251.

In the 1900s, Alternating current was used to electrocute and kill stray animals like dogs, cats and unwanted cattle. X, who had a longstanding quarrel with Y, did not advocate the usage of AC current as Y was for it. In 1903, an elephant named Topsy in Coney Island Circus had gone astray and killed three men. AC Current was used to electrocute the elephant. (Picture below) X shot this electrocution in film, highlighting the potential dangers of the usage of AC current in day to day life, and made a video to discontinue the usage of AC.

Unfortunately for X, AC was found to be more convenient and it was adopted.

Identify X and Y.