U. S. Coast and Geodetic Survey Office
Washington, D. C., April 24, 1883

Sir,

In accordance with Department letter dated April 23, 1883, a copy of which is enclosed herewith you will please proceed forthwith to London, Paris, Geneva, and other points as they may be found necessary for the due execution of these instructions.

You are expected to follow the following route: -New York, Havre, Paris and Breteuil, London and vicinity including Cambridge, Brussels, Basle, Geneva, Paris, Havre, New York. You will only deviate from this route in case the exigencies of the work require it, at the same time reporting to me the reasons for the change.

The duties to be performed are as follows:

1st You will compare the standard iron Yard nº 57 belonging to the U. S. Bureau of Weights and Measures with its mate Nº 58 deposited in the Ordnance Office at Southampton and also with the bronze yard Nº b, known as the "generator" and kept at the British Standard Office. The last comparison will be made as nearly as possible at a mean temperature of b. 0.7. A letter to H. J. Chaney, the officer in charge of the Standards, will be furnished you.

2nd You will transport the Arago platinum kilogram of the United States to the International Bureau at the pavilion of Breteuil for comparison.

3rd You will place the Repsold tripod in its former position on the pier at the Kew Observatory Richmond and there measure the flexure.

4th You will place the same tripod on the wooden table formerly used at Geneva, and there measure its flexure.

5th You will consult with different instrument makers and prepare plans for estimates for three new pendulums-head adapted to the "Peirce" pendulums, together with two new pendulums of this description, and should you deem it advisable, will order their construction for a sum not to exceed $1200.

6. You will cause to be made a Hardy’s "noddy" according to the indications given in the Superintendents Report for 1881, expense not to exceed $200.

7. You will order an escapement pendulum on the plans of M. Saegmuller, expense not to exceed $200.

8. You will consult with Turretini of Geneva and other instrument makers and prepare plans and estimates for a vacuum chamber for the new pendulums.

9. You will consult with men of scientific authority in matters discussed at the Gravity Conference whenever they can be easily reached, and especially with Professor Stokes in Cambridge; and you will inform yourself and report to me on the state of Gravity Investigations in the different countries through which you may pass, particularly in regard to Belgium.

10. You will report upon any new comparators, micrometers, pendulums, gravimeters, etc. of which you may be able to obtain information on your route or by slightly deviating from it.

At each station whose measures are made you are authorized to employ temporarily a recorder at a maximum compensation $3.50 per diem, and such hands as may be necessary.

J. E. Hilgard
Superintendent