An automatic fluid sampler includes a substantially watertight housing and a structure for drawing fluid from outside the housing, wherein the fluid drawing structure is powered by stored potential energy within the housing. The apparatus comprises a first stripping portion that at least partly houses the conductor arranged along a prevailing extension, so as to rest on one of said longer sides cantilevered relative to a pair of supports. Squeeze arms are used to secure the bale stack to the support frame. Several methods are disclosed for producing such treated surfaces including the covalent attachment of hydrophilic surfactants. In another form, the endodontic instruments have an elongate shank having a cutting edge extending from a distal end of the shank along an axial length of the shank. The coin barrel has an outer position where the coins can be inserted into the coin receiver and an inner position where the coins are checked by a coin discriminating mechanism, and, if proper, will allow the coin barrel to be rotated further by the customer to activate the vending machine to release the particular selected product.