Heller & Brightly advertised this as an Improved Complete 'Combined Transit and
Leveling Instrument' For Civil Engineers and Surveyors. The serial number indicates that it was
made around 1884. New, the basic transit cost $220. The vertical circle was an extra $25. The
horizontal circle is silvered, graduated every 30 minutes of arc, and read by verniers at N and S to
single minutes. There are level vials at N (this one covers a vernier) and at E. The vertical
circle, also silvered, is read by vernier to single minutes, and is protected by an aluminum guard.
To reduce weight, the vertical standards are ribbed and braced. The telescope is equipped with stadia wires for determining distances.
The tripod head of this transit allows the instrument to be leveled, and also to be adjusted
horizontally in order to be brought over a fixed point on the ground. Daniel Hoffman obtained a
patent (#197,369) on this design in 1877, and assigned the rights to Heller & Brightly in
exchange for $5 for each unit sold.
Ref: Heller & Brightly, Remarks on Surveying Instruments (Philadelphia, 1886).