* * * * * 1873 "Chronographic registration having been established at the Paris Observatory, Mr Hilgard, principal officer of the American Coast Survey, has made use of it for determining the longitude of Harvard from Greenwich, through Paris, Brest, and St Pierre. For this purpose Mr Hilgard's Transit Instrument was planted in the Magnetic Court. I understand that the result does not sensibly differ from that obtained by Mr Gould, through Valentia and Newfoundland.--It was known to the scientific world that several of the original thermometers, constructed by Mr Sheepshanks (in the course of his preparation of the National Standard of Length) by independent calibration of the bores, and independent determination of the freezing and boiling points on arbitrary graduations, were still preserved at the Royal Observatory. It was lately stated to me by M. Tresca, the principal officer of the International Metrical Commission, that, in the late unhappy war in Paris, the French original thermometers were destroyed; and M. Tresca requested that, if possible, some of the original thermometers made by Mr Sheepshanks might be appropriated to the use of the International Commission. I have therefore transferred to M. Tresca the three thermometers A.6, S.1, S.2, with the documentary information relating to them, which was found in Mr Sheepshanks's papers; retaining six thermometers of the same class in the Royal Observatory.--The Sidereal Standard Clock continues to give great satisfaction. I am considering (with the aid of Mr Buckney, of the firm of E. Dent and Co.) an arrangement for barometric correction, founded on the principle of action on the pendulum by means of a magnet which can be raised or lowered by the agency of a large barometer.--The Altazimuth has received some important alterations. An examination of the results of observations had made me dissatisfied with the bearings of the horizontal pivots in their Y's. Mr Simms, at my request, changed the bearings in Y's for bearing in segments of circles, a construction which has worked admirably well in the pivots of the Transit Circle." (And in various other respects the instrument appears to have received a thorough overhauling. Ed.)--"With the consent of the Royal Society and of the Kew Committee, the Kew Heliograph has been planted in the new dome looking over the South Ground. It is not yet finally adjusted.--Some magnetic observations in the Britannia and Conway tubular bridges were made last autumn. For this purpose I detached an Assistant (Mr Carpenter), who was aided by Capt. Tupman, R.M.A.; in other respects the enterprise was private and at private expense.--The rates of the first six chronometers (in the annual trials) are published, in a form which appears most likely to lead to examination of the causes that influence their merits or demerits. This report is