LIGHTNING AND LIGHTNING CONDUCTOES. 17 



standing any flash of lightning that may assail them, are 

 strong recommendations for the employment of globular 

 terminations to conductors. They offer precisely the same 

 amount of protection as pointed conductors, should lightning 

 come in their way, whether the discharges be vertical or 

 oblique ; and as they can never be accessory to its approach, 

 they possess important advantages over those of the usual 

 form. 



87. I know of no better general guide for the application 

 of lightning-rods, than that embraced in the following motto : 

 Offer no facilities for the approach of lightning ; but pre- 

 pare for its reception in case it comes, 



88. With respect to the practical application of conductors 

 to buildings, no individual plan will answer for every fashion 

 of edifice. The most simple systems of conductors are those 

 that would be applicable to cottages, powder magazines, 

 steeples, tall factory chimneys, &c, for which some general 

 rules might be given ; but buildings with complicated irre- 

 gular roofs, and decorated gables, chimneys, &c, would re- 

 quire a peculiar plan of conductor for each fashion of house. 

 But no building, however plain in its structure, can be 

 rendered secure against lightning by one individual rod only. 



89. I have devised the following system of conductors for 

 powder magazines. It consists of three vertical arches of 

 cylindrical copper rod, which are united by a horizontal rod 

 of the same metal, and furnished with three balls. 



90. Steeples, of the form of square towers, ought to have 

 a vertical copper rod at each angle, united by a copper band 

 at the top, or just above the uppermost weather mouldings. 

 The vertical rods should reach to above the highest pinnacles, 

 and be surmounted with copper balls; or the whole might 

 unite in one ball directly over the axis of the steeple. 



91. Spires may be protected by three copper rods united 

 in a ball at the apex of the cone, and reaching downwards, 



