Optical Square Complete In Wooden Box Round Type

Description

• With steel pole Size 1.5mm dia with tilting type • With steel pole Size 1.5mm dia without tilting type • With steel pole Size 2.0mm dia with tilting type • With steel pole Size 2.mm dia without tilting type

Specifications :

• The levelling staff of sturdy design that meets the requirements for intensive field work. • The staff material should be one of the following: teak, cypress, kail, aimi, champ, hollock or aluminium alloy. • If timber is used as staff material, then it has well seasoned, sawn in radial direction and free of defects. • The staff is telescopic, comprising three sections without any joint in length. • The top plate made of aluminium, anodised black. • Length 4 m

Accessories

• Circular bubble sensitivity of 25 minutes per 2 mm run. • Carrying case canvas. • Plummet fittings for test and adjustment of bubble.

Description

• Made of Aluminium/brass. • Size 100mm, 125 mm, 150 mm dia. • Complete in Case with Aluminium Telescopic/Rigid/Wooden Tripod. • Aluminium circle consist of a needle graduated to 30min (0.5) graduations. • Painted with water proof paints. • Carrying cases are made of Fibre with carrying straps. Least count 30'.

Description

The Cross-Staff was used at sea from the beginning of the 16th century until the first half of the 18th century. It was used to measure the sun's altitude, especially at the meridian passage. With the knowledge of the sun's declination, the mariner could then obtain his latitude. The staff is original, with the inscription. The cross pieces are replicas. Different cross pieces were used depending on the altitude. A different scale is on each side of the staff.