Western Union splice
The Western Union or Lineman splice was developed during the introduction of the telegraph to mechanically and electrically connect wires that were subject to loading stress. The wrapping pattern is designed to cause the termination to tighten as the conductors pull against each other. This type of splice is more suited to solid, rather than stranded conductors.
The Western Union Splice is made by twisting two ends of a wire together, traditionally counterclockwise, 3/4 of a turn each, finger tight. Then, usually using needle-nose pliers, the ends are twisted at least five more turns, tightly. The cut off ends are pushed close to the center wire.
NASA tests on 22 and 16 AWG wire showed that the Western Union Splice when soldered is very strong and is stronger than the wire alone if done properly.