112 On Lightning Conductors. 



building, to place it on the side of the building most likely 

 to be moistened by rain, and, as far as possible, so to arrange 

 it that any considerable charge of electricity in or upon any 

 part of the building may be, so to speak, drained away as 

 easily as possible. If these last requirements be attended 

 to, little or no harm will result, even though the lightning 

 should in the first case strike a part of the building some 

 distance from the conductor. 



Several years ago the Meteorological Society of England 

 invited the co-operation of the Royal Institute of British 

 Architects, the Physical Society, and the Society of Tele- 

 graph Engineers in a conference upon lightning conductors. 

 The last-named societies responded to the invitation, and a 

 number of delegates were appointed, amongst whom were 

 Messrs. Latimer Clark, Preece, Ayrton, and Hughes, gentle- 

 men whose eminence in the electrical world is unquestioned. 

 The conference collected all accessible evidence, discussed 

 the same at numerous sittings during the years 1878, 1879, 

 1880, 1881, and ultimately published a most valuable report, 

 accompanied by a code of rules, for the construction and 

 erection of conductors, together with replies to questions 

 that had been widely circulated as to damage by lightning 

 and efficiency of conductors. 



Through the kindness of G. Watson, Esq., architect, Public 

 Works Department, I am enabled to submit this valuable, 

 but, unfortunately, little-known report, to the Royal Society 

 of Victoria. 



The code of rules is as follows: — 



RULES. 



1. Points. — The point of the upper terminal should nob 

 be sharp, not sharper than a cone of which the height is 

 equal to the radius of the base ; but a foot lower down a 

 copper ring should be screwed and soldered on to the upper 

 terminal, in which ring should be fixed three or four sharp 

 copper points, each about six inches long. It is desirable 

 that these points be so platinised, gilded, or nickel-plated as 

 to resist oxidation. 



2. Upper Terminals. — The number of conductors or 

 points to be specified will depend upon the size of the build- 

 ing, the material of which it is constructed, and the com- 

 ;parative height of the several parts. No general rule can 

 be given for this, but the architect must be guided by the 



