1776263127Code 8452 Brass SextantBrass sextant, signed Hayes Brothers Cardiff Barry & Port Talbot, from the second half of the 19th century, housed in its original mahogany box with brass latches, handle, and hinges, complete with original lock and key.
Silver vernier scale and vernier, wooden handle, three colored glasses for the fixed mirror and four for the movable mirror, three telescopes, a filter, an adjustment key, and a microscope for reading the vernier graduated from 0 to 150°, an index and horizon mirror.
Good condition, fully functional, complete with custom-made wood and brass stand.
Box dimensions: 25.8 x 23.8 x 12.7 cm - 10.1 x 9.4 x 5 in.
Hayes Brothers was a British company active since the second half of the 19th century. It specialized in the production and maintenance of nautical instruments such as compasses, sextants, marine chronometers, and navigation equipment. It operated primarily in the Welsh ports of Cardiff, Barry, and Port Talbot, which at the time were among the most important maritime traffic hubs for the coal industry.
The company began as a family business run by the Hayes brothers, amidst the rapid expansion of the British merchant navy. It developed into a provider of essential services to departing and arriving ships, including instrument calibration and the supply of certified equipment.
Thanks to the growth of traffic in the Bristol Channel, the company consolidated its presence by opening or managing offices in various ports in the area, becoming a local point of reference for captains and shipping companies.
The sextant is an ancient astronomical instrument used to measure the altitude of a celestial body (for example, the Sun). The instrument is placed on a vertical plane and, looking through the sighting device, the horizon line visible through the non-silvered half of the fixed mirror is sighted. By moving the alidade, with which the mirror is attached, the light rays emanating from the celestial body, which are subsequently reflected by the movable mirror and the silvered half of the fixed mirror, are reflected by the latter in the direction of observation. Looking through the sighting device, the image of the celestial body, obtained by double reflection, appears to coincide with the horizon line. The altitude of the celestial body is expressed by the angle whose value is read on the graduated scale. The filter is used when the celestial body being sighted is the Sun.
Sir Isaac Newton invented the principle of double reflection in navigational instruments, but his research was never published. Subsequently, two men, independently of each other, discovered the sextant around 1730: John Hadley (1682-1744), an English mathematician, and Thomas Godfrey (1704-1749), an American inventor. But it was not until 1758 that Admiral John Campbell conducted a series of trials on the open sea to test a new method that relied on the lunar distance as a means of calculating longitude. This is how the sextant was developed. Initially made of brass, their scales were divided with great precision by mathematicians who made scientific instruments.
