Nautical Sextant - Brass Pillar Frame, 220 Mm Graduated Silver Arc, Adjustable Plane Mirrors, Fine-motion Adjustment For Precise Measurements

we are the popular distributor and supplier of Nautical Sextant in Roorkee, Uttarakhand, India. This nautical sextant is specially designed for navigational and astronomical purposes and allows horizontal and vertical angles to be measured. It is used in marine navigation for measuring vertical angles to stars, occasionally, also for measuring angles between terrestrial targets. The instrument is constructed in a brass pillar frame and is a fairly large instrument with a graduated silver arc of about 220 mm radius. The instrument includes two plane mirrors, both of which are fastened on the frame normal to the graduation surface, and the angle between these mirrors can be varied. The vernier enables angles to be read to 10 seconds and the range of the scale is such as to enable angles up to 120 to be measured. The instrument is also fitted with filters, or dark-coloured glasses, which can be swung into position when needed, and are generally used for solar observations. A clamp attached to the index arm enables the vernier to be clamped in any position to the graduated arc, and a tangential slow-motion screw provides the necessary fine-motion adjustment to bring the images into contact.