Care Messrs John Munroe & Co
7 Rue Scribe, Paris
Paris
June 21 1880
C. P. Patterson Esq.
Dear Sir,
I read on the 14th a paper before the Academy on the value of gravity. It was very well received and the discussion of it was resumed today, when I had the satisfaction of receiving a vote of thanks for the research. The error which I have discovered in the old value excites so much interest that a new determination will at once be undertaken by the French. These gentlemen are anxious that I should also make a new determination with new apparatus, owing to the faults of that previously used. If I could have an apparatus with a long and short pendulum to be swung in vacuo, I should make a better determination than they are going to
