256 POWER DISTRIBUTION FOR ELECTRIC RAILROADS. 
equipment is much the same. The working conductor 
is here a forty-eight pound T rail, located much as in the 
Metropolitan line, but supported on special insulators in- 
stead of wooden blocks. ‘These insulators have a cast iron 
base and clamping top, united by a bolt sheathed like a 
    
  
     
= i o i e S o 
Position guard rail-—-old structure. 
   
Street Ry.Journal 
FIG. I3I. 
trolley hanger in dense insulation. This bolt is screwed 
into the base and secured to the cap by a coarse thread 
cast in cap and insulation and packed with melted sulphur. 
Fig. 131 shows the arrangement of this standard with its 
rail and guard planks. These insulating chairs support 
the rail every six feet. The bonding of the third rail is 
with copper strips, secured to the rail with two rivets,