34 KANSAS CITY REVIEW OF SCIENCE. 
been struck since. The chapel of Count Orsini in Carinthia, standing in an 
exposed situation, was so frequently struck and injured that divine service was no 
longer celebrated within its walls. But in the year 1778 a conductor was applied. 
Since then the edifice has been struck less frequently than before, and every 
stroke has been carried harmlessly away. A similar instance is furnished by the 
tower of St. Mark at Venice, 340 feet high. This tower was repeatedly and | 
seriously damaged by lightning until in 1766 a conductor was put on. Since that 
time no harm has been done. The tower has passed unscathed through every 
storm. Still another example is offered by the cathedral at Sienna, which was a 
favorite victim of the lightning. After a while, about the year 1777, a rod was 
attached to the building, causing much anxiety among the ignorant neighbors, 
who called it the ‘‘heretic rod.”” Soon, however, another stroke fell upon the 
cathedral and was rendered harmless by the dreaded conductor. The 
natives began to respectt the ‘‘heretic,”” and have since had no cause to 
alter this feeling. I will cite one miore instance, in which a flash of light-. 
ning, after working serious mischief, was caught up and tamed by a metallic 
‘chain. The ship Hyacinth was struck in the Indian Ocean in 1833. ‘The top 
gallant and topmasts, forty feet long and weighing nearly eight hundred pounds, 
were knocked into bundles of laths which scarcely held together. At the base of 
these masts the electricity encountered an iron chain, fifty feet in length and made 
of half inch metal, which communicated with a copper pipe running through the 
vessel. By these conductors the flash was carried off safely. After reaching them 
the flash could do no more harm. 
The question whether buildings armed with lightning-rods are more likely 
than others to be struck, is partly answered by some of the foregoing examples. 
But, had I space, I might cite evidence of a more convincing character. The 
matter has been many times tested by houses standing closely together, one pro- 
tected by a rod, and the other without defense. Time and time again the unpro- 
tected edifice has been struck and damaged, while its neighbor, which should, 
according to the popular theory, have attracted the lightning, escaped altogether. 
The same thing has also been observed at sea. ‘Two ships, the one equipped 
with conductors and the other not, have been exposed to a storm scarcely half a 
cable’s length apart. And the flash has fallen, not upon the attracting conduc- 
tor, but upon the masts of the unarmed vessel. In fact, nothing is more certain 
than that lightning rods do not increase the danger from lightning. 
That a lightning conductor may be adequate to its purpose several things are 
needful. The rod must be made of proper material. It must be large enough 
to carry off any stroke which may fall upon it. It must be continuous through- 
out, it must terminate in a proper locality, and it must be in part at least pro- 
tected against rust. Negligence on one of these points might render the whole 
affair worthless. 
First, of what material should the rod be made? Of course, the better the 
conducting power of the material, the more efficient the rod. Now, but two 
