346 Barns often struck by lightning. 
necessary to enter on the proof of the fact, which will there- 
fore be taken for granted.—What then is the cause: 
t will be observed, that these events more generally oc- 
cur after harvest, or hay-time, when the barns are more or 
less filled with hay and grain ;* which renders the calamity 
peculiarly distressing, as, in many instances, the farmers’ 
hopes are blasted in an hour. 
It is obvious, that the produce of the fields, when stored 
in a barn, must give rise to a copious evaporation. ‘This is 
peculiarly the case with hay, which, especially when put up 
still damp, (and it always is so in a degree,) sweats (as it is 
termed) very powerfully ; a hand thrust into the mow, is 
often rendered sensible of great heat and moisture, and a 
visible vapour is often abundantly exhaled, when a heap of 
such hay is moved. As the large barns of the farmers often 
contain many tons of hay and grain, it is obvious, that this 
cause is sufficient to produce the rise of a great column of 
AS f Te wane gee 
Vapour is a good conductor of the electric fluid; and thus 
the lig tning may be determined, by the attraction of the va- 
PVs 
There is an additional fact, which is worthy of being men- 
ble nature of the usual contents of barns, as well as of the build- 
ings themselves, it is in no way surprising that, when struck, 
they are st inevitably consumed. The most interesting 
question remains—What can be done to remedy the evil? — 
etrical excitement, produced by evaporation, is seen in the f2- 
a ment of putting a r live coals into a crucible; the crucible 
the coals, when the gold leaves of the electrometer insthatly Seedege 
