M. Van den Broeck reports in Ciel et Terre, 16-485, that he heard “detonations like discharges of artillery” on June 25, 1894, at Louvain. He tabulated the intervals of the sounds at 4 minutes and 23 minutes, then 3 minutes, 4, 3 quarters, 3 and 3 quarters, then 3 quarters. Other such detonations were heard in July and August 1892, August and September 1893, and September 1895.
–Charles Fort, New Lands, p. 472 (The Complete Books of Charles Fort, Dover, c1974).