In one aspect of the invention, a piston is sized to slide along a first axis within a hollow cylinder, and the piston and cylinder assembly is rotatable about a second axis with respect to a support structure. In another aspect of the invention, a container is sized to receive a bag having a mouth larger than a characteristic cross-section of an article to be deposited therein. A member supported by the container has a hole sized in accordance with the characteristic cross-section of the article, and the mouth of the bag is releasably secured to the hole so that the bag is gathered to provide an opening into the bag sized in accordance with the characteristic cross-section of the article.