telescopical

 Of or pertaining to a telescope; performed by a telescope.  [1913 Webster]

 Seen or discoverable only by a telescope; as, telescopic stars.  [1913 Webster]

 Able to discern objects at a distance; farseeing; far-reaching; as, a telescopic eye; telescopic vision.  [1913 Webster]

 Having the power of extension by joints sliding one within another, like the tube of a small telescope or a spyglass; especially (Mach.), constructed of concentric tubes, either stationary, as in the telescopic boiler, or movable, as in the telescopic chimney of a war vessel, which may be put out of sight by being lowered endwise.  [1913 Webster]