DAMAGE CAUSED BY LIGHTNING TO SEAL EOCKS LIGHTHOUSE. 101 



Another lesson to be learnt from this occurrence is the necessity 

 for insulating the bell wires. . The whole of the lantern is a metal 

 structure with a copper roof, and the modern lighthouse practice 

 is to attach the lightning conductor not directly to the vane on 

 top, or the copper roof, but to attach it to the base of the lantern 

 and thus depend upon the lantern collecting the current and 

 conveying it to the conductor. 



The bell wires are invariably in metallic contact with some 

 portion of the lantern, and therefore just as liable, as in the case 

 in question, to be charged with lightning as the proper conductor. 



It is proposed to attach a copper band 1 J in. by -f- 6 - in. to Seal 

 Rocks Lighthouse from the copper dome of lantern, and lead it 

 down outside and take it to earth, taking steps to so bury the 

 earth plate and maintain it in a state of efficiency by leading the 

 discharge from overflow and down water pipes over the pit where 

 the plate is sunk. 



When replacing the bell wires stops will be taken to carefully 

 insulate them from any metallic contact in the lantern. 



The following reports as to the state of the weather on the coast 

 north and south of Seal Rocks on the 10th July, have been kindly 

 supplied to me by Mr. H. C. Russell, c.m.g., the Government 

 Astronomer. The matter is of special interest inasmuch as it is 

 most unusual for thunderstorms to occur on the coast in the month 

 of July : — 



Port Macquarie, sixty-five miles north. Pilot reports — I neither 



saw or heard thunder that day. 

 Manning River, thirty-four miles north. Pilot reports — No- 

 thing of any consequence took place near this station, but 

 thunder was heard previous evening. 

 Port Forster, Cape Hawke, eighteen miles north. Pilot reports — 

 On day lighthouse was damaged the weather was very 

 threatening to the south-east, heavy squalls passing out to 

 sea with distant rolling thunder, and at night there was 

 bright lightning in the direction of Seal Rocks. About- 

 11 p.m. a very heavy clap of thunder. 



