1. The description of a new, easy, and accurate method of adjusting the back observation glass : of Creator: Wright, Gabriel, mathematical instrument maker Published / Created: ca. 1785] Call Number: 1986 361 Image Count: 5 Found in: Beinecke Rare Book and Manuscript Library > The description of a new, easy, and accurate method of adjusting the back observation glass : of Wright's improved patent octant, and the method of using it in taking the apparent altitude of the sun at sea and measuring angular distance from 0 to 180 [de