Children riders rehearse for their big day . One of the features of the Harringay Horse Show , which opens tomorrow , will be the riding and jumping performance by a team of young riders , all of them members of the Crawley and Horsham Pony Club . For some time now the youngsters have been practicing hard under the supervision of Brigadier and Mrs John Allen of Ashington , Sussex , and today they have a rehearsal at Harringay for tomorrow's opening . Photo shows ; Watched by horsewomen at Harringay today a youthful rider practices one of the demonstration jumps for tomorrows show . 12 September 1949