252 Major Cardew and Major Bagnold. On the [June 21, 



The modus operandi is first to adjust the dial and Brush V until 

 Galvanometer V remains at zero, then adjust the index and Brush C 

 until Galvanometer C remains at zero. The angle indicated is then 

 exactly 2irt/T, measuring the difference of phase between E.M.F. and 

 current. 



It will be seen that as this is a null method, the self-induction of 

 the galvanometer circuits does not affect the results. 



V. " On the difference of Potential that may be established at 

 the Surface of the Ground immediately above and at 

 various distances from a buried mass of Metal charge from 

 a High Pressure Electric Light Supply." By Major 

 CARDEW, R.E., and Major BAGNOLD, R.E. Communicated 

 by LORD KELVIN, P.R.S. Received June 21, 1894. 



On the 8th January, 1894, an accident occurred at Bournemouth of 

 an unusual nature. An omnibus was in the act of drawing up in the 

 roadway outside the Imperial Hotel, when the horses suddenly fell 

 down, and one of them died in a few minutes. 



All the men who assisted in extricating the horses felt tingling sen- 

 sations in their limbs suggestive of electrical shock, and the con- 

 nexion from the mains of the Bournemouth Electric Light Company 

 to the hotel was known to pass underneath the spot at which the 

 accident occurred. 



This Company use the high pressure alternating system at 2,000 

 volts pressure, and in the case of this hotel the transformers were 

 installed upon the premises. 



On investigation, a defect in the insulation of one of the high pres- 

 sure service lines was discovered, from which sparking had evidently 

 taken place to the enclosing l|-in. wrought iron pipe. 



This pipe was 32 ft. long, laid at a depth of about 18 in., and ter- 

 minated at a brick junction box under the roadway, and a brick and 

 cement area wall at the hotel. The ends were thus fairly insulated, 

 while the rest of the pipe was in contact with the earth. 



The accident took place during the progress of a thaw, after a 

 very severe frost. 



Upon consideration of the case, Major Cardew reported to the 

 Board of Trade that in his opinion the accident was caused by 

 leakage from the short length of charged pipe, affecting the poten- 

 tial of the surface of the ground to such an extent that between 

 the fore and hind feet of the horse a sufficient difference of poten- 

 tial was established to give rise to the current which proved fatal. 



At the same time, as the fact of such a result following from a 

 simple contact with ordinary road material was a new experience of 



