Unpublished MSc Thesis. Supervisor: Dr. Len Berggren, Simon Fraser University, Burnaby, British Columbia, Canada

During the Middle Ages and the Early renaissance in the Latin West the quadrant in its many guises was an important scientific and mathematical instrument for a number of scientific disciplines. The earliest use of the quadrant, as r. T. Guther in his Early Science in Oxford suggests, was in surveying and then subsequently in the service of astronomy when horary lines were added. However, the quadrant was not limited just to the computational and mensurational needs of astronomers and surveyors. Cartographers, navigators and militiamen and bombardiers also adopted the quadrant for their wok in the years to follow.

Not only was the quadrant useful in the work of the astronomer et al., but in the hands of these specialists the quadrant was adapted and modified (either in the manner in which it was employed or through changes to various incorporated scales). The aim of this work will be to examine developments in the ways in which the quadrant was constructed ad used during the early renaissance from the early sixteenth century to the mid-seventeenth century in Western Europe by specialists in the areas of astronomy, surveying, navigation and military science.