Item 219 - Letter from Peter Barlow

2 pp.

PB returns WW's work On the Theory of the Moon and on the Perturbations of the Planets. PB is presently engaged on the production of 'a new magnetic chart founded on the most recent observations and as far as possible corrected for the local attraction of vessels and I would be much obliged to you if [you] could give me two copies of your chart of the tides for drawing in my first lines'.