Yesterday, I visited a school in Bucharest, Romania. A new school with an old tradition. With a group of enthusiastic teachers from Lexis Schools of Languages, I participated in a lesson on the European Day of Languages with games, flags and cartoons - everything primary school kids love in a language lessson.The lesson was over. The kids were leaving the classroom when I saw a boy coming straight to me with a picture of Big Ben in his hand. Most seriously and unexpectedly for me, in the circumstances, he asked  if I could explain how the clock mechanism powers the famous Big Ben.I didn't hesitate to give him brief explanations, but I realized it was not enough. He seemed to have been fascinated with technology and here I made this selection of videos for him.Help needed!!If anybody has more information for David S., the10 year-old boy with such a desire to learn new things, please post or recommen