Davis MkIII / Mk3 sextant
Small plastic sextant that succeeded the MkII. Originally labeled as the MkIII, later called the Mk3.
Product details: Davis MkIII / Mk3 sextant | Davis Instruments | Octant | Home / hobby | Material: Plastic
The MkIII is the direct sucessor to the MkII and is probably the sextant that has been in production the longest. Not bad for a very cheap product that still gives decent results. The MkIII only differs slightly from the MkII. The main differences are in the index bearing which has become larger (probably to provide more stability) and the adjustment which no longer requires a hex key but can be adjusted with the hand. Another improvement is that the scale is painted making it much easier to read, especially under conditions with low or too much light.
I have been using the Mk3 in training for years. I bought two to replace the second hand Freiberger(s) we were using. For hydrographic training (horizontal angles) the real sextants had the disadvantage of the telescope magnifying the images too much making it hard for the students to find the targets. The Mk3 only has a sight tube and as such not that problem. It is also more than accurate enough (it can be read to the minute) for horizontal work. Even for astronomical work it is not a bad instrument according to tests performed by Celestaire.
More information:
Davis MkIII
Data sheet
- Type of use
- Home / hobby
- Material
- Plastic
- graduation
- deg
- measuring range
- 100
- diameter scale in mm
- 175
- accuracy
- 2'
- fine reading
- vernier (single)
- Size instrument (l x w x h) in m
- 0.21 x 0.22 x 0.08
- weight instrument in kg
- 0.16
- country obtained from
- United States
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Small plastic sextant that succeeded the MkII. Originally labeled as the MkIII, later called the Mk3.
Product details: Davis MkIII / Mk3 sextant | Davis Instruments | Octant | Home / hobby | Material: Plastic