1846] WRITINGS OF JOSEPH HENRY. 245 



elevated part of the wire which is supported on a high mast 

 at the place where the telegraph crosses the Hackensack 

 river. The fluid passed along the wire each way from the 

 point which received the discharge, for several miles, strik- 

 ing off at irregular intervals down the supporting poles. At 

 each place where the discharge to a pole took place a number 

 of sharp explosions were heard in succession, resembling the 

 rapid reports of several rifles. During another storm, the 

 wire was struck in two places in Pennsylvania, on the route 

 between Philadelphia and New York ; at one of these places 

 twelve poles were struck, and at the other eight. In the 

 latter case the remarkable fact was observed that every other 

 pole escaped the discharge; and the same phenomenon was 

 observed, though in a less marked degree, near the Hacken- 

 sack river. In some instances the lightning has been seen 

 coursing along the wire in a stream of light; and in another 

 case it is described as exploding from the wire at certain 

 points, though there were no bodies in the vicinity to attract 

 it from the conductor. 



In discussing these, and other facts to be mentioned here- 

 after, we shall for convenience adopt the principles and 

 language of the theory which refers the phenomena of elec- 

 tricity to the action of a fluid of which the particles repel 

 each other, and are attracted by the particles of other matter. 

 Although it cannot be affirmed that this theory is an actual 

 representation of the cause of the phenomena, as they are 

 produced in nature, yet it may be asserted that it is, in the 

 present state of science, an accurate mode of expressing the 

 laws of electrical action, so far as they have been made out; 

 and that though there are a number of phenomena which 

 have not as yet been referred to this theory, there are none 

 which are proved to be directly at variance with it. 



That the wires of the telegraph should be frequently struck 

 by a direct discharge of lightning is not surprising when we 

 consider the great length of the conductor, and consequently 

 the many points along the surface of the earth through 

 which it must pass, peculiarly liable to receive the discharge 

 from the heavens. Also, from the great length of the con- 



