The BC-1 is a comprehensive instrument designed for use with 1:250,000 Topographical and 1:50.000 Ordinance Survey Charts. Measuring 205mm x 155mm in clear plastic with an opaque circular scale. Enables easy transportation of Aeronautical Information onto Ordinance Survey Charts. The calculation of average and actual Balloon G...

For the finest quality compass dividers we sell we use solid brass, finely polished and sharpened to an acute angle. The opening mechanism is secured by a brass screw providing years of use, so much so we guarantee these dividers for life. These are traditional straight pattern dividers made in the UK and are seven inches in ov...