The floating dry card dial is in very good condition with 32 cardinal and inter cardinal points, finding North easily and pivoting on a gemstone bearing within a polished brass bowl which is free of any knocks or dents. Our compasses range from simple micro-button compasses to map compasses and military-style lensatic compasses. The needle of the compass consists of a long narrow magnetised bar of steel, pointed at both ends, with a gemstone bearing at its centre for reduced friction.

The shapely blued steel needle sits above a clean paper compass rose divided into four 90 degree quadrants, and also showing all the points of the compass with a fleur de lys for North. These compasses generally use a liquid-damped capsule [28] and magnetized floating compass dial with an integral optical sight, often fitted with built-in photoluminescent or battery-powered illumination. The local magnetic declination is given on most maps, to allow the map to be oriented with a compass parallel to true north. Provided that you are not satisfied with the models listed above, we propose Proster IP65 Hiking Compass for you.However, tritium has a half-life of only about 12 years, [27] so a compass that contains 120mCi of tritium when new will contain only 60 when it is 12 years old, 30 when it is 24 years old, and so on. The effect of ferromagnetic materials in the compass's environment can be corrected by two iron balls mounted on either side of the compass binnacle in concert with permanent magnets and a Flinders bar.

LIGHTWEIGHT AND DURABLE: This map compass is an essential piece of survival gear to have in your pocket or hiking backpack. Familiarising yourself with the different lensatic compass parts will make learning to use it significantly easier. Cover: The cover holds the sighting wire as well as the luminous sighting dots necessary when navigating at night. Also, be aware of any magnets or metal near the compass: mobile phones, magnetic buttons, metal belts and similar can 'deflect' the compass needle, making it inaccurate. Compasses often show angles in degrees: north corresponds to 0°, and the angles increase clockwise, so east is 90°, south is 180°, and west is 270°.

The brass body measures 54mm in diameter not including the bow, and is also in good condition with no dents. The silvered aluminium compass dial has 8 cardinal points and an outer scale divided into four quadrants, calibrated in one degree increments. MULTI-FUNCTION: Azimuth Bearing and a 360-degree rotating bezel are included on an acrylic baseplate compass.

Of course, you cannot go wrong when checking out our package of information and guide, too, as they come from reliable sources and years of experience. Compasses are particularly difficult to use accurately in or near trucks, cars or other mechanized vehicles even when corrected for deviation by the use of built-in magnets or other devices. A quality antique instrument measuring 75mm in diameter it comes in a leather case which is also in good condition with some repairs to the straps. A compass should be laid down on a level surface so that the needle only rests or hangs on the bearing fused to the compass casing – if used at a tilt, the needle might touch the casing on the compass and not move freely, hence not pointing to the magnetic north accurately, giving a faulty reading.Thumb placement: Insert your thumb in the thumb loop and let the rest of your fingers support the base. Most of these compasses are designed for heavy-duty use, with high-quality needles and jeweled bearings, and many are fitted for tripod mounting for additional accuracy. The first compasses in ancient Han dynasty China were made of lodestone, a naturally magnetized ore of iron. FLUORESCENT】: The interface of the compass glows in the dark( please put it under light or sunshine 1~3 mins), so you can still use it even when night falls. Not much information is available on the early history of the company in London, but its reputation as makers of high quality scientific instruments was well known.