Abstract: A positioning device, particularly for positioning an object head in a cryostat microtome, has a mechanism for selectively positioning an object or specimen to be worked upon. The device includes a ball and socket joint having two spherical half shells pivotally holding the ball between the shells. An object head is connected to the ball. A clamp is operatively associated with the two spherical half shells to maintain the ball in position relative to the shells. A cross-joint is connected to the ball, diametrically opposite to the object head. The positioning mechanism includes rotatably geared or threaded members controlled with handles to independently position the object head in the x- and y-directions or paths.

Abstract: A housing for a microtome which is capable of being employed in a cryostat. The microtome housing includes a waterproof microtome chamber having an elongate slot formed in the wall thereof through which an object holding device extends. The elongate slot has a seal disposed about its periphery and the slot is covered by a coverplate which is provided adjacent to the seal. The coverplate is rotatable about the axis of a pin which is provided on the interior of the chamber wall. The chamber further includes magnets which are arranged on the wall of the chamber adjacent to the elongate slot such that the magnets retain the coverplate over the elongate slot. This arrangement allows the object holding device to be easily inserted into and removed from the chamber, while at the same time maintaining substantially moisture free conditions within the chamber.