About April 15 83

My dear Sir,

The serious matters for my attention abroad are, so far as I know, the following:

1. Yard comparison in London.

2. Kilogram comparison in Breteuil. In regard to this I beg to call attention to the fact that I have considerable experience in the matter of weighing.

3. I desire very earnestly to recommend the construction of a new pendulum apparatus, the pendulums to be substantially on my pattern, invariable reversible pendulums of cylindrical form, 1 metre between the knife-edges, and with the centre of mass ¼ metre from one end. The heads to be of a new construction.  Two pendulums and two heads to be made, and a vacuum chamber. In my opinion, Brunner should make the pendulums & heads and Turretini the vacuum chamber. I think

4. The high degree of accuracy of my European determinations, has received a striking confirmation since Förster has sent his last value of the correction to metre Nº 49; since my values have now been shown to be very close to the most accurate measures & only to differ much from those that are doubtful.

But on page 81 of my "Measurements of Gravity at Initial Stations", it is acknowledged, 1st, that the correction for flexure at Geneva is conjectural to such an extent that the result is without precise value, until the Repsold support has been put on the wood stand there used and the flexure measured; 2nd, that at Kew the flexure of the pier should be measured, I may add that this is important, because it was of a peculiar shape and very high, and because the comparison

I think that the measurements at Kew and at Geneva could be conveniently made this year. At Kew when I go to London to compare the yards; at Geneva when I go there to see Turretini or the representative of that shop.

5. I desire to go to Rome this year for the following reasons: 1^st, I desire to report the results of actual experiments made last summer with two pendulums on one support; 2^nd, I was personally consulted by the Italian Commission in regard to their plans for pendulum work and I think I might learn of them something of value now that they are fairly at work;

6. I want to know how they are progressing with their researches in France into the methods of determining gravity. I have been consulted by those men before & have discussed with them their plans. Among other matters, I very carefully went over with Villarceau & St. Claire Deville their work upon the gas-gravimeter. I don't think this is a matter of much consequence. Still, I learnt accidentally that experiments on the subject have been conducted by Mr. Schott under General Cutts. I do not think that it is either friendly to me or advantageous to the survey for them to keep what they are doing a secret from me. But if be judged proper to obtain further information respecting this gravimeter, I think that I should be charged with

I will now privately state to you my personal reasons for wishing to go abroad.

I wish to marry a French lady, Madame Pourtalai, who has been in this country for a good while being detained here by the bad state of her health. Her condition of health has now become almost desperate, her financial affairs are going wrong and demand her presence, she will not consent to being married here unless I will go to France to have the ceremony repeated, and for all these imperative reasons she must go and I must go with her.

What I want to do, then, is this. I want to sail from New York on the 2nd of May for Hâvre. I want to go to Paris and remain a few days longer than enough to attend to the C. S. business. I then want to go

I propose, and you will dispose: I ask a great favor. But the occasion is exceptional and unique. The excuses remarkably good and solid. I hope you will able to act favorably.

C. S. P.