Abstract: An optical system including a stage for supporting a material to be observed and mounted for rotation on a given axis, a Dove prism mounted for rotation on the given axis and having an optical axis aligned therewith, a drive mechanism, a prism coupling mechanism coupled between the drive mechanism and the prism, and a stage coupling mechanism coupled between the drive mechanism and the stage. The prism coupling mechanism rotates the prism on the given axis and the stage coupling mechanism rotates the stage on the given axis.

Abstract: A collapsible stand including a unitary sheet having a central portion; a pair of wing portions, one joined to each lateral edge of the central portion at a bendable joint; a pair of leg portions, one joined to a bottom edge of each wing portion and extending downwardly below a bottom edge of the central portion; a connecting portion extending upwardly from the central portion and joined thereto at a bendable joint; and a bottom portion joined to an upper edge of the connecting portion at a bendable joint. The bottom portion defines a pair of oppositely directed laterally projecting insert portions; and each of the leg portions defines a receptacle disposed to receive one of the insert portions with the wing portions bent forwardly into positions substantially perpendicular to the central portion, the connecting portion bent downwardly into a position substantially parallel to the central portion, and the bottom portion bent forwardly into a position extending transversely to the central portion.

Abstract: A tool including a shaft having a drive portion, a lateral stop portion, and an intermediate portion straddled by the drive and lateral stop portions, the drive portion being adapted for detachable engagement with a rotary drive; a router blade mechanism retained by the intermediate portion of the shaft and projecting radially outwardly therefrom; a first coupling keying rotation of the shaft to the router blade mechanism so as to form a rotatably engaged unit; a longitudinal stop defining a bearing surface projecting radially outwardly from the router blade mechanism; and a second coupling securing the longitudinal stop to the unit and permitting axial adjustment between the router blade mechanism and the bearing surface.