On a Protractor for use in Constructing Stereographic and Gnomonic Projections of the Sphere

Description:

Reprint from The Mineralogical Magazine No.69. pp 93-112. Arthur Hutchinson (1866-1937) was Professor of Mineralogy, at the University of Cambridge. In 1908 Hutchinson devised and put on sale 'at a reasonable price' a protractor for constructing stereographic and gnomonic projections which bears his name and became widely used. He described his protractor in this paper which includes a historical appendix on the projections of the sphere.