Julian played the cello as a child for a short period of time.
Julian had been studying the piano since the age of 10. Two years later he won a Junior Exhibition Award, awarded by the London County Council, for playing the piano. Julian is granted free tuition to learn piano at London's Royal College of Music on Saturday mornings. He was only 12 years old when he was awarded this free tuition. The lessons started in September of that year (1945). Julian had also started learning how to play the guitar around the same time he started studying the piano. Julian's father, Henry, thought it would be a good idea for Julian to formally study a second instrument at the Royal College of Music. Given that the classical guitar was not officially considered an instrument of formal study at that time, another instrument would have to be chosen. Julian had been attracted to the sound of the cello therefore considered making the cello his second official instrument of study. In May of 1946, Henry inquires at the Royal College of Music for the possibility of Julian learning a second official instrument and suggested the cello. Henry is notified in September of the same year that Julian will be allowed to study the cello at the Royal College of Music along with the piano. His cello studies started that same month.
By December 17, 1946, Julian is proficient enough that he is playing the cello at a public concert for the London County Council Junior Exhibitioners. In February of the the next year he is playing his second public concert, again for the London County Council Junior Exhibitioners.
Julian was between 12 and 13 years of age when he was playing the cello so he played a 3/4 sized instrument.
It is not clear exactly when Julian discontinued his cello studies. Sadly, there does not appear to be any pictures of young Julian playing the instrument.