previous next

Tran′sit-cir′cle.

Troughton's transit-circle (Fig. 6611) unites the functions of the mural circle and the transit-instrument.

The telescope is fixed between two parallel, flat metallic circles, or rings, the exterior faces of which are graduated to 5′. These rings are connected with the horizontal axis by two sets of hollow, radial arms, so as to form two wheels 4 feet in diameter, and are connected with each other by a system of transverse and diagonal rods. The axis, 3 feet in length, consists of a central cylindrical portion into which the spokes are inserted, and two projecting cones resting on Y's in two stone piers. The faces of these piers coincide with the plane of the meridian. The Y's are provided with vertical and horizontal adjustments for placing the line of collimation of the telescope exactly in the plane of the meridian.

Creative Commons License
This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 United States License.

An XML version of this text is available for download, with the additional restriction that you offer Perseus any modifications you make. Perseus provides credit for all accepted changes, storing new additions in a versioning system.

hide Places (automatically extracted)

View a map of the most frequently mentioned places in this document.

Download Pleiades ancient places geospacial dataset for this text.

hide People (automatically extracted)
Sort people alphabetically, as they appear on the page, by frequency
Click on a person to search for him/her in this document.
Philip Tran (1)
hide Display Preferences
Greek Display:
Arabic Display:
View by Default:
Browse Bar: