a1703 R. Hooke Disc. Earthquakes in (1705) 358 A Telescope Tube of a due length and bigness for the Object-glass made use of.
1839 XV. 175/1 Instead of fixing the wire to the telescope tube, it is stretched across a sliding-piece.
1931 H. S. Williams 90 The telescope tube, as the axis revolves, follows the movements of the star-field on which it is focused.
2012 G. North 460 The manufacturer may well have set the secondary mirror off-centre within the telescope tube.