Letter, from Henry Oldenburg to Christiaan Huygens That there is concensus about the laws of motion set down by Huygens and Wren; sends printed copy of the English translation of his instructions for pendulum clocks; concerning Hooke's new pendulum clock; concerns a new method of printing; that trials on a 60-foot telescope have begun and would like to know about his progress in this field; concerning literary notices 31 May 1669