DuringthefirstthreemonthsofoperatingthePearlStreetstationlightwassuppliedtocustomerswith-
outcharge。Edisonhadperfectconfidenceinhismeters，andalsointheultimatejudgmentofthepublicastothesuperiorityoftheincandescentelectriclightasagainstotherilluminants。Herealized，however，thatinthebeginningoftheoperationofanentirelynovelplanttherewasampleopportunityforunexpectedcontingencies，althoughthegreatestcarehadbeenexercisedtomakeeverythingasperfectaspossible。Mechanicaldefectsorotherunforeseentroublesinanypartoftheplantorundergroundsystemmightariseandcausetemporarystoppagesofoperation，thusgivinggroundsforuncertaintywhichwouldcreateafeelingofpublicdistrustinthepermanenceofthesupplyoflight。
Astothekindofmishapthatwaswonttooccur，Edisontellsthefollowingstory：“Oneafternoon，afterourPearlStreetstationstarted，apolicemanrushedinandtoldustosendanelectricianatonceuptothecornerofAnnandNassaustreets——sometrouble。AnothermanandIwentup。Wefoundanimmensecrowdofmenandboysthereandintheadjoiningstreets——aperfectjam。Therewasaleakinoneofourjunction-boxes，andonaccountofthecellarsextendingunderthestreet，thetopsoilhadbecomeinsulated。Hence，bymeansofthisleakpowerfulcurrentswerepassingthroughthisthinlayerofmoistearth。Whenahorsewenttopassoverithewouldgetaverysevereshock。WhenI
arrivedIsawcomingalongthestreetaragmanwithadilapidatedoldhorse，andoneoftheboystoldhimtogooverontheothersideoftheroad——whichwastheplacewherethecurrentleaked。Whentherag-
manheardthishetookthatsideatonce。Themomentthehorsestrucktheelectrifiedsoilhestoodstraightupintheair，andthenrearedagain；andthecrowdyelled，thepolicemanyelled；andthehorsestartedtorunaway。Thiscontinueduntilthecrowdgotsoseriousthatthepolicemanhadtoclearitout；