Description
Gunter quadrants were used to carry out astronomical calculations and to tell the time. This example was made by Oxford mathematical instrument-maker John Prujean. By engraving the quadrant onto a printing plate, Prujean was able to run off multiple copies that could then be cut out and pasted onto wood, producing a more affordable instrument for Oxford’s student and ‘poor scholar’ market.
19/11/2021
Created by: Morgan Bell on 19/11/2021

Description
A quadrant is an instrument used to measure up to 90-degree angles. There are many different types of quadrants, each used for different purposes.

The Gunter quadrant was used to tell the time and carry out astronomical calculations. Edmund Gunter’s work of 1623, De Sectore et Radio, explains that the instrument could be used:
"to finde the day of the moneth
to finde the houre of the day.
to find the beginning of day-breake, and end of twi-light
to find the houre of the night by the stares
to find the houre of the rising and setting of the Sun, and thereby
the length of the day and night"

This one shows the Gunter projection for the latitude of about 51°45' (Oxford and London) and was designed for vernal equinox of about 11th March, which is consistent with 17th-century England.

It was made by mathematical instrument maker John Prujean. He started his career in London, apprenticed to Thomas Alcock in the Clockmakers' Company, then prominent instrument maker Elias Allen. On 11th March 1664, he acquired the right to trade in Oxford as a mathematical instrument maker, where he remained for the rest of his life. He made instruments for the University and maths tutors, but also for students and poorer scholars. As this one is made of paper pasted on wood, it was likely to have been designed for this poorer market.
04/02/2021
Created by: Morgan Bell on 04/02/2021