Night Watchman
... that the Canadian Night Watchman was the first operational radar system in North America?
... that the Canadian <b id="mwAdw"><a href="./Night_Watchman_(radar)" id="mwAd0" rel="mw:WikiLink" title="Night Watchman (radar)">Night Watchman</a></b> was the first operational <a href="./Radar" id="mwAd4" rel="mw:WikiLink" title="Radar">radar</a> system in North America?