Abstract: The invention contemplates an intermediate tube-attachment accessory, which may be interposed between standard parts of a conventional microscope, namely, between the objective turret or other mount, and the viewing tube, whether monocular or binocular. The attachment accessory includes a first or base part adapted to fit the objective mount and a second or swing-arm part adapted to receive a viewing tube fitted thereto. The swing action of the attachment is about a horizontal axis, and a mirror on the swing axis is geared to tilt at half the angle of adjusted swing elevation. Optical elements within the attachment perform an image-inverting function which enables erect image viewing, regardless of the adjusted angle of swing.