Signedprinted on instrument label: Wm. AINSWORTH & SONS / DENVER, COLO. / MADE IN U. S. A.
Inscribedin ink under case lid: B. M. Shaub / Northhampton, / Mass.
printed on instrument label: D. W. BRUNTON'S / POCKET TRANSIT
FunctionThis instrument can be used for measuring horizontal angles and inclination of a sloping ground, and so is recommended for mine surveying. A geologist would find it useful in his field work for determining the strike and dip of geologic deposits.
Although called a mine transit or pocket transit, the instrument is sometimes classified in trade catalogues with prismatic compasses.
Historical AttributesD. W. Brunton patented his "pocket transit" on September 18, 1894. This was a magnetic compass with sights, levels, and clinometer in small package for commercial and legal use in mine surveying. For a while, Ainsworth was the sole manufacturer of Brunton's pocket transit.
According to Brunton's account in 1905, the instrument was widely used from "from Australia to Alaska" and used in teaching at the Lawrence Scientific School, Harvard University, Columbia University, and western mining schools.
This particular example belonged to Benjamin Martin Shaub (1893-1993), Professor of Geology at Smith College.
ProvenanceBenjamin Martin Shaub, Professor of Geology, Smith College; gift to CHSI by his wife, Mary Church Shaub, 11/20/96.