“Stand by” storage batteries

The people of every city make sudden heavy demands upon their electric light company. The approach of storms and resultant daytime gloom is one of the commonest causes of this. To meet such demands and to guard against power failures many companies maintain immense storage batteries to handle the load during the few minutes that are sometimes, required to bring the generating machinery up to speed. These batteries usually are the largest to be found anywhere — some weighing over three tons each. A few electric light plants keep as much as 500 tons of batteries always standing ready for service.