440 The Ohio Naturalist. [Vol. XV, No. 4, 



insured and with a total risk of not far from $300,000,000, most 

 of them reporting for the years 1912 and 1913, quite a number 

 covering the past 5 years, and 5 for between 13 and 25 years, 

 with not one building ever burned or damaged to any extent by 

 lightning that had a lightning rod on it. 



These findings of the efhcacy of the lightning rod in preventing 

 lightning stroke are contrary to the general opinion, but they 

 substatiate those by Professor W. H. Day, of the Ontario Agri- 

 cultural College, as published in their Bulletin 220. His inquiry 

 covered Ontario, Iowa and Michigan, and included the records 

 for several years and found the efficacy of a lightning rod in 

 preventing lightning stroke to be from 92% to 99.9%. 



Damage to Rodded Buildings. — In addition to actually 

 preventing the lightning stroke, the properly installed lightning 

 rod is of very great value in preventing damage to a building 

 when it is struck by lightning. 



The table in this report shows that the total claims paid on 

 farm buildings due to lightning in 1912 and 1913, was $336,171. 

 Inasmuch as 31% of the buildings insured by these companies were 

 rodded, we would expect a loss on rodded buildings of 31% of 

 $336,171, or $10-1:, 213, but as a matter of fact the total claims 

 paid by these companies by lightning damage on rodded buildings 

 during the two years was only $12,788. In other words the 

 actual loss was only 12% of what would have occurred if the 

 lightning rods did not serve as a protection. 



The total number of buildings burned by lightning in 1912 and 

 1913 as reported by these companies was 407, and of these only 9 

 were equipped with lightning rods, or only 2%. Of those struck 

 that had rods only 5% were burned and the other 95% simply 

 damaged. Showing that the danger of a building being burned by 

 lightning that is equipped with lightning rods is exceedingly 

 slight. 



A further study of the reports sent shows that where the 

 buildings were struck by lightning and damaged, but not burned 

 down the average damage per building was less than $10 on those 

 equipped with lightning rods and \'er\' nearly $200 per building 

 where not equipped with lightning rods. 



Imperfect Rodding. — In some of the cases where rodded 

 buildings were bunied or damaged by lightning, the rods were 

 recently installed and appeared to be in good condition. But in a 

 large number of cases the rods were known to have been in poor 

 condition or improperly installed. Some of the rods were old and 

 defective, some not properly grounded, in some cases the lightning 

 entered the building on a clothesline, in others the lightning 

 struck a nearby building and the fire was communicated to the 

 rodded one. 



