106 
Annual Bepobt of the 
trees, are very liable to be struck. This is particularly the case 
with barns when filled with moist hay. Both the moisture and 
the vapor ascending ftom the newly-gathered crop, by their con¬ 
ducting character, strongly invite the fearful lightning stroke. 
Finally we say, study this subject; trust not the erection of rods 
upon your buildings entirely to agents, however knowing and 
plausible. See to it that they are put up in accordance with the 
well established laws of electricity and in compliance with the 
practical rules furnished by science. 
Mr. Benton - . Tell us what would be the best method of attach¬ 
ing the rod to the house. 
Prof. Sterling. If it is a brick house, it is well enough to use 
the glass insulators with the hooks driven in between the bricks, 
but I do not regard the glass insulators as of Any importance at all. 
As soon as they are thoroughly wet they become perfect conduct¬ 
ors, and the fluid is as likely to go into the building as it is into the 
ground. The insulators are just as likely to carry the fluid into 
the house as into the ground, if the connection between the rod and 
the ground is not good. They should not get out of place. I 
think that near the ground, the rods should be cased in wooden 
boxes so as to protect them. 
Mr. Clark, of Trempealeau. Some places the rod requires much 
more preparation than in others, where the rod enters the ground. 
In some places it is only necessary to stick a pin of iron down to 
secure connection for the telegraph wire, and in other places it is 
almost impossible to get a connection for the return current. 
Now is there any means by which we can tell whether the ground 
is a good or bad conductor? 
Professor Sterling. If the ground is wet it is a good conductor. 
Clay is generally moist, if it is dry, it is not a good conductor, but 
that is a matter of great importance, the consideration of the na¬ 
ture of the soil. I had a case where a rod was brought to me some¬ 
time ago, one of the scroll rods. The house was situated on a 
sandy bluff and the rod passed nearly over one of the water 
conductors, and down into the sand, and an excessive discharge 
took place, and it passed off on to the water conductor, and the 
rod was collapsed just as though it had been pounded together 
with a hammer. It was owing entirely to the want of proper con¬ 
nection with the ground. That is a matter of very great impor- 
