"But one who knew how to make an Infernal Device, triggered by clock-work, might rig it in more than one way," Daniel said. "I hypothesize that the machine uses phosphorus to create fire at a certain time. In one case, that fire might be conveyed to a powder-keg, which would explode. In another, it might simply ignite a larger quantity of phosphorus, or of some other inflammable substance, such as whale-oil."