Путешествие на Луну
Reply from the Observatory of Cambridge
But,inasmuchasitisequallynecessarytotakeintoaccountthedeviationwhichtherotarymotionoftheearthwillimparttotheshot,andastheshotcannotreachthemoonuntilafteradeviationequalto16radiioftheearth,which,calculateduponthemoon’sorbit,areequaltoaboutelevendegrees,itbecomesnecessarytoaddtheseelevendegreestothosewhichexpresstheretardationofthemoonjustmentioned:thatistosay,inroundnumbers,aboutsixty-fourdegrees.Consequently,atthemomentoffiringthevisualradiusappliedtothemoonwilldescribe,withtheverticallineoftheplace,anangleofsixty-fourdegrees.
TheseareouranswerstothequestionsproposedtotheObservatoryofCambridgebythemembersoftheGunClub:
Tosumup—
1st.Thecannonoughttobeplantedinacountrysituatedbetween0°and28°ofN.orS.lat.
2nd.Itoughttobepointeddirectlytowardthezenithoftheplace.
3rd.Theprojectileoughttobepropelledwithaninitialvelocityof12,000yardspersecond.
4th.Itoughttobedischargedat10hrs.46m.40sec.ofthe1stofDecemberoftheensuingyear.
5th.Itwillmeetthemoonfourdaysafteritsdischarge,preciselyatmidnightonthe4thofDecember,atthemomentofitstransitacrossthezenith
