Jacob's staff

The instrument is mounted on a tripod or Jacob's staff by means of a socket on the underside.

Just previous, we were given a quick intro/review on how to use a Brunton compass and a Jacob’s staff.

It is clearly a case of one fraud patronizing another, and when Hudibras sees the astrologer's ludicrous array of tools�a stuffed crocodile, a Jacob's staff�he feels duped, and the two men quarrel.

Also, the name of the geometrical cross called Jacob's staff.

Lying upon the Calendar Stone was what at first I took to be a cross-bow made of gold; but more careful examination convinced me, especially in view of the place where I had found it, that this certainly was an arbalest—called also a Jacob's staff and a cross-staff—such as in no very ancient times, until the invention of the quadrant, was used by Europeans in taking the meridional altitude of the sun and stars.