TRIGONOMETRICAL SURVEY OF NEW SOUTH WALES. 177 
as far as it had gone, in determining the dimensions of the 
spheroid best conforming to the actual surface covered by the 
survey. This work, together with some added since, seems to be 
of sufficient importance to warrant reference to it in greater 
detail than could be given in the return mentioned, and as some 
interest may attach to a matter which is here, it is believed, 
treated for the first time as far as this part of the world is con- 
cerned, the following remarks have been prepared. 
It is regretted that the practice followed in so many other 
countries where work of this nature is proceeding, is not adhered 
to by us. As a rule, publication of not only the results of a 
survey but of the data and details of reduction is made elsew here, 
the object being to enable the data to be combined with those 
afforded by other surveys in order to secure the most reliable 
results, and also to permit anyone desiring to use the survey at a 
future time, when possibly the methods of reduction may be much 
improved, to apply such improved methods to the original data. 
Of course it will be understood that these remarks as to publica- 
tion apply more particularly to the primary triangulation, for, 
although the breaking down of that triangulation for the purposes 
of governing chain surveys and aiding construction of maps is of 
the highest importance, and in fact forms the bulk of the 
work of a survey, yet it possesses little scientific interest. It is 
hoped that in due course a full report of the primary triangulation, 
such as is indicated above, may be published ; in the meantime 
such details as may be included within the limits of a short paper 
will be presented, giving first a short sketch of the progress of 
the survey, which may be needed to assist in following the sub~ 
sequent matter and in estimating the value of the steps taken in. 
carrying it out. 
It is proposed also to give a brief description of the similar 
surveys made or in progress in the other colonies. For information 
regarding these the writer has to thank the Surveyors-General of 
the several colonies ; the description of the Victorian work has, 
however, been mainly drawn froma paper by Mr. R. L. J. Ellery, 
C.M.G., F.R.S., published in the proceedings of the Victorian 
Institute of Surveyors. The intention is to give here only such a 
sketch of the work done by our neighbours as will enable the 
general scope and methods to be gathered, though a study of the 
history of higher surveying in these colonies forms an object. 
lesson which should prove useful in guiding our future steps. 
NEW SOUTH WALES—BASE LINES. 
The trigonometrical survey of New South Wales had its in- 
ception in 1867, when information was first sought with regard 
to suitable sites for base lines ; the measurement of a base line at 
Lake George being commenced in 1868, under the direction of the- 
M 
