134 J. A. POLLOCK AND S. H. BARRACLOUGH. 



are due to the heating of the pipe by the discharge or to 

 weathering. Probably the upper part of the tube which 

 has collapsed was raised to a higher temperature than the 

 rest of the pipe as it formed portion of the end of the elec- 

 trode where the development of heat is always considerable. 

 The tube as shown in one of the photographs (Plate in.) has 

 apparently buckled as a column under the small weight of 

 the ball (3|flbs.), allowing the latter to subside vertically. 

 This would indicate that the material at this point was in 

 a plastic condition. 



It is probable that the fusion at a figure 1 was due to an 

 arc which occurred on account of the right angled bend in 

 the conductor, and it is not to be considered as indicating 

 more than a very local high temperature. On this view 

 one should perhaps expect that the signs of fusion would 

 appear in the right angled piece shown to the left of the 

 tube in figure 1 ; the only signs of fusion however are found 

 to the right of the tube on the outer edge of the collar. 



Mr. G. H. Clark under whose supervision the conductor 

 was erected, supplies the following particulars: — "The 

 conductor was erected in 1889 on the chimney stack of the 

 Hartley Vale Kerosene Refinery. The finial, which stood 

 about 3 ft. above the cap of the chimney, consisted of a gun 

 metal ball 3| inches in diameter, having one large centre 

 point and four smaller radiating ones. The weight of the 

 ball was about 3J tbs. The copper pipe connected the 

 flnial with a somewhat massive copper goose neck just 

 below the cap of the chimney, which was attached to the 

 conductor, consisting of a copper band 1 X j inch. Prom 

 the base of the chimney the conductor was run in a trench 

 18 inches deep some 30 feet, thence into a well 30 ft. deep, 

 the band terminating in a grid, of 1 x -§- inch copper, 2\ x 2J 

 feet. This well supplied the works boiler with water; 

 when the water became foul with the soakage from the 

 Refinery it was usual to blow it out clean with a jet of 



