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Section G.— MECHANICAL SCIENCE. 

 Peesident op the Section— W. H. Preece, F.R.S., M.Inst.C.E. 



THURSDA Y, SEPTEMBER 6. 

 The President delivered the following Address : — 



' Canst thou send lightnings, that they may go, and say unto thee, Here 

 we are ? ' were pregnant words addressed to Job unknown centuries ago. They 

 express the first recorded idea in history of the potentiality of electricity to minister 

 to the wants of mankind. From Job to Franklin is a long swing in the pendulum 

 of time. It was not until that American philosopher brought down atmospheric 

 electricity by hia kite-string in 1747, and showed that we could lead it where we 

 willed, that we were able to answer the question addressed to the ancient patriarch. 

 Nearly another century elapsed before this mysterious power of Nature was fairly 

 conquered. It has been during this generation, and during the life of the British 

 Association, that electricity has been usefully employed ; and it is because I have 

 taken a subordinate position in inaugurating nearly all of its practical applications, 

 that I venture to make the developments of them the text of my address to this 

 section. 



People are singularly callous in matters afiecting their own personal safety ; 

 they will not believe in mysteries, and they ridicule or condemn that which they 

 do not understand. The Church itself set its face against Franklin's 'impious' 

 theories, and he was laughed to scorn by Europe's scientific sons ; and even now, 

 though commissions composed of the ablest men of the land have sat and re- 

 ported ou Franklin's work in England, France, and nearly every civilised nation, 

 the public generally remains not only ignorant of the use of lightning conductors, 

 but absolutely indifferent to their erection, and, if they are erected, certainly careless 

 of their proper maintenance. I found in a church not very far from here the conductor 

 leaded into a tombstone, and in a neighbouring cathedral the conductor only a 

 few inches in the ground, so that I could draw it out with my hand. Although 

 I called the attention of the proper authorities to the absolute danger of the state 

 of affairs, they remained in the same condition for years. 



Wren's beautiful steeple in Fleet Street, St. Bride's, was well-nigh destroyed by 

 lightning in 1764. A lightning rod was fixed, but so imperfectly that it was again 

 struck. In July last (1887) it was damaged because the conductor had been 

 neglected, and had lost its efficiency. 



As long as points remain points, as long as conductors remain conductors, as 

 long as the rods make proper connection with the earth, lightning protectors will 

 protect ; but if points are allowed to be fused, or to corrode away ; if bad joint* 

 or faulty connections are allowed to remain ; if bad earths, or no earths, exist, 

 protectors cease to protect ; and they will become absolute sources of danger. 

 Lightning conductors, if properly erected, duly maintained, and periodically in- 

 spected, are an absolute source of safety; but if erected by the village blacksmith, 

 maintained by the economical churchwarden, and never inspected at all, a loud report 

 will some day be heard, and the beautiful steeple will convert the churchyard into 

 a new geological formation. 



