RecordSurveyors' circle< 1 of 1 > Back made in Holland
Surveyors' circleA surveyors' 'Holland' circle was used for taking horizontal survey angles when mounted on its stand (not shown), or vertical angles when suspended. This brass example dates from the late 17th century. The instrument has a thumb-ring support on its perimeter at the N point for vertical use. There are fixed sights at N,S,E and W and two others on the movable alidade. The central compass has a magnetic pole line and is lacking its needle. Instruments of this type - which subsequently became known as 'plain theodolites' - were commonly, although not exclusively, made in the Netherlands and were thus known as 'Dutch' or 'Holland' circles. Record detailsTo search on related items, click any linked text below.
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