In April, 1815, Mount Tambora, on the island of Sumbawa, erupted. Historians report that this incident was the most explosive eruption in 10,000 years. At the end of the volcano's convulsions, 4,200 feet of its 13,000 foot height were gone as 25 cubic miles of ash was released into the atmosphere. Within an area of 200 miles from the eruption site there was total darkness for three days. Mariners reported a one-foot-thick layer of volcanic debris on the sea surface that lasted four years. The immediate fatalities from the eruption totaled 10,000 with an additional 82,000 deaths on Sumbawa and neighboring islands due to starvation. It was identified as the Year Without a Summer indicated in 1816 as the result of the eruption of Mount Tambora. The volcano discharged dust and sulfurous gases that spread around the globe. The diary of Hiram Harwood of Bennington, Vermont, noted that on June 11, 1817, frigid temperatures found New Englanders building roaring fires in their hearth, as killing frosts turned leaves and gardens black. Once the cold spell ended, the farmers replanted their crops only to have temperatures plummeting again in July. On August 21, hard frosts killed crops in Boston and a snowstorm whitened the peaks of the Green Mountains. The eruption inflicted climatic changes all over the Northern Hemisphere and is one of the first examples of global cooling.