OPEN-WIRE TELEPHONE LINES 



733 



preserve the nominal spacing between wires and thus avoid the ir- 

 regularities in spacing which occur when drop bracket or "rolHng" 



Fig. 3 — Transposition of wires with drop bracket. 



transpositions are used. With the point transpositions, however, 

 two pairs of insulators are required at each transposition point as corn- 



Fig. 4 — "Point" transposition on break irons. 



pared with a single pair of insulators at a non-transposition point. 

 This results in an increase in the total number of insulators and in 



