354 Lightning Conductors in Ships. 



ships, in consequence of their masts, the only parts to which they 

 can be attached, being exposed to chances of injury, to motion in a 

 variety of ways, to frequent elongation and contraction, and to the 

 necessity which frequently arises for removing the higher masts alto- 

 gether, and placing them on deck. It was probably from these causes 

 that the small flexible chains or links above mentioned were employ- 

 ed. Such conductors, however, will probably, on examination, be 

 found less applicable than fixed continuous lines of metal, and, in 

 every point of view, inefficient substitutes for them. Their great 

 want of continuity, as well as their want of mass and surface, is very 

 unfavorable to the transmission of severe explosions, the electric mat- 

 ter becoming sensible at the points of junction, as is evident by the 

 sparks which appear upon them at the time of the discharge, so that 

 in some instances they have been actually disunited : they are like- 

 wise objectionable as being liable to every species of injury incident 

 to a ship's rigging, and much difficulty is experienced in keeping 

 them in their position, and unbroken, more especially during gales of 

 wind, and at night, when the ship is under sail, and when it is per- 

 haps required, as is already observed, to remove some portion of the 

 higher masts. It has therefore been long considered desirable to ap- 

 ply, if possible, a permanent conductor, which should be always in 

 its place, and ready for action ; and various attempts have been made 

 and suggestions advanced, at different times, to apply fixed lightning 

 conductors in ships, as the subject from time to time has demanded 

 further consideration. 



14. To protect a ship effectually from damage by lightning, it is 

 essential that the conductor be as continuous and as direct as possi- 

 ble, from the highest points to the sea — that it be permanently fixed 

 in the masts, throughout their whole extent, so as to admit of the mo- 

 tion of one portion of the mast upon another; and, in case of the re- 

 moval of any part of the mast, together with the conductor attached 

 to it, either from accident or design, the remaining portion should 

 still be perfect, and equivalent to transmit an electrical discharge into 

 the sea- 

 ls. To fulfil these conditions, pieces of sheet copper, from one- 

 eighth to one-sixteenth of an inch thick, and about two feet long, and 

 varying from six inches to one inch and a half in breadth, may be 

 inserted into the masts in two laminse, one over the other ; the butts 

 or joints of the one being covered by the central portions of the other. 

 The laminae should be rivetted together at the butts, so as to form a 



