Davis Mk3

Yachting Monthly - - BUYING A SEXTANT -

This is a stu­dent sex­tant, re­ally only good for sun sights. It lacks a mi­crom­e­ter, so the only way of gaug­ing min­utes of arc is the vernier scale (less ac­cu­rate than the mi­crom­e­ter).

It also lacks a clamp for the arc, so the arm can be jogged and the read­ing lost. In prac­tice this is im­por­tant be­cause it means you can’t risk tak­ing the sex­tant, un­read, to the chart ta­ble, where you do the stop­watch & chronome­ter read­ings be­fore read­ing the sex­tant.

The ab­sence of a tele­scope doesn’t mat­ter for sun sights, but for star sights you should def­i­nitely look else­where. I find the lim­ited num­ber of shades a dis­ad­van­tage, too.

The Davis Mk3 is a stu­dent sex­tant and can only re­ally be used for sun sights Price £69.95 Weight 198g Arc ra­dius 180mm Tele­scope None Shades 2 full-width, 2 in­dex Con­tact Davis In­stru­ments Web www.davis­net.com Tel +1 (510) 732-9229

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