Millstones were made out of granite or volcanic rock using tools sent to California Missions from Mexico, and Native American laborers at the missions were taught how to build the millstones (Buckland Webb 1952, p. 163). The tools range from 2.5 feet to nearly 4 feet in diameter and approximately 7 inches to 12 inches in width. Although there were two types of stone mills -- water powered and animal powered -- we focus on animal powered grinding stones, also called tajonas (can be tahona).
There is evidence of tajonas and water-power mills throughout Bay Area mission sites, although both were used to grind wheat or other grains (Buckland Webb 1952, p. 164). Records indicate that tahonas were more sustainable than water-power mills, largely because they were more sturdy and able to withstand earthquakes (Spearman 1963). Tajonas also do not require water, which was a scarce resource because of the frequent three-year droughts, because they are powered by animals (Spearman 1963). They have been found at many missions that also had water-power mills, such as Missions San Francisco and Santa Cruz. Historical and narrative reports indicate that the vast majority of tahonas were first used in the beginning of the 18th century (Buckland Webb 1952, p. 164-165).
Labor and Cultural Persistence of the Natives
A common misconception with native within living within the mission system was that they had lost their culture. While the Spanish missions did employ a strict enculturation program on native laborers, scholars have agreed that the natives continued to practice certain traditions. In archeological findings on Santa Clara University's campus, traditional objects were found within rancherias, the private dwellings of natives in the mission complex (Peelo et. al. 2018). Archeaological findings show how natives continued to practice their traditions even when being forced to participate in the Spanish enculturation programs. These findings also included European objects, which had been modified to be used in traditional native ways.
Another common misconception with mission natives is that all aspects of their culture were denied by the padres. However, padres had accepted aspects of native culture that they believed would help the development of the missions. For example, Junipero Serra had seen how certain natives tribes acquired their food by fishing and allowed for some natives to continue fishing in order to bring more food for the misson (Thomas 2014).
These aspects of labor practices and cultural persistence of the natives gives us insight into how these millstones could have been used during colonial times. Research from various sources shows us how multiple native tribes throughout California used millstones in order to grind their grain. It is possible that mission padres had seen how valuable this traditional native tool was and allowed its use within the mission. The use of millstones would then be modified by Spanish influence by using livestock to power the stones. While a complete historical background of the Ricard Observatory millstone is foggy, we believe that it is important landmark of native cultural persistence on campus.
