372 Royal Society. 



the chain was made to descend along the back-stay, and below was 

 kept at a distance of ten feet from the starboard bulwarks by a light 

 wooden outrigger, or spar. Its whole length was 145 feet, of 

 which about nine feet of its lower part descended into the sea. 

 The wisdom of adopting this precaution was soon apparent, for in 

 the course of the same morning the ship was struck by a second 

 explosion, which is stated by the unanimous testimony of all on 

 board to have far exceeded in violence the first. It melted a great 

 part of the conductor, producing a vivid combustion of many of the 

 links, which burned like so many tapers ; and descending into the 

 sea, darted off to a considerable distance along the surface of the 

 waves. The resistance to its passage was so great as to cause the 

 ship to recoil with a sudden and violent shock, so as to throw down 

 several of the crew. The melted iron of the conductor fell in large 

 drops on the deck, which although already strewed with hailstones 

 that had previously fallen, intermixed with rain, was set fire to in 

 many places by the ignited metal. No damage, however, was done 

 to the masts or rigging, not the least injury to any of the crew, with 

 the exception of a carpenter, who being at work with an iron auger 

 in his hand, received a smart shock through the wrists, which oc- 

 casioned a livid tumour which was still visible six weeks after the ac- 

 cident. 



Soon after the arrival of the vessel in Liverpool, she was docked 

 in order to ascertain what damage she had sustained. Some of her 

 planks were found to have started, but her timbers were uninjured. 

 Every instrument made of steel, — such as the carpenter's tools, and 

 the knives and forks ; and also those made of soft iron, even to the 

 very nails in every part of the ship, — had been rendered permanently 

 magnetic. All the watches and chronometers were either stopped 

 or rendered useless, by the magnetism imparted to the balance- 

 wheels and other parts of their works that were made of steel. Con- 

 trary to what usually happens from shocks of artificial electricity, 

 the lightning had given a strong northern polarity to the upper part 

 of the conductor. Many parts of the iron-work indeed had ac- 

 quired the magnetism corresponding to their position with respect 

 to the magnetic direction ; but in others no relation of this kind 

 could be traced. Great changes were produced on the magnetism 

 of the compass needles, in many of which were formed several 

 sets of poles, and their indications could therefore no longer be 

 relied on. 



The circumstances attending the accident which is the subject of 

 this paper, are considered by the author as strongly confirming the 

 value of conductors to ships in obviating the destructive effects of 

 lightning. From the inquiries he has made, he is led to the belief 

 that injuries from lightning at sea are much more frequent than is 

 generally imagined. One source of increased danger of late years 

 is to be found in the greater proportion of metal, and particularly 

 of iron, which is employed in the rigging ; more especially as the 

 metallic masses are there nearly insulated, or connected only by 

 very imperfect conductors. In the instance before us, it is in the 

 highest degree probable, that if the New York had been without 



the 



