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Annual Report of the 
si upon is the connection with the ground. You may insulate as 
you please, and if it is not connected with the ground properly, it 
i 3 worthless as a rod. That is the main thing. In those grooved 
rods, the agents will tell you they have a great deal more surface. 
Well, they have, but not as large conducting surface. If a large 
charge passes down one of these rods the fluid will be confined to 
the edges. The tendency is to go off explosively into the building, 
and so far as form is concerned, it is objectionable. 
Professor Daniells. There is a difference of opinion between 
men of this day and twenty years ago, isn’t there? 
Professor Sterling. No sir, I don’t think there is. 
Mr. Sherman, of Columbus. The question is whether the rod 
will contain all the fluid when it strikes the rod. 
Professor Sterling. Sometimes the rod will be destroyed, and 
yet it will protect the building if it is well connected with 
the ground, but if it passes from the rod, as it sometimes does, 
wherever it strikes, there will be the greatest effect produced. 
Sometimes it passes right through a wall by the repulsive force im¬ 
parted to the particles. 
Mr. Porter. I wish to ask in reference to one point. What is 
the professor’s opinion in reference to the wind mills reaching twen¬ 
ty or thirty feet above a barn, with iron gearing necessary to man¬ 
age and hold the mill properly. How would the professor attach 
the rod to protect the barn, or would that wind mill have any effect 
on the building with so much iron attached to it ? 
Professor Sterling. I do not know how they are constructed, but 
if there was a point attached to the iron rod above and the iron 
well connected with the ground, it might take the place of the con¬ 
ductor, if it is soft iron. If a point was attached to the iron and 
extended sufficiently above the barn, it might protect the barn. It 
would have a tendency to strike the shaft just in proportion to the 
length of the conductor in a vertical direction. When the cloud 
came along, the induction would take place according to the length 
of it. If it was connected with the ground, it would be more likely 
to strike that. 
Mr. Porter. How would you attach the rod ? 
Professor Sterling. I could tell better if I saw just how it was 
constructed, but I should run the rod above the point and have it 
well connected with the ground, or if there was sufficient iron run- 
