Preview

PDF kingsmill-hobar...pdf | Download (18MB) Available under University of Tasmania Standard License.

Abstract

The object of my paper is to bring under your
notice a piece of astronomical work done at the Hobart Observatory,
in the first instance by myself, and afterwards more completely by
Captain Cust, of the Dart. This work was the determination of the
meridian of the Hobart transit instrument by means of star observations
taken with the instrument itself. The American astronomers
determined a meridian with great accuracy when they came here on
the transit of Venus expedition, and it would be possible to draw
a parallel to it by offsets, as the Hobart Observatory is only 57ft. west
of their meridian. But this method would be far less accurate than
the determination of a fresh meridian by independent observations.
There is a meridian mark for the Hobart transit instrument near Mount
Nelson, just above the rifle range, and a little to the east of it. A
stone something like a milestone has been erected in brickwork with a
crosscut in it to indicate the exact meridian. When I came to the
Observatory I was told that the cross was wrong, and that the true
meridian was close to the eastern edge of the stone, but there was no
record of the exact amount of the error. To obtain the exact local
time it is necessary to find out all the errors of the instrument. It is
by a number of small corrections that accuracy is obtained. However,
this error appeared to require a pretty large correction. In December,
1893, I took some observations of the Southern Pole Star and Octantes
which,satisfied me that the true meridian was clear of the stone altogether
and to the east of it.

Item Type:	Article
Authors/Creators:	Kingsmill, Henry Charles
Keywords:	Royal Society of Tasmania, Van Diemens Land, VDL, Hobart Town, natural sciences, proceedings, records
Journal or Publication Title:	Papers & Proceedings of the Royal Society of Tasmania
Collections:	Royal Society Collection > Papers & Proceedings of the Royal Society of Tasmania
Additional Information:	In 1843 the Horticultural and Botanical Society of Van Diemen's Land was founded and became the Royal Society of Van Diemen's Land for Horticulture, Botany, and the Advancement of Science in 1844. In 1855 its name changed to Royal Society of Tasmania for Horticulture, Botany, and the Advancement of Science. In 1911 the name was shortened to Royal Society of Tasmania.
Item Statistics:	View statistics for this item

Actions (login required)

Item Control Page