44 DAVENPORT ACADEMY OF NATURAL SCIENCES. 



conductor, or any other, be insulated or not. A flash that can leap 

 from the cloud to the rod can certainly leap from the rod to the roof. 

 The necessary inferences from the views above put forward are : 



1. That the Chambers rod possesses no virtue which ordinary rods 

 do not possess, except a slightly lower cost. 



2. That the Chambers rod can, and doubtless does, in many cases, 

 protect buildings when they are extensive and the points at considera- 

 ble distances from each other. 



3. That the Chambers rod loses its virtue when applied to small 

 buildings. 



4. That the Chambers rod has least protective power when the dan- 

 ger is greatest — that is, when the mass of charged air i^ very large. 



5. That while these objections diminish the protective power of the 

 Chambers rod, a rod with good earth connection of sufficient size, and 

 in perfect order, with a sufficient number of points, affords protection, 

 if not absolute, yet so nearly absolute that the danger from lightning 

 to a building thus protect^ is infinitesimally small. 



