nd four
excellent lightning-rods, have had the effect of neutralizing the air
about it by constant conduction of mild currents. Yet the rod on the
spire of Somerset Street Church, nearby and eastward of the State-House,
but lower, has been seen to receive a disruptive discharge. Bunker Hill
Monument, about a mile north-west and some twenty feet higher, has
several times received powerful discharges, which a good conductor has
always carried harmlessly away.

There has also been observed a tendency of the current not only to
strike certain buildings, but to enter the earth at a certain point
whenever such buildings are struck. Some of our oldest and most
successful appliers of rods believe that at certain points there are
natural electric currents, or at least readier conduction for them than
at others. Yet these points can become known only by repeated disasters.
Lightning-rod men who are adepts in their business now take care to
overcome adverse currents by enlarging the lower part of the conductors
and by carrying them to greater depth.

Soon after the powder-magazine of the Boston Navy Yard was completed the
neighboring residents grew fearful, and petitioned the authorities that
it should be better protected from lightning. It had already four
excellent rods, one at each corner of the building; but to these
peaceful and unwarlike citizens every thunderstorm was a great battle in
which their homes were in danger of destruction and their own lives in
jeopardy. The result of their action was, that a trench four feet deep
was dug entirely around the magazine, and in its bottom was laid a
continuous line of sheet copper four inches in width: to this the plate
of each rod was soldered, and then the soil was replaced.[6] No one
could doubt now that the stealthy upward stroke would be caught and the
mysterious earth-currents overcome. It is supposed that thenceforth the
tremors of the good citizens ceased. The massive magazine with its fiery
contents yet stands, though terrible peals of thunder have shaken it and
fearful bolts have fallen near.

GEORGE J. VARNEY.

FOOTNOTES:

[5] Among other beliefs in regard to lightning is that of the upward
stroke. It has even found expression in the _American Journal of Science
and Arts_. On careful consideration of the cases offered in support,
both printed and unprinted, I find that every one is susceptible of a
reasonable explanation without this theory.

[6] It is not usu