Instrument	:	Equerre
Manufacturer	:	Unknown
Country of origin	:	Belgium or The Netherlands
Manufacturing year	:	Late 19th, early 20th century

In my collection since 2005 is this instrument which is the predecessor of the modern optical square. The instrument is divided in 8 directions with corresponding visors, four of which have horse hairs as reticle. This type of visor can also be found on a graphometer.

The compass shows the directions of the winds as 'N', 'O', 'Z' and 'W' (Noord, Oost, Zuid and West, in English: North, East, South and West), indicating that the instrument was intended for the Dutch market. The handle has a conic hole, to make it possible to attach the instrument to a tripod (similar to the one of the graphometer) or staff.