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Annual Report of the 
lightning as far off the building as possible. It is the white oak 
trees that I notice have suffered. In many cases we have trees 
around our buildings, and I think it is a safe thing to put the rod 
there. 
Mr. Tuttle, of Kenosha. I think the Professor in his paper gave 
us that idea very plainly, and I think the lightning-rod business is 
about pla} r ed out. I would rather have one good white oak, or a 
Lombardy poplar near my house than all the rods that could be 
put up. I put out trees around my house; let them grow up 
and let the lightning hit them. 
Mr. Stilson. The question has been raised here in regard to the 
lightning striking the trees, and its preference for certain kinds of 
wood. I would like to ask why it is that it hardly ever breaks more 
than the bark of some trees, and in others, sometimes, it will shat¬ 
ter them all to pieces, and it will rupture some trees that will live, 
while those struck in summer die. The willow, the maple, and the 
beach ordinarily, the bark is not even ruptured when struck. 
Professor Sterling. All I can say is, that if it is more liable to 
strike one tree than another, it is because it is a betier conductor. 
I presume that Professor Daniells can answer that question better 
than I can 
Professor Daniells. Whenever a plant is in full vegetation and is 
injured in any way so that the circulation of the sap is injured, the 
tree is very apt to die. Take a tree in full leaf and trim away a very 
large portion of the branches, so that a large portion of the leaves 
are taken away, the vitality of the tree is seriously injured, because 
we have taken away just that portion of the ability of the plant to 
prepare food for its own sustenance. So if you injure a tree in any 
other way while the functions of the plant are going on, you in just 
that degree injure the life of the tree. It is with the tree just as 
with any other organism. In the winter, the functions of the tree 
are nearly dormant, and if struck then, it may recover. 
Mr. Wood. The thought has struck me, that a platinum point at 
the bottom of the rod would be as important as one at the top. 
• Professor Sterling. I think the remark is in point. I see no 
objection to having points from the rod into the ground, because the 
fluid cannot be retained on the conductor where there are points. 
I never knew rods to be constructed in that way, but I believe the 
idea is correct. I think it would be a valuable addition to the rod 
