THE CHRONOMETER AND TIME SERVICE OF THE UNITED STATES NAVAL OBSERVATORY AND THE PRESENT STATUS OF STANDARD TIME

[1] THE CHRONOMETER AND TIME SERVICE OF THE UNITED STATES NAVAL OBSERVATORY AND THE PRESENT STATUS OF STANDARD TIME, Lieut, Commander, EDWARD EVERETT HAYDEN, U. S. Navy, REPORT of THE EIGHTH INTERNATIONAL GEOGRAPHIC CONGRESS HELD IN THE UNITED STATES 1904, Edited by The Committee on Printing, GOVERNMENT PRINTING OFFICE, 1905.
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時差の表

The following abstracts of official reports received by the superin- tendent of the United States Naval Observatory, through the cour- tesy of the Department of State and of the Office of Naval Intelli- gence, Navy Department,

重複は省略

c: Country
t: System of time in actual use
w: Difference from Washington standard

c: Agrentina
t: The official time in use throughout the Argentine Republic is referred to the meridian of Cordoba, 4^h 16^m 48.2^s west from Greenwich. At 11 a. m. a daily signal is telegraphed from the Cordoba Observatory. The greatest deviation of local mean time from the official time would not ex- ceed 28 minutes. La Plata is 25^m 45^s east from Cordoba. and Mendoza, the most western town of importance, is 18^m 32^s west from Cordoba.
w: +0.43.11.8

c: Austria-Hungary
t: Standard time does not exist in Austria except for the service of the railroads. Central Euro- pean time, 15° east from Greenwich, is required to be used by all the railways. This is not a matter of law, but is in force by order of the proper authorities.
w: +06:00:00

c: Belgium
t: Official time in Belgium is calculated from 0 to 24 hours, zero corresponding to mean midnight at Greenwich. The Royal Observatory at Brus- sels communicates twice daily the precise hour to the central telegraphic administration and Government offices, also to important corpora- tions. The telegraphic administration trans- mits it to the other towns in Belgium.
w: +05:00:00

c: China
t: An observatory is maintained by the Jesuit mis- sion at Zikawei, near Shanghai, and a large ball suspended from a mast on the French bund in Shanghai is dropped electrically precisely at noon each day. This furnishes the local time at the port of Shanghai, which is adopted by the railway and telegraph companies repre- sented there, as well as by the coastwise ship- ping. From Shaiighai the time is telegraphed to other ports. The cable companies repre sented in Peking receive this time from Chefoo: the Imperial Chinese telegraphs from the office of that company in Tientsin. The imperial railways of north China use the same time, taking it from the British gun at Tientsin and passing it on to the stations of the railway twice each day at 8 a. m. and 8 p. m. No information yet from the Peking-Hankow Railway.
w: +13:04:43.3

c: Colombia
t: At Bogota the time used is that of the meridian of Bogota. This time is taken every day at noon in the observatory, but there is no method em- ployed in correcting this time daily by signal from a central observatory. Some few people, such as jewelers go to the observatory daily: but the great mass of business men, railroad officials, etc., let their time run sometimes for weeks without correcting it, until the incon- veniences caused thereby compel them to make the necessary corrections. As far as communi- cating the time as corrected in Bogota to other parts of the country is concerned this is ren- dered impossible by the very poor telegraph service, it frequently taking four and five days to send messages a distance of from 50 to 100 miles.
w: +00:03:05.8

c: Costa Rica
t: The Government has established an observatory at the capital. San Jose, in latitude 9° 56' north, longitude 84° 04' 14" west from Greenwich; alti- tude, 4,567 feet, or 1,160 meters, above sea level. The Greenwich meridian is used exclusively to regulate observatory time, which is corrected by observation and reduced to mean time. This time is issued to public offices, railway and tele- graph offices, churches, and to all residents whose occupations necessitate correct time. There is no method employed to correct time by signal from the observatory, the corrected time being taken by applicants"from the stand- ard chronometer at the observatory.
w: -00:36:13.1

c: Cuba
t: The official time of the Republic is civil mean time of the meridian of Habana, and is used by the railroads and telegraphic lines of the Govern- ment. The central meteorological station gives the time daily to the port and city of Havana as well as to all the telegraph offices of the Re- public.
w: -00:28:50.4

c: Denmark
t: Standard time is Axed at one hour earlier than that of Greenwich, corresponding to mean solar time of the fifteenth degree of longitude east from Greenwich. In Iceland, the Faroe Islands, and the Danish West Indies local mean time is used. +06:00:00
Local mean time for the Danish West Indies gives for—
Curacao +00:24:18.1
St. Thomas +00:40:17

c: Ecuador
t: The legal and common time is that of the meridian of Quito. It is corrected daily from the Na- tional Obsorvatory of Quito.
w: -00:15:01.0

c: England
t: The meridian of Greenwich is the standard time meridian for England, Scotland, the Orkneys, Shetland, the Isle of Man, and Gibraltar. +05:00:00
That of Dublin (25^m 21.1^s slow of Greenwich) for Ireland. +04:34:38.9
Longitude 15° east for Malta +06:00:00
Longitude 30° east for Cape Colony. Transvaal, Orange River Colony, Rhodesia, Natal, and Egypt, +07:00:00
The meridian of Fort Fullerton, Singapore (6^h 55^m 25^s fast of Greenwich) for Straits Settlements. +11:55:25
Longitude 120° east for West Australia +13:00:00
Longitude 142 $\frac{1}{2}$ ° east for South Australia, includ- ing northern territory. +14:30:00
Longitude 150° east for New South Wales, Queens- land, Tasmania, and Victoria. +15:00:00
Longitude 172 $\frac{1}{2}$ ° east for New Zealand and Chat- ham Island. +16:30:00
Longitude 120° west for Alberta, Assiniboia, and Athabasca. -03:00:00
Longitude 90° west tor Keewatin and Manitoba -01:00:00
Longitude 75° west for Montreal, New Bruns- wick, Ontario, and Quebec. +00:00:00
Longitude 60° west for Nova Scotia and Prince Edward Island. +01:00:00
Assuming local mean time for other British colo- nies gives the following results:
Antigua +00:40:00
Arabia (Aden) +07:59:54
Bahamas (Nassau) -00:09:29.5
Barbados (Bridgetown) +01:01:30.8
Bermudas (Hamilton) +00:40:41.7
Borneo (Labuan) +12:31:01
Hongkong +12:38:41.7
Falkland Islands (Port Stanley) +01:08:34
Fiji Islands (Suva) +16:55:44
Guiana (Demerara) +01:07:20.5
Honduras (Belize) -00:52:47
India:
Madras +10:20:59.1
Calcutta +10:53:20.8
Bombay +09:51:15.7
Jamaica (Kingston) -00:07:10.4
Newfoundland (St. Johns) +01:29:10.5
Trinidad (Port of Spain) +00:53:57.5
NOTE.―Local mean time of the Madras Observ- atory is practically used as standard time for India and Ceylon, being telegraphed daily all over the country, but for strictly local use it is generally converted into local mean time.
NOTE―Local mean time of St. Johns is prac- tically used as standard time for the entire island.

c: Egypt
t: Standard time is that of the thirtieth meridian east from Greenwich (eastern European time) and is therefore 2 hours fast of Greenwich or west European time and 1 hour fast of central European time. It is sent out electrically by the standard clock of the observatory to the citadel at Cairo, to Alexandria, Port Said, and Wadi Haifa.
w: +07:00:00

c: France
t: Legal time in France, Algeria, and Tunis is local mean time of the Paris observatory. Local mean time is considered as legal in other French colonies. This gives the following results: +05:09:21.0
For Cochin China, Cambodia, and Anam (Saigon). +12:16:56
Corsica +05:25:36.0
Guadeloupe +00:56:00.0
Madagascar (Antananarivo) +08:10:07.0
Marquesas Islands -03:39:00.5 to -03:45:07.0
Martinique +00:55:16.0
Mauritius +08:50:12.6
Miquelon +01:15:16.0
New Caledonia (Noumea) +16:05:48.0
Paumotu Archipelago -03:19:12 to -04:54:54.4
Senegal +03:50:18.0
Tonkin +12:04:39.5

c: Germany
t: Legal time is mean solar time of longitude 15° east from Greenwich. +06:00:00
In the colony of Kiautschou mean solar time of longitude 120° east from Greenwich is used. +13:00:00
It is proposed to adopt standard time as follows:
For Togo, the meridian of Greenwich +05:00:00
For Kamerun, 15° east +06:00:00
For German East Africa, 30° east, or, possibly, 37 $\frac{1}{2}$ ° east. +07:00:00 +07:30:00
For Bismarck Archipelago, New Guinea, Caroline and Mariana islands, 150° east. +15:00:00
For Samoa, 180° east; but only after an under- standing with the Government at Washing- ton. +17:00:00

c: Greece
t: By royal decree of September 14, 1895. the time in common use is that of the mean time of Athens, which is transmitted from the observ- atory by telegraph every day to all towns.
w: +06:34:53.7

c: Holland
t: The local time of Amsterdam (5^h 19^m 39^s later) is generally used, but Greenwich (5^h later) time is used by the post and telegraph administra- tion and the railways and other transportation companies. The observatory at Leyden com- municates the time twice a day to Amsterdam, The Hague, Rotterdam, and other cities, and the telegraph bureau at Amsterdam signals the time to all the other telegraph bureaus every morning. In the Grand Duchy of Lux- emburg central European time is the legal and uniform time.
Local mean time for the colonies gives for―
Java (Batavia) +12:07:20
Sumatra (Padang) +11:41:20.9
Iceland (Reikiavik) +03:32:20
w: +06:00

c: Honduras
t: In Honduras the half hour nearest to the merid- ian of Tegucigalpa, longitude 87° 12' west from Greenwich, is generally used; said hour is fre- quently determined at the national institute by means of a solar chronometer and communi- cated by telephone to the industrial school, where, in turn, it is indicated to the public by a steam whistle. The central telegraph office communicates it to the various suboffices of the Republic, whose clocks serve as a basis for the time of the villages, and in this manner an approximately uniform time is established throughout the Republic.
For Belize, see England.
w: -01:00:00

c: Italy
t: Mean solar time of the fifteenth meridian east from Greenwich is the standard time adopted by royal decree of August 10, 1893. for the kingdom of Italy. This time is to be kept in all Government establishments, offices, dock yards, and is to be used by all ships of the Italian navy in the ports of or doing duty on the coast of Italy. All railroads, post and tele- graph offices, and Italian coasting steamers are to use this time and regulate their business and time-tables in accordance therewith. The hours run from midnight to midnight that is to say, in Italy 1 p. m. is thirteen hours, 5 p. m. is seventeen hours, etc.
w: +06:00:00

c: Japan
t: Imperial ordinance No. 51 of 1886: “The merid- ian that passes through the observatory at Greenwich, England, shall he the zero (0) me- ridian. Longitude shall be counted from the above meridian east and west up to 180°, the east being positive and the west negative. From January 1, 1888, the time of the one hun- dred and thirty-fifth degree east longitude shall be the standard time of Japan.” +14:00:00
Imperial ordinance No. 167 of 1895: “The standard time hitherto used in Japan shall henceforth be called central standard time. The time of 120° east longitude shall be the standard time of Formosa, the Pescadores, the Yayeyama, and the Miyako groups, and shall be called western standard time. This ordinance shall take effect from the 1st of January, 1896.” +13:00:00

c: Korea
t: Tokyo time (135° east from Greenwich) is tele- graphed daily to the Imperial Japanese post and telegraph office at Seoul. This is corrected by subtracting 30 minutes, which nearly repre- sents the difference in longitude, and is then used by the railroads, street railways, and post and telegraph offices, and most or the better classes. In the country districts the people use sun dials to some extent. +14:00:00 +13:30:00

c: Mexico
t: The National astronomical observatory, of Tacu- baya, regulates a pendulum twice a day, which marks the local mean time of the City of Mex- ico (6^h 36^m 31.6^s west from Greenwich), and a signal is raised twice a week, at noon, upon the roof of the national palace, such signal being used to regulate the city's public clock. This signal, the clock at the central telegraph office, and the public clock on the cathedral serve as a basis for the time used commonly by the peo- ple. The general telegraph office transmits this time daily to all of its branch offices. Not every city in the country uses this time, however, as a local time, very imperfectly determined, is more commonly observed.
The following railroad companies use standard City of Mexico time, corrected daily by tele- graph: Central, Hidalgo, Xico, and San Rafael, National, Mexican. The Central Railroad cor- rects its time daily by means of the noon signal sent out from the Naval Observatory at Wash- ington, converted into City of Mexico time, and by a similar signal from the observatory at St. Louis, Mo.
w: -01:36:31.6

c: Nicaragua
t: There is no Government observatory, but the meridian of Managua is governed by the time of Corinto, the longitude of which is 87° 12' 81" west from Greenwich, giving for Managua lon- gitude 86° 17' 30". Managua time, thus ascer- tained, is issued to all public offices, railways, telegraph offices, and churches in a zone that extends from San Juan del Sur, latitude 11° 15' 44" north, to El Ocotal, latitude 12° 46' north, and from El Castillo, longitude 84° 22' 37" west, to Corinto. The time of the Atlantic ports is usually obtained from the captains of ships.
w: -00:45:10

c: Panama
t: The railroad company uses the local mean time of Colon, corrected by steamers' chronometers (5^h 19^m 39^s west from Greenwich). The Central and South American Telegraph Company now cables seventy-fifth meridian time (75° west from Greenwich) daily from Washington, and this will probably be adopted as the standard.
w: -00:19:39

c: Peru
t: There is no official time. Local mean time (0^h 8^m 9^s earlier) is used in Lima and other places. The Oroya Railroad takes its time by telegraph from the noon signal at the naval school at Cal- lao (0^h 9^m 3^s earlier), which may be said to be the official time for Callao, Lima, and the whole of central Peru. The railroad from Mollendo to Lake Titicaca, in southern Peru, takes its time from ships in the Bay of Mollendo.

c: Portugal
t: No late report received, but understood to use standard time of the Royal Observatory at Lisbon.
w: +04:23:15.3

c: Russia
t: All telegraph stations use the time of Pulkowa. St. Petersburg (7^h 1^m 18.6^s later). At railroad stations both local and Pulkowa time are given, from which it is to be inferred that for all local purposes local time is used. Local mean time for other cities gives for―
Nicolaeff +07:07:05.39
Riga +06:36:22
Irkutsk +11:57:15
Vladivostok +13:47:33.5

c: Salvador
t: The Government has established a national ob- servatory, which issues time on Wednesdays and Saturdays at 12 meridian to all public offices, telegraph offices, railways, etc., through- out the Republic. The observatory is at San Salvador.
w: -00:56:36

c: Santo Domingo
t: Local mean time is used, hut there is no central observatory and no means of correcting the time. The time differs from that of naval ves- sels in these waters by about 30 minutes.
w: +00:20:32

c: Spain
t: Official time is mean time of the meridian of Greenwich, obtained from the Madrid Observa- tory. It is used by the railroad and telegraph companies and the people of Madrid and the provinces generally, in some of which, how- ever, local time is still used for private matters.
w: +05:00:00

c: Servia
t: Central European time (longitude 15° east from Greenwich) is used by the railroads, telegraph companies, and the people generally. Clocks are regulated by telegraph from Budapest every day at noon.
w: +06:00:00

c: Sweden and Norway
t: Central European time (15° east from Green- wich) is the standard. It is sent out daily by telegraph from the Stockholm Observatory. As far as is known it is used everywhere in daily life.
w: +06:00:00

c: Switzerland
t: Central European time is at present the only legal time. It is sent out daily by telegraph from the Cantonal Observatory at Neuchatel.
w: +06:00:00

c: Turkey
t: Two kinds of time are used. i. e.. Turkish (7^h 0^m 0^s later) and eastern European time (6^h 56^m 53^s later), the former for the natives and the latter for Europeans. The railroads generally use both, the latter for the actual running of trains and Turkish time-tables for the benefit of the natives. Standard Turkish time is used gen- erally by the people, sunset being the base or beginning and 12 hours being added for a theo- retical sunrise. The Government telegraph lines use Turkish time throughout the Empire and St. Sophie time (1^h 47^m 32 ahead of Paris) for telegrams sent out of the country.

c: United States
t: Standard time baaed on the meridian of Green- wich is universally used and is sent out daily by telegraph to all parts of the country and to Habana and Panama from the Naval Observa- tory at Washington (for the Pacific coast from the observatory at Mare Island Navy-Yard, Cal.). Standard times used are as follows:
For the Atlantic coast and Panama Canal Zone, eastern standard time, longitude 75° west. +00:00:00
For the Mississippi Valley, central standard time, longitude 90° west. -01:00:00
For the Rocky Mountain region, mountain standard time, longitude 105° west. -02:00:00
For the Pacific coast, Pacific standard time, longitude 120° west. -03:00:00
For Sitka, Alaska standard time, longitude 135° west. -04:00:00
For the Hawaiian Islands, Hawaiian standard time, longitude 157 $\frac{1}{2}$ ° west. -05:30:00
For Tutuila, Samoa, Samoan standard time, longitude 172 $\frac{1}{2}$ ° west. -06:30:00
For the island of Guam, Guam standard time, longitude 145° east. +14:30:00
For the Philippine Islands. Philippine stand- ard time, longitude 120° east. +13:00:00
For Porto Rico, Atlantic, standard time, longi- tude 80° west. +01:00:00

c: Uruguay
t: The time in common use for railways, telegraph companies, and the public in general is mean time of the meridian of tho dome of the Metro- politan Church of Montevideo. The correct time is indicated by a striking clock in the tower of said church, with an approximate error of about a minute. An astronomical geodetic observatory, with meridian telescope and chronometers, has now been established and will fix the hour exactly. It is proposed to install a time ball for the benefit of navigators at the port of Montevideo. This electric time service will be extended throughout the coun- try, using at first the meridian of the church and afterwards that of the National Observa- tory, when constructed.
w: +01:15:11.1

c: Venezuela
t: The time is computed daily at the Caracas Ob- servatory (longitude 66° 55' 53.6" west from Greenwich) from observations of the sun, and is occasionally telegraphed to other parts of Venezuela. The cathedral clock at Caracas is corrected by means of these observations. Railway time is at least 5 minutes later than that Indicated by the cathedral clock, which is accepted as standard by the entire people. Some people take time from the observatory flag, which always falls at noon.
w: +00:32:16.4

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メモ

[5] Appendix IV of the Publications of the United States Naval Observatory の時差の表はこの表の改訂版のようです。