Care Morton, Rose & Co.
Bartholomew Lane E. C. London
Brühl, Prussia
August 1, 1883

Dear Sir,

I have the honor to render my report for July. Although I have received no word of either my May or my June report having reached you.

I have already fully explained the circumstances of the comparisons upon which I was still engaged at the end of June, i. e. between the Imperial Standard Nº 1 and the Low Moor Wrought Iron Yard Nº 57, belonging to the U.S. These comparisons were finished on July 3, 1883. They consist of 48 sets; 24 by Chaney, 24 by Peirce. Each set contains 10

On July 4 and 5, the thermometers were intercompared and compared with three standards, two of which then had their zeros determined by me.

On July 5, the values of the screw-revolutions of the micrometers were determined by both observers independently by means of the standard inches.

July 6-12. Comparisons of Yards Nº 57 and 58. Twelve sets by Peirce, six sets by Chaney. Bars were transposed. All the temperatures between 66º and 68º. Peirce’s results concordant but differ markedly from Chaney’s owing to peculiarity in ruling of one line.

July 13. Redetermination of the values of the screw revolutions by both observers independently.

Operations at the Kew Observatory were commenced July 2nd and lasted until July 28th. The Hardy's noddy constructed by Breguet was used, while the Repsold pendulum mounted as in my experiments of July, 1876, was in oscillation. The result showed that the oscillation of the stone pier, walls, and vaulting was sufficient to cause an error of 4 microns in the length of the second's pendulum.

During this time, I also made a new mathematical discussion of the motion of the noddy, and developed the method of using the instrument. I have little doubt it will come into practical use, as it is most satisfactory. I have written a paper on the subject for presentation at Rome by General Cutts or Mr. Schott. I hope they will do justice to my two papers, which appear to me to be the most important I have yet produced on the subject of pendulums.

I left England July 25th and proceeded to Brussels where I was kept in the house

From Brussels, I went to Liége, in order to see Wéry establishment; with which I was not much impressed. I then went to Cologne, and being pressed by Chaney to finish the reductions of our work, I remain here in the neighborhood to do up a little necessary office work.

In yours of the 29th April you say that you will on the 30th send me the address of a party in Paris from whom I am to order instruments and apparatus. This address never reached me; but in my case I could not have dealt with Breguet

For my work in Richmond, I found myself in need of some kind of chronograph. I went to Casella for one of his marking watches, but found he had given up making them. He recommended me to go to Dent, which I did and paid 6 pounds for a timing watch. As well as I can understand from the brief explanation in yours of April 29, you only want vouchers in England signed by Casella. I therefore went back to him, but owing to Mr. Casella being dangerously ill or for some reason I did not see him. I therefore append Dent's bill to my voucher. I got a thermometer of Negretti & Zambra which I trust I may not be obliged to pay for personally.

I did not take either the yard or the kilo from London. The reason I did not take the yard was that both Chaney and I think that further comparisons are desiderable. The reason I did not take the kilo was that Dr. Brock talked so much of the necessity of having a special box made

I have received a second letter, not having received any first, from a firm in Baltimore (Seemüller) with whom I had some things stored; from this letter I infer that the things have been burnt, and there must have been some Coast Survey property destroyed. I cannot now say precisely what there was, but it was not much.

It is plain my absence will somewhat overrun the time allowed for the work. But you will see that I have no lost any time that could be saved, not one day. Chaney’s being in Paris prevented my doing anything

Yours very respectfully,

C. S. Peirce
Asst.