(1) Miscellaneous papers concerning geodesy pendulums

Correspondence with Kew Observatory, 1874, concerning the correction of the sidereal clock and the extending of the period of transmission of time signals.

Printed extract from Walker's report of the survey of India, 1874.

Letter from W. Harkness of the U.S. Naval Observatory concerning pendulum swings at the Transit of Venus stations and asking what base stations to use, 1874.

Correspondence with Captain Heaviside of the Indian Survey regarding the above letter, 1874.

Letter from W. Harkness in reply to Heaviside, 1874.

Letter to Captain Heaviside at Kew, 1874.

Written mathematical reductions for the pendulum, 1875.

Correspondence with G.G. Stokes concerning mathematical reductions of pendulum vibration, 1875.

Letter from J. Whitford asking for information on pendulums, 1875.

List of personnel concerned with experiments at Dolcoath Mine, Cornwall, in 1827, compiled 1875.

Letter from Manager Spen Colliery, Blaydon on Tyne, asking for copies of the account of the Harton pendulum experiments, with a letter of rejection from the Astronomer Royal, 1875.

Correspondence with Dr Bryce of Edinburgh concerning experiments at Harton, 1875.

Written unsigned and undated memorandum concerning pendulum measurements in the Himalayan Plateau.

Correspondence with M. Plantamour concerning the vibration of pendulum supports, 1878.

Correspondence with G.G. Stokes and M. Corvu concerning the re-determination of the Earth's density, 1878.

Letter from A.J. Perry requesting a copy of results of the mine experiments in Cornwall, with a letter of rejection from the Astronomer Royal, 1879.

Letter from Major General Walker, Surveyor General's Office, India, concerning instrumentation for gravity experiments, with a reply from the Astronomer Royal, 1880.

Printed extract from the Royal Society of Major Herschel's paper on pendulum experiments, 1881.

Letter to the President of the Royal Society giving the Astronomer Royal's comments on the above extract, 1881.

Correspondence with G.G. Stokes, Edinburgh, concerning experiments in India, 1881.

Correspondence with, and papers relating to, Major Herschel's experiments at Greenwich including data relating to errors in the Greenwich Clocks, 1881-1883.

Correspondence with K.F. Tessary concerning Cdr Sabine's experiments, 1886.

Letter from L.T. Walker requesting permission to set up a pendulum at Greenwich for comparison with Kew, 1886.

Correspondence with G.G. Stokes concerning pendulum facilities at Greenwich, 1886.

'Rough Estimate' for repeating the base observations at Kew, prepared by G.M. Whipple, 1886.

Letter from W.H.M. Christie to W. Huggins asking whether Kew observations would be better done at Greenwich, 1886.

Correspondence with General Walker concerning setting up a comparison of observations and whether the telegraph line from Greenwich to Kew would be sufficiently rated for the purpose, 1886-1887. There is also a record of the temperature variations in the rooms at Greenwich.

Letter to M. Defforges concerning a visit to Paris to compare the five foot bar, 1888.

Correspondence with General Walker concerning the journey to Paris for the comparison of the Shuckburgh scale, 1888.

Correspondence with G.M. Whipple of Kew concerning arrangements for the deliver of the pendulum apparatus to Greenwich and the facilities for the observing staff, 1888.

Letter from General Walker concerning clock comparisons, 1888.

Reply from M. Defforges of Paris to a letter from the Royal Observatory concerning comparison of the Shuckburgh scale, 1888.

Two handwritten memoranda concerning the receipt and erection of pendulum apparatus, 1888.

Correspondence with General Walker concerning clock comparisons and a delay due to changes in the weather, 1888.

Record of equipment taken to the Royal Observatory for pendulum observations, 1888.

Letter from General Walker asking that pendulum observations be carried out forthwith, 1888.

Letter to G.M. Whipple at Kew, 1889, enclosing a report of errors in the 10pm time signal from 5 November to 8 December 1888.

Correspondence with General Walker concerning the expenses for the Paris trip, 1889.

Correspondence with General Walker concerning the location of the pendulum apparatus in the Royal Observatory and changes not to be carried out to the room, 1889.

Reply from G.M. Whipple to the report of the time signal errors, 1889.

Correspondence with General Walker concerning arrangements for two officers to visit the Royal Observatory, with a telegram in reply, 1889.

Letter to Richard Foeres of France concerning the possible delivery dates of a new thermograph, 1889.

Letter from General Walker asking for a thermograph to be ordered for him at his expense, 1889.

Letter from G.M. Whipple concerning details of thermographs, including price, 1889.

Reply to the above giving the price and other details, 1889.

Letter from R. Foeres stating that the thermograph can be built in an acceptable time, 1889.

Letter to R. Foeres placing an order for a thermograph and giving details of the requirements for calibration, 1889.

Notes on proposed pendulum swings at Greenwich, 1889, including notes of the correct entry on the report sheets and the corrections to be applied for temperature and pressure.

Written notes, 1889, containing useful details for working with an invariable pendulum, including a plan of the pendulum room at Kew in 1888.

Correspondence with General Walker concerning the reduction of Greenwich pendulum swings to sea-level and the contouring of Greenwich Hill, 1889.

Letter to R. Foeres asking when the thermograph will be delivered, with a reply, 1889.

Letter to R. Foeres stating that if the instrument is not delivered by the end of April then the order will be cancelled, 1889.

Letter from R. Foeres promising delivery of the thermograph by 10 May 1889 and a reply from the Royal Observatory accepting delivery by that date.

Letter from General Walker proposing a visit to the Royal Observatory for the setting up of equipment, 1889.

Letter to R. Foeres asking if the thermograph is to be delivered as promised, with a telegraph in reply stating that it 'left yesterday', 1889.

Correspondence with General Walker reporting that the reduction of swings is now nearly complete and the results will be sent to him for his perusal, 1889.

Letter to the Kew Observatory enclosing a bill for the thermograph and requesting the refund of carriage charges, with a reply, 1889.

Letter from General Walker proposing to visit Greenwich to see the results of the swings and a further letter enclosing his extract of results, 1889.

Manuscript account of the pendulum observations at Greenwich, June and July 1889.

Letter from General Walker requesting a press copy of the pendulum swing observations and a reply enclosing the same, 1889.

Letter from General Walker setting out serious differences between successive values of the time of coincidence, 1889.

Reply to the above stating that the differences are not all valid and some of the observations have been rejected, 1889.

Letter from General Walker apologising for retaining the observation sheets, 1890.

Letter from General Walker asking for the height of the Royal Observatory above sea level and a reply from the Astronomer Royal giving a figure of 153 ft 3½ ins, 1890.

Letter to General Walker concerning clock times and enclosing a list of the swing durations, 1890.

Letter from General Walker asking for the equipment to be dismantled for return to Kew and a reply stating that the equipment is ready for transport, 1890.

Letter of authority for a carter to pick up the pendulum equipment from the Royal Observatory, 1890.

Inventory of pendulum equipment returned to Kew, 1890.

Acknowledgement of the receipt of the equipment from Kew, with a top copy of the inventory, 1890.

Results of the pendulum swings at Kew, November 1888, with meteorological observations, 1890.

(2) Papers relating to Commandant Defforges' pendulum observations at Greenwich

Correspondence with Defforges concerning the transport of his equipment to France, 1888.

Written record of hourly barometer readings, 7-13 November 1888.

(3) Papers relating to Bassat's and Defforges' pendulum operations at Leith Fort

Letter from the Foreign Office outlining the journey of Bassat and Defforges and asking for every facility to be given them, 1892.

Letter of acknowledgement to the above from the Astronomer Royal, 1892.

Letter to the Post Office requesting time signals to be sent to Leith Fort, 1892.

Telegram to the Post Office requesting time signals be sent to Leith Fort, 1892.

Telegram to the Post Office requesting wire be freed for use, 1892.

Letter from the General Post Office stating times when the telegraph would be free for time signals, 1892.

Letter from the Great Northern Railway giving rates and timetables for transporting equipment to Scotland, 1892.

Telegrams between the Royal Observatory and the General Post Office concerning the failure of time signals to Leith Fort, 1892.

Correspondence between H.H. Turner, General Walker and Commandant Defforges concerning ½ second pendulum experiments, 1892.

Correspondence with the Foreign Office concerning proposed pendulum experiments by Lt. Col. von Sterneck of Vienna, 1893.

Correspondence with Lt. Col. von Sterneck concerning his experiments, 1893.

Letter from Lt. Col. von Sterneck giving brief results of his experiments and thanking the Royal Observatory for the facilities extended to him, 1893

Written records of errors and the rates of the sidereal standard clock during swings, 1893.

Correspondence with A. Hermann of Paris concerning the publication of the pendulum experiments, 1893.

Correspondence with E.J. Love concerning his pendulum swings, 1894.

Correspondence with J.D. Everett concerning comparisons between Kew and Greenwich, 1901.

Letter from J. Nophat of Paris enclosing an extract from 'Science Revue' concerning pendulum experiments, 1902.

Correspondence with J. Mann of Bedford concerning the length of a pendulum at the equator, 1903.

Correspondence with Dr Greene concerning the design of pendulums and experiments in general, 1919.

Correspondence with G.M. Whipple concerning Col. Cowie's pendulum swings and time signals, 1925.

Correspondence with Kerr Grant concerning his proposed pendulum swing experiments, turning facilities and what room will be available, 1927, including correspondence with the National Physical Laboratory, Teddington, and Adam Hilger Ltd of London.

Letter from Lenox-Conyngham concerning pendulum experiments at the National Physical Laboratory, Teddington, with comparisons at Greenwich, 1927.

Letter from R. Threllfall asking that his visit to the Royal Observatory be postponed, 1927.

(4) Papers relating to the India Survey pendulums from 1902

Correspondence with R. Glazebrooke of the National Physical Laboratory, 1902, concerning experiments proposed by Major Burrard, and including statements of experiments carried out in the years 1881-1900.

Correspondence with Major Burrard and with the India Office concerning the pendulum experiments at Kew and Greenwich, 1903.

Unsigned memorandum asking what arrangements are to be made for registration, 1903.

Correspondence with Major Burrard concerning his experiments, including the question of the accommodation and position of time signals, 1903.

Unsigned memorandum asking about arrangements for setting up Major Burrard's apparatus and for getting clocks into position, 1903.

Three letters from Major Burrard concerning accommodation and the dispatch of equipment to Greenwich, 1903.

Correspondence with Major Burrard and C. Chree of the National Physical Laboratory regarding errors in time signals during pendulum swings, 1903.

Correspondence with C. Chree concerning errors in time signals, 22-27 June 1903.

Letter from Major Burrard regarding apparent errors in the clock rates during experiments, with a reply, 1903.

Correspondence with Major Lenox-Conyngham concerning his takeover of the pendulum swing experiments and the installation of the equipment at Greenwich, 1903.

Correspondence with C. Chree concerning time signal errors and their application to pendulum observations, 1903.

Letter from Major Lenox-Conyngham asking for a daily postcard giving the time error, 1903.

Letter to C. Chree concerning corrections for the sidereal clock, 1903.

Letter to C. Chree enclosing a statement of the errors on the standard sidereal clock, 19-25 and 31 October 1903.

Letter from Major Lenox-Conyngham thanking the Royal Observatory for the facilities granted to him, 1903.

Correspondence with C. Chree concerning errors in the time signals, 26-31 October 1903, and enclosing a statement.

Correspondence with Sears of the National Physical Laboratory concerning the Shortt clock errors and rates and enclosing extracts from an article on gravity at the National Physical Laboratory, 1927.

Advanced proof copy of Major Lenox-Conyngham's paper on pendulum swing experiments in India, 1909.

Letter from the United States Coast and Geodetic Survey team requesting the use of facilities at Greenwich and the supply of time signals for the rating of a chronometer, 1900.

Reply to the above stating that the facilities requested can be granted, 1900.

Letter to G.R. Putnam, United States Coast and Geodetic Survey, 1900, stating that the arrangements are complete and asking that time signals be sent and for confirmation of the start date at Greenwich.

Correspondence with G.R. Putnam concerning clock and time signal errors, 1900.

Letter from the United States Coast and Geodetic Survey offering thanks for the facilities provided, 1900.

Correspondence with R. Glazebrooke, National Physical Laboratory, concerning the publication of the American results, 1902.