It is not clear when the first milk bottles came into use. Extending from the 1860s to the 1890s, there were several experimental "jars" that were not patented but, nonetheless, used to carry milk. The milk jar of the Tuthill Milk Company/Tuthill's Dairy of Unionville is an example of one of these early jars that features a ground lip and a pontiled base. Other early milk jars during this time include the Mackworh "Pure Jersey Cream" crockery jar, the Manorfield Stock Farm jar, the Manor, and the PA wide-mouth jar. In 1878, George Henry Lester patented the first glass jar intended to hold milk. This jar featured a glass lid that was held on the jar by a metal clamp. In the same year that Lester invented his milk jar, the Brooklyn milk dealer Alex Campbell is credited with first selling milk in experimental glass bottles. These bottles likely did not resemble common milk bottles.