Таємничий острів

           Therefore,ifthiscasewasbroken,thewaterwouldescapebytheopeningandformastream,which,flowingovertheinclinedsurfaceoftheplateau,wouldrushontothebeach.Consequently,thelevelofthelakewouldbegreatlylowered,andtheopeningwherethewaterescapedwouldbeexposed,whichwastheirfinalaim.

           Undertheengineer’sdirections,Pencroft,armedwithapickaxe,whichhehandledskillfullyandvigorously,attackedthegranite.Theholewasmadeonthepointoftheshore,slanting,sothatitshouldmeetamuchlowerlevelthanthatofthewaterofthelake.Inthiswaytheexplosiveforce,byscatteringtherock,wouldopenalargeplaceforthewatertorushout.

           Theworktooksometime,fortheengineer,wishingtoproduceagreateffect,intendedtodevotenotlessthansevenquartsofnitro-glycerinetotheoperation.ButPencroft,relievedbyNeb,didsowell,thattowardsfouro’clockintheevening,theminewasfinished.

           Nowthequestionofsettingfiretotheexplosivesubstancewasraised.Generally,nitro-glycerineisignitedbycapsoffulminate,whichinburstingcausetheexplosion.Ashockisthereforeneededtoproducetheexplosion,for,simplylighted,thissubstancewouldburnwithoutexploding.

           CyrusHardingcouldcertainlyhavefabricatedapercussioncap.Indefaultoffulminate,hecouldeasilyobtainasubstancesimilartoguncotton,sincehehadazoticacidathisdisposal.Thissubstance,pressedinacartridge,andintroducedamongthenitro-glycerine,wouldburstbymeansofafuse,andcausetheexplosion.