Sextent

SIGMA Sextenta s are made to measure true angles with easy and minimum adjustments.

Technical specifications:
1. Made of brass. Radius of the frame is 6-7/16 . Stainless steel scale embedded in brass arc is divided into 5-0-130 divisions.
2. An index arm carrying the full silver mirror moves on the stainless steel scale. A fine motion is given by a micrometer head provided under the index arm by rack & worm system.
3. Micrometer head has 60 divisions. Its one rotation moves the index arm through 1min. A vernier is also provided against the micrometer whose vernier constant is 12sec.
4. Half silvered mirror is mounted in front of the telescope holder and can be moved by a knurled screw in the vertical plain. Similarly the full mirror on the index arm is provided with a spring loaded screw to move it in the horizontal plain. These horizontal and vertical slow motion movements are used for zero adjustments or initial readings (an improvement for easy setting.)

One Galilean and one astronomical telescope are provided.
Complete in polished wooden box.