I believe that’s the first printed statement that Bostonians packed snow around rocks to throw at the soldiers. Earlier I’ve said that the earliest place I’d found that detail stated was in Sgt. Roger Lamb’s Journal, published twenty years later. It appears Lamb picked up the detail from Ramsay.
Or from intervening authors. The “snowballs covering stones” also appeared in Jedidiah Morse’s The American Geography (London: 1794), “History of the Rise and Fall of the British Empire in America” in The Britannic Magazine (1795), and William Winterbotham’s An Historical, Geographical, Commercial and Philosophical View of the American United States (London: 1795).
The snowballs with stony cores became a standard detail of descriptions of the Massacre in the nineteenth century. Even though that detail can’t be traced back to anyone who was at the event. Following the standards of his time, Ramsay didn’t specify his source, and the many authors who copied his language (at much greater length) didn’t even cite him.
A lot of eyewitnesses to the Massacre left testimony about it, and none described people packing snow around rocks. Lots of people said there was snow and ice on the ground, and in the air. Thomas Hall and Daniel Cornwall testified to seeing people throw oyster shells at the soldiers. An enslaved man named Andrew testified that people threw “pieces of sea coal” (i.e., coal imported from Cape Breton). So there’s better evidence that the locals didn’t even bother padding their stones with snow.