996 T'ransactions.—Miscellanéois. 
largely on the report of Major Palmer as an authority in connection with 
the system of survey to be used throughout the Colony, and I have had no 
hesitation in doing so, not merely because that report has emanated from a 
gentleman whose knowledge upon the subject under discussion is ad- 
mittedly profound, but also because his views coincide with those of several 
surveyors in this Colony, whose opinions on the matter are entitled to the 
highest respect. I now propose, with some diffidence, however, to offer a 
few remarks on the adaptability of Mr. Thomson’s system to the Colony as 
a whole, and to discuss it in comparison with that suggested by Major 
Palmer. 
It is necessary to premise that where a country practically admits of 
the bearings of all its sectional lines being run by the theodolite in the 
open, and also of nearly all those lines being chained, a method of survey 
may be adopted which would not be applicable where neither of these 
operations can be performed, and therefore that a system might fairly be 
used as an expedient for the rapid settlement of an open and moderately 
hilly country which would in no degree answer for a country of a different 
aspect. 
Now those portions of Otago which have been surveyed under Mr. 
Thomson’s system consist chiefly of open and undulating or moderately 
hilly lands, the process of surveying which is easy as compared to that of 
surveying the densely wooded and broken tracts which, for the most 
part, prevail in other parts of the Colony, and especially in the North 
Island. Otago, therefore, does not furnish for the purposes of a system of 
survey, either as regards cost or accuracy, a fair example of what can be 
accomplished for New Zealand as a whole. 
Let me call attention, in the first place, to the probable ratio of error 
between the meridian circuit system of minor triangulation of three-mile 
sides executed with five-inch theodolites divided to minutes of arc, and a 
major triangulation of twelve to fifteen-mile sides, with eight or ten-inch 
theodolites divided to ten seconds of arc. This ratio is quoted by Mr. 
Thomson as two links to one link per mile only in favour of the better class 
of instrument and higher standard of execution. 
Now I apprehend that the limit of the measuring power of a theodolite 
may be said to be represented by the degree of accuracy with which an 
observation can be read with it. Thus all measures of an angle taken 
between two objects with a five-inch theodolite divided to minutes of arc 
only, might result in giving the same whole minute of reading. The 
accordance of such observations is, therefore, not conclusive as infallible 
evidence of their accuracy. On the other hand a similar number of obser- 
vations with an eight or ten-inch theodolite between the same objects would 
