While searching online I found a page of the Illustrated Sporting and Dramatic News (27th September 1884) full of pictures of the Hertfordshire Polo Club tournament held at Panshanger. It is being sold by prints-4-all on ebay and if you want to see the full page of pictures visit the advert before it is sold. I decided to look at the Herts Mercury to see what it says and found the pictures show a meeting at Panshanger between the Herts Polo Club, the Royal Field Artillery Polo Club and the West Essex Polo Club in September 1884. I also located details of four other meetings including one with the Cambridge University Polo Club.
Further details (including the full text of the September meeting and references to the other meeting - together with some thumbs from the advert.)