Stand er bestemt ved Tidssignaler. Den sandsynlige Fejl 

 eller Afvigelse fra den absolut jevne Gang sætter jeg, da 

 den midlere Gang hos Chronometref Reid viser sig saa ud- 

 merket jevn. til + 0/25 (A)- 



Den galvaniske Strøm, ved hvilken Tidssignalerne 

 gives, gaar.ikke directe gjennem alle Stationers Apparater. 

 men sendes ved Overdrag videre fra visse Overdrags- 

 stationer. For de Stationers Vedkommende, hvorom her 

 er Spørgsmaal, er der Overdrag i Christiania. Throndhjem. 

 Lodingen og Kistrand. Ved Overdragene lider Signalet 

 en Forsinkelse. Størrelsen af denne fik jeg ved Telegraf- 

 direktør Nielsens og Telegrafintendant Colletts Velvilje 

 bestemt paa følgende Maade: Strømmen sendtes fra Chri- 

 stiania over Throndhjem til Lødingen og tilbage til Chri- 

 stiania ad to forskjellige Traade med 3 Overdrag paa Vejen. 

 Det med en Nogel givne Signal kom igjen og hørtes paa 

 et ved Siden af Afsendelsesapparatet staaende Apparat. 

 Naar jeg signalerede med Xoglen i Takt og Coincidents 

 med mit Lommechronometer, hørtes det tilbagekommende 

 Signal midt imellem de med Nøglen givne Signaler. I >a 

 mit Uhr slaar 4 Tiendedels Secunder, var Signalets For- 

 sinkelse 0. s 20 for 3 Overdrag. Sættes Forsinkelsen lige 

 stor for hvert Overdrag, bliver den 0/07 for hvert, og alt- 

 saa for 2 Overdrag 0/14, .og for 4 Overdrag 0.*28. 



Ved Beregningen af Normalpendelens Angivelse for Sig- 

 nalojeblikket er gaaet nd fra en Tidsforskjel af 0* 42'" 54/5 

 mellem Christiania og Greenwich. Elter den af Prof. 

 Auwers i Geographisches .Jahrbuch fur 1880 givne Tabel 

 over de vigtigste Observatoriers Bredde og Længde er den 

 nævnte Tidsfoi-skjel 0* 42™ 53/8. Forskjellen mellem ile 

 to Tal beror paa de nyere telegrafiske Bestemmelser af 

 Længden af Kjobenhavns Observatorium, med hvilket Chri- 

 stianias er forbundet chronometrisk. Idet jeg gaar ud fra 

 den nyere Bestemmelse, bliver følgelig Klokkeslettet i Green- 

 wich i Signaløjeblikket 0/7 større end oprindelig antaget. 



Observator Geelmuyden har velvilligen meddelt mig 

 de corrigerede Tidspunkter for Signalernes Afsendelse, der 

 ere beregnede efter Tidshestemmelser gjorte saavel før som 

 efter Signalernes Afsendelse. Den følgende Tabel viser de 

 efter de oven anførte Correctioner, Strømtid. Lamgdecorrec- 

 tion og senere Tidshestemmelser, rettede Signaløjeblikke, 

 som ere observerede under Expeditionen, samt Hovedchrono- 

 metrenes Stand og Gang. 



at which its error was found by the time-signals. The 

 probable error or deviation from a uniform rate. I shall 

 put -- the mean rate of the Reid cbronometer having 

 proved so remarkably uniform — at + 0/25 (D 7 ). 



The galvanic current by which the time-signals are 

 transmitted, does not reach every station direct, being sent 

 on by relays from certaln stations selected for that pur- 

 pose. As regaxds the' stations at which the time-signals 

 were observed on the Expedition. the relay-stations were 

 at ( 'liristiania. Throndhjem. Lodingen. aud Kistrand. These 

 breaks occasion some loss of time in transmitting the signal. 

 The approximate extent of the delay I was enabled by the kind- 

 ness of Mr. Nielsen, Director of Telegraphs, and of Mr. Collett, 

 Electrician. to determine as follows: — The galvanic current 

 was transmitted from Christiania, via Throndhjem, to Lo- 

 dingen, and thence back to Christiania, by two different 

 wires, and broken by three relays. The signal, given with 

 a key, ca me back. being distinctly delivered from another 

 apparatas, also standing beside the observer. When sig- 

 nalling with the key. its clicks eoinciding with the beats 

 of mv pocket-cbronometer, the returning signal would be 

 heard at the mid-point of the interval between two 1 succes- 

 sive signals given with the key. Ndw, as my ]>ocket-chron- 

 ometer beats four-tenths of a second, the delay in trans- 

 mitting a signal must have been 0. 8 20 with three relays; 

 hence. with one relav. assuming it equal for each, the 

 delay will be 0.O7, with two- relays 0/14. and with 

 four 0/28. 



In computing the indication of the. standard-clock for 

 the moment of the despatch of a signal, the difference in 

 time between Christiania and Greenwich has been put at 

 0* 42™ 54. 5. According to the Table furnished by Pro- 

 fessor Auwers in Geographisches Jahr bucli for 1 Sst i. show- 

 ing the latitude and longitunde of the chief Observatories. 

 the difference is 0'' 42™ 53/8. The want of agrement in 

 the respective figures must be ascribed to the late tele- 

 graphic determination of the longitude of the Copenhagen 

 Observatory, with which that at Christiania is chronome- 

 trically connected. Taking the latter of the .two deter- 

 minations. the assumed Greenwich time at the moment of 

 despatcli will require a correction of -f- 0/7. 



Mr. Geelmuyden, of the Christiania Observatory, 

 has kindly furnished me with the corrected moments for 

 the despatch of the signals, computed from transists ob- 

 served alike before and after transmission. In the follow- 

 ing Table will be found the moments of despatch for the 

 signals observed on the Expedition. corrected for the above- 

 specified errors. viz. the propagation of the current. correc- 

 limi ul assumed longitude, and subsquent determinations ut' 

 clock error — as also the error and rate of the chief 

 chronometers. 



