No. 



Lightning Rods, — JVo. 1. 



247 



For the Farmers' Cabinet. 



Lightning Rods, — No. 1. 



My attention was recently turned to the 

 subject announced in the caption to this arti- 

 cle, by reading two papers in tlie current 

 volume of the Cabinet, one signed J. M. P.,* 

 the other from the pen of Professor Olm- 

 sted. f 



If I am not mistaken in the person of our 

 old friend Observer, deep family affliction 

 and more engrossing cares have for a long 

 time withdrawn him from the pages of his 

 favourite Cabinet. Perhaps / may therefore 

 be excused for offering a few remarks on the 

 subject of Lightning Rods, which might 

 , more appropriately come — and in a more 

 ._, instructive tbrm too — from his pen. I ac- 

 knowledge myself much indebted to his val- 

 uable papers, and as the suggestion- of a 

 correspondent (vol. 5, page 228,) in favour 

 S of republishing those papers, did not meet 



* with a favourable response from the then 

 editor, I shall make free use of the materi- 

 als which are there to be found. 



J. M. P. say.«, — and perhaps truly — "it 

 , must be manifest that there exists a culpa- 

 ble ignorance on the part of the community 

 in relation to this whole subject." To me 

 this ignorance is more lamentable than cul- 

 pable — more a cause of regret than of sur- 

 prize. How shall the people be otherwise 

 . than ignorant, when it is " manifest" that 

 the priests — those who undertake to teach 

 '• knowledge — too often themselves, betray 

 something a little worse than ignorance — 

 error — and error is always worse than igno- 

 rance. For ignorance merely implies a 

 .want of the knowledge of the true, and 



* may lead to the omission of what is right — 

 but error is the adoption of the false, and 

 must lead to the commission of what is 

 wrong. Indeed such are the discrepancies 



:■ between writers on lightning rods, as fre- 

 quently to suggest the sarcastic query — 

 who shall decide when doctors disagree] 



I can hardly hope to be more fortunate 

 than those who have preceded me — or to 

 be able wholly to extricate my readers from 

 the bewildering labyrinth of error and in- 

 certitude into which they have been unfor- 

 tunately led. Indeed I know that some of 

 my views are opposed by high authorities; 

 but I do not hold my opinions subject to 

 their dictum. 



The object of these papers is : — 



First, To lay down a few relevant principles 

 of electrical science, and to illustrate them 

 as fully as my means will admit. 



Second, To draw from these principles cer- 



* Number 2, page 61. f Number 3, page 97. 



tain inferential rules for the construction of 

 lightning rods, which will be intellifrible to 

 common readers. It is too much to ask the 

 implicit confidence of any one, in facts which 

 he cannot comprehend — and the whys and 

 ivherefores of which he does not understand. 



1. Electricity is a universally diffused 

 principle— a variable quantity of it pervades 

 all material bodies. This is called their 

 natural quantity of electricity. 



2. Some bodies — as the metals, water, 

 and moist substances generally — possess the 

 property of allowing electricity to pass free- 

 ly through them, and are thence called con- 

 ductors of electricity. 



3. Another class of bodies — as glass, wax, 

 resin, silk, atmospheric air, earth^and wood 

 when perfectly dry — do not allow electricity 

 to pass through them, and are therefore 

 called non-conductors of electricity. 



4. The particles of the electric fluid have 

 a strong mutual repulsion for each other, 

 which causes them to disperse with a force 

 which decreases as the squares of their dis- 

 tances increase. This is called electrical 

 repulsion. 



5. The same particles strongly attract, 

 and are attracted by other bodies, and thus 

 attach themselves to them. This is called 

 electrical attraction. 



6. When the repelling and attracting 

 forces are unequal, the fluid will be put in 

 motion in the direction of the stronger force 

 This is called the electrical current. 



7. When the two forces are equal, the 

 fluid will remain at rest. This is called 

 electrical equilibrium. 



8. Electrical phenomena can only be pro- 

 duced by interposing some nonco7iductor, 

 so as to intercept the electrical current, and 

 cause the fluid to collect in more than its 

 natural quantity. If all bodies were good 

 conductors of electricity, it would soon find 

 an equilibrium, and forever remain in a qui- 

 escent state without being in any way cog- 

 nizable to our senses. It is only when this 

 equilibrium is disturbed by means of non- 

 conductors, that we can recognize its exist- 

 ence. This is called the accumulation of 

 electricity. 



9. When two substances are rubbed toge- 

 tiier — one or both of which are nonconduct- 

 ors — as the glass and cui-hion of an electrical 

 machine, the natural electricity of both will 

 be disturbed, and they will exhibit electrical 

 phenomena. This is called electrical ex- 

 citement. 



10. When by means of the electrical ma- 

 chine we give to a body more than its na- 

 tural quantity of electricity, it is called the 

 electrical charge, and the body is said to be 

 electrifed, or charged. 



