IN REPLY RKP'KII TO - THl OC u WAR D EPARTMENT NO • f _ - S 1 OF__ f _COPIES SERIES -A U N ITED STATES ENGINEER OFFICE ·es MANHAiTAN DISTRICT -· CHICAGO AREA OFFICE P 0 EIDM CGD-1 Bo x 6140 A CHICAGO 80 ILLI N OIS 14 October 1943 Subject P-9 Pr ogram To Bri g Gen L R Groves Washington Liaison Office P O Box 2610 Washington n C I -- J 1 Forwarded herewith is a copy of a letter from Dr A H Compton to Dr H c Urey concerning the limitations of the P-9 Program to be conducted by the Metallurgica l Proj ect A V PETERSON Maj or Corps of Engineers 1rea Engineer l Inclosure Copy ltr 10 7 43 DECLASSIFIED Authority I Jl f1Jl 1Q i l - s£CR T 4 u c n a ts of X ffletallurgital l aborator 'pages and ___________ o· ·-----------iig - No - of_ L_copies Series A October 7 1 -943 Pr £ f J• r n C Urey op-rtmont or Ch ist- 7 Columbi Or · v 1·slt·· ow o-rk ·o Yo r •nrold1 l r y t_ c md on to Y U tho a·ovif ion l • rn n the •-j proj ct hich e Tr er- -wore uost1o ls in t e for into1·oh t1 of UL ' t' r Uon 9th t th tir ctlvo o ilb rry 1a 1- ay u t ituution P rho v opin rd t t - u doubt-OB 1£ tlOW th 1 t 011tr au i - the Brl ti This d ocument contains information affecting the national defense of the United States within the mean 'lg of the Esp onnge Act U S C 50 31 ll 'd 32 lts transmission or the 1ev •lation of j courents in any manner to an unauthorized person ia prohibited by law rti - D E - C L' ' A ss IF-l_E__ D __ Authority 71 'foJDq ' Q_ - Prc f o ol' H C SEC T • fflttallurgital J aboratorp f cto r 7 r 7 1943 c n i r ng 1 9 yroductlon c • i ort 11 r ct or ln de t r i init is no balc' ncf of l rl U t ry 1 0 r 1n th O »l - r worl1' M d r t tl y ttin6 it i s to ut hfllped t y the a tc r n on to tlU ion ocientiflc pl nt uoin P- oororo our o • u Lt tht t l • ' fl u tr L i l 1 n cttvit J u d i llne l o n a e or tha e t ttt r l t ow p roLT ti ecared in d olsively uso 'ul produc tion in t 1 nl· Clln 1 l l h otlly by ol 1 nlnc fro I th c rt 111 inc A ntol i ch · ·1 · y obtoJ n ln i-ticul 1· 11e c ulc 8' 8 no th t t C n ·iiCII c w d conut ru et n roduotton • t ulo cont1•ibut e oit nit'lc ir tly to tho 49 au •ly l- bl all in h nd Aocc r-din y lOno of 1 dy for f l-sc lo dt r u ply-inc the liriti lh rto tth c ny c thlu 7 yet bocoi o ot 11 u ort nce ill stLll tion intw n ee to th t ull tubo-a lloy o of' P- o t- r t th it Gt 1 rvl l h our othor Your CCt inc roly rt bur Oo B ton 3 Thu document contains information affecting the national defense of t he U n't ed S tates y i•hin t he mea i ng of t be Esp onoge Act · S C 5 31 nnd 32 I ts transmission or t he re v ation of its contents in any manner to an unauthoru d person ia proh bited by law SECRET DECLASSIFIED- Authority 'foJ C O f' Q I