Just got back from the library, do u have the newspaper article on the explosion killing John SAMMON? I have it plus there is a write up in the Dominion Annual Register 1878"" on pg. 229. Heading "MARCH" "3rd.- John SAMMON, foreman of Riordan's Paper Millls at Merritton, is instantly killed by the explosion of dynomite cartridges for blasting. Another man named Madill, and a boy named O'Neil, suffer severe injuries by the same explosion. The shock of the explosion is heard at a considerable distance."

Victoria Lawn Cemetery
[SAMMON]/ William F. Sammon / born / July 3, 1863 / Died / May 2, 1871 / Eliza M.Sammon / Born / April 6, 1852 / Died / Feb. 14, 1890 {side} John SAMMON / born / Sept 27, 1829 / Died / Mar. 9, 1878

As you may notice there is a discrepancy on the date, 3rd or 9th.