Abstract: A crystallographic observation apparatus for the observation of behavior of crystals under pressure and for the measurement of the crystallization pressure and pressure of fusion of substances. The apparatus comprises a pressure chamber having a cavity and provided with a transparent observation window or windows, a pressurizing device for pressurizing the cavity of the pressure vessel, and small, entirely or partly transparent, entirely or partly elastic sample containing means for containing a sample, provided within the cavity of the pressure vessel. The sample can easily be changed for another sample simply by changing the sample containing means containing the former sample for another sample containing means containing the latter sample, or the apparatus can easily be cleaned after the completion of observation of a sample for the observation of the next sample, simply by washing the sample containing means.

Abstract: A pipe joint in which a force for retaining a semirigid plastic pipe to a joint body is provided in such a manner that an outward expanded portion of the pipe which is formed by inserting an annular shape-retaining member which does not obstruct the flow of fluid into the pipe is connected to the joint body by a box nut. This pipe joint portion is formed by employing an apparatus having a clamp for temporarily fixing the pipe at one end of a base arm, a grip portion disposed at the other end thereof, a toggle lever pivotally attached to the grip portion, a sliding rod engaging at its one end with an end of the toggle lever and capable of moving to the left and right while being supported by a guide base attached to the base arm. The shape-retaining member is inserted into the pipe by this sliding rod.