October 20, 2020

Housing the sextant

Before housing the sextant in its case, set the index arm to the middle of the graduated arc and turn all the shades inwards (ie towards the centre of the instrument). Place the sextant carefully in the box ensuring that the three legs at the rear of the instrument enter […]
Do you like it?0
0 Read more
October 20, 2020

Reading the sextant

Reading the sextant is very simple: Degrees are read directly from the graduated arc opposite the index mark on the index arm. Minutes are read from the micrometer drum opposite the vernier index mark. Seconds are read from the vernier where one of the vernier graduations lines up with one […]
Do you like it?0
0 Read more
October 20, 2020

Sextant errors and their correction

Adjustment screws. Every sextant is equipped with error adjustment screws.  The design of these screws varies from sextant to sextant.  Some have ordinary screw driver slots while others have round heads with a hole drilled through it.  The first requires the use of a suitable screw driver whilst the others […]
Do you like it?0
0 Read more
Prev page
12