Q. I would like to have your opinion regarding the extra danger from lightning where cast-iron or wrought-iron pipes are run through the roof of a building for vent-pipes. Is there not more danger of such a house being struck by lightning? Where an iron pipe is run to the roof from a lead trap, will the lead waste-pipe act as a conductor and carry the lightning to the ground?

A. If the house is provided with lightning-rods, as every house should be, the extra danger from vent-pipes run through the roof amounts to very little, if anything. Chimneys are sometimes struck by lightning, but no one thinks of abolishing those necessary structures on that account, and the same may be said of the vent-pipe. The electrical conductivity of lead is small, only about one-half that of iron, but under ordinary circumstances, and in the case supposed, it would serve as a conductor. Joints should always be of metal, however, to avoid the mechanical effects consequent upon the lightning jumping from one conductor to another. In several cases on record more damage has resulted in consequence of a lightning-rod not properly connected than would have resulted had the rod been connected with gas or water pipes even.