These bottoms with the 1877 patent date and large mold numbers are from the extremely rare and valuable Royal blackglass Fruit Jar made by Hemingray. There have been blackglass shards found of 1858 Mason's Patents and a no name plain wax sealer as well as Royal blackglass lids. Strangely enough, all these shards were found in a location well away from the Covington factory site. Hope you've enjoyed the archaeological tour!