wn, November Leth, vashin,tou time, depending, upon reathor Seen detonation will be a proof-test of a high yicld fission bomb dropped from a edo aircraft. v@ are atlemotin, Lo keep the hussians in the dark as to what has been and will be exploded in the Lest series. In view of the large number of ocrsonnel involvcd in the operation, and in view of the sise o: the detonation and the fact that the Llizht could be observed at sea for several hundred miles, it is not likely that we con for Lom; Keep fron the iussians the fact that there has .cen a thermonuclear explosion; althouch to date weather hus playcd into vur hands in that the winds have held the cloud for a period o: seven days over the Pacific making: it virtually impossible for the sussians to obtain sain,les fron the cloud and thus actermine the nature of the explosion. Unclassified seismile stations picked up the explosion. ahoey will be able to p»lace the epicenter of what they will probably regard a8 an underwator earth tremor as b.in; in the neighborhood Ooi the sniwelok .toll. ¢ nevertheless do not propose to confirm thal the tremor was acbrioutable to our test serivs. Since callin: ;ou on November 7th a speculuvive story, originating in Los .ngelces, to the effect that we have detonated a hydrogen bomb, has received rather wide dissemination, However, varring some now unloreseeable circumstance, it 15 our pian to make Me announcement concernin, the Lest geries until elter it is coucluded -— yrovavly on Jovember lsth. oe have always made such conctludin,, announcen.nts 1a the past. In the announcement we propose bo Say, as we did ab ine conclusion of the 1/51 tests, that “the test program incluced cexcerinents contributin: to thermonuclear weapons research,” while the information concerning the Lniwetok tests is of imnedLate Significance, there are other provlems facing the Goumission in the next few months concernin:; which you may wish to be informed. 4@ have prepnred for you a Top Secret memorandum, running to avout fifteen pices, duahing with our current stockpile position, the organisa. tion and oporution of the Co-mrission, its relationship ~ 2 -