The Boreal Arrow 

Code BA131119515: Georgian Ivory Leather-Cased Compendium with Thermometer and Sundial/Compass, by Brooks, c. 1830

This is a unique and extremely rare Georgian compendium made by Brooks of London in the early 1800. The compendium has a thermometer and a sundial/compass. It comes in a leather wooden case that is still in excellent condition with no loss of leather. It has a strong hinge, opens and closes properly by using two small hooks. The bottom of the case that receives the instruments is covered with blue velvet. The inside of the lid is covered with blue linen, all in excellent condition.

The sundial/compass and thermometer are placed on a disc made of Ivory. There is no damage to the base: no cracks or chips. It is clearly signed BROOKS, LUDGATE STREET, LONDON. On the back of the disc, it is marked CALCUTTA.

The thermometer base is marked with two temperature scales: Fahrenheit and Reaumur. The scales are graduated in degrees. It says FREEZING at 0°R, TEMPERATE at 10°R, SUMMER HEAT at 20°R and BLOOD HEAT at 30°R. The markings are sharp and can be read easily. The thermometer is in working order and reads the correct temperature even after more than 150 years.

The sundial/compass has a rotating dial with a gnomon attached on top of the dial to allow reading solar time. The dial is still in excellent condition as can be seen in the pictures. It is covered with a thick high domed and glass crystal free of chips or scratches. The compass is in working order and finds North without any problem. The sundial/compass can be screwed in and out of the Ivory disc so it can be used alone.

It is a large instrument ideal for display on a desk: the leather case measures 11.5cm (115mm) in diameter. The Ivory disc measures 10cm (100mm) in diameter. This is an extremely rare find and still in excellent condition.