Lightning Conductors. 



G. E. V. Thomas, A. M. Inst. E. E. 



Notes on Material and Method of Erecting 

 in the Straits Settlements. 



1. The number of many-branched terminals and massive 

 rods and cables of pure copper which adorn most of the build- 

 ings, indicate that the importance of attempting to safeguard 

 against the effect of lightning discharges is generally appreciat- 

 ed. A study of the attempts too frequently reveals a consider- 

 able lack of knowledge of modern methods. 



2. Numerous cases which have come under the writer's ob- 

 servation are applications of a theory, which obtained general 

 credence twenty or thirty years ago, that a conductor " pro- 

 tected" a defined area bearing some direct relation to its 

 height. A " law " to this effect was actually laid down and 

 found many adherents possibly because of its simplicity. 



3. In other cases a quite disproportionate amount of atten- 

 tion is paid to the earth connection, sometimes at the expense 

 of the material and work above ground. Tests which show a 

 resistance of more than an ohm or two, though made, frequent- 

 ly, during dry weather, are often considered sufficient to con- 

 demn a conductor satisfactory in other respects. 



4. The writer has been called upon to inspect a large num- 

 ber of conductors upon Government and Municipal buildings 

 during the past few years, and is forced tq the conclusion that, 

 in a large majority of instances, much greater protection could 

 be provided for a smaller initial outlay. 



5. To illustrate this the case of a certain powder magazine 

 in the Colony may be cited. As is usual for buildings of this 

 sort, very considerable care had been exercised by the Authori- 

 ties in the provision of elaborate conductors-and a very con- 

 siderable sum expended upon material and work. Broad strip of 

 pure copper is the material used and this is run along the main 



Jour. S. B. R. A. Soc, No. U, 1905. 



