back staff
|
noun
an obsolete instrument for determining the altitude of the sun by facing away from the sun, sighting upon the horizon, adjusting a cursor until its shadow falls upon the sight through which the horizon appears, and measuring the resulting arc.
RELATED CONTENT
bounce back
Read more in this article about some frequently asked questions and fun facts related to our definitions.
READ MORE
back dimples
Read more in this article about some frequently asked questions and fun facts related to our definitions.
READ MORE
Origin of back staff
First recorded in 1620–30
Dictionary.com Unabridged
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Examples from the Web for back staff
Historical Examples of back staff
This instrument was known also as "the back-staff" from the position of the observer with his back to the sun when using it.
Life Aboard a British Privateer in the Time of Queen AnneRobert C. Leslie