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III. An Account of the Observations on the Great Nebula in Orion , made at Birr Castle, 
with the %-feet and §-feet Telescopes, between 1848 and 1867. With a drawing of the 
Nebula. By Lord Oxmantown. Communicated by the Bari of Rosse, K.P., F.B.S. 
Received June 17, — Read June 20, 1867. 
Many drawings of the Great Nebula in Orion have already been published by different 
astronomers ; still as the present drawing was made with the advantage of instrumental 
power far exceeding that at the disposal of previous observers, and as great care has 
been taken to make it accurate, in fact every available hour during the winter months of 
seven seasons having been employed upon it, perhaps it may be of some interest to the 
Royal Society. 
Several drawings of this wonderful object were published previous to the year 1825, 
but they were made with instruments of little power ; however, in 1825, Sir J. Herschel 
published a drawing made with his celebrated 18-inch reflector (Memoirs of the Astro- 
nomical Society, 1826). Sir J. Herschel’s second drawing with the same instrument, 
but under more favourable circumstances, together with a description and a catalogue of 
stars, was published in 1847* (Cape of Good Hope Observations). That was succeeded 
in 1848 by Mr. Bond’s drawing, also with a description and catalogue of stars (Memoirs 
of the American Academy of Arts and Sciences, 1848). 
In 1854 Mr. Lassell published his observations on the Nebula in Orion made at 
Malta in 1853 (Memoirs of the Royal Astronomical Society, 1854); and in 1862 
MM. O. Struve and Liapounov’s memoir, with a catalogue of stars, was published at 
St. Petersburg. 
The observations upon this nebula, recorded in the Journal of the Observatory at 
Parsonstown, date from 1849. From that time till February 1858 there are entries of 
54 observations. 
In the year 1852 Mr. Bindon Stoney made a drawing of the Huygenian region, which 
is a very interesting record. Mr. Bindon Stoney was a highly educated civil engineer, 
well accustomed to use his pencil ; he accepted the office of assistant till he was enabled 
to obtain an engineering appointment. His drawing was made with great care, and he 
was engaged upon it the whole season. It was compared by several persons with the 
nebula, and was considered exact. When we compare this drawing with the nebula as 
it is at (Plate I.) present, there are strong indications of change f. 
* This drawing appears to have been executed principally during the years 1835, 1836 & 1837. 
f An outline of the principal features of this drawing is given at the upper right-hand comer of the Skeleton 
Map (Plate II.). 
MDCCCLXVIII. 
