Curiosities of Science. 167 



ANCIENT LIGHTNING-CONDUCTOR. 



Humboldt informs us, that " the most important ancient 

 notice of the relations between lightning and conducting metals 

 is that of Ctesias, in his Indica, cap. iv. p. 190. He possessed 

 two iron swords, presents from the king Artaxerxes Mnemon 

 and from his mother Parasytis, which, when planted in the 

 earth, averted clouds, hail, and strokes of lightning. He had 

 himself seen the operation, for the king had twice made the 

 experiment before his eyes." Cosmos, vol. ii. 



THE TEMPLE OF JERUSALEM PROTECTED FROM LIGHTNING. 



We do not learn, either from the Bible or Josephus, that 

 the Temple at Jerusalem was ever struck by Lightning during 

 an interval of more than a thousand years, from the time of 

 Solomon to the year 70 ; although, from its situation, it was 

 completely exposed to the violent thunderstorms of Palestine. 



By a fortuitous circumstance, the Temple was crowned with 

 lightning-conductors similar to those which we now employ, 

 and which we owe to Franklin's discovery. The roof, con- 

 structed in what we call the Italian manner, and covered with 

 boards of cedar, having a thick coating of gold, was garnished 

 from end to end with long pointed and gilt iron or steel lances, 

 which, Josephus says, were intended to prevent birds from roost- 

 ing on the roof and soiling it. The walls were overlaid through- 

 out with wood, thickly gilt. Lastly, there were in the courts 

 of the Temple cisterns, into which the rain from the roof was 

 conducted by metallic pipes. We have here both the lightning- 

 rods and a means of conduction so abundant, that Lichtenberg 

 is quite right in saying that many of the present apparatuses 

 are far from offering in their construction so satisfactory a 

 combination of circumstances. Abridged from Arago*s Meteoro- 

 logical Essays. 



HOW ST. PAUL'S CATHEDRAL is PROTECTED FROM LIGHTNING. 



In March 1769, the Dean and Chapter of St. Paul's ad- 

 dressed a letter to the Royal Society, requesting their opinion 

 as to the best and most effectual method of fixing electrical 

 conductors on the cathedral. A committee was formed for the 

 purpose, and Benjamin Franklin was one of the members ; their 

 report was made, and the conductors were fixed as follows : 



The seven iron scrolls supporting the ball and ci-oss are connected 

 with other rods (used merely as conductors), which unite them with 

 Several large bars, descending obliquely to the stone-work of the lantern, 

 and connected by an iron ring with four other iron bars to the lead 

 covering of the great cupola, a distance of forty-eight feet ; thence the 



