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Electricity In Surveying

Electricity In Surveying image
Parent Issue
Day
22
Month
August
Year
1873
Copyright
Public Domain
OCR Text

Tlio une of eleotricity in deterraining raphioal longitudes keeps rapid pai ■■ with thu continua] extensión of tele i lines and cables ovof iho world, ately chronicled thfl third doterminof the differcnae of losgitude between Washington and üreenwich, which datura, so higlily important tu asironoiuy, may now be cousidered eis known to witbiii the twetLtioth part of a seoond of time. The union of Londoa willi Teheran, Persia, and through il with Madras, India, was oomplet the latter part of 1871, and a telegraphio circuit of 3,870 milos of wire was usod in the longitude detirminiition. The longitude of Ban Franoisoo frora Washington 'u determinad by a oircuil of 2,000 miles by thn astronomers of the ( Survey. The not-work thua gradually girdiug the nortbern hemiRphere no f;ins to bo supplementcd by the detached portions of what at some dktant dy müv beoome the conneetcd links of a similar serius oí' longitudes in tlie Bonthern hemisphere. In HBtithern África and in Australia the telegraph linos already offor facilities for most extensiva geographioil operatione, but we believe the principal work that has as yet been done in the Southern hemisphere lias been recontly effeoted by Dr. üould, the director oí be "Viitionj.1 Observatory at Cordova. During the past year he ñau niade puoh doterminatious between big own central observatory aud the cities ot' Buenos Ayres and Rosario to Üio east ward. As the result of ibis work he announces an orror of ono minute of tiruo in the relativo longitude of theso places as given on tho best maps. Preparations hare also beun made for the longitude work botween Cordova and Santiago de Chili, but the accounts of the resulta of this work have not yet been received.

Article

Subjects
Old News
Michigan Argus