Hi Serendipidy,
The photo of Alex and Pat is a frontispiece in all the early editions of his book, 'Ballroom Dancing'. The caption reads:
/*Famous teachers and demonstrators of ballroom dancing show the position of the feet and body in the Whisk variation.*/
Philip J. S. Richardson wrote of Alex:
/* I have known him for a number of years and one of my first recollections of him is his success, with his sister, in the big 'Blues' competition at Princes Galleries in 1923, and when for three years the World's Championships were held in London. I seem to remember he was 'close up' in the professional section. */