On Lightning Conductors generally. 101 



tube one inch and a quarter in diameter has been fixed; 

 these are connected together, and from them a copper rod 

 one inch diameter passes down and out through one of the 

 dormers to the outside conductor, with which it is connected. 



The total cost of these conductors, fixed complete, internal 

 and external, was about ninety pounds. 



The ordinary construction of the rod has now been tried 

 many years, and the accidents are as numerous as ever; but in 

 the one just described we have nearly the most perfect rod 

 that science has invented, and, I doubt not, as perfect as any 

 conductor in this city. 



I am, however, of opinion that the continuation of the 

 conductor to its extreme point should have been of the same 

 diameter as the longer portion of the rod, but as the reduced 

 piece is only two feet six inches in length, it may not be of 

 much importance . Another improvement that might probably 

 have been made, would have been to have added another line of 

 escape under ground; this opinion is founded on the practice 

 of Sir S. Harris, who endeavours to make the escape not only 

 direct, but by as many channels through ships' bottoms to 

 the water as possible. One writer says he feels assured that 

 if the ship's powder magazine were in the way, Sir S. Harris 

 would not hesitate to convey the rod through it. I need 

 hardly remark that bands of copper, where considered desir- 

 able, are just as efficacious as the rod, provided that requisite 

 width, thickness, and solidity are kept in view ; neither is it 

 necessary that the conductor should be on the outside of the 

 building ; if found more convenient, it could be built in the 

 walls or carried through the centre of the building. This 

 mode is partially adopted in the column erected to the 

 memory of Sir C. Hotham, in the New Cemetery; a portion 

 of the conductor is passed behind the emblematical figures in 

 the niches, and built in with the masonry. Neither do I 

 think is it necessary to have more than one point of attraction. 



Since the foregoing remarks were written, I have paid a 

 visit to the Powder Magazine on Batman's Hill, where I 

 find the old principle of small rods and wooden insulators 

 still in use. The situation of the magazine, on the side 

 of the hill and deep into the ground, is certainly favor- 

 able for security; but it is to the providence of the Almighty 

 we have to attribute the safety of the city when an over- 

 charged electric cloud passes over it, and not to the im- 

 perfect precautions taken to prevent such a calamity as the 

 explosion of the magazine would produce. 



