An antique European multi-draw brass field telescope, dating to the first half of the 19th century, approximately 1800–1850. The telescope is constructed in brass and collapses to a remarkably compact 12 cm, extending through its nested draw tubes to approximately 28.6 cm. Its portable format is characteristic of terrestrial hand telescopes or “prospect glasses” made for observing distant subjects. The instrument retains a five-lens optical system: two lenses are housed in each of the two internal optical tube sections, together with the larger front objective lens. The individual optical sections have been examined and transmit recognizable images, with the two internal sections producing clear inverted images when viewed separately. The front optical section also transmits a recognizable image. All five lenses appear physically intact, without obvious cracks or breaks. When fully assembled, the telescope transmits and magnifies an image. Optical sharpness has not been fully assessed at the longer viewing distances for which an instrument of this type was intended, so no definitive claim is made regarding final image sharpness or orientation when correctly focused. The brass body retains an attractive naturally aged surface with patina, fine scratches, small marks and general handling wear consistent with its considerable age. The draw tubes extend and retract correctly. No maker's signature or identifying inscription has been found. The all-brass construction, compact multi-draw configuration and optical arrangement are consistent with European portable field telescopes produced during the first half of the 19th century. The maker and specific country of manufacture remain unidentified. Dimensions: Closed length: 12 cm Fully extended length: approx. 28.6 cm Maximum diameter: approx. 2.4 cm Weight: 148 g A compact surviving example of early 19th-century portable optical technology, retaining its aged brass surface and complete five-lens optical system. Please examine the photographs carefully for the condition and details of the instrument. It will be carefully packed for shipment, with particular attention given to protecting the lenses and draw-tube mechanism.