At the request of the authors, the conventional horizontal
tangent screw on the T2 was modified in order to extend the slow
motion run to approximately six degrees of arc, and to enlarge the
knurled knob. These changes were made notwithstanding the
manufacturers declared policy of retaining the conventional tangent
screw and recommending the "transit" procedure as outlined below,
for T2 (single second) theodolites. Nonetheless, the authors felt
justified in making the above request since one of the tasks en
visaged was a comparison between the tracking and transit
procedures a task which was to entail a considerable amount
of tracking observation.
The theodolite and attachment used in the test are shown m
Figure x.
Figure x
Observation Methods and Field Routines
After an initial "trial" period, the tests proper were commenced
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