten days . If much boron were to be lost by evaporation, one might expect to find a significant difference in the amount of boron found in the two cases . I therefore do not think it worth while fo r us t o undertake any other wor k on the determination of boron in your gr aphit e .

Our New York Office is being given such information as we have concerning our ability to supply graphite according to your specifications. This matter will be handled through the Sales Department .

Very truly yours,

1/.'-11 m(k~ RESEARCH LABORATORIES .

H. G. MacPherson:MB

ROUGH DRAFT

January 30, 1941

Dear Mr. Hamister:

The director of the research project, which is being

carried out under the authority of the National Defense Research

Committee, and with which our work is associated, plans to call

a conference on the subject of graphite • .¥ wbi:gli:, among o'bft€rs,

~fti:ieft'6 ef ]re~~ ~!!:!11'1 9~'f/ and a boron content of less than one

part in two million, without processing the graphite after it

comes out of the graphitizing furnace? / .,_~ ;-....... -.A&.r

If the answer to this question is in the negative, ..- L

1 l ~ ~

propose:~ to investigat¢' the possibility of processing the graphite /

for the purpose of purification on an industrial sea ~r the

ur-pose , of arxi~ing a~ an eetimate-crf~t for such processing, I ...

and a--l:so. to find some chemical firm which has equipment that ~

~be available (, required-, ,.__A_ j/M/l ~ c: ,<. •. . "" • ,

Apart from you and Mr. McPherson and those who are

~ea!abeiy concerned with this work at Columbia University, a

representative of the Bureau of Standards would probably be

invited to attend this meeting.

I assume that you have formed in the meantime some

views on the subject whether the boron gets into the graphite

through the coke which is used or during the process of con-

verting this coke into graphite. The answer to this question is

important for us, in so far as it will enable us to make a

forecast concerning the accidental variations of the boron content

(

Page 2

r

~-­which would have to be ~~"da Should you at present be

studying this question and feel that you would know more about

the subject in the near future than right now, then perhaps

it would be wiser to postpone this proposed conference for another

two or three weeks.

Unfortunately, apart from certain general decision~we

have also to decide specifically in rather of a hurry on the question

of placing an order for four tons of graphite which we need right

away for certain experiments ·f#'i c:b han& 'beeR f'P~p'M"ed. In order

to bring this issue to a quick decision, it would perhaps be best

to ask a representative of your sales department to attend the

proposed conference. Alternatively, if it is found best to postpone

this conference, I could perhaps ask Mr. R. J. Hoffman to arrange

for a conference between a representative of your sales department

and either you or Mr. McPherson and someone from our group, so that

we should be able to arrive quickly at a compromise between purity

and price, and be able to decide on the spot whether or not this

order for four tons can be placed with the National Carbon Company.

This being a matter of urg·ency and the other questions of general

policy touched upon in my letter also requiring a decision in the

near future, I should appreciate having by wire any comment which

you may wish to make on the subject of having a conference in the r. ~~ r ... ._

near future. If~ do~snot seem pract•c~nl§, then" special

delivery let~ addressed to 420 Street, ~(.jn- .~

~

L.._,r)

NKriONAL CAR1:lON CoMI~.ANY, INc.

FACTORIES ~EDGE"\\'ATEH W"ORKS C L EVELA ND. C .

PHILAD E LPHI A. PA.

F R E MONT, 0 . SAN FRA NCI S CO,C AL .

Prof. Leo Szilard Columbia University Department of Physics New York City

Dear Prof. Szilard:

CLEVELANl~, o.

January 31, 1941

Subject: Boron-free Graphite

FACT<?RIES

F OS TO R IA . O . NIAGA RA FALLS , N .Y. C LARKSBURG ,W . VA. COLUMBIA , TENN .

In reference to the graphite brick that you have dis­cussed with our Messrs . Hamister and MacPherson, and regarding which you have corresponded with MacPherson, after having developed an accurate method of measurement for determining the quantity of boron in graphite, we have carried out pre­liminary investigations to an extent that was necessary to determine what the boron content of our graphite might be .

From this investigation, it is apparent that we are not in a position to supply you graphite brick sufficiently free of boron to meet your specifications . In order to deter­mine whether formed graphite blocks can be commercially pro­duced sufficiently boron-free to meet your desires would require a time consuming research of a magnitude that we do not consider desirable to undertake .

HDB:WRJ

Our New York office has been advised of our findings .

Very truly yours,

0/t/;Y~~~ H. D. Batchelor DIRECTOR OF RESEARCH

February 7 1 1 41

• H. D. atchelor, Director of areh ti n 1 Carbon Co pany1 Inc.

d ter .·arks Clevelllnd , Ohio

r ~r. Batch lor:

any t hanks f r yoJr kine l tter of January ~1 .

e ~~ ~r c11te v ry rillch the tten ion g jven to this tter by yo.Jr R ec <> rch LaborRtory and inv st1gat1on

conducted hy ~.~ssrs . Fuuister rl c .. Ler on, nd re ret t) henr th~t yJu are not in a o 1t1on to

u nly ~r nhite bricks fre of boron to reeet c r t a1n s ecific!tions of ours .

sl ould be v ry nmch 1nter ~ted t o lr;:arn t.ough t he boron eont nt of the best r aphite vhich you re

b e t;. suf1 , ly. For ce1·t· ln · e of . r; h te , '· e ' t::>Uld be a blf' to toler . te mor boron th .~n for oth r

u s , although · c 1'\t" :l ntere!-:ted in fl'V ry c .1 s ln he . ~1ng t hP boron contett ~ low • rossible. Perh p

your gra"hite c uld be ed at le st f~r sow~ of our ·,ork.

Very truly your

/It (L. ~ 2:tl. rd)

L8/ h

/

B 4 13!iif /

' ' I

I I

NriONAL CARBON CoMPAN"l.; INc.

FACTORIES

CLEVELAND. C . PHILADELPHIA. PA.

FA_s: T'?RIES FOSTO R IA , O .

FREMONT. 0~

CLEVELAND, o. N IAGARA FALLS , N . Y. CLARKSBURG,W. VA.

SAN FRANCISC O .C AL .

Prof. Leo Szilard Columbia University Department of Physics New YorK City

Dear Prof. Szilard:

COLUMBIA , TENN .

February 26, 1941

Careful consideration of the last paragraph of your

letter of February 7 again leads us to the same conclusion

given you in my letter of January 31. There is no known

procedure for controlling the boron content of artificial

graphite and there is no information that indicates the ex-

tent and variability of its presence in our products. Excep-

ting for the analysis made for you, no other determinations

have ever been made. One determination made in the course of

this work gave us a result of . 00016 percent.

HDB:WRJ

Very truly yours,

H. D. Batchelor DIRECTOR OF RESEARCH

j

Dr. E. G. MacPherson Research Laboratories National Carbon Company, Inc.

dgewater Works, Cleveland Ohio

Dear Dr. MacPherson

Thanks for your letter of January 22. ~ e shall now probably ask your Sales Department whether you are able to supply four tons of graphite with an ash content of less than 0.1 % and a boron of less than one part in 500,000 by weight. I am writing this to you in advance so that you shall have time to prepare the information for which your Sales Department will undoubtedly return to you. This proceedure rill perhaps make it possible to have the reply of your Sales Department with a ~J minimum loss f time. ?, J,t, f{v • /~ 4 / 'f -

l · ~ or· . f£n ' ,, r? ,..,., .

Before &iscussi your letter of January 22, and before nally deciding whether the arguments which you are putting forward.are sufficiently con­clusive for us to stop worrying about the possible loss of boron in the process of ashing, I should like to ask you some questions in connection with~ ~arguments in your letter of January 26.

~·~ 1. Taking it for grant{d that the presence

of calcium in the ash wouldf~~event an evaporation of boron from the ash, does it really conclusively follow that when graphite is burned, which may per­haps contain separate boron carbide and calcium carbide crystals, the amount of boron oxide carried away by the carbon dioxide wou}d~ correspond to the vapor pressure\ 8 B so liM~ re.,het te conslde!'-.,.h, u _] "'-UL.OF ~. t:::Vv ./_; ~ ~d ~ .__ ·,-t~ ~ ( ...... "'""""-'""'~

2. Were not, in the case of the two samples ~ ~ of 20 grams ashed forl'36 and one large brick ashed forA10 1 the amount of arbon dioxide flowing away during the ashing subst ntially the same per gram of carbon ~' and als the temperatures substan­tially the same, and · view of this fact, would one not expect, · , to have the same frac~on of boron in the process of ashing in ~ th cas es?

Page 2.

Since a large number of measurements have been car ried out with these four tons of graphite which we have here, and since it is necessary for us to correct the values obtained in these measure­ments for the amount of boron which is contained in these four tons of graphite, we shall have to try to determine the amount of boron in the graphite by some direct method unless it can be made absolute­ly certain on theoretical grounds that there can be no loss of boron in the process of ashing. This is the reason why I am againtroubling you with questions, but ~erhaps it would be better to discuss this matter orally when an opportunity arises.

Very truly yours