45, CORNHILL, E.G., AND 122, REQENT STREET, W., LONDON. 



127 



LIGHTNING CONDUCTOKS AND FITTINGS. 



180. Lightning Conductors should be pointed at 

 the top, and extend a few feet above the highest point of 

 the building or mast. They are best made of Solid 

 Copper Hods or Copper Bands of sufficient diameter 

 and thickness to convey the discharge without melting. 

 Wire Hope of Copper is now much used, owing to its 

 convenient adaptability to uneven surfaces, but great 

 care must be taken to have it of sufficient diameter to 

 prevent fusion, and that both solid rods and wire rope 

 should be perfectly continuous and unbroken throughout 

 the entire length, and carried down some considerable 

 distance into the earth, which should be moist, or better 

 still, carried down a well some distance beneath the 

 surface of the water, or the conductor should terminate 

 in several branches on a large sheet of stout copper. 

 In large towns these conductors are carried down and 

 connected with the large water pipes. On no account 

 should Lightning Conductors be connected with Gas 

 pipes; it is exceedingly dangerous. Where a building is 

 large, several conductors should be used, and all large 

 and detached masses of metal in the fabric connected together and then united 

 with capacious conductors leading directly from the highest points of the 

 structure to the earth or sea. In applying such conductors to ships, each 

 mast should have its own conductor, of sufficient size, permanently fixed, and 

 connected with bands of stout copper passing through the sides of the ship 

 under the deck beams, and with the large bolts leading through the keels and 

 keelson to the water, including in the circuit all the principal masses of metal 

 used in the construction of the vessel. 



It is of the utmost importance, that Lightning Conductors be periodically 

 examined to see that they are in perfect condition, as any defects in continuity of 

 the metal rod or wire may lead to serious results. Several instances of most 

 destructive damage both to buildings and ships having lately occurred, arising 

 from defective conductors, we cannot too strongly urge the attention to this caution. 



FIG. 128. 



