TRIGONOMETRICAL SURVEY OF NEW SOUTH WALES. 227 
Conder, to whom is due in a great measure the high degree of 
precision attained. The names of Messrs. P. F. Adams, late 
Surveyor-General of the Colony, and H. C. Russell, C.M.G., 
F.R.S., must also be recorded in any such sketch as this. To the 
former the very existence of the survey is in a large measure due, 
and it owes much also to his wide practical knowledge and experl- 
ence, while the latter has, during its whole progress, aided in 
many ways where his scientific attainments were of the greatest 
service. 
QUEENSLAND. 
The extent of the triangulation effected in Queensland is shown 
by the accompanying map (marked F) from which it will be seen 
that it covers nearly 3 degrees of latitude and 2 of longitude. 
Unfortunately the further progress of the survey is held in 
abeyance, having been stopped some few years back, when the 
position of public and private finances alike demanded the stoppage 
for the time being of all expenditure not absolutely necessary for 
the maintenance of existence. As, however, our northern neigh- 
bours now find themselves in as prosperous a condition as they 
were then in the reverse, it is possible that this work, which is 
agreed on all hands to form one of the best means of securing 
economy in land administration, will be shortly resumed. 
The base line from which lengths are derived is situated at 
Jondaryan (see map), its whole extent of about 7 miles being 
divided into ten sections. It is upon an open plain, the terminals 
of which, Mounts Irving and Maria, are respectively 216 and 162 
feet above the general level of the remainder. It was originally 
proposed that measurement should be confined to the plain, 
extension east and west to the hills named to be made by 
triangulation ; but experience gained in the measurement showed 
that the system adopted was capable of satisfactory application to 
the inclined parts of the line, and the slopes were accordingly 
measured also. The length was determined by two steel tapes, 
each 100 feet long, which were compared with a steel bar floating 
in mercury, carefully standardised by measurement against the 
standard bars of New South Wales. 
This bar had in 1883 a length of 99998581 feet at a tempera- 
ture of 62° Fahrenheit, but subsequent reference (in 1895) to the 
New South Wales bars would make it appear as though the 
Queensland bar was slowly shortening. The tapes were con- 
tained by wooden troughs to protect them from the sun and wind 
the troughs resting on pegs placed so as to follow the general 
slope of the ground, which was measured and allowed for in 
the computations. The tapes were kept at a constant tension 
of 20 lb. during use, and temperatures were obtained from five 
thermometers distributed along the length of the tapes, it being 
