. 



l.MHTS. 



angular jfele 

 ML The Iran. 



tiie hingv c D. while r U the conductor on the 

 conductor, fanned of double copper, U secured 



to the beams, and connected at each side with the iron knees, g M /< y, 

 and the bolt* pqr, naming through the ship and terminating in the 



copper sheathing as newly a* potable in the plane of the water-line. 

 The conductor* on all the maiU, in pining through the ship, are con- 

 nected with similar tnuuvene bands, led to the side as nearly as 

 puanble in the plane of the low water-line. The bands of copper 

 employed for these conductor* are 4 feet in length, and vary from 

 U to 6 inches in width, and from jjth to ,' th of an inch in thickness. 

 Holes are drilled in them inches apart, by which they are secured to 

 the marts by abort copper nails. The plates are fitted into shallow 

 grooves in the mart, and are inserted in a double series, placed so as to 

 allow the joints nt every two platen to fall upon the centre of another 

 plate immediately above or below it. This plan, which U not in any 

 way protected by a patent, is very minutely described in (),".- 

 "Instructions" for the application of Harris's conductor, printed by 

 order of the Lords Commissioners of the Admiralty. After many yean 

 of opposttioo, the pUn was at length introduced into' U. M. Navy, and 

 its inventor was rewarded with one of the annual peunioiui grouted to 



distinguuhed men of science, a parliamentary gr.n 

 knighthood; a reward by no means excessive, coming as it <ii<l in tli.- 

 rear of success, H.M. ships having been struck by lightning in all parts 

 of the world without sustaining any damage ; and in some caws the 

 hip has been so severely struck, that she actually " reeled under the 

 force of the discharge " (as the log of one of these ships has it), and, 

 instead of the wreck and devastation which would certainly have 

 followed the absence of conductors, and probably the presence of 

 inefficient ones, no sort of damage occurred. 



The application of lightning conductors t" 1. nil. lilies U guided by 

 the same principles as to ships. All the metal work of the building 

 should be *o connected as to render the whole a good conduct^ 

 throw it into that passive or non-resistant condition, with n- ; 

 the electrical discharge, that, when struck at any given i- 

 ning conductors would be so capacious that the electricity v. . . > I i li i\ 

 unlimited space for expansion on the surface of the earth 

 in all directions, farVhich, as we have seen, the charge is 

 determined. Probably the most extensive system of con- 

 ductors ever erected are those at the new palace at West- 

 minster, on a plan funiixhed by Sir \V. Snow Harris, and 

 described in the ' Estimates, &c., Civil Service, for the 

 year ending March 31, 1856, ordered by the House of 

 Commons to be printed.' 



Harris's conductors for buildings consist cither of wide 

 bands of copper, or of copper pipes from 1 to 2 inches in 

 diameter, the metal about Jth of an inch thick. It U pre- 

 pared in lengths of about 10 feet, which arc united by 

 means of short intermediate pieces furnished with screw?. 

 There is a notion among architects that the rod should 1 c. 

 insulated, and, accordingly, they attach it to the building 

 by means of rings of glass, forgetting, probably, that 

 when these become wet by the storm they no longer 

 insulate. This is quite unnecessary : the conductor may 

 be supported against the wall by means of coupling- 

 pieces or clamps ; the upper extremity should project 

 freely into the air, and should be pointed somewhat like 

 a bayonet, which pointed end may be about 18 inches, 

 | inch diameter, and be screwed into a solid plug fixed 

 into the tubing.* In cases where metallic vane-spindles 

 or other metallic points exist, the rod may ounm-nce at 

 once from them. The lower extremity of the rod lias 

 three divergent branches, which should pass under the 

 surface of the ground, and if possible be connected with 

 a spring of water, a drain, or some other conducting 

 channel Should the length of the conductor be con- 

 siderable, its diameter should be increased. In ext< i 

 ranges of buildings the most prominent parts should bo 

 furnished with conductors, and be connected by horizontal 

 lines running along the ridges of the roofs, &c. In the 

 accompanying figure the strong black lines represent the metallic con- 

 duoton, of which there is one to each spire a 6, leading to the metal- 



work of the roof and spires, while from the east end or gable c, ami the 

 transept gables d t, there are three conductors which unite in the centre 

 of the roof, fmni which they descend down one of the valleys to the 

 gutters. There is the same arrangement for the smaller gables fgh, 

 where the conductors are connected with the rain-water pipes. 



I . I ( 1 HTS, ANCIENT, are known to the law as the foundation of a 



right for which a man may prescribe over the premises ol m>t In r t., 



'obstructed passage of light in the same degree to which it has 



theretofore been enjoyed by him or those whom he has succeeded in 



occupation. The light of day is the property of none, and cannot bo 



* It Is curioun, that >t the time we are writing, a committee appointed by 

 the Academy I'nrin have jut lulled their ' Rapport lur leu pointer 



Ue pruumnc'rrc8.' ll 1 priuud iu llii> ' AnonK.i do Chiiuic,' 3 t-> ; 



