106 ANNUAL OF SCIENTIFIC DISCOVERY. 



phorc, just as it would seek to do if assailed by an explosion from the cloud. 

 But thousands of rods have been put up by the peddlers in direct violation 

 of this rule, even when the prominent points of the building were in tlic 

 proper quarter. The gable-ends of barns most remote from the approaching 

 cloud are selected by them as frequently as the proper end. Persons of the 

 highest pretensions in their business of making conductors are constantly 

 committing this grievous error. It cannot be too speedily and generally 

 corrected. Some five years ago a young woman was picking cherries in a 

 tree which stood near her father's house, in Warren County, New Jersey. A 

 cloud was seen to be approaching, though at a great distance. But it was 

 surrounded and preceded by a highly excited electrical atmosphere. There 

 was no rain, as the cloud was a great way off. Yet persons in the neighbor- 

 hood saw a flash traverse the air in an almost horizontal line, and shatter the 

 tree in which the girl was seated, and she was killed. This was an unusual 

 occurrence; and yet a similar discharge has been seen to leave a cloud and 

 traverse a great distance, until it reached a stream of rarefied air, sent up 

 from a barn but recently filled with new hay. It followed this stream as a 

 choice conductor, struck, and destroyed the barn. 



This presence of an electrical atmosphere has sometimes exhibited the 

 most remarkable phenomena. The great lightning storm of June, 1848, was 

 especially productive of them. Mr. Cooper's rolling-mill at Trenton, N. J., 

 seemed to be charged in every part with electricity. Though that storm 

 extended over a surface of seven hundred miles, yet no place witnessed a 

 more singular display of its mighty energies than Trenton. The lightning 

 struck the earth there repeatedly. A workman at the rolling-mill attempted 

 to lower the iron-damper, which was connected with iron chains, but he no 

 sooner laid his hand on the latter than he received a shock which prostrated 

 him. A second workman repeated the attempt, and was in turn knocked 

 down, while the third also received a severe shock. A fireman attempted to 

 stir the melted iron in the furnace, but the instant his iron-stirrer touched the 

 fluid metal he received a violent shock. Other similar facts occurred, show- 

 ing that the whole atmosphere was charged with electricity to an extraor- 

 dinary extent, and that chains, bars, furnaces, and even the melted metal, 

 were silently acting as conductors between the cloud and the earth, giving 

 out neither shock nor spark unless touched by the unconscious workman. 

 The masses of metal which surrounded the three hundred hands employed 

 in the mill were so many potent protectors. But the same precautions should 

 be used to guard against the electrical atmosphere which invariably precedes 

 and surrounds a thunder-cloud, as against the cloud itself. 



The true position in which the rods should be affixed having been ascer- 

 tained as mentioned above, the next important question is as to the quantity 

 of iron to be used. A wire one-quarter inch thick will effectually protect any 

 building, providing there be a point of stiff metal set up on every prominent 

 part, with as many outlets into the ground as there are points in the air, the 

 whole being connected by cross wires extending over the building. Galvan- 

 ized wire is preferable to all others, as it is not liable to oxidation. The 

 greater the quantity of iron, and the more numerous the outlets, the greater 

 the safety. This is in accordance with Franklin's directions, except that the 

 quantity of iron is increased. A large building should have some hundreds 

 of feet of rod, and any building whatever should have not less than two 

 points and two outlets. There is a good reason for this apparent profusion 

 of iron. Explosions of electricity vary in intensity, some being very feeble, 



