162 Mr Harris o)i the Utility (yf fixing 



manently fixed in the masts, throughout their whole extent, so 

 as to admit of the motion of one portion of the mast upon ano- 

 ther ; and, in case of the removal of any part of the mast, to- 

 gether 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. 



15. 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 laminae, 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 to- 

 gether at the butts, so as to form a long elastic continuous line ; 

 the whole conductor is inserted under the edges of a neat groove, 

 ploughed longitudinally in the aft side of the different masts, 

 and secured in its position by wrought copper nails, so as to 

 present a fair surface. The metallic line thus constructed, will 

 then pass downward from the copper spindle at the mast-head, 

 along the aft sides of the royal-mast and top-gallant-mast, being 

 connected in its course with the copper about the sheeve-holes. 

 A copper lining in the aft side of the cap, through which the 

 top-mast slides, now takes up the connection, and continues it 

 over the cap, to the aft side of the top-mast, and so on as be- 

 fore, to the step of the mast. Here it meets a thick wide copper 

 lining, turned round the step, under the heel of the mast, and 

 resting on a similar layer of copper, fixed to the keelson. This 

 last is connected with some of the keelson-bolts_, and with three 

 perpendicular bolts of copper, of two inches diameter, which are 

 driven into the main keel upon three transverse or horizontal 

 bolts, brought into immediate contact with the copper expanded 

 over the bottom. The laminae of copper are turned over the 

 respective mast-heads, and secured about an inch or more down 

 on the opposite side ; the cap which corresponds is prepared in 

 a somewhat similar way, the copper being continued from the 

 lining in the aft part of the round hole, over the cap, into the 

 fore part of the square one, where it is turned down and secu- 

 red as before, so that when the cap is in its place, the coDtact is 

 complete. In this way, we have, under all circumstances, a 

 continuous metallic line, from the highest points to the sea, 



