For Practical Workers 



Term/no/j 0/ //^/)fn/n^ rod 



A Radium Lightning Rod 



By Lucien Fournier 



A LIGHTNING ROD does not pre- 

 vent the occurrence of lightning". 

 It even provokes it, but suppresses its 

 incendiary effects. Such, indeed, is its 

 chief object. 



May we not increase its efficacy in 

 this direction? The problem is an in- 

 teresting one. We know that if the 

 air were a very good con- 

 ductor of electricity there 

 would be no electrical 

 storm. All that is neces- 

 sary for our purpose, 

 therefore, is to give the 

 air this quality artificially. 



Nothing is more simple 

 — we need only to ionize 

 it. To ionize the air is, 

 so to speak, to "metallize" 

 it by means of infinitesi- 

 mal particles like those 

 which are given off by 

 radium and which are 

 discharged into the sur- 

 rounding space from the 

 point of emission. From 

 the recognition of this 

 fact to the construction 

 of a radium lightning rod 



was only a step. Its con- a radium lightning rod which 

 Struction is not diflicult ; depends on the ionization of 

 it is only necessary to ^^^ ^i"" fo^ efficacy 



put a few milligrams of radium on 

 a plate, installed on a lightning rod 

 near its terminal. The inventor of the 

 process has constructed an experiment- 

 al rod consisting of three brass tubes 

 fitting into one another and having a 

 total length of about 12 feet. The tubes 



are mounted on a massive support of 



ebonite, restmg on a cast iron base 

 fixed in the ground. At the summit of 

 the apparatus is a cluster of three 

 points, and below them the plate con- 

 taining the radio-active substance. This 

 plate, slightly convex upward, is of 

 copper, about one-tenth of an inch 

 thick and ten inches in diameter. The 

 radio-active substance is spread in the 

 form of a ring on its upper surface, the 

 ring being about three- 

 quarters of an inch in 

 breadth and concentric 

 with the edge of the plate. 

 The amount of radium is 

 only 0.2 milligramme 

 (about .003 grain), and it 

 is deposited on the plate 

 by electrolysis. 



What effects are pro- 

 duced by this small 

 amount of radio-active 

 substance upon the sur- 

 rounding air? The in- 

 ventor declares that the 

 conductivity of the air is 

 increased several million- 

 fold, and that this con- 

 ductivity extends to a con- 

 siderable distance from 

 the point of emission, 

 \ iz., the terminal of 

 the lightning conductor. 

 Under these conditions 

 the passage of electricity will take place 

 between earth and air. not by brus(|ue, 

 irregular discharges, limited to a single 

 point, but by a constant, steady current 

 passing through a column of air hriving a 

 radius of thirty or forty feet. The pro- 

 gressive conductivity of the air toward 

 the terminal concentrates the flow of 



//e/i' of p/afe from 

 above. .sf)omng nng 

 of rac//o ocf/ve Ji/hjfonce 

 Tubes 



Ebonite iupporf 



^- Cosf/ron bo^e 



123 



