A letter from a reader to an editor, stated that the previous article from China Mail 'Education By Film.' It is said that the only cinema machines which have fixed optical centre are covered by American Patents. This is a wrong statement as the fixed optical centre with which our Pathe-University cinema projectors are provided is covered by French patents and has already been in use in numerous schools and other institutions in China since more than two years. Another ambiguous information also means that Pathe-Gazette has no particular British bias.