TRANSACTIONS OF SECTION A. 599 



proving that it did protect an area. He knew Mr. Preece's theory about the pro- 

 tection of areas because it had been published in the ' Phil. Mag.' The area, as 

 Mr. Preece knew, was so extremely small that he thought they might almost 

 give it to him witbout much argument. 



Even then they would not be sale. Xow why did he object to such a bit of 

 protection as that ? He objected to it mostly because he thought that areas of 

 protection directed one's attention to side issues, to a thing which it is better not 

 to think about because there is no certain area of protection as one could show 

 in this way. Take another rod completely enclosed in this area of protection 

 and bring it up near to the lightning-conductor. Now if area of protection 

 has any meaning, that rod ought be protected ; but he said that when a light- 

 ning flash — this was merely an assertion — strikes that conductor they woidd 

 most likely, almost certainly, get a spark down the second rod, and it would 

 take its share in operating to convey the current. Therefore that is not pro- 

 tected. If a man holds a lightning-conductor when a flash passes down it he will 

 most likely be killed ; and if it passed through — well, he did not know about 

 gunpowder because gunpowder got blown about. It did not matter about the 

 earth — about that being a good earth and this being a bad earth — still the same 

 effect will occur ; a spark is likely to occur if the distance be not too great. He 

 said that that is so because he had made experiments in the laboratory after this 

 fashion among others: he took a rod (which might be as thick as they pleased) a 

 yard long and put it in circuit with a Leyden jar discharge, sending discharges 

 through the rod. He then took a Wollaston platinum wire or any other wire, as 

 line as possible to make the contrast greater, and arranged it so as to make a kind 

 of tapping circuit ; if then the bottom end was arranged so as to be in contact with 

 the rod and then let the top end be an eighth of an inch away or a sixteenth of an 

 inch away, then they would have a splendid conductor, better than any lightning 

 conductor ever was. They would have no trouble about earth ; they would have 

 close to it a little tapping circuit, the Wollaston wire which they could hardly see. 

 It seemed absurd for any portion of the discharge to leave this conductor to jump 

 across the sixteenth of an inch and to make for the little strip of wire. Neverthe- 

 less a portion of it did and from every spark that went to the conductor a side 

 branch went to that little wire. 



There was one point where Mr. Preece might have attacked him, but where he 

 did not think that gentleman had made out the full strength of his case, namely, 

 the question, What are the conditions of a flash? He (Professor Lodge) had 

 assumed that a flash behaved like experiments in a laboratory, but it was a question 

 whether a cloud discharge was of this kind. A cloud is not like a conductor ; it 

 consists of globules of water separated from one another by interspaces of air ; it 

 may be compared to a Spangle jar; when a Spangle jar discharges you have no 

 guarantee that the whole of it discharges, it discharges in a slowish manner. It 

 may be that there was with a cloud flrst a bit of a discharge and then another bit, 

 and so on ; so that there might be a kmd of dribbling of the charge out of it, and 

 they might therefore fail to get these oscillatory and sudden rushes. At the same 

 time he did not think that they could always guarantee doing this, and it would 

 not be safe in arranging for protectors to protect for only one case and that the 

 easiest. They must provide for the possibility of a sudden and actual discharge. 

 Still the conditions of actual lightning were to be met by observing lightning, and 

 not by experiments in the laboratory. Thus they had the momentum of one spark 

 exciting others ; he was sure there were multiple flashes. There was a photograph 

 which Mr. Abercromby had with him, and which he hoped would be shown to the 

 meeting, where the flash is breaking the air down in all directions at once. It was 

 most extraordinary the way in which there seemed to be a rod set up in the air so 

 that one flash began and the whole thing smashed up in all directions. There was 

 a point there which could only now just be called attention to, namely, the light 

 of one spark assisting others to form. A spark of an induction coil here would be 

 able to start the spark of another induction coil up in the gallery merely by its 

 light ; if it was closer it would do better but it would do it at a very considerable 

 distance. When they came to consider the very bright light of a lightning flash 



