30 May 1667 – 5 June 1667

To London, to wait on the Duchess of Newcastle (who was a mighty pretender to learning, poetry, and philosophy, and had in both published divers books) to the Royal Society, whither she came in great pomp, and being received by our Lord President at the door of our meeting-room, the mace, etc., carried before him, had several experiments shown to her. I conducted her Grace to her coach, and returned home.

I went to Greenwich, where his Majesty was trying divers grenadoes shot out of cannon at the Castlehill, from the house in the park; they broke not till they hit the mark, the forged ones broke not at all, but the cast ones very well. The inventor was a German there present. At the same time, a ring was shown to the King, pretended to be a projection of mercury, and malleable, and said by the gentlemen to be fixed by the juice of a plant.