

AND HORTI CULTURAL REGISTER. 



PUULISHED BY JOSEPH BRECK & CO., NO. 52 NORTH MARKET STREET, (Agricultural WahehouseO-ALLEN PUTNAM, EDITOR. 



voii. xixo 



BOSTON, WEDNESDAY EVENING, MAY 5, 1841. 



[NO. 44. 



N. E. FARMER. 



[Communicated.] 

 LIGHTNING CONDUCTORS. 



Is there amj effectual method upon which we may re- 

 ly ivith confidence of protecting buildings from 



the disastrous effects of. Lightning '7 

 This riucstion is an important orte, and involves 

 the most raoinentons conser|iionces, inasmuch a.s 

 life and property are concerned. It is a qiiestinii 

 upon which many doubts have arisen as objeclions 

 to thi: use of Liirhtniiig Conductors, from the fart 

 that a great number of buildinjjs havi> been struck 

 with lightning' with the common round rods attach- 

 ed to them. But these doubts would be removed 

 if those who possess them could become fully ac- 

 quainted with the principle of Strong's Patent Light- 

 ning Conductors, which are constructed after the 

 manner of Dr. King's well known tnethod, with 

 some, though very important, improvements. 



It is for the purpose of showing, in some degree, 

 the utility of these conductors, and the advantages 

 they possess over any others now in use, that the 

 following facts are presented for your considera- 

 tion. 



It is not necessary to go into any detail of causes, 

 but is sufficient to know that clouds are formed in 

 the atmosphere and become charged with electri- 

 city, and whenever two bodies, such as two clouds, 

 or a cloud and the earth, become charged to a cer- 

 tain intensity, according to the resistance opposed 

 to its passage through the atmosphere, it will over- 

 come that resistance and break through the inter- 

 vening space ; and it is while thus restoring its 

 equilibrium, that it so frequently passes through 

 buildings and other (jbjects in its course, and cau- 

 ses such terrific effects. 



Probably every person is aware that lightning 

 does not always go in one directiim. This is ob- 

 vious to the eye. Its course is as variable as the 

 wind. It darts from the earth t;) the clouds, from 

 the clouds to the earth, and from one cloud to 

 another through the atmosphere, going horizontallv, 

 obliquely, and vertically, and sometimes taking the 

 earth iu its course as a conductor, alike regardless 

 of life, property and vegetation. Dr. Franklin was 

 the first who proposed the use of metallic conduc- 

 tors for the purpose of controlling the discharges 

 of lightning in such a marmer as to prevent their 

 passage through buildings. With the knowledge 

 ho then possessed of the science of electricity, he 

 supposed that a single round rod of iron would, in 

 every respect, answer the 'purpose intended. But 

 after having made a fair trial, he found' that build- 

 ings were sometimes struck, notwithstanding this 

 precaution. He then sought for a remedy ; and, 

 reasoning from the fact that a sharp pointed or 

 rough piece of metal would restore the equilibrium 

 of electricity without explosion, and with much 

 greater facility than a round smooth piece, he was 



I led to the conclusion that a square slit nail rod 

 would bo preferable on account of its sharp cor- 

 ners, and accordingly, towards the close of his life, 

 he affi.\ed them to a number of buildings in Phila- 



delphia, and recommended them fur that purpose in 

 preference to any other form. 



But improvement did not stop here. The fol- 

 lowing is one of the circumstances which led Dr. 

 King to study into the subject, which resulted in 

 the application of a system of protecting buildings 

 which has thus far proved his theory to be correct: 

 As a company of U. S. Infantry was returning 

 from the funeral of an officer, in the t.'wn of Baton 

 Rouge, La., they were overtaken by a thunder 

 storm, and while passing the residence of Dr. King, 

 who stood at the door with his attention directed 

 towards them, he b^w a flash of lightning which 

 appeared to descend like a sheet of (ire onto their 

 bayonets. He inmiodiately made inquiries as to 

 the effect it |)roduced, and was informed " that they 

 nil received a severe shock." If there had been no 

 more than three or four persons, they would, in all 

 probability, have been killed; for as their gim bar- 

 rels did not extend to the ground, the charge was 

 obliged to pass through their bodies, which served 

 as a part of the conductors. But as there were a 

 great number of points presenteu to the charge, it 

 was civided, and each peison receiving a propor- 

 tion, almost entirely destroyed its effects. He in- 

 ferred from these facts, that if a groat iiuinber of 

 points were erected on a building, it would, in the 

 same manner, disperse and weaken the 'charge. 



The prmcipal filature of the Improved Conduc- 

 tors consists in their presenting metallic points to 

 the atmosphere iu all directions, in descending in- 

 to the ground at two or more e.xposed corners of 

 the building, and in being so connected that no 

 one portion of the rods shall be detached from 

 another; and their usefulness depends chiefly up- 

 on their being properly arranged and secured on 

 the building, so that tliey may be able to receive 

 the various discharges of lightning, and, each rod 

 connected with the ground receiving a proportion, 

 conduct it off in a divided state ; or silently to ef- 

 fect its equilibrium, which is by fur the most fre- 

 quent. A demonstration of the dispersing power 

 of these conduct(jrs occurred a few weeks after 

 they were affi.xed to the Hollis Street Church, Bos- 

 ton, which was previously struck by lightning four 

 times, notwithstanding it had a round rod attached 

 to it, and twice it was set on fire. . The circum- 

 stance was related to the subscriber by persons who 

 were eye witnesses. As a thunderstorm was 

 passing over the city, their attention was directed 

 towards the churcli by a vivid flash of lightning, 

 which appeared to descend obliquely, in the form 

 of a ball, to.within a short distance of the building, 

 when it burst into innumerable fragments, and dis- 

 appeared oii the points of the rods. Another of a 

 similar character was observed on a building in the 

 Navy Yard, Portsmouth, N. H. 



Ever since Dr. King first applied his conductors 

 to buildings, (whicli was about twenty years ago,) 

 they have been constructed in the following man- 

 ner, viz: — Iron nail-rods three eighths of an inch 

 square, and from five to nine feet in length, or cop- 

 per of proper dimensions, cut from sheets about the 

 same length, and twisted, are made to connect to- 



gether by means of a point ab(mt two inches and a 

 half in length, turned at right angles with the rod 

 on one end, to fit into an eye turned on one end of 

 the ne.xt rod in series, and the whole secured to 

 the building by a staple. 



Now there is a very serious objection to this 

 mode of connectmg the rods. Not but that the 

 use of tlie staple is well enough, fur a charge of 

 electricity will never leave a good conductor to 

 follow a bad one, (such as wood,) providing that 

 conductor be sufficient to ctmtHin and carry "it off. 

 But the objectinn lies in the fact that the conncc- 

 lion depends almost entirely on the staple ; which, 

 if by any means, either by the action of the wind, 

 the decay or shrinking of the wood, or its being 

 improperly driven, it should work loose and come 

 out, (a very common occurrence,) the rod having 

 the eye is liable to hang away or spring from the 

 point, in which case their power as conductors. of 

 electricity would be entirely cut off, and would 

 serve only to lea,d the charge into the building and 

 even render it more liable to damage than if there 

 were uo conductors attached to it. 



The subscriber is happy to inform the public, 

 that in order to remedy this defect, he has made 

 an e.ssential improvement, the importance of which 

 niust be obvious to every one. 



Instead of making an eye and a point on the 

 ends of the rods, the ends are flattened and screw- 

 ed together by means of the points, which are made 

 separate from the rods. In this way a close and 

 permanent contact is made, independent of the sta- 

 ple, and although the staple may come out, still the 

 connection will always remain perfect. Besides it 

 affords a free ar.d uninterrupted passage for the 

 electric fluid, which is necessary for the safety of 

 the building; whereas in the other case, it is very 

 much obstructed in passing through so many im- 

 perfect connecUons. i his we know from e.xperi- 

 iiient. But, notwithstanding this, no buildimr to 

 which Dr. King's conductors have been affi.xed, has 

 as yet been reported as having been struck by 

 lightning, except in a few instances where the rods 

 were disordered in the manner above mentioned. 



Again: there are many persons who would like 

 to have lightning conductors aflS.xed to their build- 

 ings, but consider copper too e.xpensive,* and ob- 

 ject to iron because it is so subject to oxydation, 

 or corrosion. Rust does not essentially impair the 

 conductive power of metals, but, like paint,t it al- 

 most entirely destroys their receiving and discharg- 

 ing power, because it is a Jion-cnnductor of elec- 

 tricity. The points being the most important part 

 of the rods, it is necessary that thej' lie preserved 

 from rust as much as possible. For this purpose 

 the subscriber uses iron points coated with zinc,X 



•Copper is much less liable to corrosion than iron, 

 and lor this reason it is used, in preleriince to the latter, 

 fur that part of tlie rod which is placed in the irrouiid. 

 It is also .1 better conductor. 



tLightning conductors should in no case whatever le 

 painted. 



tit is well known that the electro-chemical action be- 

 tween zinc and iron, when in contact with each other, 

 eirectually preserves the latter from the least degree of 

 oxydation. 



