Three levelling devices, Prague and Vienna, 19th/20th centuryBrass, steel, nickel, glass, some of the metal surfaces blackened. Telescope with horizontal swivel function, two bubble tubes and angle scale (lateral magnifying glass). The manufacturer's signature on one side of the telescope, "Praha 2920" on the other. The eyepiece extension finely adjustable, length of the telescope 24 cm. Plus a smaller device with one bubble tube, the same manufacturer's mark and "1643 Praha", telescope length 18.5 cm. Also includes a device labelled "Neuhöfer & Sohn, Wien, Nr. 4273". Two of the three bubble tubes are new replacements, telescope length 26.5 cm. All with traces of use, the lenses cloudy.Condition: II