LIGHTNING AND LIGHTNING CONDUCTORS. 5 



.cilitated by pointed vegetable conductors, the rule ap- 

 plies to pointed metallic conductors also, and the tendency of 

 lightning towards them will depend on their number and pro- 

 icy, and the sharpness of their points. Hence those tall 

 conductors which present several pointed branches to the air, 

 are better adapted for facilitating lightning discharges than 

 those that terminate with one point only. Hence also (57) 

 several distinct pointed conductors, distributed over a com- 

 paratively small area of ground, or attached to different parts 

 of an extensive building, are more likely to cause strokes of 

 lightning in the locality than one conductor only, though 

 furnished with the same number of points. 



61. With respect to the ocean, which is a better conductor 

 than either wet land or lakes of fresh water, its natural elec- 

 tric fluid would be easily displaced by the repellent force of a 

 thunder-cloud, although not so well prepared for the reception 

 of fluid from the air as wet land well clothed with vegetation. 

 The presence of shipping, however, whose masts and rigging 

 stand prominently above the surface of the water, tend much 

 to facilitate those electric intromissions which qualify the air 

 for the transport of lightning from a cloud to its destination ; 

 and since every portion of metal in the rigging enhances the 

 conduction, and thus increases the tendency of lightning dis- 

 charges in the direction of the ship, there appears every 

 reason to infer that those vessels which expose pointed con- 

 ductors, more lofty even than the masts themselves, are more 

 likely to experience strokes of lightning than any other. 



62. The above inference (61) appears to be somewhat 

 countenanced by the "return ordered to be laid before the 

 House of Lords, by precept, dated 4th May, 1848," in which 

 it is shown that sixteen men-of-war, fitted with pointed con- 

 ductors in the masts, were struck by lightning between March, 

 1840, and January, 1848. One of these vessels, the Favorite, 

 is reported to have been struck "several times," and the 



ird and Dido appear to have been struck twice each, 



