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XXI.—On the Total Eclipse of the Sun, on July 28, 1851, observed at Goteborg ; 
with a description of a new Position Micrometer. By Wi1u1am Swan, 
F.R.S.E. 
(Read 1st December 1851.) 
Having long desired to witness a total eclipse of the sun, I resolved to proceed 
to some place in the line of the moon’s shadow, for the purpose of observing that 
which took place on the 28th of last July. 
Various reasons induced me to prefer the town of Goteborg in Sweden to any 
other station. It had interesting historical associations connected with eclipses ; 
and there was something pleasing in the prospect of seeing the red prominences, 
which excited so much attention at the eclipse of 1842, at the very spot where 
they were observed, probably for the first time, in 1733 ;* but a more import- 
ant ground of preference, was its proximity to the central line of the moon’s 
shadow, and its being directly accessible from England. 
I accordingly sailed from Hull on the 19th July, by the Courier Steamer, and 
reached Goteborg on the 24th. Among the passengers were Mr Lasset, Mr 
Apams of Cambridge, Mr Carrincton of Durham Observatory, Mr Roper? CuHam- 
Bers and Mr Joun Avie of Edinburgh, Mr Dunkin of Greenwich Observatory, 
and the Astronomer-Royal. 
Mr Atry had determined to observe the eclipse at Goteborg, and at his request 
a meeting was held there on the 26th July, when it was agreed by those who 
were present to separate as much as possible, in order to increase the chance of 
at least some one seeing the eclipse, in the event of the weather proving cloudy,— 
a precaution which its unfavourable aspect at that time rendered the more advis- 
able. Professor CHEVALLIER of Durham and Mr Joun Apis, had previously de- 
termined to observe the eclipse from the roof of their hotel in town. Lieutenant 
_ Perrersson of the Navigation School of Goteborg, kept by the Observatory of that 
institution. The Astronomer-Royal selected a station to the east of the town, and 
Mr CHAMBERS, one about three miles to the west. I chose for my station a hill 
named Ramberget, situated about a mile to the north of Goteborg, and on the op- 
posite bank of the river. This, being the highest eminence in the neighbourhood of 
the town, commanded an extensive view of the country on every side, and was 
therefore a very favourable station for witnessing the effects produced on the land- 
scape during the eclipse. I referred its position to that of Lieutenant Perrers- 
son’s Observatory, by the magnetic bearings of several conspicuous objects, taken 
by means of a prismatic compass. (See Tablel., page 345.) The observations, when 
* See Observatio Eclipsis Solis totalis cum mora facta Gothoburgi Svecie, &¢., 4 Dom. Birgerc 
Vassenio.—Phil. Trans., vol. xxxviii. 
VOL. XX. PART III. AY 
